JPH11236514A - Near infrared ray transmitting and dark colored azo-based pigment composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase distinction and tinting strength and restrain random reflection of near infrared ray by making a composition comprising a dark colored azo-based pigment having a specific average particle diameter and a transmitting carrier therefor have a specific value of transmittance of near infrared region. SOLUTION: A crushed dark colored azo pigment having an average particle diameter of 0.01-1.0 μm represented by the formula is mixed with a predetermined amount of a transmitting carrier material such as a vehicle resin, oil or a binder resin, etc., to prepare an azo-based pigment composition having 80-100% of a transmittance of light in near infrared region of 750-1,200 nm. The vehicle resin to be used for printing ink includes a natural resin such as a dry oil, a rosin, etc., a petroleum resin, a phenol resin, etc., and the vehicle resin to be used for coating includes a natural resin, an alkyd resin, an amino resin, an epoxy resin, etc., wherein A in formula is a residual group of a diazo component of the azo pigment, halogen, a 1-3C alkyl group, or the like; B is phenyl, naphthyl, phenylene, or the like which may have a substituted group represented by X1 ; and n is 1 or 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine-particle dark azo pigment composition which improves sharpness and coloring power and suppresses irregular reflection of near infrared rays.

[0002]

2. Description of the Related Art Carbon black, aniline black, iron oxide black and the like have been generally used as dark pigments. However, these pigments absorb light of wavelengths from the ultraviolet region to the far infrared region,
It has no transparency to near-infrared light, easily absorbs infrared rays, that is, heat rays, and easily becomes hot due to direct sunlight.
Further, it has a property of poor electrical insulation.

[0003] In recent years, with the development of lasers, especially semiconductor lasers and sensors therefor, there have been an increasing number of fields seeking properties that are not found in conventionally used black pigments such as carbon black and aniline black. For example, in addition to infrared camouflage, optical filters, recording materials for the purpose of preventing forgery, etc., there are fields such as electronic parts paints, prevention of temperature rise of automobiles or building materials, and agricultural cold gauze.

[0004]

However, carbon black, aniline black, and the like have been conventionally used as black pigments for various colorings, but have a drawback that they have poor electrical insulation and are not suitable for coloring electrical parts and the like. there were. Such properties are essential to the pigment itself and cannot be removed even if the particle size is reduced, and there is a need for another black pigment that does not have such disadvantages. Accordingly, an object of the present invention is to provide a black pigment composition which can be used for coloring electric parts and the like and transmits near infrared rays with high transmittance. The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that by further reducing the size of the black azo pigment, it is possible to increase the sharpness, increase the coloring power, and suppress diffuse reflection of near infrared rays. The present invention has been completed based on the findings.

[0005]

The above object is achieved by the present invention described below. That is, the present invention is represented by the following general formula (1) and has an average particle diameter of 0.01 to 1.0 μm.
m and a transmittance of 8 in the near infrared region of 750 to 1200 nm.
A near-infrared transparent dark azo pigment composition, which is 0 to 100%. [However, A in the formula is a residue of a diazo component of the azo pigment, and is a halogen atom, a C _{1 to} C ₃ alkyl group,
C ₁ -C ₃ fluoroalkyl _group, an alkoxy group of _{C 1 ~C 3, C 1 ~C} 4 alkoxycarbonyl group having at least one substituent selected from the group consisting of a nitro group _{(X 1)} Represents at least one group selected from the group consisting of a phenyl group, a naphthyl group, a biphenyl group and the following groups (provided that X ₂ is a substituent represented by X ₁ or a hydrogen atom, and B is X ₁ A phenyl group, a naphthyl group, a phenylene group, which may have a substituent represented by 4,
It is at least one group selected from the group consisting of 4'-oxybiphenylene group, 4,4'-sulfone biphenylene group, and 4,4 '-(1 ", 2" -ethylenedioxy) biphenylene group. ), N represents an integer of 1 or 2. ]

[0006]

Next, the present invention will be described more specifically with reference to preferred embodiments of the present invention. When a pigment having a high polarity and a high boiling point is used for synthesizing a pigment, pigment particles are largely finished depending on conditions. If the particle size is large or irregular, the pigment will scatter for short light. Therefore, the use of such a pigment lowers the quality as a colorant in the visible light region,
In the near infrared region, the transmittance is reduced. The inventor has
By reducing the size of the black azo pigment particles represented by the general formula (1) to an average particle size of 1 μm or less, the degree of blackness in the visible light region is improved and jet-blackness is increased, and at the near infrared ray. Was found to suppress light scattering and significantly improve the transmittance.

The black azo pigment represented by the general formula (1) used as an infrared non-absorbing pigment in the present invention can be synthesized, for example, by a method similar to that described in JP-B-4-15265. is there. As a method for obtaining such pigment fine particles, a conventionally known method can be used. For example, (a) a method of treating a once synthesized pigment with sulfuric acid,
(B) dry grinding of pigments, (c) wet grinding of pigments, and (d) mixing of immersion during pigment synthesis (simultaneous coupling method).

[0008] These methods will be described in more detail. In the sulfuric acid treatment method, a pigment synthesized once is dissolved in 10 to 20 times (by weight) sulfuric acid, and then a sulfuric acid solution of the pigment is dropped on ice or ice water of 10 to 50 times (by weight) sulfuric acid. And re-precipitation to make it finer. The dry grinding method is a kneader, ball mill, vibratory grinding machine, etc.
This is a method of physically reducing the size by using inorganic salts in combination as needed. The wet grinding method is a method in which a pigment is mixed with water, a solvent, or a binder by using a sand mill, an attritor, a ball mill, a three-roll mill, or the like, and physically refined. Simultaneous coupling method means that at the time of pigment synthesis, two or more types of diluents are simultaneously coupled to the prepared diazonium compound (or conversely, using a mixed system of diazo components) to suppress crystal growth. This is a method for obtaining fine particles.

In order to improve the degree of blackness of the pigment in the visible light region, increase jet blackness, suppress the scattering of light in the near infrared, and remarkably improve the transmittance, the pigment of the present invention is prepared by the above method. And the average particle size is 0.01 to 1.0 μm.
m, more preferably 0.02 to
0.7 μm. The coloring matter of the pigment composed of the fine particles has a coloring power of 20 to 50 in the visible light region as compared with the coloring matter of the same pigment composed of coarse particles having a particle size of more than 1.0 μm and 5.0 μm or less. % And blackness increases jet-blackness. In the infrared region, the highest reflectance is 5% in the coarse particle system when compared with the coloring matter having the same film thickness.
What was 0% is reduced to 15% in the fine particle system of the present invention. When the transmittance is compared, the light having a wavelength of 800 nm is 45% in the coarse particle system, and is 82% in the fine particle system of the present invention.

[0010] Such a difference is mainly caused by light scattering by the pigment particles, and this property becomes more remarkable in laser light. In other words, when a near-infrared laser is irradiated on unrefined pigment (dye) particles, the laser light causes strong scattering when passing through the coarse particle layer, the transmitted light decreases, and the amount of light reaching the light receiver decreases. I do. Therefore, in order to increase the detection sensitivity, the amount of dye must be reduced to maintain the amount of light, or the sensitivity of the photodetector itself must be increased, and electrical control such as amplification and S / N ratio is required. However, in the fine particle system, even if the same amount of dye is used, the decrease in the amount of transmitted light is small, and the amount of light to the light receiver is also small, so that the intensity of the irradiation light becomes the dominant factor, and the electrical control factor is reduced. can do.

[0011] When used as a recording material for special purposes such as forgery prevention, the reading is usually made based on whether or not the irradiation light is absorbed. For example, when infrared light is used as irradiation light, it is generally read using reflection on a recording surface (base) after passing through a recording layer to discriminate absorption recording such as carbon black. Passes through the recording layer twice, at the time of incidence and at the time of reflection, so that the irregular reflectivity has a significant effect. That is, in the fine particle system, since there is almost no factor of irregular reflection, the specular reflection component increases, and the factors that affect it are the smoothness and reflectance of the recording surface.

The near-infrared transmitting dark azo pigment composition of the present invention comprises the above-described fine particle dark azo pigment and a permeable carrier material, and is used for the production of various paints, printing inks or recording materials. . Transparent carrier materials are vehicle resins, oils, binder resins, and the like that are usually used in the production of paints, printing inks, recording materials, and the like.These can be any of those conventionally used in the above applications. There is no particular limitation. As the vehicle resin, in the printing ink, for example, drying oil, rosin, natural resin such as gilsonite, petroleum resin, phenol resin, alkyd resin, vinyl resin, polyamide resin,
Acrylic resins, nitrocellulose and the like are used in coatings, for example, the above-mentioned natural resins, alkyd resins, amino resins, epoxy resins, unsaturated polyester resins, vinyl resins, acrylic resins, polyurethane resins and the like. The proportions of these transparent carrier materials and the fine-particle dark azo pigments are not particularly limited, as are the proportions of the various pigments and the vehicle resin in the above-mentioned respective applications.

[0013]

Next, the present invention will be described specifically with reference to Synthesis Examples and Examples. In the description, parts or% are based on weight.

Synthesis Example 1 3.75 parts of 3- (4'-aminophenylimino) -1
-Oxo-4,5,6,7-tetrachloroisoindoline was suspended in 11.3 parts of glacial acetic acid, and 3.7 parts of concentrated hydrochloric acid was added thereto, followed by stirring. 2.6 parts of water are added thereto, and the temperature is reduced to 0.
~ 54 ° C, 40% sodium nitrite aqueous solution 2.0
And stirred at the same temperature for about 30 minutes to obtain a yellow diazonium salt solution. To this, 4.6 parts of sodium acetate trihydrate was added to prepare a diazonium salt solution.

Separately, 3.06 parts of 2-hydroxy-N- (4'-methoxyphenyl) -11-H-benzo [a] -carbazole-3-carboxamide and 2-hydroxy-N- (2'-ethyl) Phenyl) -11-H-benzo [a] carbazole-3-carboxamide 1.3 parts were suspended in o-dichlorobenzene 250 parts and 20-3
The above diazonium salt solution was added at 0 ° C., and the mixture was kept at 30 to 40 ° C., and 20 parts of glacial acetic acid was added. This temperature was maintained for 5 to 6 hours to perform coupling. Further, acetic acid and water were heated while being distilled, and heated at 140 to 150 ° C. for 4 hours, then cooled, filtered, washed with methanol, washed with water, and dried to obtain a black azo pigment. When confirmed by an electron microscope, the average particle size was 0.2 μm.

Synthesis Example 2 3.75 parts of 3- (4'-) as a diazo component
Aminophenylimino) -1-oxo-4,5,6,7
-Tetrachloroisoindoline as diazo component, 1.35 parts of 2-hydroxy-N- (4'-methoxyphenyl) -11-H-benzo [a] -carbazole-3-carboxamide and 2.77 parts of A black pigment was obtained in the same manner as in Synthesis Example 1 using 2-hydroxy-N- (2'-methyl-4'-methoxyphenyl) -11-H-benzo [a] -carbazole-3-carboxamide.

Synthesis Example 3 Similarly, 0.01 mol of 4-benzoylamino-2,5-diethoxyaniline was used as a diazo component, and 2-hydroxy-N- (4'-methoxyphenyl) -11 was used as a coupling component. -H-benzo [a] -carbazole-3-carboxamide was added to 0.1%.
A black pigment similar to that of Synthesis Example 1 was prepared using 0.05 mol of 0.05 mol and 0.05 mol of 2-hydroxy-N- (4′-butoxycarbophenyl) -11-H-benzo [a] -carbazole-3-carboxamide. Obtained.

Synthesis Example 4 Similarly, 0.01 mol of 4- (benzoylamino) -2-methyl-5-methoxyaniline was used as the diazo component, and 2-mol was used as the coupling component.
Hydroxy-N- (4'-methoxyphenyl) -11
A dye was obtained using 0.011 mol of H-benzo [a] -carbazole-3-carboxamide, and 5 parts of this dye was dissolved in 75 parts of concentrated sulfuric acid while keeping the temperature at 10 ° C. or lower, and then dissolved in 50 parts of concentrated sulfuric acid.
It was poured into ice water consisting of 0 parts of ice and 500 parts of water to precipitate. After filtration, washing with water and drying, a pigment was obtained.

Synthesis Example 5 Similarly, as the diazo component, 4- (4'-
(Chlorobenzoylamino) -2,5-dimethoxyaniline (0.01 mol), 2-hydroxy-N- (4'-methoxyphenyl) -1 as a coupling component
A dye was obtained using 0.011 mol of 1-H-benzo [a] -carbazole-3-carboxamide. Contents A half amount of a ball was put into a 1-liter ball mill, 8 parts of the above-mentioned dye and 250 parts of water were taken, and after grinding for 16 hours, filtration, washing and drying were performed. The pigment synthesized as described above was evaluated by the following method.

Example 1 A coating material was prepared using the dye of Synthesis Example 1 according to the following formulation. The dye of Synthesis Example 1 3 parts Base varnish 12 parts Thinner 6 parts Glass beads 48 parts were placed in a 100 ml glass bottle, shaken with a paint conditioner for 90 minutes, added with 39 parts of base varnish, and shaken with the same machine for another 30 minutes. Then, a thermosetting alkyd paint was prepared. In the above formulation, the base varnish is
Super Beckamine J-820 (Dai Nippon Ink Co., Ltd.)
60% and phthalkid 133-60 (manufactured by Hitachi Chemical)
40%, thinner 70% xylene
And 30% butanol.

This paint was used as a bar coater No. After applying to a quartz plate using 16 and curing at 120 ° C. × 30 minutes,
The transmittance was measured using a Hitachi 330 type recording spectrophotometer manufactured by Hitachi, Ltd. The results were as follows, and a high transmittance was obtained. Transmittance wavelength (nm) Transmittance (%) 700 92 800 91 900 92 1000 93 1100 95 1200 97

Example 2 An offset lithographic ink was prepared using the pigment of Synthesis Example 2 according to the following formulation. Offset lithographic inks varnish of Synthesis Example 2 of a dye 30.0 parts offset lithographic inks formulated varnish 61.7 parts Dryer 0.8 parts Ink solvent 7.5 parts Total 100.0 parts The above is a rosin-modified phenolic resin, It contains a drying oil-modified alkyd isophthalate and a drying oil as main components, to which an ink solvent and an aluminum chelate are added. Using this ink, a screen ruling of 1 is applied to cellophane paper with an offset printing machine.
Printing was performed on the entire surface with 50 lines at an average density of 100%. The transmittance of the printed matter was measured with a 330 type self-recording spectrophotometer manufactured by Hitachi, Ltd. as described above, and the following results were obtained. Transmittance wavelength (nm) Transmittance (%) 700 97 800 97 900 98 1000 1000 98 1100 98 1200 1200 98

Example 3 Dye of Synthesis Example 3 35 parts Acrylic ester emulsion (activator-free type, solid content 40%) 30 parts Antifoam 0.5 part Dispersant 1.0 part Daimonex EX-6 (Dainichisei) Kasha Ltd.) 3.0 parts terpene 15 parts water 15.5 parts total 100 parts pasty black paste obtained by dispersing a black pigment in the formulation of ethylene imide-based crosslinking agent was added 1%, 2 mm thick Is applied on the acrylic plate of silk screen by
For 15 minutes to obtain a black coating material. When the transmittance of this coated material was measured in the same manner as described above,
The transmittance at a wavelength of 850 nm was 89%.

Example 4 5 parts of the dye of Synthesis Example 4 and a curable resin composition 1 having the following composition
And 00 parts were mixed and dispersed to obtain a black thermosetting paint. Resin composition polyester acrylate 40 parts Urethane acrylate 40 parts Epoxy acrylate 20 parts Phosphate acrylate 4 parts Azobisisobutyronitrile 4 parts Silicon 0.1 part Mixed solvent 50 parts The above mixed solvent is 30 parts toluene, 20 parts butyl acetate ,
20 parts of ethyl cellosolve and isopropyl alcohol 3
It consists of 0 parts. The above black paint was applied to a PET film to a thickness of 12 to 15 μm using a roll coater. The coated film was dried with hot air at 60 ° C. for 1 minute, and further heated at a temperature of 50 to 100 ° C. for 1 hour to obtain a cured film. When the transmittance of this coated product was measured in the same manner as described above, the transmittance at a wavelength of 850 nm was 91%.

Example 5 12 parts of the dye of Synthesis Example 5 Hitaloid # 3088 (manufactured by Hitachi Chemical Co., Ltd.) 24 parts Toluene 5 parts Xylene 5 parts Isobutyl acetate 5 parts Glass beads 120 parts were dispersed with a paint conditioner for 10 minutes. After adding 40.1 parts of 70B (manufactured by Hitachi Chemical Co., Ltd.) and 45 parts of thinner and further mixing with a paint conditioner for 1 hour, the glass beads were removed to prepare an acrylic urethane paint. This black room-temperature-curable resin composition was applied to a PET film in the same manner as in Example 3, and the transmittance of the coated product was measured. The transmittance at a wavelength of 850 nm was 82.
%Met.

Example 6 Contents of 20 ml of methyl methacrylate in a 300 ml flask.
Take 0 part and 1 part of benzoyl peroxide, heat to 90 ° C. in a water bath with stirring, and cool to room temperature with cold water after about 1 hour to obtain a syrup solution. 95 parts of syrup solution 5 parts of the dye of Synthesis Example 1 230 parts of glass beads 230 parts are placed in a glass bottle having a content of 300 ml, dispersed with a paint conditioner for about 30 minutes, and then the glass beads are removed. After degassing the black resin liquid under reduced pressure, the gap was 3 mm.
And gently pour it between two glass plates whose surroundings are sealed. It was then suspended in a water bath with the inlet up, heated at 50 ° C. for 1 hour,
After heating at 0 ° C. for 1 hour, put in cold water. The glass plate was removed to obtain a black PMMA thin plate. When the transmittance of this black thin plate was measured, the transmittance at a wavelength of 850 nm was 90%.

[0027]

According to the present invention as described above, the blackness of a clear color and a black pigment increases, the jet blackness increases, and the coloring power increases. Advantageously, a dark pigment composition is provided. Furthermore, in this pigment composition, diffuse reflection of near-infrared rays is reduced, and excellent optical characteristics showing high transmittance are exhibited. As a result, when this pigment composition is used for a filter or the like, the performance is remarkably improved, When used for materials, sensitivity is improved.

Claims (2)

[Claims] 1. A near-infrared light of 750 to 1200 nm, comprising a dark azo pigment represented by the following general formula (1) and having an average particle size of 0.01 to 1.0 μm and a transparent carrier material. A near-infrared-permeable dark azo pigment composition having a transmittance of 80 to 100%. Wherein A is a residue of a diazo component of an azo pigment, and is a halogen atom, a C ₁ -C ₃ alkyl group,
C ₁ -C ₃ fluoroalkyl group, C ₁ -C ₃ alkoxy group, an alkoxycarbonyl group having C ₁ -C _4, at least one substituent selected from the group consisting of a nitro group (X ₁₎
Represents a phenyl group, a naphthyl group, a biphenyl group, and at least one group selected from the group consisting of the following groups (provided that X ₂ is a substituent represented by X ₁ or a hydrogen atom; a phenyl group which may have a substituent group represented by X ₁ is a naphthyl group, a phenylene group, 4,4'-oxy-biphenylene group, 4,4' over sulfone-biphenylene group, 4,4 '- (1 ", At least one group selected from the group consisting of 2 ″ -ethylenedioxy) biphenylene groups), and n represents an integer of 1 or 2. ] 2. The near-infrared transmitting dark azo pigment composition according to claim 1, wherein the average particle diameter is 0.02 to 0.7 μm.