JP2996951B2 - Recording material for inkjet - 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 jet recording material used for ink jet printing or copying using a water jet ink or the like using a jet printer.

[0002]

2. Description of the Related Art Ink jet recording is a method in which ink is ejected from nozzles and adheres to a recording medium to perform recording. In recent years, with the spread of electronic still cameras and computers, the technology for recording those images on paper or the like has rapidly developed.However, in particular, the inkjet method is easy to use in full color and the printing noise is low. In recent years, it is developing rapidly.

[0003] If the ink of the ink jet system is of the solvent type, it dries quickly and the nozzles are easily clogged.
Since the solvent type has a problem in safety to the human body, an aqueous ink is generally used.

[0004] The aqueous ink used in the ink-jet system is an ink using a pigment or a dye or both as a colorant and a water-soluble dispersant.
The target color is expressed by the overlapping of the four black inks.

[0005] As a recording material used in the ink jet system, a material suitable for various uses such as a place of use (for example, outdoors and indoors) and a use method is selected.
Thermoplastic films, translucent films, paper, cloth and the like are used.

Usually, a polyhydric alcohol is often added to the aqueous ink in order to prevent nozzle clogging and improve ejection stability. As a recording material for ink jet recording, it is required that ink is rapidly absorbed (that is, ink dries quickly), and when ink dots are overlapped, the recording liquid that has adhered later has a smaller amount of ink that has adhered earlier. That the shape of the dots is close to a perfect circle and the density is high, the color properties of the ink components are excellent, the ink fixability is excellent, the surface is glossy, the whiteness is high, etc. Performance is required.

[0007] Many of the recording materials for surface image observation that have been conventionally used employ a method in which ink is absorbed into pores of a porous material to fix the recording material. JP-A-8-
Japanese Patent Application Laid-Open No. 11421 discloses a technique of forming an ink absorbing layer using a coating liquid obtained by mixing polyvinylpyrrolidone, a water-insoluble acrylic resin, and porous silica and organic fine particles with a solvent.

However, since the surface of the recording material is porous, there is no gloss on the surface of the recording material. On the other hand, in order to obtain gloss, it is necessary to provide a non-porous ink-receiving layer, but in this case, there is a drawback that the drying property is extremely poor.

JP-A-59-33177 describes that a polyoxyethylene having an amino group is contained as an ink receiving layer on a substrate. JP-B-3-42590 discloses an ink-receiving layer containing a reaction product of an isocyanate compound and a polyether polyol.

When an attempt is made to directly print on a thermoplastic resin film, cloth, tarpaulin, or the like using an aqueous ink, the ink is repelled without absorbing the aqueous ink because the material is resin or fiber. It is difficult to print a desired picture or pattern clearly. In particular, water and non-volatile organic solvents (such as ethylene glycol, diethylene glycol, and methyl carbitol) are used as solvents in the aqueous ink, and the drying speed is low. When the first color and the second color are printed, the inks of the first color and the second color tend to be mixed and blurred. For this reason, it was necessary to take a long drying time, and workability was not good. In the ink receiving layer as described above, in terms of ink concentration and ink sticking property,
Sufficient performance has not always been obtained.

Further, polyoxyethylene has an amino group at a terminal and is therefore weak to water and poor in water resistance. The reaction product of the isocyanate compound and the polyether polyol also did not have sufficient water resistance due to hydrolysis because it contained a urethane bond.

[0012]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink jet recording material which is excellent in ink drying property, ink density and ink sticking property.

[0013]

Means for Solving the Problems When the present inventors used a resin which swells at the same time as absorbing water in the ink when it comes into contact with the aqueous ink, the expected effect is exhibited. And completed the present invention. That is, the present invention relates to an ink jet recording material provided with an ink receiving layer containing a resin, wherein water is brought into contact with a film made of the resin as the resin constituting the ink receiving layer for 30 seconds. A resin having a contact angle of 20 to 80 degrees with water and a water swelling ratio of 50 to 100% after 1 hour of immersion of the film in water. Recording material. Hereinafter, the present invention will be described in detail.

The recording material for ink jet of the present invention includes:
An ink receiving layer containing a resin is provided, and as the resin, a contact angle with water 30 to 30 seconds after contacting water with a film made of the resin is 20 to 80 degrees, and
The water swelling ratio after one hour of immersing the film in water is 50
-100% resin is used.

If the contact angle with water is less than 20 degrees 30 seconds after the water is brought into contact with the film made of the above resin, the density of the ink becomes thin due to the horizontal and vertical bleeding of the pigment and the like, and the vividness Prints lacking. When the temperature exceeds 80 degrees, the water absorption of the water-based ink becomes insufficient and its drying property deteriorates. If the elapsed time after printing is short, the undried ink flows, sticks to the hand, Since the ink is easily transferred to another object when another object is stacked, workability is poor, and it is difficult to obtain a good finish. In the case of multicolor printing, the first color ink,
The color ink mixes with the color ink and easily bleeds, resulting in poor finish.

The value of the contact angle can be obtained by dropping water on the film and measuring the contact angle of the water with the film using a contact angle meter. In the present invention, the contact angle is measured 30 seconds after the water is dropped.

If the water swelling ratio after one hour of immersion of the film in water is less than 50%, the hydrophilicity is poor and the properties of the aqueous ink are insufficient. Occurs, so that it is limited to the above range.

The water swelling ratio is an index for simultaneously evaluating the water absorption performance and the swelling performance. When the area of the film made of the resin before immersion in water is Acm ² , and after immersion in water, the area becomes Bcm ² , the water swelling ratio can be calculated from the following formula. . Water swelling ratio (%) = {(BA) / A} × 100 In the present invention, a 100 cm ² film made of the resin is immersed in water for 1 hour, and then the area of the film is measured and the above calculation is performed. The water swelling ratio is calculated from the equation.

Examples of the resin include a urea resin having a contact angle and a water swelling ratio in the above ranges.

Examples of the urea resin include a reaction product of a polyamine containing at least polyethylene oxide and an isocyanate compound. Examples of the polyether polyamine that can be used in combination with the polyethylene oxide include polyether polyamines such as polyoxypropylene polyamine. Since the urea resin contains polyethylene oxide, it is excellent in absorbing water in the aqueous ink when contacted with the aqueous ink, and also excellent in water resistance because of the presence of a urea bond.

The concentration of polyethylene oxide in the polyamine is preferably 20 to 100% by weight. The average molecular weight of the polyethylene oxide polyamine is preferably from 500 to 5,000, more preferably from 1,000 to 3,000. The number of functional groups is preferably from 2 to 4, more preferably from 2 to 3.

Examples of the isocyanate compound include aromatic isocyanates such as tolylene diisocyanate and diphenylmethane diisocyanate (MDI);
Aliphatic isocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, alicyclic isocyanates such as water-added MDI, adducts of organic isocyanates with trimethylolpropane or prepolymers of polyamines and the like, dimers, trimers, etc. Examples thereof include polyfunctional isocyanate compounds. Preferred are aliphatic isocyanates and alicyclic isocyanates.

In obtaining the urea resin, a low molecular weight polyhydric alcohol and a low molecular weight polyamine compound can be used, if necessary. Examples of the low molecular weight polyhydric alcohol include ethylene glycol, 1,4
-Glycols such as butanediol, and triols such as glycerin and trimethylolpropane. Examples of the low molecular weight polyamine compound include amines such as ethylenediamine and isophoronediamine.

The urea resin has a hydroxyl group or an amino group in its molecule, and can be dissolved in an organic solvent such as N, N-dimethylformamide, methyl ethyl ketone and the like. In this case, the number average molecular weight of the urea resin is preferably 10,000 to 500,000, and more preferably 20,000 to 200,000. The urea resin is preferably a chain polymer from the viewpoint of being easily dissolved in the organic solvent, but may be a polymer having a branched molecular structure.

[0025]

[0026]

[0027]

The ink-receiving layer constituting the recording material for ink-jet recording may be composed of an inorganic powder and / or
Alternatively, it is preferable that organic powder is contained. Such an inorganic powder or an organic powder assists or promotes water absorption by the polyethylene oxide, thereby improving the drying property of the ink and the fixing property of the ink.

The inorganic powder and the organic powder include:
For example, silica, collagen, cross-linked acrylic acid, calcium carbonate and the like can be mentioned. In the present invention, these can be used alone or in an appropriate combination of two or more. The amount of the inorganic powder and / or the organic powder is preferably 0 to 500 parts by weight, more preferably 1 to 100 parts by weight of the urethane resin and the urea resin.
It is 00 to 300 parts by weight.

The recording material for ink-jet recording may be constituted by providing an ink receiving layer on a sheet-like substrate. In this case, the thickness of the ink receiving layer is determined by ensuring that the ink receiving layer absorbs the water-based ink.
In order to fix, the thickness is preferably 5 μm or more,
More preferably, it is 10 μm or more.

The upper limit of the thickness of the ink receiving layer is not particularly limited. When the ink receiving layer is formed by coating on a sheet-like substrate, it is preferable that the thickness be reduced to about 50 μm. However, even if the thickness is 100 μm or 200 μm, no problem occurs in terms of fixing aqueous ink.

The means for forming the ink-receiving layer on the surface of the sheet-like substrate is not particularly limited, and the above-mentioned coating method can be employed. The ink receiving layer may be formed by pasting a release paper through an adhesive layer, peeling the release paper and attaching a film of the ink receiving layer to a sheet-like substrate.

When the ink receiving layer is formed on the surface of the film-like sheet-like base material to form a laminated film, the sheet-like base film may be, for example, a vinyl chloride resin film or a polyolefin resin. Films such as films, polyester resin films and acrylic resin films, polyester cloths, cotton cloths, tarpaulins and the like can be used. An adhesive layer can be formed on the back surface of such a laminated film (the surface of the sheet-shaped substrate opposite to the ink receiving layer). By forming the adhesive layer on the sheet-like base material as described above, it is possible to attach the recording material printed by inkjet to various articles.

As the pressure-sensitive adhesive in the case of providing the above-mentioned pressure-sensitive adhesive layer, for example, an acrylic pressure-sensitive adhesive can be employed, but the type is not limited as long as the adhesiveness with a counterpart material can be obtained. . Also in the case of forming an ink receiving layer on the surface of the sheet-like substrate by the above coating,
If there is a possibility that the adhesion between the substrate and the ink receiving layer may be insufficient, a primer which mediates the adhesion between the two may be applied, and the ink receiving layer may be applied thereon. Further, the ink receiving layer may be formed on the surface of the sheet-like substrate via the pressure-sensitive adhesive layer by a transfer method.

The aqueous ink suitable for the above-mentioned recording material for ink jet is an ink in which a pigment and / or a dye is used as a coloring agent and the dispersing agent is water-soluble, and includes, for example, a pigment, a dispersing agent, and a solvent. An aqueous ink composition, wherein the dispersant has an aromatic ring or an alkyl group having a predetermined number of carbon atoms or more as a lipophilic moiety, and a carboxylic acid (salt).
Is a polymer mainly composed of an alkyl ester of acrylic acid or methacrylic acid having a group or a sulfonic acid group as a hydrophilic portion, and the solvent is a mixture of water and a non-volatile hydrophilic organic solvent. Are preferred.

The ink receiving layer containing the above resin absorbs moisture in the ink and swells when contacted with the aqueous ink. That is, the resin constituting the ink receiving layer has both a water absorbing function and a swelling function.

In an ink receiving layer having only a water absorbing function, when an aqueous ink comes into contact with the ink receiving layer, pigments and / or dyes and the like in the ink penetrate from the surface of the ink receiving layer to the inside, and at the same time, And spreads in the horizontal direction, so that bleeding easily occurs. However, in the ink jet recording material of the present invention, since the ink receiving layer containing the resin having both the water absorbing function and the swelling function is provided, the above-described horizontal penetration can be prevented, and the water resistance is improved. Also excellent.

As described above, the ink-jet recording material of the present invention is provided with the ink receiving layer, and the resin constituting the ink receiving layer has the water absorbing function and the swelling function simultaneously. Therefore, the ink has excellent drying properties, ink density, and ink adhesion.

[0039]

The present invention will be described in more detail with reference to examples of the present invention, but the present invention is not limited to these examples.

REFERENCE EXAMPLE 1 28 parts by weight of a plasticizer, titanium-based pigment, Ba-Zn with respect to 100 parts by weight of a vinyl chloride resin (degree of polymerization: 1050)
Material that blends an appropriate amount of a system stabilizer and an acrylic processing aid,
Sheeting was performed at a thickness of 50 μm by calendering to obtain a film for a substrate as shown in FIG.

Next, in order to form the pressure-sensitive adhesive layer 3 on the back surface of the base film, an acrylic pressure-sensitive adhesive (main material is a mixture of 2-ethylhexyl acrylate, butyl acrylate, acrylic acid ( SK Dyne 1311 manufactured by Soken Chemical Co., Ltd., a curing agent is a TDI-based isocyanate, and an adhesive obtained by mixing a base agent and a curing agent in a ratio of 100: 3) is applied and dried to obtain a 3
An adhesive layer 3 having a thickness of 0 μm was formed. Then, the release paper 4 having the pressure-sensitive adhesive layer 3 and the base material 1 were laminated by a pressure roll.

Next, 3 moles of isophorone diisocyanate (Desmodur I, manufactured by Sumitomo Bayer Urethane Co.) was dissolved in a mixed solvent of N, N-dimethylformamide (DMF) and methyl ethyl ketone (MEK) so as to have a solid content of 30%. 1 mol amount of polyether polyamine (manufactured by San Techno Chemical Co., Ltd., ED-900: molecular weight 985, number of functional groups: 2) and isophorone diamine (manufactured by Huls Japan, VESTAMIN IP)
D) 2 moles of a solid content of 30 with a mixed solvent of DMF and MEK
% Of the urea resin was added dropwise at room temperature and reacted with stirring at 50-60 ° C under a nitrogen atmosphere to obtain a urea resin.

Next, in order to form the ink receiving layer 2,
With respect to 100 parts by weight (solid content) of urea resin, 120 parts by weight of whisker-like calcium carbonate (Whiscal A, manufactured by Maruo Calcium Co., Ltd.) as an inorganic powder and DMF as a solvent
Was added and stirred for 30 minutes to obtain a coating solution. Next, this coating solution was applied to the surface of the vinyl chloride resin base material on which the release paper 4 was laminated by a bar coater method, and dried to form the ink receiving layer 2 having a thickness of 50 μm.

Reference Example 2 An ink receiving layer was formed in the same manner as in Reference Example 1, except that ethylene glycol was used instead of isophoronediamine. Reference Example 3 In place of isophorone diisocyanate, dicyclohexylmethane diisocyanate (manufactured by Sumitomo Bayer Urethane Co., Ltd.)
Reference Example 1 except that Desmodur W) was used.
An ink receiving layer was formed in the same manner as described above.

Comparative Example 1 A urea resin was used as a polyether polyamine (manufactured by Kawaken Fine Chemical Co., Ltd., PEO amine # 6000: molecular weight 600).
An ink receiving layer was formed in the same manner as in Reference Example 1 except that the number of functional groups was 0 and the number of functional groups was 2). Comparative Example 2 An ink receiving layer was prepared in the same manner as in Reference Example 1 except that polyether polyamine was changed to polyether polyol (manufactured by Sanyo Chemical Industry Co., Ltd., PEG1000: molecular weight: 1,000, number of functional groups: 2) and isophoronediamine was changed to ethylene glycol. Formed.

[0046]Performance evaluation  (1) Drying of ink Inkjet printer manufactured by Mimaki Engineering
(JV-1300 type)referenceIn Examples and Comparative Examples
An aqueous pigment ink is applied to the obtained inkjet recording material.
After printing, the dry state after 10 minutes was judged by finger touch. So
And if it is determined that it is dry, "dry"
If it is determined that it is not dry, it will be “undried”
did. The results are shown in Table 1. (2) Weather resistance According to JIS B 7753 using a weatherometer.
Thus, after irradiation for 200 hours, a change in appearance was observed. (3) Water resistance Immerse in hot water of 60 ° C for 14 days and observe the change in appearance.
Was. The results are shown in Table 1.

[0047]

[Table 1]

From the results shown in Table 1, although there is no difference in the drying property of the aqueous ink, Reference Examples 1 to 3 are superior in the weather resistance and water resistance to the comparative example, and the reaction products of the present invention are obtained. The effect by was recognized.

Example 4 28 parts by weight of a plasticizer, titanium-based pigment and Ba-Zn were added to 100 parts by weight of a vinyl chloride resin (degree of polymerization: 1050).
Material that blends an appropriate amount of a system stabilizer and an acrylic processing aid,
Sheeting was performed at a thickness of 50 μm by calendering to obtain a film for a substrate as shown in FIG.

Next, in order to form the pressure-sensitive adhesive layer 3 on the back surface of the base film, an acrylic pressure-sensitive adhesive (main material is a mixture of 2-ethylhexyl acrylate, butyl acrylate, acrylic acid ( SK Dyne 1311 manufactured by Soken Chemical Co., Ltd., a curing agent is a TDI-based isocyanate, and an adhesive obtained by mixing a base agent and a curing agent in a ratio of 100: 3) is applied and dried to obtain a 3
An adhesive layer 3 having a thickness of 0 μm was formed. Then, the release paper 4 having the pressure-sensitive adhesive layer 3 and the base material 1 were laminated by a pressure roll.

Next, an aliphatic isocyanate (Hürs.
Japan Corporation, VESTANAT TMDI) 2.5 mol amount was dissolved in a mixed solvent of N, N-dimethylformamide (DMF) and methyl ethyl ketone (MEK) so as to have a solid content of 30%. ED-900, manufactured by San Techno Chemical Co., Ltd., molecular weight 985, number of functional groups 2) 1 mol and aliphatic amine (VESTAMIN TMD, manufactured by Huls Japan)
A solution of 5 moles dissolved in a mixed solvent of DMF and MEK so as to have a solid content of 30% was added dropwise at room temperature, and reacted under stirring at 50 to 60 ° C under a nitrogen atmosphere to obtain a urea resin.

Next, in order to form the ink receiving layer 2,
For 100 parts by weight (solid content) of urea resin, calcium carbonate (manufactured by Shiraishi Industry Co., Ltd., Callite K) is used as an inorganic powder.
T) 100 parts by weight of DMF and 100 parts by weight of DMF as a solvent were added and stirred for 30 minutes to obtain a coating solution. Next, the coating solution is applied to the release paper 4
Was coated on the surface of the vinyl chloride-based resin base material laminated with a bar coater method and dried to form an ink receiving layer 2 having a thickness of 50 μm.

Example 5 An ink receiving layer was formed in the same manner as in Example 4 except that 1,4-butanediol was used instead of the above aliphatic amine.

Comparative Example 3 Instead of the urea resin, a vinyl chloride resin (manufactured by Mitsubishi Chemical Corporation,
SC-26V: An ink receiving layer was formed in the same manner as in Reference Example 1 except that a vinyl chloride resin dissolved in a mixed solvent of MEK and alcohol was used (solid content: 10%).

Comparative Example 4 An ink receiving layer was formed in the same manner as in Reference Example 1, except that a polyvinyl alcohol resin (R-1130, manufactured by Kuraray Co., 100% solid content) was used instead of the urea resin.

Comparative Example 5 In place of the urea resin, a urethane resin (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
An ink receiving layer was formed in the same manner as in Reference Example 1, except that Elastron C-2: urethane resin solution dissolved in water, solid content 30%) was used.

Comparative Example 6 A urethane resin (Tecophilic HP-80A-15 manufactured by Okada Engineering Co., Ltd.) was used instead of the urea resin.
0, solid content 100%), except that the ink receiving layer was formed in the same manner as in Reference Example 1.

[0058]Evaluation of water absorption function and swelling function of resin  (1) Contact angle Only the resin used in Examples 4 to 6 and Comparative Examples 3 to 6 was used.
Coating and drying commercial PET, followed by a contact angle meter
(Kyowa Interface Science Co., Ltd.) to drop water on the coating surface
30 seconds after dropping, the coating surface comes into contact with water.
The antenna was measured. The results are shown in Table 2.

(2) Water swelling ratio Only the resins used in Examples 4 to 6 and Comparative Examples 3 to 6 were coated on commercially available PET, dried to a thickness of about 100 μm, and peeled off from the release PET. Film (1
(0 cm × 10 cm), the film was immersed in water, and after one hour, the length and width dimensions were measured, and the water swelling ratio was calculated from the following equation. Water swelling ratio (%) = [{(area after 1 hour) −100} /
100] × 100 The results are shown in Table 2.

[0060]Performance evaluation of inkjet recording material  (1) Dryness of inkreference Evaluation was performed in the same manner as in Examples 1-3 and Comparative Examples 1-2.
Was. The results are shown in Table 2. (2) Concentration of ink (print density) Ink jet recordings obtained in the above Examples and Comparative Examples
Print on the recording material using the above inkjet printer.
After that, the density of the ink and the density difference were visually evaluated. So
Then, for the ink density, "very high density" and "high
Density ”and“ Low Density ”are evaluated in three steps, and the density
When there was a difference, "there was a density difference". Table 2 shows the results
Indicated.

(3) Ink adhesion (ink bleeding and repelling) After printing on the ink jet recording materials obtained in the above Examples and Comparative Examples using the above-described ink jet printer, the ink bleeding and repelling conditions were determined. It was evaluated visually.
When it is determined that there is no ink bleeding or repelling, the evaluation is further performed in two steps of “very good” and “good”, and when there is ink bleeding, “there is ink bleeding” When there was repelling, "there was repelling of ink". The results are shown in Table 2.

[0062]

[Table 2]

As is clear from the results in Table 2, Example 4
In the case of ５5, the drying property of the ink, the concentration of the ink, and the ink sticking property were superior to those of Comparative Examples 3 to 6, and the contact angle with water 30 seconds after contact with water was 20 to 〜. 80 °, and the water swelling ratio after one hour of immersion in water is 50 to
It has been proved that an inkjet recording material provided with an ink receiving layer containing 100% of a urea resin is excellent in ink drying property, ink concentration, and ink sticking property.

[0064]

According to the present invention having the above-mentioned structure, it is possible to provide an ink jet recording material excellent in ink drying property, ink density, and ink sticking property.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an embodiment of an inkjet recording material of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sheet-like base material 2 Ink receiving layer 3 Adhesive layer 4 Release paper

Continuation of the front page (56) References JP-A-61-154988 (JP, A) JP-A-61-158495 (JP, A) JP-A-4-341885 (JP, A) JP-A-7-186522 (JP) JP-A-10-292137 (JP, A) JP-A-59-33177 (JP, A) JP-A-61-148091 (JP, A) JP-A-6-222604 (JP, A) JP-A-8-11421 (JP, A) JP-A-8-183243 (JP, A) JP-A-10-226989 (JP, A) JP-A-7-21362 (JP, U) JP-B-3-42590 (JP, A) B2) (58) Field surveyed (Int. Cl. ⁷ , DB name) B41M 5/00

Claims (7)

(57) [Claims] An ink jet recording material provided with an ink receiving layer containing a resin, wherein 30 seconds after water is brought into contact with a film made of the resin as the resin constituting the ink receiving layer. the contact angle with water is 20 to 80 degrees, and the water swelling ratio of 1 hour after immersing the film in water is 50-100% U
A recording material for ink-jet recording, characterized by using a rare resin. 2. A reaction product of an isocyanate compound and a polyether polyamine having an amino group at a terminal and having an ether bond in a main chain is used as the resin constituting the ink receiving layer. 2. The recording material for inkjet according to 1. 3. The polyether polyamine has a molecular weight of 1
The inkjet recording material according to claim 1, wherein the number is from 000 to 3,000 . 4. The isocyanate compound is an aliphatic isocyanate or an alicyclic isocyanate.
Or the recording material for inkjet according to 3. 5. The ink receiving layer according to claim 1, wherein the ink receiving layer contains an inorganic powder and / or an organic powder.
Or the recording material for inkjet according to 4. 6. The ink-jet recording material according to claim 1, comprising a sheet-like base material and an ink-receiving layer provided on the sheet-like base material. 7. The ink-jet recording material according to claim 1, wherein an adhesive layer is provided on the back surface of the sheet-like base material.