JPH0280486A - Composition for near-infrared absorber, near-infrared absorptive material and molding containing same - Google Patents

Abstract

PURPOSE:To obtain the title composition which is lowly colored and has excellent durability by mixing a thiourea derivative with a lead compound. CONSTITUTION:At least one thiourea derivative selected from the compounds of formula I [wherein R1-3 are each H, a (cyclo)alkyl, an aryl, an aralkyl or a five- or six-membered heterocyclic residue and they may be combined together to form a ring] (e.g., 1,3-diphenylthiourea) is mixed with at least one lead compound desirably represented by formula II [wherein R is H, a (cyclo)alkyl, an aryl, an aralkyl or a heterocyclic residue; X is -COO, -SO4, -SO3, -PO or -O; and n is 1-4] (e.g., lead p-chlorobenzoate).

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a composition for a near-infrared absorber comprising a lead compound and a thiourea derivative, a near-infrared absorbing material, and a molded article containing the same. .

Near-infrared absorbing materials are functional materials that have been particularly actively researched and developed recently, and are used in information recording materials such as photosensitive materials and recording materials for optical disks that use semiconductor laser light with a wavelength in the near-infrared region as a light source. , light combined with optical materials such as infrared cut filters and films, and heat-sensitive materials.
It can be used as a heat conversion type recording material.

[Prior art] Near-infrared absorbing materials developed so far include chromium and cobalt complex salts in Japanese Patent Publication No. 60-42269, thiol nickel complexes in Japanese Patent Application Laid-Open No. 60-21294,
JP-A No. 61-125958 discloses anthraquinone derivatives, JP-A No. 61-218551 discloses 700-80
A novel squarylium compound having a maximum absorption wavelength in the 0 nm region is disclosed.

Furthermore, in addition to this, “Near-infrared absorbing dye” (Chemical Industry 43
．． (May 1986), nitroso compounds and their metal complex salts, polymethine dyes (cyanine dyes), thiols, cobalt, and platinum.

Complex salts with palladium, phthalocyanine dyes, triallylmethane dyes, immonium, diimmonium dyes, naphthoquinone dyes, etc. are known.

[Problems to be Solved by the Invention] Conventional near-infrared absorbing materials, such as organic ones, have poor durability and are susceptible to changes in environmental conditions and over time. The problem is that the initial performance deteriorates over time.On the other hand, complex-based materials are durable, but absorb not only in the near-infrared region but also in the visible region, and compound-dried materials are strongly colored. There was a problem in that there were many things that had been used, and their uses were limited. Furthermore, in both systems, an absorption peak was observed at a specific wavelength, and there was almost no absorption ability at wavelengths deviating from that peak. When considering a recording medium using these materials as a light source, for example, a laser beam having a near-infrared wavelength, it is necessary to match the wavelength of the laser with the absorption peak of the material. However, since only a limited number of laser wavelengths and absorption wavelengths of near-infrared absorbing materials can be obtained, the combinations in which the laser wavelength and near-infrared absorbing material's absorption peaks match are limited. However, when considering absorption capacity, durability, coloring, economic efficiency, etc., there are practically no combinations that can be used, and the fields in which they can be used are extremely limited.

Therefore, the present invention focuses on near-infrared T of 700 to 2.000 nm.
The object of the present invention is to provide a near-infrared absorbing material that exhibits uniform absorption throughout the I region, has little coloration, and has excellent durability, a composition that can be easily made into a near-infrared absorbing material, and a molded article containing the same. And so.

[Means for Solving the Problems] The above problem is solved by - formula (I) (wherein R,, R2, R3 are hydrogen, alkyl groups, alkenyl groups, cycloalkyl groups, aryl groups, aralkyl groups, and 5-membered or a monovalent group selected from the group consisting of 6-membered heterocyclic residues, each branch may have one or more substituents, and R1 and R2 or R2 and R1 are linked to form a ring. A composition for a near-infrared absorber containing at least one thiourea W conductor selected from the group consisting of: and at least one lead compound, or a reaction obtained by heat-treating these compositions. The problem was solved by using near-infrared absorbing materials made of these materials or molded articles containing them.

Substituents that can be used in general formula (1) include amino groups, alkyl groups, alkenyl groups, aryl groups, aralkyl groups, nitro groups, halogen groups, hydroxyl groups, alkoxy groups, and acyl groups, but t 1111-C -NIICIl, Cl12011 Other substituents and ethyl-3-(
2-hydroxyethyl)thiourea may also be used.

Examples of the thiourea conductor represented by the general formula (I) used in the present invention include the following: 1-ethyl-3 phenylthiourea C+all*t-NH-C-Ntl-ClaHzy1.
3-Distearylthiourea 1.3 -Diphenylthiourea Czd14s-Nll-C-NH-Czzt14s1.
3-diethylthiourea El-Nil-C-N11-εL I 1.3 Diethylthiourea E t -N H-C-N H - Phenylthiourea 1-p-hydroxyphenyl-3- Phenylthiourea 1-(2-thiophenyl) Phenylthiourea 1.3 -di-m-chlorophenylthiourea 110cHtcHJIl-C-NHCIItCH! Oi
1-membered l, 3-bis(2-hydroxyethyl) thiourea-p-aminophenyl-3-phenylthiourea ■-methyl-3-p-hydroxyphenylthiourea-p-nitrophenyl-3- phenylthiourea 1.3- dicyclohexylthiourea l-m-nitrophenylthiourea l-phenyl-1-p chlorophenylthiourea 1-p-nitrophenylthiourea 1-phenyl-3-, -methoxyphenylthiourea+
1. C-NH-C-111-1-C11゜1.3-dimethylthiourea 1.1-diphenylthiourea 1.1-dibenzyl-3-phenethylthiourea Furthermore, the lead compound used in the present invention has the general formula (rl) ( R-X)
pb (■) (wherein R represents hydrogen, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and a heterocyclic residue (8 groups may have one or more substituents). represented, X is -COD
, -5Oi, -5Oz, -po4゜0, n
is an integer of 1 to 4) or at least one selected from lead chlorophyll, sodium lead chlorophyllin, and lead bisacetylacetonate. - Specific examples of the compound represented by formula (■) include, but are not limited to, the following.

Lead stearate, lead panamitate, lead oleate, lead hehenate, lead laurate, lead caprate, lead caproate,
Lead valerate, lead isobutyrate, lead butyrate, lead prodionate, lead acetate, lead formate, lead hydroxide, lead benzoate, lead orthotoluate, lead metatoluate, lead paratoluate, lead paratertiary butylbenzoate , lead orthochlorobenzoate, lead methachlorobenzoate, lead parachlorobenzoate, lead dichlorobenzoate, lead trichlorobenzoate, lead ρ-bromobenzoate, lead p-iodobenzoate, lead p-phenylbenzoate,
Lead 0-benzoylbenzoate, lead ρ-nitrobenzoate, lead anthranilate, lead p-aminobenzoate, lead oxalate,
Lead malonate, lead succinate, lead glutarate, lead adipate, lead pimelate, lead sperate, lead azelaate, lead sebacate, lead phthalate, lead monoester phthalate, lead naphthenate, naphthalene carboxylic acid Lead, lead tartrate, lead diphenylamine-2-carboxylate, lead 44-cyclohexylbutyrate, lead diethyldithiocarbamate, lead gluconate, lead 5-diethoxy, di-propoxy lead, di-n-butoxy lead, lead octylate, lead alkylbenzene sulfonate .

Lead p-toluenesulfonate, lead naphthalenesulfonate,
Lead naphthylamine sulfonate, n)' Lead decylhenzenesulfonate, Lead dodecyl sulfate.

Lead 2.5-dimethylbenzenesulfonate, Lead 2-carbomethoxy-5-methylhenzenesulfonate, Lead α-naphthyl phosphate, Lead stearate, Lead lauryl phosphate, Lead di-2-ethylhexyl phosphate, Isodecyl phosphate lead.

The above-mentioned thiourea derivatives and lead compounds alone have almost no absorption in the near-infrared region, or even if they do, they only slightly absorb specific wavelengths. Further, even if these compounds are subjected to heat treatment alone, there is no substantial change in near-infrared absorbability. However, by simply heating a mixture of a thiourea derivative and a lead compound, it has almost uniform and strong absorption over the entire near-infrared region.

If thiourea V represented by the general formula (I) of the present invention, a conductor, and the compound represented by the general formula ([1) or lead bisacetylacetonate, chlorophyll carriers, or lead chlorophyllin sodium are present together, the strong near-infrared rays It does not indicate absorption. However, if thermal energy is applied to this composition or a molded article containing this composition by some method when necessary, the area to which thermal energy is applied will immediately have the property of strongly absorbing near-infrared rays. Since the portion to which thermal energy has been applied has almost no absorption in the visible region, this portion becomes a latent image of the heating pattern. Therefore, by utilizing this change in the properties of the composition of the present invention, it can be made into a recording paper using a heating pattern detection device or a suitable developing means.

Furthermore, since the product obtained by heat-treating the composition containing the thiourea compound and lead compound of the present invention has strong absorption over almost the entire region of strong near-infrared rays, it is difficult to detect near-infrared rays. In addition to devices, it becomes possible to construct recording systems that utilize various laser beams with wavelengths in the near-infrared region.

The degree of near-infrared absorption can be arbitrarily adjusted by adjusting the type and ratio of the thiourea derivative and lead compound, heating temperature, heating time, etc.

The thiourea derivative and the lead compound may be mixed as is according to the mixing ratio to form a composition, or they may be mixed together with a binder, a valve, a thermoplastic resin powder, etc., and further mixed with additives such as a coloring agent if necessary. It can also be a thing.

Alternatively, the composition may be prepared by mixing and dissolving or dispersing it in a suitable solvent or dispersion medium, or by mixing and dispersing it in a medium in which a binder, colorant, etc. are dissolved.

Such compositions include paints, fillers, and the like. The degree of mixing and the content in the molded body or the amount blended with other substances is such that when heat treatment is performed, the thiourea derivative and the lead compound remain solid, or one or both of them melt and interact. It suffices to do so as long as it is in a state where it can be brought into sufficient contact with the

A method for incorporating a composition containing a thiourea derivative and a lead compound or a near-infrared absorbing material obtained by heat-treating this composition into a molded article is to mix these with materials constituting the molded article and mold the mixture. Alternatively, a slurry in which each of these substances is dispersed may be applied or impregnated onto a molded body by spraying, coating, printing, etc. The molded body can be used for making, weaving, heating, etc. into valves, fibers, thermoplastic resins, ceramics, etc. It is made into a film, sheet, or plate shape using known materials and methods, such as molding, and secondary processing is performed as necessary.

The heat treatment method for developing near-infrared absorbency is 2.
There is no particular restriction as long as it can add thermal energy that will cause the components to react and obtain near-infrared absorbing ability, such as electric heaters, induction heating, melt molding of films, thermal heads, semiconductor lasers, and infrared lamps. Can be done.

The heating operation may be carried out in any atmosphere such as the air or an inert gas atmosphere, but is usually carried out in the air.

The heating temperature is generally in the range of 40 to 400°C, preferably in the range of 50 to 350°C. The heating time is
Generally, it is within the range of several milliB· to several tens of minutes. In addition, it is a preferable method to add stirring, rotation, and vibration to increase the frequency of contact between the substances, to uniformly transfer thermal energy, to speed up the reaction, and to homogenize the mixing state.

The blending ratio of the thiourea derivative and the lead compound varies depending on the type of citrus, but generally it is in the range of 0.01 to 50 parts of the thiourea compound to 1 part of the lead compound, preferably 0.
．． It ranges from 1 part to 10 parts.

[Function] As mentioned above, a mixture containing the thiourea derivative of formula (I) and lead hydroxide or the lead compound of general formula (II) or lead bisacetylacetonate, lead chlorophyll, or sodium lead chlorophyllin, By heat treatment, near-infrared rays are almost uniformly absorbed over the entire range of 700 to 2,000 ntrr, but the reason for this is not clear.

As is clear from the Examples and Comparative Examples shown below, even if a thiourea derivative or a lead compound is heat-treated alone, the near-infrared region of 700 to 2,000 nm is almost uniformly and strongly approached. Considering that it does not absorb infrared rays and is the same even if it is simply mixed,
This is presumed to be due to the fact that some kind of reaction occurs between the thiourea derivative and the lead compound by heat-treating the mixture containing both the thiourea derivative and the lead compound, resulting in a complex.

[Example] Next, an example of the present invention will be described. Parts in the examples are parts by weight.

[Example 1] Each of the thiourea derivatives and lead compounds No. 1, I, No. 3, No. 5 in Table 1 and lead compounds were prepared in the following formulation to have an average particle size of 3 μm.
Wet grind with an attritor until it reaches a certain level.

(A) Thiourea derivatives of liquids No. I, No. 3, No. 5
20 parts 10% polyvinyl alcohol aqueous solution 501
/water
3o total
100 parts (B) Lead compound #J of liquid No. I, No. 3, No. 5
20 parts 10% polyvinyl alcohol water soluble
50//30 parts of water 〃 Mix 100 parts in total (A) 50 parts of Ti (B) 50 parts of liquid, and the basis weight is 60 parts.
g/m'' high-quality paper using a Mayer bar to a coating amount of 5 g/m'' and drying to obtain recording paper.

The resulting recording sheets were all white to light blue in color, and when the coated surface was brought into contact with a metal block having a surface temperature of 150° C. for 5 seconds, the color developed into brownish brown.

The near-infrared absorption of each colored part is 800.900
, 1,000, 1,500, and 2,000 nm, the average absorption value of each wavelength was 80% or more, indicating high near-infrared absorption.

In addition, thermal printing was performed using a thermal barcode label printer (BW-100T manufactured by Mecha Spotron). In both cases, a brown barcode pattern was obtained, and this pattern was read using a barcode reader (MS-Ba-Dac 230 manufactured by Mekaspotron Co., Ltd.) whose light source is a semiconductor laser beam having a wavelength in the near-infrared region of 940na+. I could read it clearly.

[Example 2] 10 parts of a mixture of 5 parts of thiourea compound and 5 parts of lead compound of combination No. 1-No. 23 shown in Table 1 in a ceramic crucible were heated at 150° C. for 15 seconds in an electric oven. did. The resulting lightly colored powdery reaction product was fixed to a certain thickness on high-quality paper, and the reflectance of the surface was measured using a spectrophotometer (JASCO VIDEC-590) to 800-2. , 500 rv was measured in the near-infrared region.

Judgment of near-infrared absorption is 800 900.1,000
．． The absorption value is the value obtained by subtracting the reflectance of each wavelength of 1.500 and 2.00 OnLl from 100, and the average absorption value is 80.
% or more ◎, 60% or more 0130% or more △,
30% or less was marked as x. The near-infrared absorbing material of the present invention exhibits a near-infrared absorbing property of 30% or more on average.

As shown in Table 1, the near-infrared absorption properties of the reaction products of the combinations No. 1 to No. 23 of Wood Examples were all 60% or more on average.

[Comparative Example 1] Each of the thiourea compounds or lead compounds shown in Table 2 was individually heat-treated under the above conditions, and the reflectance spectrum in the near-infrared region of the obtained product was measured. Infrared absorption was evaluated. As shown in Table 2, all of the samples had near-infrared absorption of 30% or less.

In order to show in detail the changes in near-infrared absorption when the thiourea conductor of the present invention and a lead compound are heat-treated alone, when they are mixed together, and when they are mixed and heat-treated, N-phenylthiobenzurea No. 1 of Example 2 in which lead P-chlorobenzoate was mixed and heat treated, Example I No. I in which the mixture was simply mixed and no heat treatment was performed, and 1.3-
No. I and No. 4 a of Comparative Example 1 in which diphenylthiourea and lead p-chlorobenzoate were each heat-treated alone
The near-infrared reflection spectrum in the range of OO to 2.000 n+s is shown in FIG.

According to FIG. 1, Example 2, No. 1, in which N-phenylthiobenzurea and lead p-chlorobenzoate were mixed and heat treated.
The near-infrared absorption properties of these materials are dramatically stronger than those obtained by heating them alone or by mixing them, and exhibit absorption of 90% or more over the entire measured wavelength range.

[Example 3] The thiourea compounds and lead compounds No. 24 to No. 32 shown in Table 3 were separately given the following compositions.

(Liquid A) Thiourea compound 50 parts 10% polyvinyl alcohol aqueous solution 25 parts water
125 parts (B solution) Lead compound 50 parts lO% polyvinyl alcohol aqueous solution 25 parts water
125 parts Eight liquids of the above composition were ground with an attritor to an average particle size of 1 micron. Next, the dispersion liquids were mixed in the proportions shown in Table 3 to form a coating liquid, and each of the above coating liquids was applied to one side of a 50 g/m'' high-quality paper to a solid content of 3.0 g/m'' and dried. . This sheet was heat-treated by pressing it against a hot plate at 150° C. at a pressure of 10 g/nf for 5 seconds to produce a near-infrared absorbing sheet.

The near-infrared absorbency of this sheet was measured and evaluated using the same method as in Example 2, and the ground color of the coated surface and the storage stability against heat, humidity, and light of the near-infrared absorbency were measured using the following methods. It is shown in Table-3.

Background color: The reflection density of the coated surface after heat treatment was measured using a Macbeth densitometer (RD-914, amber filter).

Heat resistance: After the sheet was left in an oven at 60° C. for 24 hours, the infrared reflectance was measured again using a spectrophotometer (wavelength: 1.000 parts m). The heat-resistant storage stability was evaluated by the residual rate of near-infrared absorption using the following formula.

Moisture resistance: near-infrared absorbing sheet at 40°C.

After 24 hours, the infrared reflectance was measured using a spectrophotometer (wavelength: 1.000 nm). Moisture-resistant storage stability was evaluated by the residual rate of near-infrared absorption calculated by the following formula.

Light resistance: After the near-infrared absorbing sheet was irradiated with light for 6 hours using a fade meter, the infrared reflectance was measured using a spectrophotometer (wavelength: 1.000 nm). The light storage stability was evaluated by the residual rate of near-infrared absorption calculated by the following formula.

[Comparative Example 2] The dispersion of liquid A or liquid B of the thiourea derivative or lead compound used in Example 3 was applied and dried in the same manner as in Example 3, and then heated and treated with near infrared rays. Absorption was measured.

According to Table 3, it is clear that a sheet prepared by coating and drying a mixture of an aqueous dispersion of a thiourea compound and a lead compound becomes a strong near-infrared absorbing sheet by heat treatment. or,
It can be seen that this near-infrared absorption property hardly decreases due to heating, humidification, or exposure to light, and is highly stable against changes in environmental conditions during handling and storage. The sheet was slightly colored, but it was almost gray so it wasn't too noticeable.

Further, a sheet coated with a dispersion of a thiourea derivative or a lead compound alone and dried does not substantially exhibit near-infrared absorbability even after heat treatment. Therefore, a storage test for near-infrared absorption was not performed.

[Effects of the Invention] The near-infrared absorbent composition of the present invention and the sheet containing the same are almost colorless, and the areas to which heat is applied immediately exhibit near-infrared absorbency. In addition, these compositions and sheets containing this composition are heat-treated,
Alternatively, a sheet containing a heat-treated composition has strong absorption over the entire near-infrared region of 800 to 2,000 nw. By utilizing these properties, it can be used as thermal history detection devices, optical materials such as near-infrared cut filters, recording materials, heat ray blocking materials, heat storage materials, near-infrared detection sensors, etc.

The composition of the present invention or heat treatment of this composition
? The resulting products have little coloring even though they contain metals, so molded products such as films and papers containing these products have excellent appearance.

The near-infrared absorbing properties of the near-infrared absorbing composition, the near-infrared absorbing material, or the molded article containing them of the present invention all exhibit high stability against changes in environmental conditions over time and deterioration. There's nothing to do.

Further, the near-infrared absorbing composition and near-infrared absorbing material of the present invention can be produced extremely easily by only mixing and heating. Furthermore, the present invention is suitable for industrial production since the production of molded bodies containing these does not require any new means.

[Brief explanation of the drawing]

FIG. 1 is a near-infrared reflection spectrum diagram of N-phenylthiobenzurea and lead p-chlorobenzoate heat-treated alone, a mixture thereof, and a mixture thereof heat-treated.

Claims (1)

[Claims] 1. General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R_1, R_2, R_3 are hydrogen, an alkyl group,
Represents a monovalent group selected from the group consisting of an alkenyl group, a cycloalkyl group, an aryl group, an aralkyl group, and a 5- or 6-membered heterocyclic residue, and each group may have one or more substituents. A composition for a near-infrared absorber containing at least one thiourea derivative selected from R_1 and R_2 or R_2 and R_3 may be connected to form a ring) and at least one lead compound. thing. 2. The lead compound has the following general formula (II) (R-X)_nPb(II) (wherein R is hydrogen, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and a heterocyclic residue (each group is X is -COO, -SO_4, -SO_3,
The composition for a near-infrared absorber according to claim 1, wherein the composition is a lead compound represented by -PO_4, -O, and n are integers of 1 to 4. 3. The composition for a near-infrared absorber according to claim 1, wherein the lead compound is lead bisacetylacetonate. 4. The composition for a near-infrared absorber according to claim 1, wherein the lead compound is lead chlorophyll or sodium lead chlorophyllin. 5. A near-infrared absorbing molded article containing the near-infrared absorbing composition according to any one of claims 1 to 4. 6. A near-infrared absorbing material comprising a reaction product obtained by heat-treating the near-infrared absorbent composition according to claims 1 to 4. 7. A near-infrared absorbing molded article containing the near-infrared absorbing material according to claim 6. 8. A near-infrared absorbing molded article obtained by heating the near-infrared absorbing molded article according to claim 5.