JPS61177279A - Ink jet recording medium - Google Patents

Abstract

PURPOSE:To enhance water resistance and light resistance of water base ink images and improve particularly light resistance and resistance to discoloration and fading of a water-soluble black dye and/or a water-soluble magenta dye, by incorporating a specified heterocyclic compound into a recording medium. CONSTITUTION:A heterocyclic compound having the structure of formula I, wherein X is basically C, N, O or S, e.g., one of compounds of formulas II-IV, is incorporated into an ink jet recording medium for recording images thereon by use of a water base ink containing a water-soluble dye. The recording medium containing the heterocyclic compound may be produced by, for example, a method wherein pulp fibers are beaten to form a slurry, and when making a paper from the slurry by a paper making machine, a coating liquid with the heterocyclic compound dissolved or dispersed therein is infiltrated into or applied to the paper to thereby incorporate the compound into the paper, or a method wherein a coating liquid containing the heterocyclic compound is applied to a base by an ordinary coater to thereby provide an ink-receiving layer containing the heterocyclic compound.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention relates to a recording medium recorded using ink, and in particular, the present invention relates to a recording medium recorded using ink. The present invention relates to an inkjet recording medium with excellent storage stability of recorded images.

(13) Prior art and its problems In the inkjet recording method, micro droplets of ink are ejected using various operating principles and attached to a recording medium such as paper to record images, characters, etc. ,high speed,
It has features such as low noise, easy multicolor printing, wide flexibility in recording patterns, and no need for development or fixing, making it suitable for many uses as a recording device for various shapes and color images, including kanji. It is rapidly becoming popular. Furthermore, images formed using the multicolor inkjet method can produce records that are comparable to multicolor printing using the plate making method or printing using the color photographic method, making it suitable for applications that require fewer copies to be produced. Since it is cheaper than photographic technology, it is being widely applied to the field of full-color image recording.

Efforts have been made in terms of equipment and ink composition to use high-quality paper or coated paper, which are used for ordinary printing and writing, as the recording medium used in this inkjet recording method. However, as the performance of inkjet recording apparatuses increases, such as higher speeds, higher definitions, and full-color inkjet recording apparatuses, and their applications expand, more advanced characteristics are now required of recording media. In other words, the recording medium must have high ink dot density, bright and colorful tones, ink absorption is fast and the ink does not flow out or sink even when ink dots overlap, and the ink dots must be lateral diffusion is not larger than necessary, and the periphery is smooth and does not fade. Furthermore, it is required that the resistance of the dye when the recorded image is exposed to ultraviolet rays, oxygen in the air, or water be not reduced, but preferably increased.

Several proposals have been made to solve these problems. For example, Japanese Patent Application Laid-Open No. 52-53012 discloses an inkjet recording paper made by moistening a low-sized base paper with a paint for surface treatment.
No. 113 discloses an inkjet recording paper in which a sheet to which urea-formalin resin powder is completely added is impregnated with a water-soluble polymer. Although these patterned paper type ink jet recording papers absorb ink quickly, they have the disadvantage that the periphery of dots tends to be blurred and the dot density is low.

Further, JP-A No. 55-5830 discloses an inkjet recording paper in which an ink-absorbing coating layer is fully formed on the surface of the support, and JP-A No. 55-51583 discloses a non-gelatinous pigment as a pigment in the coating layer. An example using silica powder is disclosed, and furthermore, JP-A-55-11829 discloses an example of smear paper using a two-layer structure with different ink absorption speeds. These coated paper-type inkjet recording papers are improved over general paper-type inkjet papers in terms of dot diameter, dot shape, dot density, and color tone reproducibility, but there are Many inks are water-based inks that use water-soluble dyes, and if an image formed on a recording medium is exposed to water, the dye may dissolve again and ooze out, significantly reducing the value of the recorded material. There is a point.

Therefore, in order to improve this drawback, for example,
No. 53591 discloses an example in which a water-soluble salt of a metal is applied to the recording surface, and JP-A-56-84992 discloses an example of a recording medium containing a polycationic polymer acidolate on the surface. JP-A-55-150396 discloses a method of applying a water-resistant agent to form a lake with the dye in the ink after inkjet recording, and JP-A-56-58869 describes a method of applying a water-resistant polymer to form a lake with the dye in the ink. After inkjet recording on a recording sheet, by insolubilizing the water-soluble polymer,
Each method for making it water resistant has been disclosed.

However, with these methods, the effect of water resistance is weak, or the water resistance agent causes some kind of reaction with the dye, reducing the shelf life of the dye, making it difficult to achieve both sufficient water resistance and surface properties. That was quite difficult.

Therefore, in order to improve the light resistance, for example,
-68'30'3, 54-85804 and 56
No. 18151 discloses an example in which an ultraviolet absorber is added to an ink liquid. However, these ultraviolet absorbers have problems in that they reduce the jetting stability of the ink and have low solubility, so they cannot be added in large amounts, and adding only a small amount has little effect. Another solution to this problem is to incorporate ultraviolet absorbers such as benzophenone and benzotriazole into the inkjet recording sheet, as disclosed in Japanese Patent Application Laid-open No. 5.
No. 7-74192, No. 57-74193 and No. 57-
87988, but these have poor solubility in water and are difficult to use in large amounts, are ineffective in small amounts, and are affected by emulsifiers when used in emulsified form. There is a problem with this.

(C1 Purpose of the Invention The present invention aims to improve the inkjet suitability as described above and to improve the water resistance and light resistance of water-based ink images, especially the light resistance and light resistance of water-soluble black dyes and/or water-soluble magenta dyes. The purpose of the present invention is to provide all recording media with improved discoloration and fading resistance.

(DJ Structure and operation of the invention, that is, the present invention provides an inkjet recording medium that forms a recorded image using an aqueous ink containing a water-soluble dye, in which the recording medium has a structure represented by the following general formula (I). This is an inkjet recording medium containing a heterocyclic compound having the following properties.

In the direct formula, X basically represents C, N, Ol or S - =N-1-N-R4, -0-1 or -S- (here R1
, R2, R3 and R4 represent H or a substituent such as 10H1-CH3. Also, in the formula, two □ represented by C=N-
The heavy bond may be conjugated to other constituents of the compound. Further, the heterocycle is a 5-membered negative ring or a 6-membered ring containing -X-C=N-, and may also form a polycycle with other constituent elements.

Compounds having the structure of general formula (■) in the present invention include: (1) H;

■ etc. Further, there is no problem in using these heterocyclic compounds together with hindered phenol antioxidants, benzotriazole-based or benzophenone-based ultraviolet absorbers, and the like. Furthermore, in order to apply it to a recording medium, it can be used as a metal salt, completely introduced with water-soluble groups, or emulsified and dissolved as it is in water or an appropriate solvent.

The content of heterocyclic compound (I) in the recording medium is 0.2 to
100 mmol/iy? , preferably Its 1.0
~50 mmol/m'.

In the present invention, as a method for producing a recording medium containing the heterocyclic compound (I)'(z), when pulp fibers are disintegrated into a slurry and made into paper using a paper machine, the heterocyclic compound is A method in which the coating solution containing the compound full'e dissolved or dispersed is completely immersed or coated, and a coating containing the heterocyclic compound (1) & gold is coated on the support using an ordinary coating device. to form a heterocyclic compound (Il
-e-containing ink-receiving layer, and method of coating a heterocyclic compound (Il'e) dissolved or dispersed on the ink-receiving layer consisting of an ink-absorbing pigment and adhesive. It is also possible to use fillers, pigments, adhesives, and other additives in combination.Furthermore, if it is necessary to impart water resistance to images, it is also possible to use cationic resins in combination. In order to improve water resistance and light resistance at the same time, it is preferable to use it actively.

Examples of fillers or pigments that can be used in the present invention include light calcium carbonate, heavy calcium carbonate, Kaori/,
Merck, calcium sulfate, barium sulfate, titanium oxide,
White pigments such as zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, synthetic amorphous silica, aluminum hydroxide, alumina, lithopone, and organic pigments include styrene. Examples include plastic pigments, acrylic plastic pigments, microcapsules, and urea resin pigments. In these plain wood inventions, synthetic amorphous silica and aluminum hydroxide are preferably used.

The cationic resin referred to in the present invention refers to a monomer, oligomer or polymer that dissociates and exhibits cationic properties when dissolved in water, preferably having Fl or a quaternary ammonium group, particularly preferably the following (II) to Refers to a compound having a structure represented by the general formula (■).

■ In the formula, R,, I-L2, R, is an alkyl group, m is 1-7,
n represents 2 to 20% Y represents an acid group.

I (II) ~ (In the formula of Vl, R1s '' 2 is -CH,, -
CH2-CH3, -CH2-CH2-OH, Y represent an acid group.

(Vl) Polyalkylene polyamine dicyandiamide ammonium salt condensate Compounds represented by the general formula (III) include, for example, Nalpoly-607 (manufactured by Nalco Chemical Co., Ltd.) and Polyfix 601 (manufactured by Showa Kobunshi Co., Ltd.).

The compounds represented by general formulas (III) to (Vl) are polydiallylamine derivatives, which are obtained by cyclization polymerization of diallylamine compounds, and are available in Percoll 1697 (7Ride Colloid Co., Ltd.), Cat Floe (Calgon Corp.).
), PAS (Nittobo Co., Ltd.), Neofix RPD (manufactured by NICCA Chemical Co., Ltd.), and the like.

Examples of the compound represented by the general formula (H) include Neofix RP-70 (manufactured by Nicca Chemical Co., Ltd.).

The content of the cationic resins represented by these general formulas (If) to (Vl) is usually 0.1 to 4 f/lr? , preferably 0.2 to 22 shi.

Examples of adhesives that can be used in the present invention include oxidized acids, etherified starch, cellulose derivatives such as carboxymethylcellulose and hydroxyethylcellulose, casein, gelatin, soybean protein, polyvinyl alcohol and its derivatives, maleic anhydride resin, and ordinary Conjugated diene polymer latex such as styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer, acrylic polymer latex such as polymer or copolymer of acrylic acid ester and methacrylic acid ester, ethylene vinyl acetate copolymer Vinyl polymer latex such as polymers, functional group-modified polymer latex with monomers containing functional groups such as carboxyl groups of these various polymers, thermosetting synthetic resins such as melamine resins, urea resins, etc. water-based adhesives, and polymethyl methacrylate, polyurethane resins, unsaturated polyester resins, vinyl chloride-vinyl acetate copolymers,
Synthetic resin adhesives such as polyvinyl butyral and alkyd resins can be used alone or in combination. These adhesives are used in an amount of 2 parts to 120 parts, preferably 5 parts to 70 parts, per 100 parts of the pigment, but the ratio is not particularly limited as long as the amount is sufficient to bind the pigment. However, if 120 parts or more of the adhesive is used, it is not preferable because the adhesive film formation is reduced, the void structure is reduced, or the voids are made extremely small.

Other additives include pigment dispersants, thickeners, flow modifiers, antifoaming agents, foam inhibitors, mold release agents, foaming agents, penetrants, colored dyes, colored pigments, fluorescent whitening agents, and ultraviolet light. Absorbents, antioxidants, preservatives, anti-spill agents, waterproofing agents, etc. can also be blended as appropriate.

As the support, a sheet material such as paper or a thermoplastic resin film is used. In the case of paper, it is paper with no sizing agent added or with appropriate sizing, and may or may not contain fillers.

In addition, in the case of thermoplastic films, transparent films such as polyester polystyrene, polyvinyl chloride, polymethyl methacrylate, cellulose acetate, polyethylene, polycarbonate, etc., or filled with white pigment or g! A white opaque film made of fine foam is used. The white pigments to be filled include Nt titanium oxide, calcium sulfate,
Calcium carbonate, silica, clay, Merck, zinc oxide, and many others are used.

It is also possible to use so-called laminated paper, which is obtained by pasting these resin films on the surface of paper or by processing it with molten resin. A subbing layer or corona discharge processing may be applied to improve the adhesion between the resin surface and the ink receiving layer.

A sheet simply coated on a support can be used as it is as a recording sheet according to the present invention; for example, it can be heated and/or passed through a roll nip under pressure using a super calender, cross calender, etc. to impart surface smoothness. It is possible.

In this case, excessive processing by supercalender processing may reduce the ink absorbency due to the voids between the particles, so the degree of processing may be limited.

The water-based ink referred to in the present invention refers to the following colorant and liquid medium,
A recording liquid consisting of other additives.

As the coloring agent, water-soluble dyes such as direct dyes, acid dyes, basic dyes, reactive dyes, and food colorings are preferably used.

For example, as a direct dye, C, 1, Direct Black 2.4.9.11
．． 14.17.19.22.27゜32, 36.38.
41.48.49.51.56゜62, 71.74.7
5.77, 78.80.105, 106.107.10
8.112.113.117, 132.146.154
．． 194°C, I, Direct Yellow 1.
2.4.8.11.12.24.26.27゜28,3
3.34.39.41.42.44.48°50, 51
．． 58.72.85.86.87.88°98, 100
．． 110 C, 1, Direct Orange 6.8.10.
26.29.39.41.49.51, 102 C, 1, Direct Red 1.2.4.8.9
．． 11.13.17.20.23, 24.28.31.
33.37.39.44゜46, 47.48.51.5
9.62.63.73゜75,77,80.81.83
．． 84.85.90°94, 99.101.108.1
10.145°189, 197.220.224.22
5.226°227.230°C, 1, Direct Violet 1.7.9.
12.35.48.51.90.94C,1,Dire
ct Blue 1.2.6.8.35.22.25
．． 34.6'J70, 71.7s 75.76, 78.8
0.81°82, 83.86.90.98.106.1
08°110, 120.123.158.163.16
5゜192, 193. , 194.195.196.19
9°200, 201.202.203.207.218
゜236, 237.239.246.258C, 1, I
]rect Green 1.6.8.28.33.
37.63.64C, 1, Direct Braun
IA, 2.6.25.27.44.58.95゜1
00, 101.106.112.173.194゜19
5, 209.210.211 As an acid dye, C, 1, Ac1d Black 1.2.7.16.
17.24.26.28.31゜41, 48.52.5
8.60.63.94.107゜109, 112.11
8.119.121.122゜131, 155.156 C01, Ac1d Yellow 1.3.4.7.1
1.12.13.14.17゜18, 19.23.25
．． 29.34.36.38°40, 41.42.44.
49.53.55.59゜61, 71.72.76, 7
8.99.111°114, 116.122.135.
161.172C,1,Ac1d Orange 7
．． 8.10.33.56.64C01, Ac1d Re
d 1.4.6.8.13.14.15.18.1
9゜21, 26.27.30.32.34.35.37
゜40, 42.51.52.54.57.80.82゜83, 85.87.88.89.92.94.97゜1
06, 108.110.115.119.129゜13
1, 133.134.135.154.155°172
, 176, 180.184.186.187°24 formula 2
49.254.256.260.289゜317.31
8 C, I, Ac1d Violet 7.11.15
．． 34.35.41.43.49°C, 1, Ac1dB
lue 1, 7, 9, 22, 23, 25, 27, 2
9,40°41,43.45.49.51.53.55
．． 56°59, 62.78.80.81.83.90.
92°93.102,104,111,113,117
゜120.124,126,145,167.171゜175.183,229,234,236C,1,Ac
1d Green 3.12.19.27.41.
9.16.20.25C,1,Ac1d Braun
4.14 Basic dyes include C, 1, Ba5ic Black 2.8C, T, B
a5ic Yellow 1.2.11.12.14
．． 21.32.36°C, 1, Ba5ic Orang
e 2.15.21.22C,I, Ba5ic Re
d 1.2.9.12.13.37C, I, Ba5
ic Violet 1.3.7.10.14C,L
Basic Blue 1.3.5.7.9.24
．． 25.26.28.29C,I, Ba5ic Gr
een 1.4C,1,Ba5ic Braun
1.12 Reactive dye is C11, Reactive Black 1.3.5
．． 6.8.12.14C, 1, Reactive Ye
low 1.2.3.13.14.15.17C,1
, Reactive Orange 2.5.7.16
．． 20.24C, 1, Reactive Red 6
．． 7.11.12.15.17.21.23゜24,3
5.36.42.63.66 C, 1, Reactive Violet 2.4.5
．． 8.9C, I, Reactive Blue 2.
5.7.12.13.14.15.17゜18, 19.
20.21.25.27.28°37, 38.40.4
．． 1.71 C, 1, Reactive Green 5.7C1
1, Reactive Brown 1.7.16 Furthermore, the color range for food is C, 1, Food Black 2 C, 1, Food Yellow 3.4.5C11
, Food Red 2.3.7.9.14.52
．． 87.92°94, 102.104.105.106
C,1,Food Violet 2C,1,Foo
d Blue 1.2C, 1, Food Green
Examples include n 2.3.

The aqueous ink liquid medium includes water and various water-soluble organic solvents, such as methyl alcohol, ethyl alcohol, n-,7' propyl alcohol, isobutyl alcohol, n-butyl alcohol, 5ec-butyl alcohol,
Alkyl alcohols having 1 to 4 carbon atoms such as tert-7'' alcohol and isobutyl alcohol; amides such as dimethylformamide and dimethylacetamide; ketones or ketone alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane Polyalkylene glycols such as polyethylene glycol and polypropylene glycol; ethylene glycol, glopylene glycol, butylene glycol,
Alkylene glycols with 2 to 6 alkynon groups such as triethylene glycol, 1゜2.6-hexandriol, thiodiglycol, hexylene glycol, diethylene glycol; glycerin, ethylene glycol methyl ether, diethylene glycol methyl (or Examples include lower alkyl ethers of polyhydric alcohols such as ethyl ether and triethylene glycol monomethyl ether.

Among these many water-soluble organic solvents, polyhydric alcohols such as diethylene glycol, and lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl ether and triethylene glycol monomethyl ether are preferred.

Other additives include, for example, PH locking agents, metal sequestrants, fungicides, viscosity modifiers, surface tension modifiers, wetting agents, surfactants, and rust preventives.

According to the present invention, when recording is performed using an aqueous ink containing an aqueous dye on a recording medium containing a peterocyclic compound having a structure of the general formula (Il), the light resistance of an image is improved.

The reason for this is not clear, but it is thought that the fading or discoloration of dyes is due to photooxidation caused by ultraviolet rays, etc., and the general formula (1)
It is thought that a peterocyclic compound having the structure suppresses this photooxidation reaction.

Inkjet suitability was measured by the following method.

Light resistance is determined by Canon inkjet printer (A-1)
210), the image area obtained by solid printing with C, M% Y, and Bk inks was measured at 40°C and 60°C using a xenon fade meter (manufactured by Suga Test Instruments, FAL-25X-HCL type). %, irradiated for 16 hours at an illuminance of 41W/771", and measured the color density before and after irradiation using a Macbeth densitometer)'
It was measured at tD514, and the percentage of the value obtained by dividing the color density after irradiation by the color density before irradiation was expressed as light resistance (residual rate).

In addition, the reflectance before and after irradiation was measured using a spectral reflection density box meter (Hitachi Color Analyzer Model 607) for each lQnm.
f: After both legs After calculating X, Y, Z = i using the number of threads of the C light source described in JIS-Z-8722, calculate a and b according to JIS-Z-8730 and obtain the chromaticity difference △E before and after irradiation. Ta. This value was expressed as the amount of discoloration.

Water resistance was measured using the same Canon inkjet printer by immersing the image area obtained by solid printing in C, M, Y, and Bk inks in running water at 30°C for 3 minutes, and measuring the density before and after immersion. It was measured with a densitometer RD514, and the percentage obtained by dividing the concentration after immersion by the concentration before immersion was taken as the water resistance value. The higher the value, the better the water resistance.

The ink absorption speed can be determined by using a Sharp or Canon inkjet printer, feeding the paper immediately after solid red printing (magenta + yellow) (about 1 second later), and touching it with the paper presser roll or your finger. The judgment was made based on whether or not it appeared.

(El Examples The present invention will be explained below with reference to Examples, but the present invention is not limited to these examples. In addition, parts and sections shown in Examples mean parts by weight and weight %.

Examples 1 to 3 80 parts of LBKP at offshore water level 370m/C8F, reactor water level 40
20 parts of NBKP of 0m7IC8F, 13 parts of heavy calcium carbonate, 1 part of cationic starch, alkyl ketene dimer sizing agent (Burcon W1 Deutsuku Hakuresu IJJJ
) From a slurry consisting of 0.08 parts of polyalkylene polyamine epichlorohydrin resin and 0.4 parts of polyalkylene polyamine epichlorohydrin resin, base paper with a basis weight of 6 S fy was made using a Fourdrinier paper machine, and during paper making, oxidized starch was solidified using a size press machine. A coated base paper was produced by adhering 21/l+♂. The Steckigt size degree of this base paper was 21 seconds.

As a coating liquid, 100 parts of synthetic silica (Zyroid 74, manufactured by Fuji Devine Co., Ltd.), polyvinyl alcohol (PVAI)
IO, manufactured by Kuraray Co., Ltd.) 65 parts, cationic resin (Polyfix 601, manufactured by Showa Kobunshi Co., Ltd.) 5 parts, and a small amount of antifoaming agent.
? A base paper with an ink-receiving layer was prepared by applying and drying the ink to give the following properties.

Separately, 2-mercaptobenzothiazole, 2
-g of 1 part each of mercaptobenzimidazole and 2-mercaptopenzoxazole dissolved in 99 parts of ethanol
The base paper was coated and dried to a solid content of 0.5 f/ld on the surface of the base paper, and then lightly supercalendered to obtain the recording papers of Examples 1 to 3. Table 1 shows the results of all inkjet suitability measurements for this recording paper.

Comparative Example 1 Comparative Example 1 was prepared in exactly the same manner as in Example 1 except that 2-mercaptobenzothiazole was removed from the coating solution used in Example 1.
It was used as a recording paper. The inkjet suitability of this recording paper was measured and the results are shown in Table 1.

Examples 4 to 6 80 parts of LBKP of C8F with water level of 370, reactor water level of 400
A pulp slurry consisting of 20 parts of NBKP of m7IC8F, 20 parts of Merck, and cationic starch (Cat.

F1 (manufactured by Oji National Co., Ltd.) 0.5 part total added to give a basis weight of 65
f/lt? Paper is made using a Fourdrinier paper machine, and during paper making, a size press machine is used to prepare polyvinyl alcohol (PVA117, manufactured by Kuraray Co., Ltd. → 2%, white carbon with Tubuzil LP, manufactured by Nippon Silica Co., Ltd.) 6%, 5-mercapto-1-methyltetrazole- 0.2.2.0.4.0 each of sodium salts
A size press liquid of 60% was deposited on the paper, and after drying, it was passed through a machine calender to obtain the recording papers of Examples 4 to 6. Table 1 shows the results of all inkjet suitability measurements for this recording paper.

Comparative Example 2 The recording paper of Comparative Example 2 and the recording paper of Comparative Example 2 were prepared in the same manner as in Example 4, except that 5-mercapto-1-methyltetrazole-sodium salt was replaced with 2.0% methylisothiourea sulfate in the size press liquid of Example 4. did.

The results of measuring the inkjet suitability of this recording paper are shown in Figure 1.

(The following is a blank space) ") Effects of the Invention As is clear from Table 1, in Examples 1 to 6 containing the heterocyclic compound according to the present invention in the recording medium, black ink images and magenta ink The light fastness and photofading of images are significantly improved.

1°noq−

Claims (1)

[Claims] An inkjet recording medium that forms a recorded image using an aqueous ink containing a water-soluble dye, wherein the recording medium contains a heterocyclic compound having a structure represented by the following general formula (I). An inkjet recording medium characterized by: (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, X basically represents C, N, O, or S. Also, there are ▲Mathematical formulas, chemical formulas, tables, etc.▼ (The bond may be conjugated to other constituents of the compound.)