JP3127040B2 - Anti-slip aqueous printing ink composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based printing ink which is printed on paper containers such as corrugated cardboards and cartons and various paper bags, and more particularly, a water-resistant ink for preventing paper containers and paper bags from being collapsed. The present invention relates to a printing ink composition.

[0002]

2. Description of the Related Art Agricultural products, marine products and other various foods, various industrial products, and the like are packaged and transported in paper containers such as cardboard and cartons or various paper bags. In recent years, in these transportations, etc., the efficiency of logistics has been increasing, such as automation of various packaging lines and palletization of transportation lines.
At that time, the collapse of the load due to the sliding of the cardboard case or the like is apt to occur, which is a serious problem such as being extremely dangerous.
Therefore, it is possible to prevent the collapse of a palletized cardboard case or the like by performing banding processing (fixing with a band) or shrinking processing (fixing with a shrinkable film). Cost increases due to the decrease in Accordingly, there has been a demand for a low-cost, highly slippery printed material for preventing collapse of a load which makes these processes unnecessary or can be simplified.

[0003] Conventionally, as such a printed matter, an adhesive type (one that retains adhesiveness even in a dry state after being coated on the surface of a paper container or the like and exhibits an anti-slip effect by this adhesive strength) and , Non-adhesive type (by applying to the surface of a paper container, etc., and applying appropriate treatment such as heating and foaming as necessary, fine irregularities are formed on the surface. The anti-slip varnish is used. These non-slip varnishes are used for paper containers and paper bags. For example, after pattern printing with a water-based printing ink on a corrugated cardboard case, the varnish has been partially applied to the entire surface or the top surface and / or the ground as a laminated surface.

[0004]

However, paper containers,
When a non-slip varnish is applied after printing a pattern on a paper bag with an aqueous printing ink, a decrease in printing aptitude such as a decrease in gloss, occurrence of blocking, and bleeding of the non-slip varnish of the ink occurs. In addition, when the aqueous printing ink has a slow drying property, the simultaneous printing of the aqueous printing ink and the anti-slip varnish is not sufficient, and there is a problem that the printing has to be performed in two steps. There are problems that the number is increased, the workability is complicated, time is required, and the cost is increased. Therefore, in recent years, there has been a demand in the art for a non-slip water-based printing ink having anti-slip properties and abrasion resistance without using a non-slip varnish.

[0005] However, in the aqueous printing ink itself, the method of improving the anti-slip property and the method of improving the rub resistance have contradictory performances. That is, for example, in the aqueous printing ink itself, those having anti-slip properties, the coating film is brittle, the rub resistance is reduced, and those having rub resistance,
The slip angle becomes smaller and the slip resistance becomes lower. Therefore, it is difficult to achieve both of them, and a water-resistant printing ink having both anti-slip properties and abrasion resistance has not been found yet.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems of the prior art, and an object of the present invention is to provide a water-based printing ink itself having an anti-slip property and abrasion resistance without using a non-slip varnish. Another object of the present invention is to provide a novel anti-slip water-based printing ink composition.

[0007]

That is, the gist of the present invention is as follows.
An aqueous printing ink composition mainly composed of a colorant, an aqueous binder, a film-strengthening component, an adhesive component and water, wherein (1) an alkali-soluble type having a glass transition temperature of 40 ° C. or higher as an aqueous binder component. 5 to 15% by weight of resin as a solid content; (2) 3 to 15% by weight of an aqueous styrene-acrylic copolymer emulsion having a glass transition temperature of 40 ° C. or lower as a solid component;
And (3) a glass transition temperature of 10 as an adhesive component.
Aqueous resin emulsion having a solid content of 5 to
15% by weight, and the aqueous styrene-
The present invention relates to a non-slip aqueous printing ink composition, wherein the weight ratio of the solid content of the acrylic copolymer emulsion to the aqueous resin emulsion is 0.6 or more.

As the aqueous binder contained in the anti-slip aqueous printing ink composition of the present invention, an alkali-soluble resin conventionally used for flexographic printing is used.
Specific examples of these alkali-soluble resins include a styrene-maleic acid copolymer, a styrene-acrylic copolymer, a rosin-modified maleic resin, an acrylic resin, a maleic resin, and the like. Two or more can be used in combination.

These alkali-soluble resins must have a glass transition temperature of 40 ° C. or higher. If the glass transition temperature is lower than 40 ° C., it is difficult to obtain a sufficient antiblocking effect and heat resistance. . The adjustment of the glass transition temperature in the present invention can be calculated by setting the polymerization ratio according to the approximate expression of wood. Further, those having a molecular weight in the range of 5,000 to 60,000 can be used. When the molecular weight is less than 5,000, the antiblocking effect is inferior, and when it exceeds 60,000, there is a problem in solubility and printability. Further, those having an acid value in the range of 80 to 300 can be used. When the acid value is less than 80, it becomes difficult to make water soluble, and when the acid value exceeds 300, water resistance or sliding effect is poor. These alkali-soluble resins are usually contained in the aqueous printing ink composition in a solid content of 5 to 1%.
5% by weight, preferably 7 to 12% by weight can be added. If the amount is less than 5% by weight, the dispersion of the pigment is not sufficient, and if it exceeds 15% by weight, the effect of preventing slippage becomes a problem.

In order to impart gloss and drying properties, it is also possible to use a water-dispersible resin conventionally used for flexographic printing as a component of an aqueous binder in combination with these alkali-soluble resins. it can. Specific examples of these water-dispersible resins include those obtained by emulsion polymerization of acrylic, styrene, and other vinyl monomers. These water-dispersed resins must have a glass transition temperature of 40 ° C. or higher, and if the glass transition temperature is lower than 40 ° C., it is difficult to obtain a sufficient antiblocking effect and heat resistance.

When the water-dispersible resin is used in combination, the alkali-soluble resin and the water-dispersible resin are usually contained in the aqueous printing ink composition as solids in the total amount of the alkali-soluble resin and the water-dispersible resin. 5 to 15% by weight can be added.

The film-strengthening component contained in the anti-slip aqueous printing ink composition of the present invention has a glass transition temperature of 40.
An aqueous styrene-acrylic copolymer emulsion having a temperature of not more than 0 ° C is used. Among such copolymer emulsions, a copolymer emulsion obtained by copolymerizing a (meth) acrylic acid monomer and a styrene monomer using a water-soluble acrylic resin as a polymer emulsifier, Those having the property of forming a film are preferably used because they are flexible and strengthen the film. In addition, such adjustment of the glass transition temperature of the resin can be performed by setting the polymerization ratio according to the approximate expression of wood.

The water-soluble acrylic resin used as a polymer emulsifier used in the production of the above copolymer emulsion is an acrylic resin capable of obtaining a polymer having a relatively low glass transition temperature with acrylic acid or methacrylic acid as a monomer. Those obtained by copolymerizing an acid or an alkyl ester of methacrylic acid are exemplified. Here, as the alkyl ester, for example, an ester having a linear or side chain alkyl group such as methyl, ethyl, propyl, isopropyl, n-butyl, s-butyl, t-butyl, hexyl and lauryl can be used. Further, as a monomer used for emulsion polymerization for obtaining an aqueous styrene-acrylic copolymer emulsion, styrene and its derivatives, acrylic acid, methacrylic acid, and the above-mentioned alkyl esters of acrylic acid or methacrylic acid can be used. The aqueous styrene-acrylic copolymer emulsion can be incorporated in the aqueous printing ink composition as a solid component in an amount of usually 3 to 15% by weight, preferably 3 to 10% by weight. If it is less than 3% by weight, the rub resistance of the obtained printed matter is not sufficient, and
If the content exceeds 10% by weight, blocking resistance and heat resistance become insufficient.

The adhesive component contained in the anti-slip aqueous printing ink composition of the present invention has a glass transition temperature of 10 ° C.
The following aqueous resin emulsions may be mentioned. As such an aqueous resin emulsion, for example, ethylene-
Vinyl acetate emulsion, ethylene-vinyl acetate-acryl emulsion, butadiene emulsion, styrene-butadiene emulsion, vinyl acetate emulsion, vinyl chloride-vinyl acetate emulsion, ethylene-
At least one selected from the group consisting of vinyl acetate-vinyl chloride emulsion, vinyl acetate-acryl emulsion, acrylic emulsion, urethane emulsion, and aqueous resin emulsion such as rubber latex can be used.
Preferably, an ethylene-vinyl acetate emulsion, a vinyl chloride-vinyl acetate emulsion, or a vinyl acetate emulsion can be used.

An aqueous resin emulsion as an adhesive component needs to have a property of imparting adhesiveness even in a dry state after being printed on a paper container or the like, and has sufficient compatibility with the above-mentioned aqueous binder. , According to the approximate formula of wood, the glass transition temperature is 10 ° C. or lower, more preferably −
Those having a temperature of 40 to 0 ° C can be used. If the glass transition temperature exceeds 10 ° C., the anti-slip effect is not sufficient, and -4
When the temperature is lower than 0 ° C., problems such as easy occurrence of blocking occur. Further, as the aqueous resin emulsion that can be adapted to such a purpose, an aqueous resin emulsion having a viscosity of 300 to 5000 centipoise and forming a film at normal temperature can be suitably used. If the viscosity of the aqueous resin emulsion is outside the above range, the printability is not sufficient, and those that do not form a film at normal temperature,
A special heating device is required to form a film of the aqueous resin emulsion, which is not preferable in terms of working steps. The aqueous resin emulsion used as the adhesive component is usually 5 to 15% by weight as a solid content in the aqueous printing ink composition.
Preferably, it must be in the range of 5 to 10% by weight. When the content of the aqueous resin emulsion is higher than 15% by weight, blocking resistance and heat resistance become problems, and
When the amount is lower than the weight%, the anti-slip effect becomes a problem.

In the present invention, the solid content weight ratio of the aqueous styrene-acrylic copolymer emulsion (film reinforcing component) to the aqueous resin emulsion (adhesive component) (aqueous styrene-acrylic copolymer emulsion / aqueous resin emulsion) ) Is 0.6 or more. When the solid content ratio is less than 0.6, friction resistance becomes a problem.

In the anti-slip aqueous printing ink composition of the present invention, inorganic fine particles can be further added to the anti-slip aqueous printing ink composition from the viewpoint of imparting anti-slip properties. As inorganic fine particles to be blended, celite, silica powder, silica gel, glass powder, talc, clay,
Examples thereof include calcium carbonate, magnesium carbonate, zinc white, and barium sulfate. Celite and silica powder are preferred from the viewpoint of obtaining printed matter having excellent anti-slip properties. The average particle diameter of these inorganic fine particles is 0.05 to
Those having a range of 15 μm, more preferably 0.1 to 10 μm can be used. If the average particle size is smaller than 0.05 μm, the anti-slip property, the anti-blocking effect is not obtained,
If it is larger than 15 μm, problems arise in printability and abrasion resistance. Such inorganic fine particles can be generally added in an amount of 1 to 10% by weight, preferably 3 to 7% by weight, based on the anti-slip aqueous printing ink composition. If the amount is less than 1% by weight, the effect of anti-slip properties is insufficient, and if it exceeds 10% by weight, problems such as a decrease in friction resistance of the obtained printed matter and a decrease in fluidity of the aqueous printing ink occur. .

As the colorant, dyes, inorganic, organic and extender pigments generally used in water-based inks can be used, and are not particularly limited. In addition to these components, various additives can be used as necessary, and conventionally used in aqueous inks such as antifoaming agents, water-miscible solvents, pigment dispersants, plasticizers, and waxes. Can be exemplified.

The anti-slip aqueous printing ink composition of the present invention comprises:
A colorant is mixed with the aqueous binder, and the mixture is kneaded with a bead mill or the like, and the mixture is prepared by mixing and mixing the above-mentioned film-strengthening component, the adhesive component, and, if necessary, inorganic fine particles and various additives. be able to. The mixing means is not particularly limited, and can be easily performed by using a stirrer or the like generally used for preparing an aqueous printing ink composition. In using the anti-slip water-based printing ink composition of the present invention, printing may be performed on a paper container such as a cardboard or a carton and various paper bags by a printing machine such as a flexographic printing machine or a gravure printing machine.

[0020]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples, Comparative Examples, and Test Examples, but the present invention is not limited thereto. Here, first, each component of the anti-slip aqueous printing ink composition used in Examples and Comparative Examples, that is, an aqueous binder, an aqueous resin emulsion as a film reinforcing component, an aqueous resin emulsion as an adhesive component, inorganic fine particles, and a pigment , An antifoaming agent, and a water-miscible solvent will be described.

(1) Aqueous binder: alkali-soluble resin emulsion: methacrylic acid 32
Acrylic resin (acid value: 180, molecular weight: 4000) obtained by copolymerizing wt%, methyl methacrylate 23 wt%, butyl acrylate 25 wt%, and styrene 20 wt%.
0, glass transition temperature 51.6 ° C.) 30.0% by weight, 28
% Ammonia water 7.1% by weight and water 62.9% by weight
It was synthesized by heating and melting at ℃. The glass transition temperature of the obtained resin was 51.6 ° C. Water-dispersed resin emulsion: styrene-acryl-shellac emulsion, Hiros E-80, manufactured by Seiko Chemical Co., Ltd. (viscosity 500 cps, solid content 80%, glass transition temperature 92 ° C (provided that the glass transition temperature of shellac is 30 The calculation was carried out as ° C.))

(2) Aqueous resin emulsion as a film-strengthening component: Joncryl 74J, styrene-acryl emulsion, manufactured by Johnson Polymer Co., Ltd. (solid content 4
(5%, glass transition temperature 28 ° C.) (3) Aqueous resin emulsion as adhesive component: Ethylene-vinyl acetate emulsion: Polysol EVA P
-20, manufactured by Showa Polymer Co., Ltd. (viscosity 1500 cps,
(58% solids, glass transition temperature -15 ° C)

(4) Inorganic fine particles: Syloid, manufactured by Fuji Devison Co., Ltd. (silica powder, average particle diameter: 5 μm) (5) Pigment: Fastogen Blue TGR, manufactured by Dainippon Ink and Chemicals, Inc. (6) ) Antifoaming agent: Silicone antifoaming agent, FS Antifoam 013B, manufactured by Dow Corning Co., Ltd. (7) Water miscible solvent: isopropyl alcohol

Examples 1 to 13 The above-mentioned aqueous binder, aqueous resin emulsion as a film-strengthening component, aqueous resin emulsion as an adhesive component, inorganic fine particles, pigment, defoamer and water-miscible solvent were each listed in Table 1. The resulting mixture was kneaded and mixed to prepare the anti-slip aqueous printing ink composition of the present invention. In addition, the compounding amount in the table is the amount as solid content (% by weight) except for the solvent.
Is shown.

Comparative Examples 1 to 9 A non-slip, water-based printing ink composition was prepared in the same manner as in Example 1 except that the above-mentioned components were used to obtain the formulations shown in Table 1.

Test Examples (1) Slip Angle Each of the slip-resistant aqueous printing ink compositions obtained in Examples and Comparative Examples was applied to a K liner with a hand proofer, and adjusted at 20 ° C. and 60% humidity for one day. Wet and measure the slip angle between the printing surfaces according to the inclination method test specified in TAPPI, A for a slip angle of 30 ° or more, B for a slip angle of 30 to 20 °, B for a slip angle of 20 to 20 °. ° or less was evaluated as C.

(2) Blocking resistance After coating in the same manner as described above, the humidity was similarly adjusted at a high temperature and a high humidity of 40 ° C. and a humidity of 90%.
Under the condition of cm ² , A was peeled off without resistance, B was peeled off with a resistance but the printed matter was not broken, and C was peeled off the printed matter.

(3) Abrasion resistance A non-slip water-based printing ink composition is coated on a K liner, and 500 g is applied using a Gakushin type abrasion resistance tester (manufactured by Daiei Chemical Seiki Seisakusho)
Under the conditions of a load of 500 times, A is for the case where the printed paper is not stained and the printed matter is not damaged, A is for the case where the printed paper is dirty but the printed matter is not damaged, and B is for the case where the printed paper is dirty and the printed matter is damaged. It was evaluated as C.

(4) Gloss A non-slip water-based printing ink composition was coated on a K liner and visually evaluated. A high gloss product was designated A, a normal gloss product was designated B, and a low gloss product was designated C. evaluated. Table 1 shows the results of the above evaluations. In addition, AB is an allowable range in practical use among evaluations.

[0030]

[Table 1]

As shown in the results of Table 1, Examples 1 to 13 in which the anti-slip aqueous printing ink composition of the present invention was applied showed good results in all evaluation items. On the other hand, in Comparative Examples 1 to 9 in which the components of the anti-slip aqueous printing ink composition of the present invention are outside the scope of the claims, one or more of slip angle, blocking resistance, rub resistance, and gloss are used. The results showed that the evaluation items had no marketability.

[0032]

According to the anti-slip aqueous printing ink composition of the present invention, since the aqueous printing ink composition itself has anti-slip properties and abrasion resistance, a conventional anti-slip varnish can be prepared by using it. Even if not used, a slip angle of 20 degrees or more can be obtained. Further, as compared with the case where a conventional non-slip varnish is used, a reduction in gloss, generation of blocking, and printing suitability such as bleeding of the ink to the non-slip varnish can be improved. Therefore, the workability of preventing the collapse of the load is improved, and the cost can be reduced.

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Claims (3)

(57) [Claims] 1. An aqueous printing ink composition mainly comprising a colorant, an aqueous binder, a film-strengthening component, an adhesive component and water, wherein (1) the aqueous binder component has a glass transition temperature of 40 ° C. or higher. 5 to 15% by weight of a certain alkali-soluble resin as a solid content, and (2) 3 to 15% by weight of an aqueous styrene-acrylic copolymer emulsion having a glass transition temperature of 40 ° C. or lower as a film-strengthening component. %, And (3) 5 to 15% by weight of an aqueous resin emulsion having a glass transition temperature of 10 ° C. or less as a solid content as an adhesive component, and
A non-slip aqueous printing ink composition, wherein the weight ratio of the solid content of the aqueous styrene-acrylic copolymer emulsion to the aqueous resin emulsion is 0.6 or more. 2. The aqueous styrene-acrylic copolymer emulsion is a copolymer emulsion obtained by copolymerizing a (meth) acrylic acid monomer and a styrene monomer using a water-soluble acrylic resin as a polymer emulsifier. The anti-slip aqueous printing ink composition according to claim 1, which has a property of forming a film at normal temperature. 3. The anti-slip aqueous printing ink composition according to claim 1 or 2, further having an average particle diameter of 0.05 to 15 μm.
m, wherein 1 to 10% by weight of inorganic fine particles are blended.