JPH01229683A - Material to be recorded and recording method using the same - Google Patents

Abstract

PURPOSE:To obtain an image excellent in ink color developability, hue, water resistance and light fastness, by containing a compound having an absorption band of a specific infrared absorption spectrum in an ink receiving layer composed of a hydrophilic resin. CONSTITUTION:In a material to be recorded having a base material and the ink receiving layer containing a hydrophilic resin provided on said base material, a compound having an absorption band of an infrared ray absorption spectrum at 1,510-1,570cm<-1> and 1,630-1,700cm<-1> is contained in the ink receiving layer. In a recording system for performing recording by bonding a small droplet of aqueous ink to the material to be recorded, the aqueous ink contains an acidic dye and/or a direct dye. As an embodiment of this compound, nylon or a modified substance thereof, lactams or a secondary acid amide compound such as a urea derivative are designated and pref. contained in the ink receiving layer in a ratio of 0.01-5g/m<2>.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a recording material (recording paper) used for recording with ink, and in particular, to a recording material (recording paper) used for recording with ink, and particularly to a recording material (recording paper) used for recording with ink. The present invention relates to a recording material to be formed and a recording method using the recording material.

(Prior Art) Methods of recording using ink, such as writing with a fountain pen, have been common for a long time, but recently, a so-called ink sheet recording method has appeared, and ink is also used here. ing.

The inkjet recording method uses various ink ejection methods, such as an electrostatic suction method, a method that applies mechanical vibration or displacement to the ink using a piezoelectric element, and a method that uses the pressure of heating the ink to foam it. Recording is performed by generating and flying small droplets of ink and attaching some or all of them to a recording material such as paper, which generates little noise and can perform high-speed printing and multicolor printing. This method is attracting attention.

Ink for inkjet recording methods is safe,
From the viewpoint of recording characteristics, those containing water as a main component are mainly used, and polyhydric alcohols and the like are often added to prevent nozzle clogging and improve ejection stability.

The recording material used in this inkjet system has conventionally been a recording material such as ordinary paper or a base material called inkjet recording paper on which a porous ink receiving layer is provided.

However, as the performance of inkjet recording apparatuses improves and becomes more widespread, such as faster recording and multi-color printing, recording materials are increasingly required to have more sophisticated and wide-ranging properties. In other words, as a recording material for inkjet recording to obtain recorded images of high resolution and high quality comparable to color photographs, (1) the ink must be accepted by the recording material as quickly as possible; (2) Even if ink dots overlap, the ink deposited later will not flow into the dots deposited earlier. (3) The shape of the ink dots is close to a perfect circle, and the diameter of the ink dots does not become larger than necessary. (4) It is necessary to satisfy various requirements such as that the ink has excellent coloring properties.

(The problem that the invention is trying to solve) However,
The reality is that there is still no known recording material that satisfies all of these required performances.

For example, the inkjet recording paper described in JP-A-52-74340 absorbs ink quickly, but
The diameter of the dot tends to become large, and the periphery of the dot tends to become blurred. Another drawback is that the size of the paper changes significantly after recording.

On the other hand, since the inkjet recording method uses water-based ink, there is a problem that the recorded image lacks water resistance, and when it is exposed to water, the ink bleeds and becomes unreadable, and there is a need to solve this problem. It had been.

For example, the inkjet recording paper described in JP-A-56-99693 contains quaternary ammonium halide and the like to impart water resistance. However, such water-resistant inkjet recording paper has a drawback in that the light resistance of the recording agent (dye, etc.) is significantly reduced.

Furthermore, JP-A-59-20696 and JP-A-61-5
Publication No. 8788 discloses a water-fastening agent for images having a specific structure, but although these water-fastening agents also provide sufficient water resistance to inkjet recorded images, the light resistance is not necessarily sufficient. Ta.

As described above, a sufficient solution to the problem of achieving both water resistance and light resistance of inkjet recorded images has not yet been found.

Therefore, an object of the present invention is to provide a recording material suitable for inkjet recording that satisfies the above-mentioned requirements and provides an image particularly excellent in water resistance C and good light resistance.

Another object of the present invention is to provide a recording material that improves the color development of ink and provides images with excellent color properties.

This and other objects of the present invention are achieved by the present invention as follows.

(Means for Solving the Problems) That is, the present invention provides a recording material having a base material and an ink receiving layer containing a hydrophilic resin provided on the base material,
A recording material and droplets of water-based ink, characterized in that the ink-receiving layer contains a compound having absorption bands of an infrared absorption spectrum from 1,510 to 1.570 cl' and from 1.630 to 1,700 cm-' A recording method in which the water-based ink contains an acid dye and/or a direct dye, and the recording material is the recording material described above. be.

(Function) By incorporating a compound having a specific absorption band in the infrared absorption spectrum into the ink-receiving layer made of a hydrophilic resin, an image with excellent ink color development, chromaticity, water resistance, and light resistance can be obtained. A recording material is provided.

(Preferred Embodiments) Next, the present invention will be described in more detail by citing preferred embodiments.

The base material of the recording material used in the present invention is typically paper, but cloth, resin film, synthetic paper, etc. can also be used as the base material.

The ink-receiving layer formed on the base material is formed mainly of a hydrophilic resin and a compound having a specific absorption band of an infrared absorption spectrum.

Examples of hydrophilic resins include water-soluble polymers such as starch, oxidized starch, cationized starch, gelatin, casein, gum arabic, sodium alginate, carboxymethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, polyvinylpyrrolidone, and sodium polyacrylate. In addition, SBR latex, MBR
Water-dispersed polymers such as latex, vinegar emulsion, and acrylic emulsion can also be used or used in combination.

Furthermore, the compound used in the present invention and which mainly characterizes the present invention has a vibration amplitude of 1,510 to 1,570 cm-', which corresponds to the stretching vibration of C=O and the bending vibration of N-H of amide.
and a compound having an absorption band of an infrared absorption spectrum in the wavenumber region of 1,630 to 1.700c+m-',
Specific examples include nylon 66, nylon 6, nylon 61o1, nylon 11.12, or modified products thereof, as well as secondary acid amide compounds such as lactams and urea derivatives. but not limited to.

These compounds are preferably oligomers or polymers with a molecular weight of 1,000 or more, more preferably 3.000 to 5,000.000. If the molecular weight is less than 1,000, the solubility in water is high; Sufficient water resistance of the image cannot be obtained. Furthermore, when used in combination with pigments, the binding strength is insufficient, resulting in a decrease in the strength of the coating layer and the occurrence of so-called powder falling.

In addition, in the present invention, in order to further improve the ink receptivity of the ink receiving layer, for example, silica, clay, talc, diatomaceous earth, calcium carbonate, calcium sulfate, barium sulfate, aluminum silicate, synthetic zeolite, alumina, oxidized Pigments such as zinc, lithopone, satin white, etc. can also be dispersed in the ink-receiving layer.

Furthermore, in the present invention, various additives such as a dispersant, a fluorescent brightener, a pH adjuster, an antifoaming agent, a lubricant, a preservative, and a surfactant may be included in the ink-receiving layer as necessary. .

Typical embodiments of the recording material of the present invention made of the following constituent materials are as follows: (1) A coating layer consisting only of the water-soluble polymer and/or water-dispersible polymer described above on a low-sized base paper. (2) A coating layer consisting of the above-mentioned water-soluble polymer and/or water-dispersible polymer and an inorganic pigment is provided on a low-sized base paper; (3) A coat layer comprising the above-mentioned water-soluble polymer and/or water-dispersible polymer and an inorganic pigment is provided on a base paper. Examples include those provided with two or more coating layers consisting of a polymer and/or a water-dispersible polymer and an inorganic pigment.

The recording material of embodiments (1) and (2) is LB as the base paper.
The material is mainly made of wood bulbs such as P and NBKP, mixed with various synthetic fibers, glass fibers, etc., if necessary, and made into a small size paper by a conventionally known acidic papermaking method or neutral papermaking method.

The base paper contains clay, talc, kaolinite, titanium oxide, calcium carbonate, etc. as fillers, and the ash content according to JIS-P-8128 is preferably 2 to 15%.
Preferably it is 4 to 10%. Furthermore, in order to obtain good print quality with less feathering and good ink absorption, calcium carbonate and BET specific surface h420 are used as fillers.
It is desirable to use synthetic silica having a value of 0IT+''/g or less.

The recording materials according to the above embodiments (1) and (2) are coated with a coating layer of 0.5 to 8rn"7g on these base papers.
The recording material is coated in a coating amount of 1 to 15 seconds, and the Steckigt sizing degree of the recording material is set to 1 to 15 seconds.

The above-mentioned recording material has excellent ink absorbency, has a dot shape close to a perfect circle with moderate dot bleeding and no feathering, and provides high-density images with no paper dust problems and good writability. It is a low-cost coated paper that can be coated.

The recording material of the embodiment (3) is not particularly limited as a base paper, but has an upper layer on the base paper using a pigment with a small particle size and a particle size larger than the upper layer, preferably 10 to 30 μm. This is a recording material consisting of a lower layer using a silica-based pigment.

In the recording material according to the embodiment (3) above, there is an advantage of using a large pigment by using a pigment with a large particle size in the lower layer and filling the fine irregularities on the surface with a pigment with a small particle size in the upper layer. Taking advantage of this, it is possible to obtain images with good dot shapes and no roughness without powder falling.

The specific surface area of the pigment forming the lower layer is preferably at least 200 g/g, more preferably at least 200 g/g, from the viewpoint of ink absorption. In terms of color development and ink absorption, it is preferable that the ink absorption of the upper layer is slow enough to allow ink droplets attached to the surface to bleed to an appropriate size, and the ink absorption of the lower layer is high. For this purpose, the ratio of pigment to binder in the upper layer is 1
/3 to 5/1, more preferably 1/2 to 3/1, and preferably 1/1 to 10/1 for the total coating layer.

Since the ink receiving layer is composed of two layers as mentioned above,
The coating amount of the upper layer is 1 to 20 g/rn', more preferably 5
The total coating amount of the ink receiving layer in the lower layer is 2 to 50 g/rn', more preferably 8 g/rn'.
It is preferable that the coating weight be larger than that of the upper layer within a range of 30 to 30 g/m''.

If the coating amount of the upper layer is less than Ig/rn', it will not have much effect compared to not having it, and if the coating amount exceeds 20g/rn', the effect of the lower layer will not appear, and the ink absorption speed and dye color development will be affected. This is not preferable because it lowers the temperature.

Furthermore, in order to improve the ink absorbency of the ink receiving layer, it is preferable to use JP-A-62 as a pigment forming the lower layer.
Porous silica particles having a spherical particle shape as disclosed in Japanese Patent No. 183382 can be used.

In particular, when the spherical silica having a particle size of 10 to 30 μm is used as the lower layer, it is possible to form a coat layer with a higher void volume than when conventional amorphous pigments are used.
It can provide excellent ink absorbency.

The recording material obtained in this manner is a coated paper that has particularly excellent ink absorbency and image density, and is used to provide highly detailed images.

In the various embodiments described above, the compound that characterizes the present invention is preferably contained in the ink-receiving layer in a proportion of 0.05 to 5 g/rn'. In addition, in embodiments where the ink-receiving layer contains an inorganic pigment, it is preferable that the amount of pigment is 1 to 2, although it varies depending on the coating amount and pigment content of the coating layer.
0% by weight, more preferably within the range of 2 to 15% by weight, and 0.05 to 5g/rn' as a total recording material.
is within the range of

In the present invention, in any embodiment of the recording material, if the amount of the above-mentioned compound is less than the above range, the water resistance will decrease, and if it exceeds the above range, the light resistance of the image will decrease even if the compound of the present invention is used. bring.

In the present invention, the above-mentioned materials are mixed to prepare a coating solution with an appropriate concentration and viscosity, and a coating layer is formed on the substrate. All conventionally known methods such as a bar coater, blade coater, air knife coater, reverse roll coater, etc. can be used to apply the obtained aqueous coating liquid onto the above-mentioned substrate.

The method of the present invention is a recording method using the recording material of the present invention, and in this recording method, the ink itself applied to the above-mentioned specific recording material by an inkjet recording method may be a known ink, such as Recording agents are water-soluble dyes such as direct dyes, acid dyes, basic dyes, reactive dyes, and food colorings, and are particularly suitable as inks for inkjet recording methods, and can be used in combination with the above recording materials. For example, c, i, direct black 17.19.32.51.
71.108.146, C,1, Direct Blue 6.22.25.71.86
．． 90.106.199, C,1, Direct Red 1.4.17.28.83, C,1, Direct Yellow 12.24.26.86.
98.142, C, 1, Direct Orange 34.39.44.46.
60°C, 1, Direct Violet 47.48, C, 1,
Direct dyes such as Direct Brown 109 and C,i, Direct Green 59, C,1, Acid Black 2.7.24.26.31.
52.63.112.118, C, 1,7 Shif Blue 9.22.40, 59.93.
102.104.113.117.120.167.2
29.234, C, 1, Acid Red 1.6.32.37.51.5
2.80.85.87.92.94.115.180.
256.317.315, (:, 1. Acid Yellow 11, 17.23.25.2
Acidic dyes such as 9.42.61.71, C,1, Acid Orange 7.19 and C,1, Acid Violet 49 are preferred; others, C,1, Basic Black 2, C,1, Basic Blue 1. 3.5.7.9.24.
25.26.28.29, c, r, basic red 1.2.9.12.13.1
4.37, [:,1. Basic Violet 7.14.27 and C.1, Food Black 1.2, etc. can also be used. Particularly preferred are acid dyes and/or direct dyes.

The above examples of dyes are particularly preferable for inks applicable to the recording method of the present invention, but dyes for inks used in the present invention are not limited to these dyes.

Such water-soluble dyes are generally used in a proportion of about 0.1 to 20% by weight in conventional inks, and this proportion may be the same in the present invention.

The solvent used in the aqueous ink used in the present invention is water or a mixed solvent of water and a water-soluble organic solvent, and particularly preferred is a mixed solvent of water and a water-soluble organic solvent, and a water-soluble organic solvent is particularly suitable. It contains a polyhydric alcohol which has the effect of preventing ink from drying. Further, as water, it is preferable to use deionized water rather than ordinary water containing various ions.

The content of the water-soluble organic solvent in the ink is generally in the range of 1 to 50% by weight based on the total weight of the ink. If the content of the organic solvent is less than the above range, the dye tends to precipitate at the tip of the nozzle, causing problems such as nozzle clogging. Furthermore, if the amount of solvent is greater than the above range, the ejection stability will decrease.

In addition to the above-mentioned components, the ink used in the present invention may also contain a surfactant, a viscosity modifier, a surface tension modifier, etc., as necessary.

In the method of the present invention, any recording method may be used to apply the ink to the recording material, but an inkjet recording method is preferable. Any method may be used as long as the ink can be applied to the recording material, which is a projectile. (IEEETr
ans actions on Industry
Applications) Vol, I8-13
, No. 1 (February/March 1977 issue), Nikkei Electronics April 19, 1976 issue, January 2, 1973
9 issue and May 6, 1974 issue. The methods described above are suitable for the method of the present invention, and to explain some of them, there is an electrostatic attraction method,
In this method, a strong electric field is applied between the nozzle and an accelerating electrode placed several mii from the nozzle, and the ink is turned into particles and drawn out one after another from the nozzle, and information is transmitted while the drawn ink flies between the deflection electrodes. There are two methods: a method in which a signal is applied to a deflection electrode for recording, and a method in which ink droplets are ejected in response to an information signal without deflecting the ink droplets, both of which are effective for the method of the present invention.

The second method is to apply high pressure to the ink using a small pump and mechanically vibrate the nozzle using a crystal oscillator, etc., to forcibly eject microscopic ink particles. At the same time as the injection, it is charged according to the information signal. When the charged ink particles pass between the deflection electrode plates, they are deflected according to the amount of charge. Another method using this method is called the microdot inkjet method. In this method, ink pressure and excitation conditions are maintained at appropriate values within a certain range, and two types of ink droplets, large and small, are ejected from the nozzle tip. Only the medium- and small-diameter ink droplets are used for recording. A feature of this method is that it is possible to obtain a group of microdroplets even with a nozzle diameter as large as that of conventional methods.

A third method is a piezo element method, in which a piezo element is used as a pressure means for applying pressure to the ink, rather than a mechanical means such as a pump as in other methods. This method applies an electric signal to a piezo element to cause mechanical displacement, thereby applying pressure to the ink and ejecting it from a nozzle.

In addition, there is an inkjet method in which ink subjected to the action of thermal energy undergoes a rapid volume change, and the acting force due to this state change is used to eject the ink from a nozzle. (Effects) According to the present invention as described above, in the coating layer provided on the base material, 1,510 to 1,570 cm-' and 1.630 cm
By containing a compound that has an absorption band in the infrared absorption spectrum between 1,700 cm and 1,700 cm, the ink is quickly absorbed into the ink, and when different colored inks are repeatedly deposited on the same spot within a short time, Also, there is no ink flow or oozing phenomenon, and it provides clear, high-resolution images. Moreover, the obtained image has excellent both water resistance and light resistance, and is suitable as a recording material for inkjet recording.

(Example) Next, the present invention will be described in further detail by giving examples, comparative examples, and usage examples. In the text, parts or percentages are based on weight unless otherwise specified.

Example 1 The following coating liquid was size press coated on base paper a described later to obtain a recording material of the present invention containing compound A described later in a ratio of Ig/rn'.

Polyvinyl alcohol (PVA-117, manufactured by Kuraray) 2
Part Compound A (solid content) 0.3 parts Water
98 parts Example 2 The following coating solution was coated on the base paper described below using a bar coater method so that the dry coating amount was 8 g/m'', and 5 g/m was applied at 110°C.
After drying for a minute, a recording material of the present invention containing Compound B described below at a ratio of 0.6 g/g was obtained.

Polyvinyl alcohol (PVA-117, manufactured by Kuraray) 9
Part fine powder silica (Fine Seal X-37 (B), Tokuyama Sodagen) 18 parts Compound B (
solid content) 2 parts water
71 parts Example 3 Example 2 except that compound C described below was used instead of compound B
In the same manner as above, a recording material of the present invention containing compound C at a ratio of 0.6 g/rn'' was obtained.

In addition, in the above examples, 1,510 to 1.570 co
+-' and 1,630 to 1,700clII-! The following compounds were used as compounds having absorption bands in the infrared absorption spectrum.

A: AQ nylon A-70 (manufactured by Toshi) B: AQ nylon A-90 (manufactured by Toshi) C: Cationic polymer-IP-1
02 (Nippon Shokubai Kajigen) D: Cationic polymer-IP-103 (Nippon Shokubai Kajigen) The following was used as the base material.

a: 100 parts of LBKP of C, S, F, 350 m It was used as the raw material pulp, and finely powdered silica (trade name: Nip Seal E-200, manufactured by Nippon Silikani Industry) as a filler and a neutral sizing agent (8. , D6, manufactured by Dick Vercules) o, oi part and cationized starch 0.02
A low size base paper with a proportion of 8% was obtained by blending and making paper.

b: Calcium carbonate as a filler (product name: Niscalon #
A low size base paper with a distribution of 6% was obtained in the same manner as in a, except that 200 (manufactured by Sankyo Sabako) was used.

C: Commercially available high-quality paper Ginkan (manufactured by Isumi Kokusaku Valve) was used as the base paper.

Example 4 Using the following coating liquid E on base paper C, the dry coating amount was 15
g/rn' using the bar coater method, 110
A lower layer was formed by drying with hot air at 110°C for 5 minutes, and the following coating solution F was coated on the lower layer using a bar coater so that the dry coating amount was 5 g/rn'. It was dried with hot air for 5 minutes to form an upper layer, which was used as a recording material of the present invention. Incidentally, the amount of the compound was 0.2 g/rn'.

1 Polyvinyl alcohol (PVA-117, manufactured by Kuraray) 3
Fine powder silica (Syroid 620, manufactured by Fuji Davison)
15 parts water
82 parts 1 Industrial grade 2 Polyvinyl alcohol (PVA-117, manufactured by Kuraray) 1
5 parts finely divided silica 8 parts compound D
(Solid content) 0.8 parts water
77 parts Comparative Examples 1 to 3 Comparative Example 1 was the same as Example 2 except that Compound B was not used. Recording materials of Comparative Examples 2 and 3 were obtained in the same manner as in Example 2, except that Comparative Examples 2 and 3 were used.

Color inkjet recording was performed using the following four colors of ink on the recording material of the usage example and above, and the recording characteristics were evaluated.

Yellow Ink C, 1, Direct Yellow 86 2 parts diethylene glycol 30 parts water
70 parts Magenta Ink C, 1, Acid Red 35 2 parts diethylene glycol 30 parts water
70 parts Cyan ink C, 1, Direct Blue 86 2 parts diethylene glycol 30 parts water
70 parts Bootsquinc C, 1, Food Black 2 2 parts diethylene glycol 30 parts water
Table 1 shows the evaluation results of the recording characteristics of each of the 70-copy recording materials. The evaluation method was as follows.

(1) Color development was measured using a Macbeth densitometer with optical density (0,
0,) was measured.

(2) Water resistance is determined by immersing the recording material in running water for 5 minutes, and measuring the optical density (0, 0,) after immersion using a Macbeth densitometer RD-918, which is 0.0% of the optical density before immersion. D, compared with the value.

(3) Light resistance was measured by irradiating with a xenon fade meter for 100 hours, and using a Macbeth densitometer (RD-918) after irradiation.
The optical density (0,0,) measured using
D. Evaluation was made by comparing with the value.

#1 Example Uni 1.021.301.251.38□1.081,
461.411.52 □1.30 +, 521.471,56□1.181.
261.211.33 Lyu95! J 97% 100N 99%□92 98
99 98 □99101103102 □92103101104 Rainbow University and University of Technology 98% 86% 97% 87%□79
54 73 55 1 L99 99 9a to.

1 trigram above 82 [i6 78 67 ratio
Comparison example 0, D, Y 1.26 +, 231.20□! ,3
21.351.42 □1.501,431.43 □+, :101.171.21 Rainbow water and-” Goe Sli! 991 II) It□ 4
104 +00 □ 50 98 +02 □ 39 99 99 Nijimitsu Ri-Yu Delta Engineering 99! k89! li 87X□ 8
8 24 38 □ 99100 96 □ 94 75 74

Claims (5)

[Claims] (1) In a recording material having a base material and an ink receiving layer provided on the base material containing a hydrophilic resin, the ink receiving layer is 1,510 to 1,570 cm^-^1 and 1,63 cm.
A recording material characterized by containing a compound having an absorption band of an infrared absorption spectrum from 0 to 1,700 cm^-^1. (2) In a recording method that performs recording by attaching small droplets of water-based ink to a recording material, the water-based ink contains acid dyes and/or
or a recording material containing a direct dye, wherein the recording material has a base material and an ink receiving layer provided on the base material and containing a hydrophilic resin, wherein the ink receiving layer has a molecular weight of 1,510 to 1
, 570cm^-^1 and 1,630 to 1,700c
A recording method characterized by containing a compound having an absorption band of an infrared absorption spectrum at m^-^1. (3) The recording material and recording method according to Claims 1 and 2, wherein the compound is an oligomer or polymer having a molecular weight of 1,000 or more. (4) The recording material and recording method according to Claims 1 and 2, wherein the compound is contained in a proportion of 0.05 to 5 g/m^2. (5) The recording material and recording method according to Claims 1 and 2, wherein the ink-receiving layer contains an inorganic pigment, and the compound is contained in an amount of 1 to 20% by weight of the inorganic pigment.