JPH024584A - Laser marking method of colored material - Google Patents

Abstract

PURPOSE: To form a marking of a visible contrast by illuminating a laser beam to a surface of a polymer organic material containing an azo pigment, an indanthrone pigment, an inorganic pigment and an organic pigment. CONSTITUTION: A pulsated laser beam having a wavelength in a near ultraviolet and/or visible region is emitted to a surface of a polymer organic material containing an azo pigment and/or an indanthrone pigment, and an inorganic pigment and/or an organic pigment. And, a visible color contrast marking is formed on an emitted area without damage which cannot be recognized at all on a material surface marked by it. An example of the organic material includes, for example, a polyvinylether, polyacrylate, polymethacrylate, polyester, polyamide, polyimide or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for laser marking polymeric organic materials to produce color contrast effects and to materials marked by this method.

It is known to mark plastic objects by irradiating them with a laser beam to create a color contrast marking in the irradiated area. For example, European Patent Application No. 0036680 proposes a method for marking objects, at least part of whose surface is made of synthetic resin material, using a laser beam of a specific intensity. In this case, the material to be marked contains a dye and a silicon-containing inorganic compound or a silicon-containing dye. Irradiation with the laser beam decomposes the dye, resulting in a white mark in the irradiated area, which provides a good contrast to the colored parts of the material in the non-irradiated area.

It is also known to mark plastic parts with color contrast markings. For example, European Patent Application No. 0190997 teaches a method for marking polymeric organic materials in the form of parts, sheets or films. This method uses additives, such as inorganic or organic pigments, which change color when irradiated with a laser beam. The marking is then done by a color change, usually black or white, in the irradiated area of the material.

The invention of JP-A-60-155493 also relates to laser beam marking of plastic parts or films.

This method involves incorporating yellow iron oxide into the plastic material (and also containing yellow, yellow-green or red pigments;
color contrast marking is achieved. That is, when this plastic material is irradiated with a laser beam, the yellow iron oxide within the material turns red in the irradiated area, thereby creating a red, orange or brown mark.

Furthermore, Japanese Patent Application No. 58-210937 has two different
A synthetic resin composition for laser beam marking is disclosed that contains a variety of colorants. One of the colorants contained is one that volatilizes or undergoes color fading or bleaching upon irradiation with a laser beam, and the other colorant does not change color. This difference forms a color mark. Many organic pigments and dyes are cited as examples of color-changing colorants, while many inorganic pigments are cited as stable compounds. This specification does not mention the type, energy, intensity, wavelength, or pulse duration of the laser used.

The prior art methods and synthetic resin compositions described above do not satisfy all current practical requirements. That is, the surface of the marked material is usually damaged in the irradiated area, resulting in unwanted grooves, irregularities or scratches. In addition, the overall quality of the marks themselves formed is also poor. For example, there are disadvantages such as insufficient abrasion and scratch resistance, low chemical and dirt resistance, and deformed mark contours and unclear edges.

Accordingly, the present invention provides a method for subjecting materials containing at least one radiation-sensitive additive that completely bleaches the color and at least one less radiation-sensitive compound that does not completely bleaches the desired color to the desired state. A laser beam is directed towards the surface of the material to be marked according to the shape of the marking, thus producing a visible color contrast marking in the irradiated area without causing any perceptible damage to the marked material surface. A method for laser marking polymeric organic materials in the form of objects, sheets or films, comprising forming a pulsed laser beam whose wavelength is in the near-ultraviolet and/or visible region. using at least one azo pigment and/or one indanthrone pigment as a completely bleaching additive and at least one as a non-completely bleaching compound.
It consists in using various inorganic pigments and/or organic pigments and/or polymer-soluble dyes.

Polymeric organic materials can be of natural or synthetic origin. For example, it can be a natural resin, drying oil, rubber, etc. Furthermore, modified materials of natural origin, such as chlorinated rubbers, oil-modified alkyd resins, or cellulose derivatives, such as ethers or esters of cellulose, and in particular artificial organic polymeric plastics, i.e. obtained by polymerization, polycondensation or polyaddition. It can be plastic. Examples of such plastics include: polyethylene, polypropylene, polyisobutylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetal, polyaclonitrile, polyacrylate, polymethacrylate or polybutadiene, and copolymers thereof, In particular, ABS or EVA, polyesters, especially polymeric esters of aromatic polycarboxylic acids and polyhydric alcohols; polyamides, polyimides, polycarbonates, polyurethanes, polyethers such as polyphenylene oxides, polyacetals; condensates of formaldehyde and phenol ( phenolic plastic),
Condensates of formaldehyde with urea, thiourea and melamine (aminoplasts); polyadducts and polycondensates of shrimp chlorohydrin with diols or polyphenols, also known as epoxy resins; and polyesters used as surface coating resins saturated polyesters such as alkyd resins and unsaturated polyesters such as maleic resins. It should be noted that the materials that can be used in carrying out the process of the invention are not limited to homogeneous compounds, but also mixtures of polymeric plastics such as those mentioned above or cocondensates and copolymers, such as those based on butadiene.

Also suitable are polymeric organic materials in dissolved form as film-forming agents or binders for paints and printing inks. Membranes obtained from, for example, linseed oil varnishes, nitrocellulose, alkyd resins, phenolic resins, melamine resins, acrylic resins and urea/formaldehyde resins can also be marked by the method of the invention.

Materials particularly preferably used by the method of the invention are:
Polyvinyl esters such as polyvinyl acecool, and polyacrylates and polymethacrylates, polyesters, polyamides, polyimides, polycarbonates, polyurethanes, polyethers, especially polyphenylene oxides, and polyacetals, phenolic plastics, aminoplasts or epoxy resins.

Particularly preferred are polyacrylates and polymethacrylates, polyesters, polyamides, polycarbonates, polyphenylene oxides, epoxy resins.

The most preferred materials are polymethacrylates, especially polymethylmethacrylate and epoxy resins.

Suitable radiation-sensitive and completely decolorizing additives are azo pigments, which preferably absorb light in the near-ultraviolet and/or visible region.

Here, the visible region means the region from 0.38 μm to 0.78 μm, and the near ultraviolet region means the region from 0.25 μm to 0.38 μm.

Examples of suitable azo pigments for use in the process of the invention are acetoacetoarylides, pyrazolones, 2,3-oxynaphthoyl arylamides, barhy)L'H, thiobarbyl a, 2.4° 6-triamino-1
, 3-pyrimidine type, 3-cyano-4-methylpyridone type monoazo or disazo compounds, and metal salts of azo compounds.

Particularly suitable azo pigments are disazo pigments of the acetoacetarylide type, pyrazolone type and 2,3-oxynaphthoylarylamide type. To give an example of an azo pigment,
C, 1, Pigment Brown 23, Pigment Orange 31, Pigment Orange 60, Pigment Orange 6
4. Pigment Scarlet 160. Pigment Red 220, Pigment Yellow 221, and Cyan Blue 2C (manufactured by Ilford).

A typical example of an indanthrone pigment is the commercially available product Chromophtal Blue.
e) AR3 (C,1, Pigment Blue 60, Civer Geigy product).

Examples of pigments suitable as inorganic pigments that do not completely bleach are:
Metal oxides such as titanium oxide, antimony nickel titanate, chromium antimony titanate, manganese blue,
manganese bioleft, cobalt blue, cobalt chrome blue, cobalt nickel gray or ultramine blue, as well as Prussian blue.
Blue), lead chromate, lead sulfochromate, zirconium silicates such as zirconium vanadium blue and zirconium preseodime yellow.

Suitable organic pigments which do not completely decolorize are, for example, pigments of the anthraquino, frapatorone, phthalocyanine, perinone, perylene, dioxazine, thioindigo, isoindoline, isoindolinone, quinacridone, pyrrolopyrrole or quinophthalone series, and also, for example, azo Dyes, metal complex salts of azomethine dyes or methine dyes, and azo condensate pigments, such as C01, Pigment Yellow 93, and azo pigments, Pigment Yellow 116. Examples of anthraquinone pigments are Pigment Red C,1,177 and Pigment Yellow C,1,1
It is 47. Examples of suitable Frapatrone pigments are Pigment Yellow C,I.

It is 24. Examples of phthalocyanine pigments are Pigment Blue 0, 1.15:3 and Pigment Green C, 1
, 7. Also, an example of a suitable perylene pigment is Pigment Red c, I', 149.

Examples of suitable polymer-soluble dyes that do not completely decolorize are disperse dyes such as anthraquino disperse dyes. Examples include hydroxyanthraquinone, aminoanthraquinone, alkylaminoanthraquinone, cyclohexylaminoanthraquinone, arylaminoanthraquinone, hydroxyaminoanthraquinone, and phenylthioanthraquinone. Furthermore, metal complexes of azo dyes, in particular 1:2-chromium or cobalt complexes of monoazo dyes, and fluorescent dyes such as fluorescent dyes of the series of coumarins, naphthalimides, pyrazolones, acridines, xanthines, thioxanthines, oxazines, thiazines, benzothiazoles. Appropriate. An example of such a dye is Solvent Yellow C
, 1,163 (anthraquinone derivative), Solvent Black C, 1,29 (1:2-chromium complex salt), and Pigment Yellow C, 1,147 (anthraquinone derivative).

Polymer-soluble dyes preferably used in the method of the invention are anthraquinone derivatives. Preferred organic pigments are copper phthalocyanines and chlorinated copper phthalocyanines;
Preferred inorganic pigments are metal oxides, especially titanium dioxide, Prussian blue, lead chromate, lead sulfochromate and zirconium silicate. .

It is advantageous to use inorganic or organic pigments or polymer-soluble dyes as compounds that do not completely decolorize, and azo pigments or indanthrone pigments as completely decolorizing additives.

Suitable inorganic pigments, organic pigments and polymer-soluble dyes mentioned above include fillers and/or white pigments, such as titanium dioxide (anatase rutile form), zinc oxide, antimony trioxide, zinc sulfide, basic lead carbonate or basic lead carbonate. It can also be used in combination with lead silicate, etc. Furthermore, it can also be used together with other modifiers known to those skilled in the art. The only thing to remember is that these additives should be compatible with the polymeric organic materials used and should not impair their mechanical or other properties. It is.

The following may be considered as examples of suitable additives:

Fatty acids with fewer than 12 carbon atoms such as stearic acid, behenic acid and their amides, salts or esters such as magnesium stearate, zinc stearate, aluminum stearate or magnesium behenate; tri(C+C-o)alkylbenzyl Quaternary ammonium compounds such as ammonium salts; waxes such as polyethylene waxes; and also resin acids such as abietic acid, colophonium cefkene, hydrogenated or trimerized colophonium, C+z Cps-alkanedisulfonic acids or alkylphenols.

The polymeric organic material contains additive films that completely decolorize and compounds that do not completely decolorize, preferably 0.001 to 10% by weight, based on the amount of the polymeric organic material.
It can be contained in an amount of 0.01 to 3% by weight.

Completely decolorizing additives and non-completely decolorizing compounds can be added to the polymeric organic materials to be processed into molded articles in a manner known per se. For example, the two additive ingredients, which can be in the form of a masterbatch, are
They can be added by blending into the substrate using a roll mill, mixer or attritor. after this,
The material obtained can be shaped into the desired shape in a manner known per se, for example by calendering, molding, extrusion, coating, casting or injection molding.

It is processed into a holly shape. It is often preferred to incorporate plasticizers into the polymeric material before processing to produce non-brittle molded articles or to reduce their brittleness; examples of suitable plasticizers include phosphoric acid, phthalic acid, Esters such as sebacic acid are contemplated.

In the method of the present invention, such plasticity can be incorporated into the polymer before or after the completely decolorizing additive and the non-completely decolorizing compound are mixed into the polymer.

Depending on the end use, the polymeric organic material can further contain various modifiers, such as: kaolin, mica, feldspar, wool athonite, etc.
fillers such as aluminum silicate, barium sulfate, calcium sulfate, chalk, calcite, and dolomite, light stabilizers, antioxidants, flame retardants, heat stabilizers, and are commonly used in the processing of glass fibers and plastics. Other auxiliaries known to those skilled in the art.

In order to produce paints and printing inks suitable for use in the process of the invention, the polymeric organic material and the two
The coloring components of the species (completely bleaching additives and non-completely bleaching compounds) are finely dispersed or mixed in common organic solvents or with or without further addition of auxiliary additives for paints or printing inks. Dissolve in solvent mixture. In this case, it is possible to first disperse or dissolve the individual components separately or several components together, and then to combine all the components.

This homogenized paint or printing ink is then applied to a substrate in a manner known per se and the stoving is allowed to dry. Thereafter, the coating film thus obtained is marked by the method of the present invention.

It is also possible to incorporate the coloring components mentioned separately into each coating or printing ink layer. In this case, it is preferred that the lower layer applied to the substrate contains compounds that do not completely decolorize.

Energy-rich energy sources such as lasers are
It is advantageously used for marking inorganic materials by the method of the invention. Usage is, for example, almost vertically,
An energy source is directed onto the surface of the material to be marked. That is, the energy source is applied to the surface of the material according to the figure to be drawn or focused on the graphic pattern. As a result, the surface of the marked material can now be recognized in any way. No such damage (a color change occurs in the irradiated area).

Examples of energy sources that may be used include:

Solid-state pulsed lasers such as ruby lasers and frequency multiplied Nd:YAG lasers, pulsed lasers with boosters such as pulsed dye lasers, etc.
ye 1asers) or Raman shifter (Ram
a 5hifter), or even a continuous wave laser with pulse adjustment (Q-switch, mode holder), e.g.
W-based Nd:YAG lasers with frequency multipliers or CW ion lasers (Ar, Kr), as well as pulsed metal vapor lasers such as copper vapor lasers or gold vapor lasers, or frequency doubling to emit visible light. High performance pulsed semiconductor lasers or also pulsed gas lasers such as excimer
r) and nitrogen lasers.

Depending on the type of laser equipment used, pulse components up to several Joules, intensities up to 10'W/cat, 10
−”pulse duration from 5 seconds to 10−6 seconds and 1
Frequencies down to 0'Hz are possible. preferably a pulse component on the order of microjoules to joules;
Intensities on the order of kilowatts/cd to 100 megawatts/cd, pulse durations on the order of microseconds to picoseconds, and frequencies on the order of hertz to 250 megahertz are used.

Lasers preferably used are pulsed or pulse-tuned, frequency-doubled metal vapor lasers, such as Nd:YAG lasers, gold vapor lasers or especially copper vapor lasers, as well as excimer lasers.

The following table provides a list of suitable commercially available lasers that may be used in practicing the present invention.

In implementing the present invention, for example, when the pulse component is 0
．． 01 to 1 Joule/-1 Maximum capacity is approximately 40 MW, pulse duration is 6 to 8 nanoseconds, frequency is 20H
2 frequency doubling Nd: YAG pulse laser - [Product name: Quanta Ray) DCR-2
A: SpectraPhysic, Mountain View, California, USA
s) company product] can be used.

Copper vapor laser [Plasma kinetics (Pla
If sma kinetics) 151) are used, the laser irradiation may e.g.
It is carried out at 0 mJ/cd, maximum capacity it: approximately 10 KW, pulse duration: 30 nanoseconds, frequency: 6 KHz.

Using lasers whose parameters such as pulse composition and pulse duration can be easily adjusted makes it possible to carry out an irradiation that best suits the requirements of the material to be marked.

The optimum wavelength to be chosen for irradiation is such that radiation-sensitive additives that completely bleach the color absorb light at that wavelength most strongly, and compounds that do not completely bleach as well as the material to be marked absorb light at that wavelength. This is the wavelength that absorbs the least amount. However, if additives that completely decolorize and compounds that do not completely decolorize are properly selected,
Marking by color change can be achieved even if both absorb light at the wavelengths of radiation.

When carrying out the method of the invention, three different methods suitable for laser marking can be selected. That is, there are three methods: mask method, linear marking method, and point matrix method. Of these, the latter two methods (called dynamic focusing methods) allow arbitrary combinations of a laser and a laser marking device to create arbitrary shapes, such as computer-programmed numbers, letters, and special figures, on polymeric organic materials. You can mark patterns such as

The choice regarding the capacity and frequency of the laser device essentially depends on the marking method employed. When irradiation is carried out by a mask method, a high capacity, low frequency laser, such as a solid state pulsed laser or an excimer laser, is preferred. When marking is carried out by the dynamic focusing method, it is preferable to use a metal vapor pulsed laser or a continuous wave laser with pulse modulation, which has medium to low capacity and high frequency. Beam deflection can be carried out, for example, by acousto-optical methods, holographic methods or using galvanometric mirrors or polygon scanners. The use of dynamic focusing methods allows for extremely flexible marking since the marks are generated electronically.

A very wide range of markings is possible with the method of the invention. For example, it is possible to mark: various text programs of numerical symbols by inputting text via a video display device; text programs of standard symbols or special symbols such as monograms;
Initials and inscriptions; IC cards; logos or frequently occurring data; input of consecutive numbers, measurable variables;
Input of stored programs, linear marks or decorative patterns, etc.

Furthermore, the method according to the invention makes it possible to mark a very wide variety of plastic parts, moldings, sheets as well as coatings and printing ink films. Examples include ribbons, plates, tubes, profiles, keys, electronic components coated with plastic, and differently colored parts produced by two-color injection molding.

Typical applications of the method of the invention are circuits, printed circuit boards, printed circuits, active and passive electronic components, encap high voltage transformers, plugs and plug sockets, casings,
Precision technology and surveillance marks Industrial mechanical parts, auto parts, keyboards, electronic parts, cables, tubes,
It is used to mark festivals, sheets, packaging sheets, banknotes, credit cards, securities, as well as display windows and instrument dials.

With the method of the invention it is possible to produce color contrast marks that are indelible, ie resistant to rubbing and scratching. Furthermore, the marks obtained by the method of the invention are corrosion-resistant, dimensionally stable, deformation-resistant, light-fast, heat-resistant and weather-resistant, well-defined and easily readable. Furthermore, there is virtually no loss in the mechanical and physical properties of the marked material, such as mechanical strength and chemical resistance. The depth of the mark to be formed varies depending on the type of material to be marked, but is usually less than In. Damage to the polymeric organic material is minimal. Therefore, there is no perceivable reduction in luster or luster on the marked surface, and
It does not adversely affect the mechanical strength of the processed product.

In the method of the invention, when the material is irradiated with a laser beam, a color change mark contrast occurs in the irradiated area. That is, since the polymeric organic material is colored with two different suitable coloring components, one component is partially or completely bleached in the irradiated area, and the color of the second component, which is resistant to radiation, is changed. remain. Due to this change, a color contrast mark corresponding to the color of the second colored component becomes visible to the viewer.

The present invention will be further explained below with reference to Examples.

Parts in the examples are parts by weight unless otherwise specified.

1 application Epoxy resin 0 Araldite
G Y250 (epoxy value is 5.25 to 5.4val
/kg of diglycidyl ether of bisphenol A; Ciba Geigy, Switzerland product) 45 g [F] Cromophtal Red G
(Disazo condensed pigment, C,1, Pigment Red 22
0; Ciba Geigy) and the mixture was thoroughly dispersed in a disc impeller using 100 g of glass beads at 45° C. for 100 minutes (this dispersion is referred to as Color Paste 1).

A paint containing the following components was then homogenized at 45°C and defoamed: Epoxy resin Araldit
G Y250 (Ciba Geigy)
9.85 g, curing agent, HY956 (liquid, modified aliphatic polyamine; Ciba Geigy product)
2.4g.

Said color paste 1 0.15 g.

Color paste DWO135 (diglycidyl ether/
The epoxy value of the bisphenol A base is 5.25 to 5.
4 val/kg, 0.1 epoxy resin paste containing 15% by weight of Chromophtal Blue A 3 R (Indanthrone pigment, C,1, Pigment Blue 60)
g, 2 drops of wetting agent (FC430, fluorinated alkyl ester, 3M, Switzerland).

This viscous paint was applied to a cleaned glass plate (microscope lens support) using a coating rond to a wet film thickness of 100 μm and cured for 4 hours at 100° C. in a cabinet dryer.

The cured coating was marked using a laser beam deflected by two orthogonally movable mirrors according to the desired mark shape. The laser source used was a Nd:YAG pulsed laser [Quanta Ray D] equipped with a frequency doubler (harmonic generator) and a frequency filter (harmonic separator).
CR2, a product of Spectra Physics Co., Ltd.]. Adjust this laser device and attenuate it with a neutral filter to 0.
．． A laser beam with a pulse component of 2 millijoules and a pulse time of 10 nanoseconds is
m) so as to be projected perpendicularly to the coating layer. The deflection mechanism with mirrors movable in orthogonal directions is the C-retack (
It is part of the GRETAG 6210 laser marking device (product of GRETAG, Switzerland).

However, green marks were obtained on the dark blue painted surface.

1 spoon 1 A paint containing the following ingredients was homogenized at 45°C and defoamed: Epoxy resin ■ Araldite GY250 (as described in Example 1) 9.8 g, curing agent, HY956 (execution) As described in Example 1) 2.4g
.

Color paste ■DWO132 (Epoxy value of diglycidyl ether/bisphenol A base is 5.25 to 5.4 val/kg, Cromophtal Yellow 3 G
(Epoxy resin paste containing 15% by weight of disazo condensed pigment, C,1, Pigment Yellow-93, product of Ciba Geigy) 0.15 g.

Color paste DWO133 (diglycidyl ether/
The epoxy value of the bisphenol A base is 5.25 to 5.
4 val/kg, and contains 13.5% by weight of Chromofukur Red G (disazo condensed pigment, C,1, Pigment Red 220) and Crottal Yellow 3G (disazo condensed pigment, C4■, Pigment Yellow). 93, Ciba Geigy product) epoxy resin paste containing 1.5% epoxy resin] 0.1 g.

2 drops of wetting agent (FC430, described in Example 1), apply this viscous paint to a wet film thickness of 100 μm on a grease-free glass plate (microscope lens support) that has been cleaned using a cloth rondo. Coated and cured for 4 hours at 100°C in a cabinet dryer.

When this coating layer was laser marked as described in Example 1, yellow marks were formed on an orange background.

1 ship unit leader Polymethyl methacrylate (LUCI)
TE), Schwon Co., Ltd. product] was added to 425 g of methyl ethyl ketone (MEK) and dissolved by electromagnetic stirring at room temperature for 48 hours to prepare a coating liquid.

Next, in an ultrasonic bath, 50 g of the above coating liquid was mixed with Chromofukur Red G (disazo condensation pigment, C, I).

Big Men Trend 200 (Ciba Geigy product) 75
A first colored paint was prepared by mixing thoroughly with (2).

Similarly, 50 g of the above paint liquid and Chromofukur Green GFN (copper halide phthalocyanine, C,
1, Pigment Green 7, Ciba Geigy product) 41
A second colored paint was prepared from 3 mg.

Equal parts of the first and second colored paints were homogenized and applied onto a lens supporting glass plate using a coating rond to a wet film thickness of 1.
It was applied to a thickness of 00 μm. It was then dried in a cabinet dryer at 50°C for 1 hour.

When this coating layer was laser marked as described in Example 1, a green mark was formed on a violet background.

In the same manner as in this example, 0 chromophthalrefed G was used as a compound that can be completely decolorized.
film or polyester (PES) C for example [
It can be used in the film of Dynapol L206, a product of Guinamit Norbert. For film formation, ■ Mobital (
Dynapol L 206 can be dissolved, for example, in tetrahydrofuran.

The following ingredients were dry mixed: Polyethylene (Lupolen) %
Bayer product] 100
part, calcium metasilicate 2 parts,
Glyceryl monostearate (wetting agent) 0.6 parts, ■Kromofukurlerado G (disazo condensed pigment, C,1
, Pigment Red 200. Ciba Geigy product)
1 part, titanium dioxide
3 parts.Next, the resulting mixture was passed through a screw extruder to 180 to 19
It was extruded at a temperature of 0° C. and processed into a dragon ribbon with a cross-sectional area of 2×2 L.

When this ribbon was laser marked by the method described in Example 1, a pale gray mark was formed on a red background. Furthermore, when marking was performed using a wavelength of 355 parts m instead of a wavelength of 532 parts m, a gray-black mark was obtained on a red background.

Fruit” 1 Polyacetal copolymer ■Ultra foam (Ultr
aform) N 2320 (based on polyoxymethylene, manufactured by BASF), [phase] Chromophthalbrakun SR (disazo condensed pigment, C, 1,
Pigment Brown 23, Civer Geigy) 0.2
4g, ■Chromophthallet BRN (disazo condensed pigment, C,1, Pigment Red 144, manufactured by Civer Baigy) 0.08g, ■Chromophthal Blue A
0.18 g of 3R (Indanthrone pigment, C,1, Pigment Blue 60, manufactured by Civer Geigy) and 2 g of dry titanium dioxide were mixed and extruded at 180 to 190°C. The obtained granules were cut into small pieces with a width of 5 cI11, a length of 6 cm and a thickness of 2 nuO at 180-190°C.

A gray plane that should be marked ■ Bretack 6411-
Marking was performed using System 2 (Bretac, Switzerland). A high-performance Nd:YAG laser with a frequency doubler and continuous pumping was used as the laser beam, the laser light energy being adjusted to correspond to the shape of the marking on the surface of the material to be marked.

Laser light is 0.1 to 1.0 millijoules, 100 to 4
The pulse width was 00 nanoseconds and focused on the plane to be marked with a lens of focal length 160 nv+.

A white mark was obtained on a gray background.

Flame Gomasu Polyacetal Copolymer ■Ultraform N2320
(BASF) 100g, Chromophthal Scarlet RN (disazo condensed pigment, C,1, Pigment Red 166, Civer Geigy) 0.08g, Chromophthal Green GFN (copper phthalocyanine pigment, C)
, 1, Pigment Green 7) and 0.5 g of dry titanium dioxide. Granules were formed by extrusion in the same manner as in Example 5, and small pieces were made and marked.

Green markings were obtained on a gray background.

[Act] 11ヱPolyacetal copolymer e Ultraform N2320
(BASF) 100g, ■ Cromophthal Brown SR (disazo condensed pigment, C,1, Pigment Brown 23. manufactured by Civer Geigy), ■ Croceftal Blue 4GNP (β-type copper phthalocyanine pigment, C,1 , Pigment Blue 15:3, Civer Geigy) 0.05g, ■Chromophthallet B
It was mixed with 0.04 g of RN (disazo condensed pigment, C,1, Pigment Red 144, manufactured by Civer Geigy) and 1 g of dry titanium dioxide, extruded into granules in the same manner as in Example 5, and made into small pieces with markings. Ta.

Blue markings were obtained on a gray background.

Flame 11 Glass Filled Polypropylene CG PROCOM
) 100 g of GC30H251,I (manufactured by I) was mixed with 0.74 g of a masterbatch made from 75% by weight of low density polyethylene and 25% by weight of Cromophthalbralan 5R.
, 0.56 g of a masterbatch from 75% by weight of low density polyethylene and 25% by weight of Cromophthal Blue A3R of ■, and 1.43 g of a 70% Tie-low density polyethylene masterbatch; 180-1
It was extruded at 90°C and thoroughly dispersed. After granulating, the resulting granules were cut into small pieces and marked in the same manner as in Example 5.

White markings were obtained on a gray background.

Claims (1)

[Scope of Claims] 1. Laser irradiation of a material containing at least one radiation-sensitive additive that completely decolorizes and at least one less radiation-sensitive compound that does not completely decolorize the desired material. directing a laser beam at the surface of the material to be marked according to the shape of the marking, thus marking the irradiated area with a visible color contrast without causing any perceptible damage to the marked material surface; A method for laser marking polymeric organic materials in the form of objects, sheets or films, comprising forming a pulsed laser beam whose wavelength is in the near-ultraviolet and/or visible region as the laser beam. , using at least one azo pigment and/or one indanthrone pigment as a completely bleaching additive and at least one inorganic and/or organic pigment and/or polymer as a non-completely bleaching compound. A method characterized in that it uses a soluble dye. 2. The method of claim 1, wherein the pulsed laser beam is generated by a pulsed or pulse-modulated frequency-doubled Nd:YAG laser or a metal vapor laser or an excimer laser. 3. The polymeric organic material is selected from the group consisting of polyvinyl ester, polyacrylate, polymethacrylate, polyester, polyamide, polyimide, polycarbonate, polyurethane, polyether, polyacetal, phenoplast, aminoplast, and epoxy resin. the method of. 4. The method of claim 3, wherein the polymeric organic material is selected from the group consisting of polyacrylates, polymethacrylates, polyesters, polyamides, polycarbonates, polyphenylene oxides, and epoxy resins. 5. The method according to claim 3, wherein the polymeric organic material is polymethacrylate or epoxy resin. 6. The method according to claim 5, wherein the polymethacrylate is polymethyl methacrylate. 7. The azo pigment is acetoacetarylide type, pyrazolone type, 2,3-oxynaphthoylarylamide type, barbituric acid type, thiobarbituric acid type, 2,4,6-
triamino-1,3-pyrimidine, 3-cyano-4-
2. The method of claim 1, wherein the compound is selected from the group consisting of methyl-pyridone monoazo or disazo compounds and metal salts of azo compounds. 8. The method according to claim 7, wherein the diazo pigment is selected from acetoacetarylide series, pyrazolone series or 2,3-oxynaphthoylarylamide series. 9. The method of claim 1, wherein the compound that does not completely decolorize is a polymer-soluble dye. 10. The method according to claim 9, wherein the polymer-soluble dye is an anthraquinone derivative. 11. The method of claim 1, wherein the inorganic pigment is selected from the group consisting of metal oxides, Prussian blue, lead chromate, lead sulfochromate, and zirconium silicate. 12. The method according to claim 1, wherein the organic pigment is copper phthalocyanine or chlorinated lead phthalocyanine. 13. A material marked by the method of claim 1. 14. The material containing at least one radiation-sensitive additive that completely bleaches the color and at least one less radiation-sensitive compound that does not bleach the color is irradiated with a laser to mark the material according to the desired shape of the marking. irradiating a laser beam towards the surface of the material to be treated, thereby forming a visible color contrast marking in the irradiated area without causing any perceptible damage to the marked material surface; A method for laser marking polymeric organic materials in the form of sheets or films, in which a pulsed laser beam whose wavelength is in the near-ultraviolet and/or visible region is used as the laser beam, and at least one additive is used as a completely decolorizing additive. One azo pigment and/or one indanthrone pigment is used, and inorganic pigments and/or inorganic pigments are used as non-bleaching compounds.
or a method characterized in that organic pigments and/or polymer-soluble dyes are used.