JP3045819B2 - Ink composition for inkjet recording - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink composition for use in an ink jet printer, particularly an ink jet printer which heats a solid ink at room temperature and discharges it in a molten state.

[0002]

2. Description of the Related Art An ink jet recording method in which a liquid ink is ejected from a nozzle to record an image is capable of printing on plain paper, is easy to cope with colorization, and has a high printing speed. Due to these advantages, printers based on various ejection principles have been marketed in recent years. The specific method of the conventionally used ink jet method is as follows.
For example, the Journal of the Institute of Television Engineers of Japan 37 (7) 540 (198)
3) and the like. Conventionally, water-based water-based inks and organic solvent-based oil-based inks have been used for inkjet recording. These printers that use liquid ink at room temperature have the advantage that a device for heating the ink is not required and the device configuration is simplified. However, when printing is performed on paper that is generally used, such as copy paper, the liquid ink has drawbacks in that sufficient image density cannot be obtained, color saturation is reduced, and images are blurred. In order to cover these drawbacks, recording is made on specially processed paper for ink jet recording in effect. Further, the liquid ink has a disadvantage that it takes a long time to dry or that the base water or the organic solvent evaporates during a period in which printing is suspended, and thus the ink tends to be clogged.

[0003] US Pat. No. 3,653,932, USP. 4,3
No. 90,369, JP-A-55-54368, JP-A-55-54368
JP-A-1-83268, JP-A-62-48774, and the like have proposed an ink jet recording method for heating a solid ink at room temperature to a liquid state and discharging the ink, and an ink used for the method.

[0004] By using a solid ink at normal temperature,
A clear monochrome or colored image can be obtained on a member such as a plastic film, a woven fabric, and a metal surface in addition to plain paper. However, with the conventional solid ink, when an image printed on a plastic film is projected by an overhead projector (OHP) or a slide projector, there is no problem with a monochrome image, but in the case of a color image, the color tone is not reproduced at all or the color tone is not reproduced. However, there is a problem that the color saturation is remarkably reduced even if appears. One of the causes of poor color reproduction is that a conventional solid ink contains a compound which easily forms crystals as a component thereof. In particular, in a conventional solid ink, a compound serving as a vehicle, which is a main component of the ink, easily formed crystals.

[0005] Japanese Patent Application Laid-Open No. 2-69282 proposes to use an aliphatic amide as a vehicle in order to solve this problem. However, even with the ink of the proposed formulation, the transparency of the ink was insufficient, and a decrease in chroma was inevitable.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a new ink composition which can solve the above-mentioned drawbacks of the conventionally used solid ink for ink jet recording. It is. That is,
It is an object of the present invention to supply a recorded matter such that when projected by an overhead projector (OHP) or a slide projector, the projected image becomes an image with sufficiently high saturation.

[0007]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that when cooled from a molten state with a temperature gradient of 200 ° C./sec or more, a room temperature containing a compound which solidifies in an amorphous state is obtained. It has been found that the above problems can be solved by a solid ink composition. In an ink jet recording method using a solid ink at room temperature, an ink heated to a melting point or higher to form a molten state is discharged onto a recording material near room temperature, so that it is rapidly cooled. The cooling rate is about 200-5000 ° C / sec.
c. Therefore, even if a crystal is formed when gradually cooled, an image obtained by using a compound which solidifies in an amorphous state when cooled with a temperature gradient of 200 ° C./sec or more as a base material can provide a transparent image. It will be. Traditionally used as the main material of vehicles, candelilla wax, beeswax, paraffin wax, aliphatic amide, aromatic sulfonamide, fatty acid, aliphatic ketone,
All of the aliphatic alcohols form crystals when cooled at a temperature gradient of 200 ° C./sec or higher, and an image having sufficiently high transparency cannot be obtained with an ink composition based on these compounds.

[0008] The basic constitutional requirement of the present invention is that the solid ink contains at least the general formula (I) and / or the general formula (II)
( Including electron-donating properties)
Except when a color organic compound coexists) . Since these compounds have remarkably high transparency upon cooling and solidification, it is presumed that these compounds solidify at least in a state close to an amorphous state without crystals. More specific examples of the compounds of the general formulas (I) and (II) are as follows.

[0009]

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[0010]

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[0011]

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[0012]

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By using these compounds as a vehicle, an ink composition having extremely high transparency can be obtained. That is, it is confirmed that although these compounds are recrystallized from an organic solvent, large crystals can be obtained, but when they are rapidly cooled from a molten state, they exhibit almost perfect light transmittance.

In particular, the compounds of the general formula (I) wherein R ₃ is substituted at the p-position and the compounds of the general formula (II) according to claim 4 exhibit high transparency.

The compounds of the general formula (I) do not always have a suitable melting point. That is, a suitable melting point is about 70-11.
0 ° C. An ink with a lower melting point has poor heat resistance of the obtained image, and a high ink has a high head temperature, so that the pre-heating time at startup is too long, the apparatus becomes large, and safety is reduced. There are drawbacks that cause problems. Among the compounds of the general formula (I), compounds in which R ₃ and / or R ₄ are —OH have high solubility of dyes and are excellent in safety, but their melting points exceed the above range. There are many compounds. By mixing a compound containing an amide group with these phenol compounds, a eutectic compound can be formed and the melting point can be lowered. Examples of compounds containing an amide group include oleamide, lauric amide, stearamide, ricinoleamide, palmitamide, tetrahydrofuranamide, erucamide, myristic amide, 12-hydroxystearic amide, N -Stearyl erucamide, N-oleyl stearamide, N-oleyl palmitamide, N-oleyl oleamide,
N-stearyl stearamide, N-stearyl oleamide, N, N′-ethylenebislauric acid amide, N, N′-ethylenebisstearic acid amide,
N, N'-ethylenebisoleic acid amide, N, N'-
Methylenebisstearic acid amide, N, N'-ethylenebisbehenic acid amide, N, N'-xylylenebisstearic acid amide, N, N'-butylenebisstearic acid amide, N, N'-dioleyladipamide , N,
N'-distearyl adipamide, N, N'-dioleyl sebacamide, N, N'-distearyl sebacamide, N, N'-distearyl terephthalamide, N, N'-distearyl isophthalate Examples thereof include acid amide, phenacetin, toluamide, and acetamide. In order not to decrease the transparency, it is most preferable to use the amide compound of the general formula (II).

In the ink composition of the present invention, a coloring material is used in addition to the above-mentioned vehicle material. Dyes or pigments are used as the colorant, but it is preferable to use a dye because clogging hardly occurs and transparency is excellent. Representative examples of the dye include the following.

<Black dye> Nigrosine, C.I. I. Solvent Black 3, C.I. I. Solvent Black 5, C.I.
I. Solvent Black 7, C.I. I. Solvent Black 22, C.I. I. Solvent Black 23, Vali
Fast Black 3804 (Orient Chemical), Vali Fast Black 1802 (Oriental Chemical), Orient Oil Black
BW (Orient Chemical), <Yellow dye> I. Solvent Yellow 2, C.I.
I. Solvent Yellow 6, C.I. I. Solvent Yellow 14, C.I. I. Solvent Yellow 15, C.I. I. Solvent Yellow 19, C.I. I. Solvent Yellow 2
1, C.I. I. Solvent Yellow 61, C.I. I. Solvent Yellow 80, Soldan Yellow GR
N (Chugai), Aizen Spiron Yellow
GRH Special (Hodogaya Chemical) <Magenta dye> I. Solvent Red 3, C.I.
I. Solvent Red 8, C.I. I. Solvent Red 2
4, C.I. I. Solvent Red 25, C.I. I. Solvent Red 49, C.I. I. Solvent Red 81, C.I.
I. Solvent Red 82, C.I. I. Solvent Red 83, C.I. I. Solvent Red 84, C.I. I. Solvent Red 109, C.I. I. Solvent Red 121,
Orient Oil Scarlet 308 (Orient Chemical Co., Ltd.), Alizen SpironRedG
EH (Hodogaya Chemical), Orient Oil Pin
kOP (Orient Chemical Co.), C.I. I. Solvent Red 3, <cyan dye> C.I. I. Solvent Blue 11, C.I.
I. Solvent Blue 12, C.I. I. Solvent Blue 25, C.I. I. Solvent Blue 35, C.I. I. Solvent Blue 36, C.I. I. Solvent Blue 55, C.I.
I. Solvent Blue 73, Aizen Spiron
Blue GNH (Hodogaya Chemical), Diaresi
nBlue C (Mitsubishi Kasei), Diaresin Bl
ue J (Mitsubishi Kasei), Diaresin Blue
H (Mitsubishi Kasei) The above-mentioned compound is used as a vehicle component of the solid ink of the present invention. Can be added. For example, dense wax,
Natural waxes such as carnauba wax, rice wax, wood wax, jojoba oil, whale wax, candelilla wax, lanolin, montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, petrolactam, and polyethylene wax And its derivatives, chlorinated hydrocarbons, palmitic acid,
Organic acids such as stearic acid, behenic acid, tiglic acid, 2-acetonaphthone behenic acid, 12-hydroxystearic acid, dihydroxytearic acid, dodecanol, tetradecanol, hexadecanol, eicosanol, docosanol, tetracosanol, Hexacosanol, octacosanol, 9-dodecene-1-ol, myristyl alcohol, 9-tetracene-1-ol, 9-hexadecene-1-ol, 9-eicosen-1-ol, 13-
Docosen-1-ol, pinene glycol, hinokiol, butynediol, nonanediol, isophthalyl alcohol, mesicerin, terephthalyl alcohol, hexanediol, decanediol, dodecanediol,
Alcohols such as tetradecanediol, hexadecanediol, docosandiol, tetrasandiol, tvneol, phenylglycerin, eicosandiol, octanediol, phenylpropylene glycol, benzoylacetone, diacetbenzene, benzophenone, tricosanone, heptacosanone, hepta Ketones such as triacontanone, hentriacontanone, stearone, laurone, and dianisole; esters of the above acids with alcohols such as glycerin, diethylene glycol and ethylene glycol; p-toluenesulfonamide; N-ethyl-p- It is possible to add a synthetic heat-fusible compound such as a sulfonamide compound such as toluenesulfonamide, ethylbenzenesulfonamide, and butylbenzenesulfonamide. Kill.

In the ink composition of the present invention, antioxidants such as 2,6-di-tert-butyl-p-cresol, 2-tert-butyl-4-methoxyphenol, and 3-tert-butyl-4- are used. Methoxyphenol,
2,6-di-tert-butyl-4-ethylphenol, stearyl-β- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 3,4
Monophenolic compounds such as 5-trihydroxybenzoic acid propyl ester, 2,2′-methylene-bis- (4-methyl-6-tert-butylphenol), 2,2′-methylene-bis- (4-ethyl -6
tert-butylphenol), 4,4′-thiobis-
(3-methyl-6-kaiska-butylphenol),
4,4'-butylidene-bis- (3-methyl-6-te
bisphenol compounds such as rt-butylphenol), 11,1,3-tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, tetrakis-dimethylene-3- (3 ′, 5′-) Di-tert-
Butyl-4'-hydroxyphenyl) propionate
High molecular weight phenolic compounds such as methane, bis- {3,3′-bis- (4′-hydroxy-3′-butylphenyl) -butylic acid} glycol ester, DL-α-tocopherol, and triphenylphos Fight, diphenylisodecyl phosphite, 4,4 '
Phosphorus compounds such as -butylidene-bis (3-methyl-6-tert-butylphenyl-di-tridecyl) phosphite, tris (nonylphenyl) phosphite and tris (dinonylphenyl) phosphite can be added. .

In addition to these components, additives such as a surfactant, an ultraviolet absorber, a heat stabilizer, and a preservative can be added to the ink composition of the present invention, if necessary.

[0020]

【Example】

Example 1 C.I. I. Solvent Yellow 80 1.5 wt% Aizen Spiron Yellow GRH Special (Hodogaya Chemical) 0.5 wt% Compound of compound example (1) 40.0 wt% Compound of compound example (18) 57.9 wt% 2-tert-butyl-4- Methoxyphenol 0.095 wt% 3-tert-butyl-4-methoxyphenol 0.005 wt% The mixture of the above formulation was dissolved and stirred at 130 ° C., and filtered while hot to obtain a hot melt ink composition. The head of an on-demand type inkjet printer using a known piezoelectric element was heated to 120 ° C., and the above ink was filled in the head to print an image on a 100 μm-thick polyester film. The obtained image is transferred to a reflective overhead projector (Ricoh 312).
Using R) to project at a distance of about 2 m, a bright yellow projected image was obtained.

Further, this yellow ink is filled into a glass cell adjusted so that the thickness of the gap is about 50 μm,
When the transmittance was measured with light having a wavelength of 700 nm without absorption of the used dye, a transmittance of 100% was obtained.

Comparative Example 1 Inks having the same formulation as in Example 1 except that stearic amide was used in place of the compound of compound example (1) and palmitic amide was used in place of the compound of compound example (18). The composition was prepared in the same manner as in Example 1.
In addition, printing and transmittance tests were performed in the same manner as in Example 1.
When an image using this ink was projected, the yellow color tone was not reproduced, and the projected image was black. The transmittance at 700 nm was 24%.

Embodiment 2 C.I. I. Solvent Red 49 2.5 wt% Compound of compound example (7) 30.0 wt% Compound of compound example (2) 27.45 wt% Compound of compound example (18) 40.0 wt% 2,2′-methylene-bis- ( 4-Methyl-6-tert-butylphenol) 0.05 wt% The mixture having the above formulation was stirred and filtered in the same manner as in Example 1 to obtain a test ink composition.

Using this ink, printing and tests were performed in the same manner as in Example 1.

When the obtained image was projected by an overhead projector in the same manner as in Example 1, a bright red image was reproduced. The transmittance at 700 nm is 100.
%Met.

Comparative Example 2 The dye used in Example 2 was used as it was, and an ink having a vehicle having the following formulation was prepared in the same manner as in Example 2.

C. I. Solvent Red 49 2.5 wt% Stearamide 52.45 wt% Stearone 30.0 wt% Carnauba wax 15.0 wt% 2,2′-methylene-bis- (4-methyl-6-tert-butylphenol) 0.05 wt% Using the obtained ink, printing and transmittance tests were conducted in the same manner as in Example 2. When an image using this ink was projected, a red color tone was not reproduced, and the projected image was black. The transmittance at 700 nm was 12%.

Embodiment 3 C.I. I. Solvent Blue 73 1.5 wt% Orient Oil Blue # 603 (Orient) 1.5 wt% Compound of compound example (1) 30.0 wt% Compound of compound example (8) 26.8 wt% Compound of compound example (19) 40. 0 wt% 2,6-di-tert-butyl-p-cresol 0.2 wt% The mixture having the above formulation was stirred and filtered in the same manner as in Example 1 to obtain a test ink composition. Using this ink, printing and testing were performed in the same manner as in Example 1.

When the obtained image was projected by an overhead projector in the same manner as in Example 1, a bright blue image was reproduced. The transmittance at 700 nm is 97%.
Met.

Comparative Example 3 The dye used in Example 3 was used as it was, and an ink having a vehicle having the following formulation was prepared in the same manner as in Example 3.

C. I. Solvent Blue 73 1.5 wt% Orient Oil Blue # 603 (Orient) 1.5 wt% Stearamide 9.8 wt% Stearone 25.0 wt% Lauron 30.0 wt% Carnauba wax 15.0 wt% Paraffin wax (HNP-3 17.0 wt% 2,6-di-tert-butyl-cresol 0.2 wt% Using the obtained ink, printing and transmittance tests were performed in the same manner as in Example 3. When an image using this ink was projected, the blue color tone was not reproduced, and the projected image was black. The transmittance at 700 nm was 16%.

Embodiment 4 C.I. I. Solvent Yellow 80 1.5 wt% Aizen Spiron Yellow GRH Special (Hodogaya Chemical) 0.5 wt% Compound of compound example (4) 65.0 wt% Stearamide 32.9 wt% 1,3,5-trimethyl-2,4 2,6-Tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene 0.1 wt% The mixture having the above formulation was stirred and filtered in the same manner as in Example 1 to obtain a test ink composition. Using this ink, printing and testing were performed in the same manner as in Example 1.

When the obtained image was projected by an overhead projector in the same manner as in Example 1, a bright yellow image was reproduced. The transmittance at 700 nm is 73%.
Met.

Embodiment 5 C.I. I. Solvent Yellow 80 1.5 wt% Aizen Spiron Yellow GRH Special (Hodogaya Chemical) 0.5 wt% Compound of compound example (1) 35.0 wt% Compound of compound example (5) 30.0 wt% Compound of compound example (16) 20 0.0 wt% Compound of compound example (17) 12.9 wt% 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene 0.1 wt% The mixture having the above formulation was stirred and filtered in the same manner as in Example 1 to obtain a test ink composition. Using this ink, printing and testing were performed in the same manner as in Example 1.

When the obtained image was projected by an overhead projector in the same manner as in Example 1, a bright yellow image was reproduced. The transmittance at 700 nm is 96%.
Met.

Example 6 C.I. I. Solvent Red 84 2.0 wt% C.I. I. Solvent Red 83 0.5 wt% Compound of compound example (13) 50.0 wt% Compound of compound example (14) 7.4 wt% Compound of compound example (19) 25.0 wt% Compound of compound example (20) 15.0 wt% % Stearin-β- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate 0.1 wt% The mixture having the above formulation was stirred and filtered in the same manner as in Example 1 to obtain a test ink composition. Using this ink, printing and testing were performed in the same manner as in Example 1.

When the obtained image was projected by an overhead projector in the same manner as in Example 1, a bright red image was reproduced. The transmittance at 700 nm is 98%.
Met.

Example 7 C.I. I. Solvent Yellow 61 1.5 wt% C.I. I. Disperse Yellow 238 0.5 wt% Compound of compound example (3) 52.8 wt% Compound of compound example (7) 45.0 wt% 2-tert-butyl-4-methoxyphenol 0.17 wt% 3-tert-butyl -4-methoxyphenol 0.03 wt% Example 8 C.I. I. Solvent Red 84 2.0 wt% C.I. I. Solvent Red 83 0.5 wt% Compound of compound example (2) 40.0 wt% Compound of compound example (6) 25.0 wt% Compound of compound example (10) 32.3 wt% 2,6-di-tert-butyl- p-Cresol 0.2 wt% In Examples 7 and 8, the mixture of the above formulation was stirred and filtered in the same manner as in Example 1 except that the temperature at the time of stirring and filtration was 170 ° C. to obtain a test ink composition. Obtained. Using this ink, printing and testing were performed in the same manner as in Example 1 except that the head temperature was 170 ° C.

When the obtained image was projected by an overhead projector in the same manner as in Example 1, bright yellow and red images were reproduced, respectively.

[0040]

As is clear from the above description, in the present invention, (1) a compound which solidifies in an amorphous state when cooled from a molten state by a temperature gradient of 200 ° C./sec or more is contained. As a result, the resulting image is highly transparent, and a bright color image is projected when projected by an overhead projector or a slide projector.

(2) Since the compound of the general formula (I) or (II) is contained, an image having high transparency can be obtained, and the compound of the general formula (I) or the general formula (II) is solidified. Due to its high hardness, an image having high friction durability can be obtained even when printing on ordinary paper.

3) Since the compound of formula (I) or (II) contains a compound substituted at the p-position, an ink composition having particularly excellent transparency can be obtained.

(4) In the general formula (I), R ₃ is -OH
And a compound having an amide group, the solubility of the dye in the vehicle is high, and a sufficient image density can be provided even with a small amount of ink adhered to the recording material. Since an ink composition that melts at a temperature lower than the melting point of the two compounds alone is provided, printing can be performed with the head set at a relatively low practical temperature.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-259968 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09D 11/00-11/20

Claims (3)

(57) [Claims] An ink composition for solid-state inkjet recording containing a compound of the following general formula (I) and / or a compound of the following general formula (II) ( provided that an electron-donating colorant is used):
Unless organic compounds coexist) . Embedded image (However, R ₁ and R ₂ are -H, -OH, -COOH, -C
OOR, an alkyl group substituted or unsubstituted with a halogen element, -X (X represents a halogen element), and R ₃ represents -H, -OH, -X (X represents a halogen element) ), An alkyl group, -COOH, -COOR, an amide group, or a sulfonamide group. ) (Wherein, R ₄ represents, -H, -CH _3, a -C ₂ H _5.) 2. A compound of the formula (I) wherein R ₃ is p
- inkjet recording ink composition of claim 1, wherein substituted into position. 3. At least in the general formula (I), R ₃
There compound is -OH (Compound A) and a compound containing an amide group (Compound B) according to claim 1 or claim 2 ink composition according comprising the two compounds as vehicles.