JPS58132584A - Material to be recorded - Google Patents

Abstract

PURPOSE:To provide a material with a quick ink absorption, a small dot diameter and a high dot density in which a cover layer comprising a specific polymer and porous inorganic particles is formed in such a manner as to assemble numerous film pieces finely divided. CONSTITUTION:A polymer having 2-40wt% of a hydrophilic structure part derived from an alpha, beta-unsaturated monomer or the like and a hydrophobic structure part having affinity with dye derived from alpha, beta-ethylene-like unsaturated ester carboxylate or the like and porous inorganic particles are dispersed into a solvent to make a paint. The paint thus obtained is applied on a liquid absorptive substrate 1 made a porous material up to the quantity of 1-10g/m<2> and then dried quickly to form a cover layer 2 in which numerous flake-shaped films 3 finely divided by irregular crackings 4 are arranged two dimensionally in tight contact. Thus, a material to be recorded is obtained as expected.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording material (hereinafter also referred to as recording paper) used for recording characters, figures, etc. using a recording liquid.

Conventionally, recording with recording liquid, that is, ink, has been widely performed using writing implements such as pens, fountain pens, felt pens, and the like. Also, in recent years, a so-called inkjet recording method has appeared, in which a recording liquid is especially used.

Incidentally, this inkjet recording method uses a conventional ink ejection method (for example, an electrostatic suction method, a method in which a piezoelectric element is used to mechanically pick up or displace the ink, a method in which the ink is heated and foamed, A method that utilizes the pressure generated at that time is known) to form ink droplets and make some or all of them adhere to a recording material such as paper to perform recording. It is something.

In this way, when recording using liquid ink, it is generally necessary that the ink does not bleed onto the surface of the recording paper and cause the print to become blurred. To prevent the paper from drying out and accidentally contaminating the paper surface, and
It is desirable that the pigment in the ink fixed on the paper does not fade.

In particular, in the inkjet recording method, (1) the absorption of the recording liquid (ink) into the recording paper is fast; (2) there is no overlap of ink dots, especially when performing multi-color or full-color recording; Even if there is, make sure that the ink that has adhered later does not disturb or run off the dots that have adhered to the target, and that the ink droplets do not spread on the surface of the recording paper and the diameter of the ink dots does not become larger than the core wall of the thin recording soil. ■ The shape of the ink dot is close to a perfect circle, and the surrounding area is smooth; ■ The ink dot is round and the f13 around the dot is blurred; ■ The color of the Kl paper is white, and the ink dot is smooth. ■ The color of the ink does not change depending on the type of recording paper; ■ There is little scattering of ink drops around the ink dots; ■ There is no dimensional variation in the recording paper (e.g. wrinkles, spread). Few things before and after recording, q? There is a need to satisfy various demands. However, conventionally, in order to satisfy these state requirements,
Recording paper to use! Timeliness (1) Although it is understood that the liability is large, in reality, there is still no recording paper that can meet the various demands for slanted paper, whether it is plain paper or processed paper. For example, the processed paper for inkjet recording described in JP-A-52-74340 absorbs ink quickly, but the diameter of the ink dots tends to become large, and the periphery of the dots tends to blur. However, the paper has the disadvantage that the dimensional change after recording is large.Therefore, the main purpose of the present invention is to solve the problem that the conventional technology could not solve before the slanting technology. In particular, the present invention provides a recording material (recording paper) with high performance that satisfies almost all of the requirements for recording using liquid ink using a writing instrument or an inkjet recording method. It is intended to.

Therefore, the recording material of the present invention that achieves the above object comprises a polymer having both a hydrophilic structural part and a hydrophobic structural part having an affinity for dyes, and porous inorganic particles in the base. A coating layer is formed using a coating material containing .

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be explained in detail using illustrated examples and detailed explanations.

First, the configuration of the present invention will be outlined using the schematic diagram of FIG.

In the figure, 1 is a liquid-absorbing substrate, such as paper,
Made of porous material such as cloth. 2 is a covering layer which receives ink.

This coating layer 2 is basically composed of a film-forming resin paint, but the main components of the paint are a hydrophilic structural part and a hydrophobic part that has an affinity for dyes. The polymer contains a porous inorganic particle and a polymer having both a structural part and a porous inorganic particle. Such a polymer is a polymer of monomers mainly having addition-polymerizable vinyl groups, in which hydrophilic structural moieties such as carboxylic acid groups, sulfonic acid groups, and sulfuric acid ester groups are combined with a predetermined amount of acrylic acid. acid, methacrylic acid, crotonic acid, itaconic acid, itaconic acid monoester, maleic acid,
Maleic acid monoester, fumaric acid, fumaric acid monoester, vinyl sulfonic acid, sulfoethyl methacrylate, sulfopropyl methacrylate, sulfonated vinylnaphthalene, etc. are introduced into the polymer structure with α,β-unsaturation. Ru.

On the other hand, examples of the monomer unit into which a hydrophobic structural moiety having affinity with dyes is introduced include acrylonitrile,
Vinylidene chloride, α,β-ethylenically unsaturated carboxylic acid ester other than diagonal, vinyl acetate, vinyl chloride, acrylamide.

methacrylamide, hydroxyethyl methacrylate,
Hydroxypropyl methacrylate.

Glycidyl methacrylate, N-methylolacrylamide, N-butoxymethylacrylamide, etc. are most preferred.

In addition to one unit of the above monomer, styrene.

Styrene derivatives, vinylnaphthalene, vinylnaphthalene derivatives, 08-Cts aliphatic alcohol esters of α,β-ethylenically unsaturated 111 carboxylic acids, and the like can be used.

By the way, in the present invention, it is preferable to form a matrix of the polymer for the purpose of solubilizing the polymer in the solvent of the paint or dividing it into colloidal form. The above polymer and J'
The partner forming M is an alkali metal N a
, K, and other things.

aliphatic amines such as G or tri (methylamine), mono, G or tri (eguramine);

Mono-, di- or tri-(ethanolamine).

Alcohol amines such as mono-, di- or tri-(pro-gunolamine) methylethanolamine, dimethylethanolamine, and morpholine.

Examples include N-methylmorpholine.

[7] In the above polymer, the ratio of the hydrophilic structural portion to the monomer base is particularly important.

1, carboxyl group, sulfonic acid group, or.

Monomers that become hydrophilic structural parts such as sulfate ester groups, etc.9
When the N amount ratio exceeds approximately 40% by weight, the increasing effect on the substrate 1 decreases, and the more the liquid (ink) attached to the coating layer 2 bleeds, the harder the roux becomes. If the color density of the print is too high, the color density of the print will decrease as the dyed area decreases.

On the other hand, when this weight ratio is less than 2tt%, the bonding force between the coating layer 2 and the substrate 1 decreases, resulting in the inconvenience of peeling and cracking.

Therefore, a more favorable ratio of the hydrophilic structural portion in the above-mentioned composite is considered to be about 25 to 40% by weight.

Furthermore, if the molecular weight of this polymer is too low, film forming properties will deteriorate, so it is generally desirable to use a polymer with a molecular weight of about 2,000 or more.

Such a polymer can be produced according to the following method. For example, by mixing essential monomer components in a predetermined ratio, solution polymerization method, emulsion polymerization method, @turbid polymerization method (
A polymer of a desired molecular weight is synthesized by using a hexapolymerization regulator depending on the method. Separately, polymers containing acid anhydrides, esters, IJ groups, hydroxyl groups, etc. are prepared first, and these groups are subsequently hydrolyzed, saponified, sulfonated, or sulfonated. It is also possible to adopt a method of generating carboxyl groups and the like in the polymer in a bulk manner. Also, you can make Amin Salt Temple at any time.
For example, any method can be employed, such as a method of polymerizing using an amine salt of the carboxylic acid monomer, or a method of adding an amine salt immediately or after the above-mentioned hydrolysis.

In addition, the porous particles used in combination with the polymer are components that adsorb and capture pigments (for example, dyes) in the ink in the coating layer 2 mainly by physical action. Therefore, in the present invention, it has been used for a long time.

In addition, in the present invention, a white amorphous pigment that is porous and has ionic properties on the surface of the particles can be particularly effectively used as the above-mentioned components. Specifically, natural zeolite,
Synthetic zeolite (for example, Molecular Sheep [manufactured by Union Carbide]), diatomite, fine powder silica (average particle size, 1μ or more), silica (average particle size, 20μ or more), synthetic mica [general formula; M-Mg 2.5 (8i
<・010)・F2, (l', where M is a hydrogen atom or a metal atom.], etc. may be used in the present invention. In the present invention, these polymers and particles (...generally Coating paints are prepared by dissolving or dispersing large amounts of particles (with particle diameters from several hundred millimicrons to several microns) in a paint solvent using a single component -C1 or a combination of several components.

At this time, if the amount of the polymer film formed is insufficient,
Other binder resins can also be used in combination.

As such a resin, water-soluble or solvent-soluble resins can also be used. For example, water-soluble resins include polyvinyl alcohol, starch, casein, gum arabic, g-gelatin, polyacrylamide, carboxymethyl cellulose, sodium polyacrylate, sodium alginate, etc., and examples of solvent-soluble fat-soluble resins include:
These include polyvinyl butyral, polyvinyl chloride, polyvinyl acetate, polyacrylonitrile, polymethyl methacrylate, polyvinyl formal, melamine resin, polyamide resin, phenol resin, polyurethane resin, alkyd resin, and the like. Commonly used media for preparing the paint include water alone or a mixture of water and a water-soluble pollutant.

Examples of water bathing organic solvents include methyl alcohol, ethyl alcohol, n-propyl alcohol, 1so
-Propyl alcohol, n-butyl alcohol, 5
ec-butyl alcohol, tert-butyl alcohol, 1so-butyl alcohol.

Furfuryl alcohol, tetrahydrofurfuryl alcohol: ketone or keto alcohols such as acetone, methyl ethyl ketone, diacetone alcohol; ethers such as tetrahydrofuran, oxane; esters such as ethylene carbonate, propylene carbonate; N, N'-dimethylformamide, N,N
Examples include nitrogen-containing solvents such as '-dimethylacetamide, N-methyl-2-pyrrolidone and jetanolamine.

To form the coating layer 2, a coating of about 1 g/m2 to 10 g/m2 is generally applied on the substrate 1 by a known method (for example, a roll coating method, a rod bar coating method, a spray coating method). Apply the paint described in the paste j1. Also, practically %2g/ln
It is best to apply the coating at a rate of about 5 g/rn.

After such a coating layer is provided, the coating layer is continuously dried. As shown in the partial enlarged view 2L, which depicts a partial area 21 enlarged approximately 50 times, the crack I82 formed in this way has an irregularly shaped crack 4 (...this crack 4 Most of them reach the surface of the substrate 1.) A large number of fine scale-like films 3 are arranged in a two-dimensional arrangement in close contact with each other. The size of one scaly film 3 is not particularly limited, but is generally approximately 10 μm x 10 μm to several hundred μm x several hundred μm. Although the width is not particularly limited in the present invention, it is usually about several μm. Incidentally, the individual thickness and shape of the scale-like film 3, the @ of the cracks 4, etc. can be adjusted or controlled by adjusting or controlling the composition or film forming conditions of the above-mentioned paint, especially the drying conditions after coating. J l) on the machining surface cannot be arbitrarily changed in 5. When the ink falls on the coating layer 2 described above,
The color (for example, dye) in the ink causes ionic bonding, bonding, etc. with the Mijiki group that forms the film 3, or physically transfers it to the porous inorganic particles. The film 3 selectively absorbs and is trapped.

In the present invention, since the pigment in the ink is captured on the outermost surface area of the recording paper, the coloring property is extremely good. Further, since the solvent in the ink quickly migrates to the substrate side in one layer through the cracks, an apparent dry state can be quickly obtained on the surface of the recording paper.

ψ, if the ink dots on the recording paper are larger than the bamboo tubes, the scale-like film 3 will be larger than the sieve.
This is particularly effective in preventing blurring around the dots, and this is because the pigment in the ink is intensively absorbed and absorbed into the electric area of the film 3. The quality of this adsorption ability is mainly determined by the chemical properties of the polymer (for example, ionicity).
and the surface properties of the particles (for example, voids 4).

In the present invention, it is undesirable that the area occupied by the scale-like coating 3 in the coating 1-2 is extremely reduced, and conversely, that the surface area occupied by the cracks 4 is extremely increased. First, in the case of the dye, there is a drawback that the capture rate of the dye decreases, resulting in a decrease in the color development and density of the dot. In the latter case, the amount of ink transferred to the substrate increases, resulting in the so-called ink bleed-through phenomenon and deterioration of the dot shape. Therefore, it is desirable to avoid these aspects in the present invention.

Here, more detailed examples will be described to illustrate the effects of the present invention.

In addition, prior to Examples, synthesis examples of polymers which are the main components according to the present invention and examples of commercially available polymers are illustrated below. (・
...All parts in the synthesis examples are parts by weight. ) *Synthesis Example 1. 5 liters of water in a four-flow separable flask with a stirrer
0.0%, Improvil alcohol, 30%, 0.5 parts of sulfur/lium dodecylbenzenesulfonate, and 0.5 parts of ammonium persulfate were mixed and heated to 60°C. Separately, styrene 5
Miyako.

A mixed solution of 9 parts of acrylic f# and 5 parts of butyl acrylate was placed in a dispersing funnel and gradually dripped over 60 minutes. After the temperature was 80°, the mixture was stirred for 2 hours to carry out polymerization.

The molecular weight of the obtained polymer was about 50,000.

Example 22 In the same flask as in Example 1, 8 parts of methyl methacrylate, 5 parts of styrene, 15 parts of itaconic acid, and 1 part of benzoyl peroxide were added.

1 part lauryl mercaptan, 50 parts diacetone alcohol
20 m2 of ethylene glycol was added and the mixture was mixed for 6 hours while passing through a nitrogen stream. The molecular weight of the obtained polymer was about 3.

In the same manner as in Example 2, one compound was obtained from the following raw materials.

(Molecular weight: approx. 15,000) (Molecular t: approx. 20,000) (Molecular weight: approx. 30,000) (Molecular weight: approx. 8,000) Commercial product example a, sodium naphthalene sulfonate polymeric metal condensate Product name: Demolhe Kao Atlas ■] b, Diisobutylene-maleic acid copolymer trade name; Demol h3P [Kao Atlas ■] C, Sodium polyacrylate trade name; Nobucosanto R [San Nobuco ■] d, Ammonium polyacrylate trade name: Nobucosanto tt FA [San Nopco ■] e, Sodium polymethacrylate trade name NIBLYMAR 850 [Rom & Haas ■] f, Styrene-maleic acid copolymer (monoester ammonium salt) Product name: SMA resin l 4401-1g, PEG parts Name; Macrogol] 500' [NOF ■J h, PEG-PPG block polymer Product name: Uniloop 401) P-50B [NOF
Co., Ltd. Example 1 The polymer obtained in Synthesis Example 6 (30 parts by weight), silica (50 parts by weight) and water (150 parts by weight) were thoroughly stirred and mixed to obtain a slurry.

The loquat slurry was applied to one side of five sheets of base paper (Pingqiao, 60 g/m2), each with a dry solid content of approximately 4 g/r112.
I applied it to make it look like this.

Next, dry these under the following conditions and record paper sample 1.
～■ was created.

*Drying condition sample l...Natural drying sample by leaving ■...Sample n for 2 hours in the open (60°C)
1... Sample for 30 minutes with hot air at 90"C...11
Samples were exposed to hot air at 0℃ for 1 minute. Samples were exposed to hot air at 180''C for 2 seconds. The surface conditions of each sample were taken as electron micrographs (X200) and shown in Figures 2 to 6. .

Table 1 below summarizes the results of a comparative study of the characteristics in inkjet recording of each of the samples thus obtained. In addition, in Table 1 below, the dot density was measured using a microtensitometer PDM-5 (manufactured by Konishiroku Photo Industry Co., Ltd.), with a slit width of 30 μm in width and 30 μm in cylinder length, The ratio of the sample feed rate to the axial electric speed of 10μ/5ec1 chat to the feed rate of 1 ho/ki chat is the bundle measured at 100 times.

The dot diameter was determined by measuring the diameter of the printed dot using a stereoscopic microscope.

In addition, the straightening time is determined by placing a rubber roller a certain distance away from the inkjet head used, and by varying the paper feed speed so that the time taken for the ink dots to contact the rubber roller can be changed. , with the equipment
The time taken from the time an ink dot was generated until the ink became hard to adhere to the roller was measured.

The ink jet recording apparatus used here had an ink ejection opening diameter (orifice diameter) of 50 μm, and the ink used had the following composition.

Ink physical properties: Viscosity U 3.8 cps (measured with Tokyo Keiki E type rotational viscosity set) Surface tension 52. '4 dyneA1π (measured with a hanging plate surface tension meter made by Kyowa Kagaku) Table -l (Note 2): Evaluation criteria ◎...Very good O...Good Δ...\Generally good ×...Poor Example 2 In Synthesis Example 3, sufficient amounts of Samuraida Torigita (50 parts by weight), quince earth (707 parts by weight), water (110!1 parts by weight) and ethanol (5 parts by weight) were added. A slurry was created by stirring and mixing.This slurry was
FM (coated on the surface with a dry solid content of 4g/2゜crystal) and dried for a few seconds with hot air at 180'0 to make a recording paper. When I took the tax collection photo, I found that it was the same as the one shown in Figure 6.

When inkjet recording was carried out on this recording paper in the same manner as in Example 1, the results were similar to those of Sample (2) in Example 1.

Example 3 The polymer obtained in Synthesis Example 4 (80 parts by weight), synthetic zeolite (13017'FtC?'ilS), holvinyl alcohol (20 parts by weight), water (250 parts by weight), and methanol (100 parts by weight) ) were stirred and mixed to create a slurry, which was then applied in the same manner as in Example 2, and the same results were obtained.

Examples 4 and 5 Inkjet recording was performed on the same sample as that obtained in Example 2 in the same manner as in Example 1 using the inks shown in Table 2 below, and the results are shown in Table 2 below. Met.

Table 2 In the ink composition column, the numbers in ) indicate parts by weight, and all other numbers and symbols are based on Example 1.

Example 6 Full-color recording was performed using cyan, magenta, yellow 4-1, and black inks using the same sample as in Example 3, and the fixing time, dot density, and dot diameter were all the same as in Example 1. It is possible to obtain a full-color image equivalent to the original one, and each color is extremely clear, with good color reproducibility.
I was able to reproduce the photo.

When printing was performed on the recording paper obtained in Example 2 using a commercially available 1971 rod, there was no smearing, the liquid was quickly absorbed, and very clean characters were printed. − As shown in the paper, in the present invention, attached recording liquid (ink)
is quickly absorbed into the inside of the ink, and even if a different color of the recording liquid adheres to the same spot in a short period of time, the phenomenon of the recording liquid flowing out or seeping out may cause the ink to dry out. Good color development, and the spread of ink dots is +1 to the image.
4, it is possible to use a recording medium suitable for multicolor inkjet recording, and to provide the body with a cicada.

[Brief explanation of the drawing]

FIG. 1 is an illustration of the configuration of the present invention, and FIGS.
The figures are all diagrams showing electron micrographs of the recording paper surface rh+. In the figure, 1 is a base, 2 is a coating layer, 3 is a scale-like film, and 4
is a crack. Patent applicant: Canon Co., Ltd.

Claims (1)

[Claims] A coating layer is provided on the substrate using a coating material containing porous inorganic particles and a polymer having both a hydrophilic structural part and a hydrophobic structural part that has an affinity for dyes, and this coating layer is formed by irregularly shaped cracks. A recording material characterized by being made up of a large number of finely divided films.