JP3386263B2 - Sanitary paper - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an aqueous printing ink composition for paper.
Relates printed matter using objects, when more detail printed on thin paper, such as paper napkins or tissue paper has a soft texture, without causing curling of strike through or paper ink, further bleed resistance hygiene paper also E to print the excellent aqueous printing ink composition.

[0002]

The role of binder resin is very important in that it determines most of the performance of printing ink compositions.

For example, the action of dispersing a colorant, which is an ink material, into fine particles, the action of causing the ink to have fluidity and viscosity suitable for printing, and transferring an appropriate amount from the plate to the adherend, the colorant It is no exaggeration to say that most of the action of fixing to the surface of the adherend and the action of imparting various resistances are determined by the performance of the binder resin used in the ink composition.

Therefore, as a binder resin for an aqueous printing ink using paper as an adherend, an acrylic resin, a styrene-acrylic resin, a styrene-maleic acid resin have hitherto been used.
Styrene-maleic acid-acrylic resin and the like are used, but this resin has good solubility in water because various polar groups such as carboxyl group and amino group can be easily introduced into the molecule. Further, it is easy to adjust the pigment dispersibility and the strength and hardness of the resin film itself, and good ink performance can be obtained.

However, these known binder resins having many excellent points are contained in the ink in a certain amount (at least about 5% by weight) in order to maintain the fluidity of the ink, the strength of the ink film and various resistances. It is necessary to be contained, so that it has the following drawbacks.

A) Since the binder resin itself has weak resistance to water, acid, alkali, etc., the bleeding property of the ink film is strong.

B) When the water retention of the ink film itself is high and the undried state becomes long, it penetrates when printed on thin paper, causing strikethrough and paper breakage.

C) The printed matter is curled by the shrinkage stress generated when the ink is dried, and the post-processability and the commercial value are impaired.

As a method for solving these problems, in order to avoid the problem a), a method of adding an aziridine-based or hydrazine-based crosslinking agent to the ink composition is known. The pot life of the ink becomes short, and new problems arise in terms of reduced printability and toxicity.

Further, in order to avoid the problem of b), a method of pretreating paper with a primer is known, but this method requires extra labor and cost for one step, and It cannot be used for paper materials that cannot be primed.

Further, in order to avoid the problem of c), a method of adding a plasticizer for improving the ability of the resin to relieve the shrinkage stress or a drying retardant for increasing the relaxation time in the ink composition. However, there are problems such as blocking of printed matter, reduction of printing speed, and promotion of ink strike-through due to delay in drying.

As described above, there are many unsolved problems even with respect to the problems of the water-based printing ink used for plain paper, and further, the soft texture of thin paper, which is a particular object of the present invention, is required. However, the current situation is that conventional resins cannot be used because the ink film becomes too hard.

[0013]

Therefore, the problem to be solved by the present invention is to solve all of the above problems, and there is no problem such as pot life, deterioration of printability, toxicity and the like, and bleed resistance. It is intended to provide a sanitary paper printed with a water-based printing ink composition which is excellent in print quality, has a soft texture even when printed on thin paper, and does not cause strike-through or curling.

[0014]

Means for Solving the Problems] The present invention may contain coloring agents, met aqueous printing ink composition for a binder resin and water as main components, an epoxy-modified polyamide resin to that water printing containing as the binder resin Flexographic or gravure printing method with ink composition on thin paper
The present invention relates to a sanitary paper obtained by printing with .

Further, as a good mode thereof , hygiene products obtained by printing the following aqueous printing ink compositions
It's about paper .

The epoxy-modified polyamide resin is a polyamide polyamine obtained by reacting a polyamine component containing a polyalkylene polyamine as an essential component and a dicarboxylic acid component under conditions in which amino groups are present in excess,
Print aqueous printing ink composition is an epoxy-modified polyamide resin obtained by further reacting the epihalohydrin
Hygiene paper obtained by doing .

A sanitary paper obtained by printing an aqueous printing ink composition containing 2 to 20% by weight of the epoxy modified polyamide resin in the ink composition.

A sanitary paper obtained by printing an aqueous printing ink composition in which the weight ratio of the colorant component to the epoxy-modified polyamide resin is 1: 2.5 to 1:20.

Furthermore, casein was added to the ink composition in an amount of 0.
By printing an aqueous printing ink composition containing 1-3 wt%
The resulting sanitary paper .

[0020]

[0021]

FUNCTION AND EXAMPLE The epoxy-modified polyamide resin used in the present invention has been conventionally used as a paper strength enhancer. In principle, the paper strength enhancer causes a crosslinking reaction with hydroxyl groups in the cellulose component of the paper to increase the paper strength.

However, the present invention is the first attempt to use this epoxy-modified polyamide resin as a binder for an aqueous printing ink composition.

Now, considering the epoxy-modified polyamide resin of the present invention as an ink binder, in order to solve the above-mentioned problems of the water-based printing ink, the resin itself is flexible and has a high stress relaxation ability, and a coloring agent and an adhesive agent are applied. It has an unprecedented characteristic performance such as adhesion to the body surface.

Therefore, the water-based printing ink of the present invention can prevent the occurrence of curling by alleviating the shrinkage stress generated when the ink is dried, and further, the degree of hardening of the resin even when it is crosslinked is small. It is possible to give a soft texture even when printed on thin paper. Further, the resin is cross-linked with the paper surface, so that the colorant is
It has good bleeding resistance because it hardly dissolves in alkalis, alcohols, etc., and can prevent the ink itself from penetrating into the paper and suppress the strike-through of the ink.

These effects are found in the present invention as a new concept which did not exist in the conventional printing ink composition.

The present invention will be described in more detail below.

Colorant Examples of the colorant used in the present invention include dyes generally used in paints and inks, inorganic and organic color pigments and extender pigments.

Here, as the dye, anionic (acidic,
Both direct and reactive dyes), cationic (basic and cationic dyes) and nonionic (disperse dyes) can be used.

As the pigment, a processed pigment which is treated with a nonionic surfactant, a water-soluble resin or the like and can be dispersed by a slight stress can be preferably used.

Binder resin The binder resin used as an essential component in the present invention is
An epoxy-modified polyamide resin, which is obtained by reacting a polyamide polyamine obtained by reacting a polyamine component containing a polyalkylene polyamine and a dicarboxylic acid component in the presence of an excess of amino groups with epihalohydrin.

Here, the polyalkylene polyamine is preferably a polyalkylene polyamine having 4 to 12 carbon atoms, specifically, diethylene triamine, dipropylene triamine, 3-azahexane-1,6-diamine,
Triethylenetetramine, tripropylenetetramine,
4,7-diazadecane-1,10-diamine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine and the like can be mentioned, and one kind or a mixture of two or more kinds may be used.

Further, a part of diamine components such as ethylenediamine and tetramethylenediamine may be contained.

On the other hand, the dicarboxylic acid component is preferably a dicarboxylic acid having a carbon number of 3 to 10, and specific examples thereof include aliphatic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid and sebacic acid. Examples thereof include aromatic dicarboxylic acids such as phthalic acid, unsaturated aliphatic dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, and mesaconic acid. One kind or a mixture of two or more kinds may be used.

The ratio of both components used in the production of a polyamide polyamine by reacting these polyamine component and dicarboxylic acid component is such that polyamine component: dicarboxylic acid Component = 1.0: 0.8 to 1.0: 1.2, especially 1.0:
The range of 0.9 to 1.0: 1.1 (molar ratio) is suitable, and the reaction temperature is usually 100 to 250 ° C.
Is the proper temperature.

The binder resin of the present invention is obtained by further reacting the polyamide polyamine obtained by the above method with epihalohydrin.

Examples of the epihalohydrin that can be used here include epichlorohydrin and epibromohydrin, but it is industrially preferable to use epichlorohydrin.

The amount of epihalohydrin used is usually 0. 0, based on the amino groups contained in the polyamide polyamine.
It is in the range of 8-3.0 mol times. If the amount of epihalohydrin used is less than the above range, ink bleeding or strikethrough tends to occur, while if it is more than the above range, unreacted substances increase, which is economically disadvantageous even if they can be removed.

The reaction temperature between epihalohydrin and amino group is usually 40 to 90 ° C.

The epoxy-modified polyamide resin obtained by the above reaction components and production method can be used in the form of an aqueous resin varnish while being dissolved in water.

Ink composition In the water-based ink composition of the present invention, the content of the colorant is 0.1 to 3.0% by weight in the case of dye and 0.1 to 5.0% by weight in the case of pigment. Is an appropriate amount. Further, the content of the epoxy-modified polyamide resin is preferably 2 to 20% by weight, more preferably 6 to 15% by weight, as a resin solid content.
Is.

When the content of the epoxy-modified polyamide resin in the ink composition is less than the above range,
A thickener or the like is required to maintain the viscosity that makes printability good, and the effect of suppressing the occurrence of bleeding is reduced. On the other hand, if the content is more than the above range, the amount of paper dust entrained increases, and a meshing device for removing the paper dust in the printing process is required.

From the viewpoint of the balance of coloring power, fluidity and storage stability of the ink composition, the weight ratio of the colorant to the epoxy modified polyamide resin is preferably about 1: 2.5 to 1:20.

Particularly, in the above ratio, when the amount of the colorant is 1 and the amount of the epoxy-modified polyamide resin is less than 2.5, the storage stability decreases, and the ink composition after long-term storage is agitated before printing. Since it is necessary, it is preferable to use a large amount of the epoxy-modified polyamide resin within the above range as much as possible.

Further, in the present invention, the effect of preventing bleeding and strike-through can be improved by adding casein in the ink composition as a solid content in an amount of 0.1 to 3% by weight. Further, water-miscible organic solvents such as methanol, ethanol, isopropanol, methoxypropanol, N-methylpyrrolidone, etc., pigment dispersants, antiblocking agents,
It is also optional to add various additives such as a defoaming agent and a crosslinking agent.

Ink production method, printing method and printed matter As a method for producing the aqueous printing ink composition of the present invention by using these colorant, binder resin and other components, a colorant and a binder resin are required. A manufacturing method in which an organic solvent, an additive, etc. are added according to the above, and the mixture is stirred and mixed, and then a predetermined material is further added can be used.

The printing ink composition obtained by the above method can be printed on various papers by a flexographic or gravure printing method.

The printed matter on which the ink composition of the present invention is printed has no set-off and curl even on thin paper, and is used especially for direct contact with the skin of toilet paper, tissue paper and paper napkins or removal of dirt on the skin. The printed matter of sanitary paper to be used is free from the concern of toxicity due to excellent ink bleeding resistance and the like, and has a soft texture.

Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited thereto. In addition, "parts" and "%" represent "parts by weight" and "% by weight" unless otherwise specified.

<Production of Ink Composition> According to the composition shown in Table 1, the materials were stirred and mixed to obtain water-based printing ink compositions of Examples 1 to 13 and Comparative Examples 1 to 3.

Sumilite Supra Blue FGL (manufactured by Sumitomo Chemical Co., Ltd.) was used as the dye, and Sundine Super Blue GLL-HC (manufactured by Sanyo Dye Co., Ltd.) was used as the pigment.

Further, the binder resins A to C are aqueous varnishes of epoxy-modified polyamide resin, A is Sparamine 30 (manufactured by Toho Chemical Co., Ltd., nonvolatile content 30%), B is Sparamine C-305 (manufactured by Toho Chemical Co., Ltd.). ), Nonvolatile content 30
%) And C used Euramine P5600 (manufactured by Mitsui Toatsu Chemicals, Inc., nonvolatile content 30.5%).

Further, the binder resin D is a melamine formalin resin, Euramine P-6100 (manufactured by Mitsui Toatsu Chemicals, Inc., nonvolatile content: 50% or more), Binder resin E.
Is a styrene acrylic resin varnish, John Cryl 61
J (manufactured by Johnson Polymer Co., Ltd., non-volatile content: 30%) and binder resin F: Sumireze resin 636 (manufactured by Sumitomo Chemical Co., Ltd., non-volatile content: 50%) was used as a polyamide polyurea resin varnish.

Evaluation of Examples 1 to 13 and Comparative Examples 1 to 3 Test inks of Examples 1 to 13 and Comparative Examples 1 to 3 were tested for bleed resistance, curl, strike-through texture, storage stability and paper dust entrapment. The test was conducted by the following method.

The printing paper used in the test was a commercially available tissue paper.

(Bleed resistance) A test ink was printed on a printing paper with a hand proofer of 165 lines / inch, dried with warm air, a filter paper was applied to the printed surface, and a test liquid (water, ethanol) was applied onto the printed paper. , Ammonia water adjusted to pH 10 as alkali, acetic acid aqueous solution adjusted to pH 3 as acid)
Was added dropwise (about 0.1 ml). This portion was sandwiched between glass plates and a load of 200 g / cm ² was applied for 1 hour, and then the bleeding resistance to each test solution was visually determined from the degree of coloring of the filter paper. Rank 5: The filter paper is not colored at all. 4: Less than 5% of the wet area under the test drop of the filter paper is colored. 3: 5% or more in terms of the wet area under the test droplet of the filter paper, 2
Less than 0% is colored. 2: 20% or more in the wet area under the test droplet of the filter paper,
Less than 70% is colored. 1: 70% or more of the wet area under the test droplet of the filter paper is colored.

(Curl property) The test ink was printed on the entire surface of a 10 cm × 10 cm printing paper with a 165 line / inch hand proofer, dried with warm air, and the curled state of the printed matter was visually judged. Rank 3: The printed matter does not curl at all. 2: Only the edges of the printed matter curl. 1: The printed matter curls in a semicircular shape.

(Strike-through) A printing paper was placed on the filter paper, and the test ink was printed on the print paper with a 165 line / inch hand proofer, and the degree of the strike-through was visually judged from the coloring condition of the filter paper. . Rank 3: The filter paper is not colored at all. 2: The filter paper is lightly colored. 1: The filter paper is deeply colored.

(Feeling) The test ink was printed on a printing paper with a hand proofer of 165 lines / inch, dried with warm air, and the degree of the feeling was evaluated from the feel of the printed matter. Rank 3: There is no difference in touch feeling between the printed portion and the non-printed portion. 2: Slightly grainy. 1: I feel a lot of roughness.

(Storage Stability) The test ink was tested at 25 ° C. for 30 days.
The storage stability was evaluated based on the presence or absence of precipitates after storage for a day. Rank 3: No precipitate is generated. 2: A slight precipitate is observed. 1: Many precipitates are observed.

(Incorporation of paper dust) A test ink was printed on a printing paper corresponding to a length of 5 m with a hand proofer of 165 lines / inch, and the inclusion of paper dust depending on the presence or absence of the paper dust adhering to the rubber roll of the hand proofer. Was evaluated. Rank 3: No paper dust adheres. 2: The amount of paper dust adhered is 50 or less. 1: The amount of paper dust adhered exceeds 50 pieces.

Here, the rank of evaluation is 3 or more for bleeding resistance, and the rank of evaluation of 2 or more for curling property, strike-through, texture, storage stability and paper dust entrainment is the performance of the object of the present invention. .

[0062]

[Table 1]

[0063]

As described above in detail with reference to the examples, the water-based printing ink composition obtained by the present invention is an ink composition for paper, and even when it is printed on thin paper, set-off and The printed matter of sanitary paper is excellent in bleeding resistance and the like and has a soft texture without curling the paper.

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-6-240191 (JP, A) JP-A-50-49004 (JP, A) JP-A-1-152176 (JP, A) JP-A-59- 36173 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) C09D 11/00-11/20 C08G 59/20-59/38 C08G 69/48-69/50

Claims (5)

(57) [Claims] 1. A colorant, met aqueous printing ink composition for a binder resin and water as main components, to an epoxy-modified polyamide resin as the binder resin
Flexographic printing method also that the water soluble printing ink composition in thin
Is a sanitary paper obtained by printing with the gravure printing method . 2. A polyamide polyamine obtained by allowing the epoxy-modified polyamide resin to react a polyamine component containing a polyalkylene polyamine as an essential component and a dicarboxylic acid component under conditions in which amino groups are present in excess,
Further, an aqueous printing ink composition which is an epoxy-modified polyamide resin obtained by reacting epihalohydrin is used.
Sanitary paper of claim 1, wherein that. 3. A water-based printing ink composition containing 2 to 20% by weight of the epoxy-modified polyamide resin in the ink composition.
The sanitary paper according to claim 1 or 2 , which uses a product . 4. Water in which the weight ratio of the colorant component to the epoxy-modified polyamide resin is 1: 2.5 to 1:20.
Hygiene paper according to any one of claims 1 to 3, wherein the hygienic printing ink composition is used . 5. Further, casein is added to the ink composition in an amount of 0.
The sanitary paper according to any one of claims 1 to 4, which uses an aqueous printing ink composition containing 1 to 3% by weight.