JPH1035090A - Waterproofing agent composition for ink jet recording sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve both the enhancement of waterproofness of an image and the reduction of feathering using one kind of agent under ordinary paper making conditions by adding a support with a macromolecular material produced through reaction of a polymer having a specified functional group and a crosslinking agent having a functional group shown by a specified structural formula. SOLUTION: Examples of the monomer contained in a carboxyl group or an anhydride group molecule forming a polymer include acrylic acid, itaconic acid, etc., and those of the monomer containing an amino group or a quarternary ammonium salt group include acrylamide, aminoethyl acrylate, etc. A crosslinking agent comprises a compound containing at least two functional groups shown by general formula [R<1> and R<2> represent hydrogen, 1-8C alkyl group, allyl group or halogen independently, and n is 2 or 3]. Mixing ratio of the polymer and the crosslinking agent is optimally set so that the functional group in the crosslinking agent is on the order of 0.8-1.2 for 1 equivalent of the carboxyl group or the anhydride group in the polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a waterproofing agent for an ink jet recording sheet. More specifically, an ink jet recording sheet that can be processed on a variety of supports such as paper, film, and resin-processed paper in the range of ordinary paper manufacturing conditions, has significantly improved water resistance of images, and has little feathering. And a recording sheet using the same.

[0002]

2. Description of the Related Art In recent years, ink jet printers which are inexpensive and can handle full color have been greatly expanded. At the same time, it is strongly required that the recording sheet be made into plain paper. In this case, the most problematic is low water resistance of the image. The occurrence of feathering has also been pointed out as a problem.

Conventionally, in order to improve the water resistance of an image and reduce feathering, it has been considered to improve the water resistance by using a cationic compound and reduce the feathering by imparting a size effect to the surface size. No single drug can satisfy both at the same time.

Among these, cationic compounds for improving water resistance include polyamine sulfone polymer (JP-A-59-33176), formalin condensate of dicyandiamide (JP-A-59-146889), and polyethyleneimine. Quaternary compound (JP-A-60-76386)
JP-A-6-252189), a quaternized polymer of epichlorohydrin (JP-A-61-252189), and a polyalkylenepolyamine dicyandiamide ammonium salt condensate (JP-A-6-1982).
No. 0-49990) and polyalkylamine salts (JP-A-62-174184). Certainly, the water resistance of images printed on ink jet recording sheets treated with these cationic compounds is considerably improved, but since these compounds themselves have solubility in water, it is necessary to obtain sufficient water resistance. Can not.

In order to improve this drawback, an ink jet recording sheet containing a water-absorbent resin has been studied as an ink jet recording sheet containing a polymer material which has become water-insoluble due to having a cross-linked structure (Japanese Patent Laid-Open No. 57-15757). 173194, JP-A-57-191084, etc.). However, these processes apply a water-absorbent resin composition to a support, and involve very difficult processes in an actual aqueous production process. Further, those containing a polymer material which has been made water-resistant by crosslinking have been studied (JP-A-58-893).
No. 91), which requires two types of polymer compositions, and the exemplified cross-linking methods include methods that are difficult to cross-link under ordinary papermaking conditions, and those having low cross-linking strength. And the water resistance of the image is not sufficient. In addition, a three-dimensional crosslinked product of a polymer containing a specific quaternary ammonium group and an epoxy-based crosslinking agent has been studied (Japanese Patent Application Laid-Open No. 8-142496). However, the reaction conditions for forming a crosslinked structure are severe, and the effect cannot be sufficiently exerted under ordinary paper production conditions.

On the other hand, as a method for solving feathering, a method using a copolymer of acrylonitrile and an acrylate ester (JP-A-8-50366) is known. There is a coating method (JP-A-7-199516). Although these reduce feathering, they have no effect on improving the water resistance of an image.

[0007] To improve the water resistance of images and reduce feathering, a cationic polymer and a cationic vinyl copolymer (JP-A-4-299174) and a cationic resin are used as an underlayer. Coating, and applying a hydrophobic vinyl polymer having a Tg of 40 ° C. or less to the upper layer (JP-A-7-1490).
No. 38) has been proposed. However, these process at least two or more kinds of chemicals, and the manufacturing process becomes extremely complicated.

[0008]

As described above, with regard to the improvement of water resistance of images and reduction of feathering, which are the most demanded when converting the ink jet recording sheet to plain paper, the conventional technique is to process in a normal paper manufacturing process. Yes, and 1
It is difficult to solve the problem by using various kinds of chemicals, and in particular, in the case of full-color images, it is necessary to rely on special paper. SUMMARY OF THE INVENTION An object of the present invention is to provide a water-proofing agent which is sufficiently effective under ordinary paper production conditions and can achieve both improvement of water resistance of an image and reduction of feathering with a single chemical.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the above problems, and as a result, have found that a crosslinked structure formed by reacting a polymer having a specific functional group with a crosslinking agent having a specific functional group has been developed. The inventor has found that the inclusion of the polymer material in the support significantly improves the water resistance of the printed image and significantly reduces feathering, thereby achieving the present invention. That is, the present invention relates to a polymer (A) containing a carboxyl group and / or an acid anhydride group and an amino group and / or a quaternary ammonium base in the molecule, and a polymer represented by the following general formula (1):

[0010]

Embedded image

[In the formula, R ¹ and R ² each independently represent hydrogen, an alkyl group having 1 to 8 carbon atoms, an aryl group or halogen, and n is 2 or 3. A water-proofing agent composition for an ink jet recording sheet, comprising a cross-linking agent (B) comprising a compound (b) containing at least two functional groups represented by the formula: The present invention relates to an ink jet recording sheet formed by the above method.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The monomer (a1) containing a carboxyl group and / or an acid anhydride group in the molecule which forms the polymer (A) in the present invention includes (meth) acrylic acid,
(Anhydride) itaconic acid, (anhydride) maleic acid and the like.

The amino group and / or quaternary ammonium group-containing monomer (a2) forming the polymer (A) includes, for example, (meth) acrylamide, N-alkyl (meth) acrylamide, aminoethyl (meth) A) acrylates, N-alkylaminoethyl (meth) acrylates, allylamines, N-alkylallylamines, diallylamines and quaternaries thereof. To make the polymer (A) contain a quaternary ammonium base,
After obtaining a copolymer containing an amino group, a method of neutralizing with an acidic compound such as hydrochloric acid or a quaternizing agent such as dimethyl sulfate or alkyl halide; or a monomer previously quaternized (a quaternized product of allylamine, diallylamine Of 4
And quaternized aminoethyl (meth) acrylate).
Further, it can also be obtained by copolymerizing an aromatic vinyl compound such as styrene, chlormethylating and reacting with an amine compound to quaternize.

In the polymer (A), the effect of reducing feathering can be further improved by copolymerizing the water-insoluble vinyl monomer (a3) together with the above (a1) and (a2). As (a3), styrene, α
-Hydrophobic monomers such as styrenes such as methylstyrene and alkyl (meth) acrylates such as butyl (meth) acrylate.

In the monomers constituting the polymer (A), (a)
1) is usually 0.1 to 40.0 mol%, preferably 1 to 4 mol%.
20 mol%. If (a1) is less than 0.1 mol%, the effect of improving water resistance by crosslinking becomes insufficient, and if it exceeds 40 mol%, the crosslinking density becomes too large and the rigidity of the recording sheet becomes too high, which hinders use. In addition, (a)
The molar ratio of 2) :( a3) is usually (50-80) :( 5
0:20), preferably (60-70) :( 70-3)
0) is particularly preferable from the viewpoint of improving the feathering reduction effect. In the molar ratio of (a2) and (a3), (a
If the content of 2) is less than 50 mol, the cationicity derived from the nitrogen content in the polymer (A) becomes low, and the fixing ability of the dye is lowered to lower the water resistance of the image. In some cases, a significant reduction effect cannot be obtained. Also,
The weight average molecular weight of the polymer (A) is usually from 1000 to 5
00000, preferably 10,000 to 200,000. If it is less than 1,000, the water resistance of the image becomes insufficient, and 5
If it exceeds 00000, the viscosity becomes high and handling becomes difficult. The polymer (A) is desirably water-soluble or water-dispersible.

The compound (b) constituting the cross-linking agent (B) in the present invention has two functional groups represented by the above general formula (1).
Or 5 or more compounds. In the general formula (1), R ¹ and R ² are each independently hydrogen, an alkyl group having 1 to 8 (preferably 1 to 4) carbon atoms,
An aryl group or a halogen. n is 2 [(substituted) oxazolinyl group] or 3 [(substituted) oxazodinyl group], and particularly preferably an oxazolinyl group.
The polyfunctional oxazolinyl compound can be synthesized by a conventional method. For example, a method of dehydrating and cyclizing a polycarboxylic acid and an equivalent amount of a monoalkanolamine (such as monoethanolamine and monoisopropanolamine) in the presence of an acidic catalyst. A method of obtaining a polyfunctional oxazolinyl compound by performing dehydrochlorination after passing an amide from a β-chloroalkylamine and a polyvalent carboxylic acid.

Preferred examples of the compound (b) include, for example, 2,2'- △ ^2- dioxazoline, 1,2-dioxazolinylethane, 1,4-dioxazolinylbutane,
1,4-dioxazolinylbenzene, N, N'-dioxazolinylethylenediamine, vinyl polymer having two or more oxazolinyl groups in the side chain [(co) polymer of oxazolinyl group-containing vinyl monomer , Oxazoline derivatives of (meth) acrylic acid (co) polymer, etc.] (molecular weight 50
0 to 10000).

In the present invention, the blending ratio of the polymer (A) and the crosslinking agent (B) is such that the crosslinking agent (1 equivalent) of the carboxyl group and / or the acid anhydride group contained in the polymer (A) is used. The amount in which the functional group represented by the general formula (1) in B) is usually 0.05 to 2.0 equivalents, preferably 0.5 to 1.5 equivalents, more preferably 0.8 to 1.2 equivalents. It is.
When the amount of the functional group is less than 0.05 equivalent, a sufficient crosslinked structure cannot be obtained, so that the water resistance of a target image cannot be obtained. When the amount exceeds 2.0 equivalents, bleed out of the remaining crosslinking agent onto the image is not achieved. Is generated, which is not preferable because dirt is easily generated.

The composition of the present invention may contain, if necessary, other known water-soluble or water-dispersible crosslinking agents (polyepoxy compounds, amino resins, etc.) together with the crosslinking agent (B).

When the composition of the present invention is used, it can be used in combination with a surface treating agent such as a sizing agent or starch, and other treating agents, if necessary. In particular, the combined use of a sizing agent is preferred from the viewpoint of further improving the effect of reducing feathering and boundary bleeding. It is also preferable to use starch or the like in combination for the purpose of improving the surface strength of the support. Furthermore, various known fillers can be blended for the purpose of improving the quick drying property of the ink.

In the production of the ink jet recording sheet of the present invention, the composition of the present invention may be contained on the surface or inside of the support by diluting the composition with water so as to have a predetermined content and immersing the composition in water. Examples of the method include a method of post-drying, a method of applying and drying with a size press or a coater, and a method of applying and drying with a brush. As a support,
Examples of the material include a cellulosic fiber material such as paper, a plastic material, and a composite material obtained by subjecting a cellulosic material to resin processing.

The content relative to the support of the composition of the present invention is usually 1 to 10 g / m ² on a solids weight basis, preferably 4~7g / m ^2.

[0023]

EXAMPLES The present invention will be further described with reference to the following examples, but the present invention is not limited to these examples. In the following,% indicates% by weight.

[Production of Polymer (A)] Production Example 1 36 g of acrylic acid and monoallylammonium chloride 8
To 90 g, add 800 g of water and dissolve, and add phosphoric acid to pH 3-
Adjusted to 4. To this solution, ammonium persulfate and sodium bisulfite were added in an amount of 0.6% based on all monomers and polymerized at 60 ° C. for 10 hours. Was.

Production Example 2 36 g of acrylic acid and diallylammonium chloride 1
Add 1200g of water to 270g, dissolve and add phosphoric acid to pH
Adjusted to 3-4. To this solution was added ammonium persulfate and sodium bisulfite at 0.6% based on all monomers,
Polymerization was performed at 10 ° C. for 10 hours, and water was added to obtain an aqueous solution of a polymer (A-2) containing 40% of an active ingredient.

Production Example 3 2000 g of water was added to and dissolved in 36 g of acrylic acid and 1970 g of dimethylaminoethyl methacrylate hydrochloride.
The pH was adjusted to 3-4 with phosphoric acid. To this solution was added ammonium persulfate and sodium bisulfite at a concentration of 0.1 to all monomers.
6% was added and the mixture was polymerized at 60 ° C. for 10 hours, and water was added to obtain an aqueous solution of a polymer (A-3) containing 40% of the active ingredient.

Production Example 4 Water (850 g) was added to 36 g of acrylic acid, 36 g of acrylamide and 840 g of monoallylammonium chloride to dissolve, and the pH was adjusted to 3 to 4 with phosphoric acid. To this solution, ammonium persulfate and sodium bisulfite were added in an amount of 0.6% based on all monomers and polymerized at 60 ° C. for 10 hours. Was.

Production Example 5 To 36 g of acrylic acid, 36 g of acrylamide and 1200 g of diallyl ammonium chloride, 1200 g of water was added and dissolved, and the pH was adjusted to 3 to 4 with phosphoric acid. To this solution, ammonium persulfate and sodium bisulfite were added at 0.6% based on all monomers, polymerized at 60 ° C. for 10 hours, and water was added to obtain an aqueous solution of polymer (A-5) containing 40% of active ingredient. Was.

Preparation Example 6 36 g of acrylic acid, 36 g of acrylamide, and 1870 g of dimethylaminoethyl methacrylate hydrochloride were added to water 20
After adding 00 g and dissolving, the pH was adjusted to pH 3 to 4 with phosphoric acid. To this solution, ammonium persulfate and sodium bisulfite were added at 0.6% based on all monomers, polymerized at 60 ° C. for 10 hours, and water was added thereto to obtain a polymer (A-6) having an active ingredient of 40%.
Obtained an aqueous solution of

[Production of Crosslinking Agent (B)] Production Example 7 sym-diethanol succinamide 5 which is an amide compound of 1 mol of succinic acid and 2 mol of monoethanolamine
To 1 g of sulfuric acid was added 1 g of sulfuric acid, and the mixture was heated to 160 ° C. to 180 ° C. to effect cyclization dehydration, and 1,2-dioxazolinylethane (B-
1) was obtained.

Examples 1 to 6 The aqueous solutions of the polymers (A-1) to (A-6) of Production Examples 1 to 6 and the crosslinking agent (B-1) of Production Example 7 were blended in the proportions shown in Table 1. After dilution, a treatment solution for the support was prepared. This processing solution was weighed to 65 g / m ² ,
Seconds on a commercial high-quality paper with a wire bar at 5 g / m ² and a drum dryer of 95 ° C. to 105 ° C. for 1 g.
Dried for minutes. The sheet thus obtained was heated at a temperature of 2
The sample was conditioned at 0 ° C. and a relative humidity of 65% for 24 hours and subjected to performance evaluation. In the performance evaluation, Canon "Bubble Jet Printer BJC-6" was used as the printer.
Using “00J”, the performance was evaluated by the following method. Table 2 shows the results. Water resistance of image: Immediately after the printed sheet was immersed in water, it was pulled up and dried, and the state was visually evaluated. (Evaluation criteria) ○: No image elution, no bleeding △: Little image elution, little bleeding ×: Image elution, some bleeding Image density: Measure the color density of the solid portion of cyan ink with Macbeth densitometer did.

Comparative Example 1 A 15% aqueous solution of a formalin condensate of dicyandiamide (“Sanfix 70”, manufactured by Sanyo Chemical Industry Co., Ltd.) was prepared, and using this, a sheet was prepared and evaluated in the same manner as in Example 1. Was done. The results are shown in Table 2.

Comparative Example 2 Polyalkylene polyamine dicyandiamidammonium salt condensate [manufactured by Nichika Chemical Co., Ltd., "Neofix RP"
-70Y "), and a sheet was prepared and evaluated in the same manner as in Example 1 using this.
The results are shown in Table 2.

Comparative Example 3 Polyallylamine hydrochloride [PAA manufactured by Nitto Boseki Co., Ltd.
-HClH]], and a sheet was prepared and evaluated in the same manner as in Example 1 using this. The results are shown in Table 2.

Comparative Example 4 A 15% aqueous solution of a dimethyldiallylammonium chloride polymer (“PASH-19L” manufactured by Nitto Boseki Co., Ltd.) was prepared, and a sheet was prepared and evaluated in the same manner as in Example 1 using this. Was done. The results are shown in Table 2.

Comparative Example 5 An untreated sheet was conditioned for 24 hours at a temperature of 20 ° C. and a relative humidity of 65% and subjected to performance evaluation.

[0037]

[Table 1]

[0038]

[Table 2]

[Production Example of Polymer (A)] Production Example 8 800 g of a mixed solvent of water: isopropyl alcohol = 6: 4 (weight ratio) was sufficiently purged with nitrogen and heated to 80 ° C. to 85 ° C. In the mixture, 36 g of acrylic acid, 710 g of monoallylammonium chloride, 200 g of styrene and a mixed solvent of water: isopropyl alcohol = 6: 4 800
g, and a catalyst solution obtained by dissolving 15 g of 2,2′-azobis (isobutyronitrile) in 100 g of a mixed solvent of water: isopropyl alcohol = 6: 4 over 3 hours. Was done. Isopropyl alcohol was distilled off from the obtained polymer dispersion under normal pressure to obtain a polymer (A-8) aqueous solution containing 40% of the active ingredient.

Production Example 9 800 g of a mixed solvent of water: isopropyl alcohol = 6: 4 (weight ratio) was sufficiently purged with nitrogen and heated to 80 to 85 ° C., in which 36 g of acrylic acid and diallyl ammonium chloride were added. 1015 g, 245 g of butyl acrylate and a mixed solvent 8 of water: isopropyl alcohol = 6: 4
A monomer solution consisting of 00 g and a catalyst solution obtained by dissolving 19 g of 2,2′-azobis (isobutyronitrile) in 100 g of a mixed solvent of water: isopropyl alcohol = 6: 4 were added dropwise over 3 hours to carry out polymerization. Was done. Isopropyl alcohol is distilled off from the obtained polymer dispersion under normal pressure,
An aqueous solution of a polymer (A-9) containing 40% of the active ingredient was obtained.

Production Example 10 800 g of a mixed solvent of water: isopropyl alcohol = 6: 4 (weight ratio) was sufficiently purged with nitrogen and heated to 80 ° C. to 85 ° C., in which 36 g of acrylic acid and 2-methacryloyl were added. Roxyethyltrimethylammonium chloride 158
0 g, 200 g of styrene and 800 g of a mixed solvent of water: isopropyl alcohol = 6: 4, and a mixed solvent 1 of water: isopropyl alcohol = 6: 4
2,2'-azobis (isobutyronitrile) 2
A catalyst solution in which 7 g was dissolved was added dropwise over 3 hours to carry out polymerization. Isopropyl alcohol was distilled off from the obtained polymer dispersion under normal pressure to obtain a polymer (A-10) aqueous solution containing 40% of the active ingredient.

Examples 7 to 9 The aqueous solutions of the polymers (A-8) to (A-10) of Production Examples 8 to 10 and the crosslinking agent (B-1) of Production Example 7 were blended in the proportions shown in Table 3. After dilution, a treatment solution for the support was prepared. This processing solution was weighed to 65 g / m ² ,
A commercially available high-quality paper of 0 seconds was coated with a wire bar at 5 g / m ² and dried with a drum dryer at 95 ° C. to 105 ° C. for 1 minute. The sheet thus obtained was subjected to humidity control at a temperature of 20 ° C. and a relative humidity of 65% for 24 hours, and then subjected to performance evaluation. In the performance evaluation, Canon's bubble jet printer BJC-6 was used as the printer.
Using 00J, the performance was evaluated by the following method. Table 4 shows the results. Water resistance of image: Immediately after the printed sheet was immersed in water, it was pulled up and dried, and the state was visually evaluated. (Evaluation Criteria) ；: No image elution, no bleeding Δ: Little image elution, little bleeding ×: Image elution, bleeding Feathering: The state of printing was visually evaluated. (Evaluation criteria) ：: good ：: slightly poor ×: poor Image density: The color density of the solid portion of cyan ink was measured with a Macbeth densitometer.

COMPARATIVE EXAMPLE 7 A 15% aqueous solution 9 of a formalin condensate of dicyandiamide [manufactured by Sanyo Chemical Industries, Ltd., "Sunfix 70"]
To 60 g, as a surface sizing agent, "Sunsizer SC-1"
50 g (manufactured by Sanyo Kasei Kogyo Co., Ltd.) was added to prepare a treatment liquid, and using this, a sheet was prepared and evaluated in the same manner as in Example 7. The results are shown in Table 4.

Comparative Example 8 Condensation product of polyalkylene polyamine dicyandiamide ammonium salt [manufactured by Nichika Chemical Co., Ltd., "Neofix RP"
-70Y ") in 15% aqueous solution of" Sunsizer SC-
150 "was added to prepare a treatment liquid, and using this, a sheet was prepared and evaluated in the same manner as in Example 7. The results are shown in Table 4.

Comparative Example 9 Polyallylamine hydrochloride [PAA manufactured by Nitto Boseki Co., Ltd.
[HClH]] was added to 960 g of a 15% aqueous solution, and 40 g of “Sunsizer SC-150” was added to prepare a treatment solution. Using this, a sheet was prepared and evaluated in the same manner as in Example 7. The results are shown in Table 4.

[0046]

[Table 3]

[0047]

[Table 4]

[0048]

The ink jet recording sheet comprising the support containing the waterproofing agent composition of the present invention has the following effects as compared with the conventional recording sheet. (1) The water resistance of a printed image is remarkably improved, feathering is reduced, and it is possible to use an inkjet recording sheet as plain paper without inferiority to a dedicated sheet for inkjet recording. (2) The effect is sufficiently exerted under normal production conditions of the treated paper (for example, after treatment with an aqueous system, drying at about 100 ° C.). (3) Since the water-proofing agent only needs to be treated once in the form of one liquid on the support, a complicated processing step such as a conventional dedicated sheet is not required. Because of the above effects, the waterproofing agent for an ink jet recording sheet of the present invention and the recording sheet using the same are industrially extremely useful.

Claims (6)

[Claims] 1. A polymer (A) containing a carboxyl group and / or an acid anhydride group and an amino group and / or a quaternary ammonium base in a molecule, and a polymer represented by the following general formula (1): [Wherein, R ¹ and R ² each independently represent hydrogen, carbon number 1
Represents an alkyl group, an aryl group or a halogen of from 8 to 8,
n is 2 or 3. And a crosslinking agent (B) comprising a compound (b) containing at least two functional groups represented by the formula (1): 2. The carboxyl group and / or acid anhydride group in the polymer (A) and the above-mentioned general formula (1) in the crosslinking agent (B)
The equivalent ratio of the functional groups represented by is 1: (0.05 to 2.0)
The composition according to claim 1, which is: 3. The composition according to claim 1, wherein the functional group represented by the general formula (1) is an oxazolinyl group. 4. The polymer (A) comprises a monomer (a1) containing a carboxyl group and / or an acid anhydride group and a monomer (a2) containing an amino group and / or a quaternary ammonium base as essential constituent units. (A1): (a2)
The composition according to any one of claims 1 to 3, which is a copolymer (A1) having a molar ratio of (0.1 to 40): (99.5 to 60). 5. The polymer (A1) comprises (a1), (a2)
And the water-insoluble vinyl monomer (a3) are copolymerized, the content of (a1) is 0.1 to 40 mol%, and the molar ratio of (a1) :( a2) is (50 to 90). ): (5
The composition according to claim 4, which is a copolymer which is 0 to 10). 6. An ink jet recording sheet comprising an aqueous solution or aqueous dispersion comprising the composition according to any one of claims 1 to 5 on the surface or inside of a support, heating and drying and performing a crosslinking reaction.