JP5589792B2 - Gravure printing ink composition for surface printing - Google Patents

Description

  The present invention is excellent in adhesiveness and heat resistance for various plastic films used as packaging materials for foods and the like, and also has good polyvinyl chloride blocking resistance because soft vinyl chloride sheets used for tablecloths and the like do not adhere to printed matter. The present invention relates to a gravure printing ink composition for surface printing.

  In recent years, packages are generally decorated with printing ink for decoration and surface protection. In addition, depending on the quality of printed matter such as design, cosmetics, and luxury due to differences in printing ink performance, it may affect the favorability and attention to packaging, and consumers' willingness to purchase. It is no exaggeration to say that they are directly connected.

  On the other hand, food manufacturers and converters are demanding a high level of quality and performance for printing inks due to diversification of packaging and advancement of packaging technology, and certain packaging meets certain quality standards. In some cases, it is specified that only printing ink is used.

  In particular, the gravure printing ink for surface printing according to the present invention is printed on the outer surface of the package. Therefore, the ink performance is gloss and density after printing, resistance to rubbing (friction resistance), resistance to oil (oil resistance) ), Various resistances such as heat resistance (sealing sealability) when heat sealing the mouth of the bag and blocking resistance including table cloth are required.

  Further, in recent years, there has been an increasing demand for printing inks having high versatility and high versatility that have adhesiveness to various plastic films.

  For example, increasing the density of printing ink has the advantage of reducing costs for converters by reducing the number of plates printed twice in the hues that require density during gravure printing to one, or by carving shallow plates. On the other hand, there are various performances of printing ink, such as poor adhesion to various plastic films, printability at printing, various resistances, etc., as the proportion of pigment in the ink increases and the proportion of binder decreases. There's a problem.

  Further, the conventional gravure printing ink for surface printing needs to change the ink type depending on the degree and type of surface treatment of the plastic film, and there is a high demand for a versatile ink that can be bonded to various plastic films.

  The binder resin used for the printing ink in the surface printing field is generally a polyamide resin alone or a nitrocellulose combined system, but with a polyamide resin alone, when the surface of the polyolefin film is untreated and weakly treated, it is bonded. If the ratio of the polyamide resin is high in the combined system, heat resistance and oil resistance cannot be obtained. On the other hand, if the ratio of nitrocellulose is high, adhesion to the film cannot be secured, It is difficult to obtain a well-balanced ink composition having high heat resistance and oil resistance.

  In addition, as a binder for gravure printing ink for surface printing, those using a polyurethane resin disclosed in Patent Document 1 or the like, and a vinyl chloride resistant material for preventing a printed product from adhering to a soft vinyl chloride sheet used for a table cloth or the like. There is a polyurethane resin and acrylic resin combination system disclosed in Patent Document 2 as an ink having good blocking properties, but the adhesion to a plastic film and the printing ink itself are separated as compared with a system of polyamide resin and nitrocellulose. There was a problem in storage stability due to the tendency.

JP 10-67959 A JP 2004-331841 A

  The problem to be solved by the present invention is that the adhesive property to various plastic films is good, the printing quality is excellent, the ink can be stored for a long period of time, and the soft vinyl chloride sheet and printed matter used for a table cloth, etc. It is to provide a gravure printing ink composition for surface printing which has good anti-vinyl chloride blocking property for preventing adhesion and oil resistance to edible oil.

  Therefore, as a result of intensive studies to solve the above problems, an ink composition characterized by containing a danmar resin and a polyamide resin as a binder and further containing a nitrocellulose resin and a fatty acid amide is extremely effective in solving the problem. As a result, the present invention has been completed.

That is, the first invention is a gravure printing ink composition for surface printing comprising a pigment, a binder resin , a fatty acid amide and an organic solvent.
Binder resin
Including dammar resin and polyamide resin,
Polyamide resin
Softening point 100-135 ° C
And weight average molecular weight 2,000-50,000
And
The ratio of dammar resin and polyamide resin is
5/95 to 50/50 by weight ratio of solids
It is related with the gravure printing ink composition for surface printing characterized by these.
However, the gravure printing ink composition for surface printing is used for a weakly processed film.

  The second invention relates to a gravure printing ink composition for surface printing according to claim 1, wherein the binder resin further contains a nitrocellulose resin.

In addition, the third invention relates to a printed matter obtained by printing the gravure printing ink composition for surface printing described in the first or second invention on a weakly treated film.

  The surface printing gravure printing ink composition of the present invention has excellent adhesiveness, heat resistance and oil resistance necessary for application to the surface printing of plastic films, and also has good blocking resistance against PVC sheets over time. It has become possible to provide a gravure printing ink composition for surface printing that is excellent in storage stability.

  Hereinafter, the present invention will be described in detail.

  First, as the pigment that can be used in the present invention, inorganic, organic pigments, or extender pigments that can be generally used in printing inks and paints can be used. Examples of inorganic pigments include colored pigments such as titanium oxide, bengara, bitumen, ultramarine, carbon black, and graphite, and extender pigments such as calcium carbonate, kaolin, clay, barium sulfate, aluminum hydroxide, and talc. Examples of organic pigments include soluble azo pigments, insoluble azo pigments, azo chelate pigments, condensed azo pigments, copper phthalocyanine pigments, and condensed polycyclic pigments.

  The content of these pigments is about 0.5 to 50% by weight in the ink composition.

  The polyamide resin used as the binder resin of the ink composition of the present invention is a thermoplastic polyamide that can be obtained by polycondensation of a polybasic acid and a polyvalent amine, and has a solubility in isopropanol of 30% by weight or more, Preferred. When the solubility in alcohol is insufficient, the pigment dispersibility, gloss, color development, and low-temperature stability of the printing ink composition are not sufficient.

Examples of the polybasic acid used as the raw material for the polyamide resin include adipic acid, sepacic acid, isophthalic acid, terephthalic acid, trimellitic acid, cyclohexanedicarboxylic acid, and polymerized fatty acid. Among these, polymerized fatty acid is preferable.
Here, the polymerized fatty acid is obtained by dry or semi-dry fat or fatty acid fatty acid or ester polymerization thereof, and includes monobasic fatty acid, dimerized polymerized fatty acid, trimerized polymerized fatty acid and the like.

  A monocarboxylic acid can be used in combination with the polybasic acid. Examples of the monocarboxylic acid used in combination include acetic acid, propionic acid, lauric acid, palmitic acid, benzoic acid, and cyclohexanecarboxylic acid.

  Examples of polyvalent amines include polyamines, primary and secondary monoamines. Polyamines used in the present invention include aliphatic amines such as ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, aromatic diamines such as xylylenediamine, and alicyclics such as isophoronediamine. Diamines are preferred, and primary and secondary monoamines are preferably ethylamine, propylamine, butylamine, and the like, and these polyvalent amines can be used alone or in any proportion.

  The polyamide resin of the present invention can be produced by a method similar to the usual method for synthesizing polyamide resins. The reaction temperature is 180 to 230 ° C., and the reaction is preferably performed in an inert gas. The reaction may be performed under reduced pressure. The equivalent ratio of carboxyl group: amino group of the reaction component is preferably 0.9: 1.0 to 1.0 to 0.9.

  The polyamide resin of the present invention has a softening point in the range of 100 to 135 ° C. and a weight average molecular weight in the range of 2,000 to 50,000. If the softening point is lower than 100 ° C., the printed matter The surface of the ink film is poorly tucked, and blocking is likely to occur. When the softening point is higher than 135 ° C., the ink film becomes hard, and the resistance to the soft film is reduced. When the range of the weight average molecular weight is lower than 2,000, the film strength of the ink tends to be lowered, and the friction resistance, heat resistance, and high-speed printing suitability are lowered. When the molecular weight is higher than 50,000, the viscosity of the ink becomes high and the storage stability tends to be poor. These softening points are generally measured by JISK2207 (ring and ball method).

  The polymerized fatty acid used in the present invention is a monobasic fatty acid containing an unsaturated fatty acid or obtained by ester polymerization thereof, and the monobasic fatty acid having 18 carbon atoms is 0 to 7% by weight and has 36 carbon atoms. It is preferable to use 20 to 100% by weight of the dimerized polymerized fatty acid and 0 to 100% by weight of the trimerized polymerized fatty acid having 54 carbon atoms, and the polymerized fatty acid can be used alone or in an arbitrary ratio.

  On the other hand, the dammar resin used as the binder resin of the ink composition of the present invention can be used in a ratio of 5/95 to 50/50 in terms of weight with respect to the polyamide resin. Even so, the adhesiveness, polyvinyl chloride blocking property, ink storage stability and the like of the gravure printing ink composition for surface printing obtained as the effect of the present invention are insufficient.

  This dammar resin (also called dammar, dammer, dammal resin) is obtained by diluting and dissolving sap collected from an evergreen tree of Dipterocarpaceae growing in Southeast Asia with an organic solvent. Dammar resin is generally used in painting protection varnishes and can be easily obtained at large art supply stores or online shops handling paints.

  Next, a nitrocellulose resin can be used as the binder resin of the ink composition of the present invention. By using a nitrocellulose resin, it is possible to expect an improvement in blocking resistance and heat resistance. In addition, the addition amount is 1.0 to 6.5% by weight as a solid content in the ink composition.

  This nitrocellulose resin is obtained as a nitrate ester obtained by reacting natural cellulose with nitric acid to replace the three hydroxyl groups in the 6-membered ring of anhydrous glucopyranose groups in natural cellulose with nitrate groups. Those having a degree of polymerization of 35 to 480, preferably 50 to 150 are suitable. An average degree of polymerization of less than 50 is not preferable because the strength of the ink film is lowered, and the scratch resistance and the rub resistance are lowered. On the other hand, when the average degree of polymerization is higher than 150, the solubility in a solvent, the low temperature stability of the ink, and the compatibility with the combined resin are reduced, which is not preferable.

  Next, the organic solvent used in the printing ink composition of the present invention is mainly an alcohol-based organic solvent such as methanol, ethanol, 1-propanol, isopropanol, butanol, or a ketone system such as acetone, methyl ethyl ketone, or methyl isobutyl ketone. Organic solvents, ester organic solvents such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate, aliphatic hydrocarbon solvents such as n-hexane, n-heptane, n-octane, cyclohexane, methylcyclohexane, ethylcyclohexane, cyclohexane Examples thereof include alicyclic hydrocarbon solvents such as heptane and cyclooctane, and aromatic hydrocarbon solvents such as toluene and (o, m, p-) xylene. These solvents are preferably mixed and used in consideration of the solubility and drying properties of methanol and binder resin. For example, as alcohol-based solvents, methanol, 1-propanol, isopropanol, ester-based organic solvents are used. Is preferably toluene or xylene as ethyl acetate, propyl acetate, alicyclic hydrocarbon solvents, ethylcyclohexane, and aromatic hydrocarbon solvents. The amount of these organic solvents used is 20% by weight or more in ordinary ink.

  Next, fatty acid amides used in the printing ink composition of the present invention include saturated fatty acid amides, unsaturated fatty acid amides, modified fatty acid amides, etc., from the blocking resistance to the soft vinyl chloride sheet used for the table cloth, It is particularly preferred to use a modified fatty acid amide. Specific examples include Amide Polymer-Ex-1 manufactured by Tenka Polymer Co., Ltd., but are not limited thereto.

  In the present invention, a wax, a pigment dispersant, a leveling agent, an antifoaming agent, a surfactant, and a plasticizer can be added as necessary for the purpose of having a function required as an ink.

  It is also possible to use an organometallic compound in the printing ink composition of the present invention. In this case, improvement in heat resistance, oil resistance and friction resistance can be expected.

  Specific examples of the organometallic compound include tetraethoxy titanium, tetraisopropoxy titanium, tetra-n-butoxy titanium, tetrakis (2-ethylhexyloxy) titanium, tetrastearyloxy titanium, triisopropoxy titanium monostearate, tri-n. -Butoxytitanium monostearate, diisopropoxytitanium distearate, di-n-butoxytitanium distearate, bis (2-ethylhexyloxy) titanium distearate and its weight 2-10 (n = 1-5) Examples thereof include titanate compounds such as coalescence, and zirconium compounds such as tetraethoxyzirconium, tetra-n-butoxyzirconium, and di-n-butoxyzirconium distearate. These organometallic compounds can be used as appropriate, alone or in admixture of two or more.

  The ink composition of the present invention is produced by a known method using the above materials. For example, a mixture of a binder resin, a pigment, an organic solvent and, if necessary, a pigment dispersant is prepared with a high-speed mixer, a colloid mill, etc., and is kneaded using a ball mill, a bead mill, an attritor, a medialess disperser, etc. Furthermore, the method of adding and mixing the remainder of a predetermined material is common.

  The ink composition of the present invention can be printed on various adherends using a known gravure printing method.

  Here, as an adherend on which the ink composition is printed, polyester film such as normal stretched polypropylene (OPP) film, unstretched polypropylene (CPP) film, modified polypropylene film, polyethylene terephthalate (PET) film, nylon, In addition to various plastic films such as polystyrene, stretched polypropylene (VM-OPP) films, non-stretched polypropylene (VM-CPP) films, polyethylene terephthalate (VM-PET) films, etc., on which a metal such as aluminum is deposited, are listed. .

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail, this invention is not limited to each of these examples. In each example, “part” represents “part by weight” and “%” represents “% by weight”.

<Preparation of polyamide resin varnish>
35 parts of a commercially available polyamide resin having a softening point of 112 ° C. to 120 ° C. and a weight average molecular weight of 3000 to 4000 (Rheamide S-2800 manufactured by Kao Corporation) is mixed with 45 parts of toluene and 20 parts of isopropyl alcohol. Dissolved to obtain a test polyamide resin varnish (resin A) having a solid content of 35%.

  In addition, 35 parts of a commercially available polyamide resin (Polymide S-52 manufactured by Sanyo Chemical Co., Ltd.) having a softening point of 98 ° C to 108 ° C and a weight average molecular weight of 1000 to 2000 is added to 45 parts of toluene and 20 parts of isopropyl alcohol. By mixing and dissolving, a test polyamide resin varnish (resin B) having a solid content of 35% was obtained.

  Furthermore, 35 parts of a commercially available polyamide resin (Macromelt 6900 made by Henkel Japan Co., Ltd.) having a softening point of 130 ° C. to 150 ° C. and a weight average molecular weight of 50,000 to 60000 is mixed with 45 parts of toluene and 20 parts of isopropyl alcohol. Dissolved to obtain a test polyamide resin varnish (resin C) having a solid content of 35%.

<Preparation of dammar resin varnish>
50 parts of natural dammar resin (solid), which is generally commercially available as a material for painting protective films and writing varnishes, was mixed and dissolved in 50 parts of toluene to obtain a test dammar resin varnish having a solid content of 50%.

<Preparation of nitrocellulose resin varnish>
20 parts of nitrocellulose (trade name NC HIG 1 / 2G KCNC, manufactured by Korea CNC Co., Ltd.) were mixed and dissolved in 30 parts of ethyl acetate and 50 parts of isopropyl alcohol to obtain a nitrocellulose resin varnish having a solid content of 20%.

( Examples 5 and 6, Reference Examples 1 to 4, Comparative Examples 1 to 8)
First, gravure printing ink compositions for surface printing of Examples 5 and 6, Reference Examples 1 to 4 and Comparative Examples 1 to 8 were prepared at the blending ratio shown in Table 1. In addition, the following were used as a pigment, fatty acid amide, a crosslinking agent, and a mixed solvent, and dispersion | distribution was performed with the small bead mill.
Pigment Titanium oxide Titanics JR603 Teica Co., Ltd. Fatty acid amide Amide polymer EX-1 Tenka polymer Co., Ltd. Crosslinker Tetraisopropoxy titanium Nippon Soda Co., Ltd. Mixed solvent Toluene: Ethyl acetate: Isopropyl alcohol = 60:30: 10
(Weight ratio)

<Evaluation test>
Next, the quality of the gravure printing ink compositions for surface printing of Examples 5 and 6, Reference Examples 1 to 4 and Comparative Examples 1 to 8 produced in the following manner was measured by the following method. In addition, the printed material used for the evaluation was a polypropylene film (FOH, manufactured by Nimura Chemical Co., Ltd.) printed with a gravure proofing machine and used after 1 day from printing.

[Ink viscosity]
The ink viscosity immediately after the production was measured with a Zahn cup (manufactured by Kosei Co., Ltd.), and it was confirmed whether the viscosity as a gravure ink was in an appropriate range. Evaluation was performed according to the following evaluation criteria. If the viscosity of the ink is too low (10 seconds or less with Zaan Cup No. 3), the pigment is likely to precipitate, and is poor in separation and storage stability. If the viscosity is too high (30 seconds or more with Zaan Cup No. 5) ) Difficult to take out from pumping and oil cans and difficult to handle in the printing process.
(Evaluation criteria)
A: Zaan Cup No. 4 and in an optimum viscosity range of 15 to 25 seconds and excellent B: Zahn Cup No. 3 or 4 or 5 which is not in the optimum viscosity range but has no practical problem C: Zahn Cup No. 3 or 5 with low or high ink viscosity and practical problems

[Adhesiveness (1)]
After sticking a 12mm wide adhesive tape made of Nichiban Co., Ltd. to a printed surface printed using a normal printing film having a surface oxidation treatment degree of 38 mN / m, the tape is peeled off to remove the ink film. Were confirmed and evaluated according to the following evaluation criteria. The results are shown in Table 2.
(Evaluation criteria)
A: The ink film does not peel at all B: The ink film peels slightly, but there is no problem in practical use C: The ink film of 10% or more of the printing area peels off, and there is a problem in practical use

[Adhesiveness (2)]
Nichiban Co., Ltd. cello tape (registered trademark) 12mm wide adhesive surface is attached to the printed surface printed using a weakly processed film for adhesion evaluation with a surface oxidation treatment degree of 30 mN / m, and then the tape is peeled off. The degree of peeling of the ink film was confirmed and evaluated according to the following evaluation criteria. The results are shown in Table 2.
(Evaluation criteria)
A: The ink film does not peel at all B: The ink film peels from the film in the range of 1% or more and less than 25% of the printing area C: The ink film peels from the film by 25% or more of the printing area

[Glossy]
The gloss value of the printed material was measured using a gloss meter manufactured by Big Gardner Inc. with an incident angle of 60 ° and a light receiving angle of 60 °, and evaluated according to the following evaluation criteria. The results are shown in Table 2.
(Evaluation criteria)
A: Gloss value is 50 or more and very excellent B: Gloss value is 30 or more and less than 50, no problem for practical use C: Gloss value is less than 30 for practical use

[concentration]
The density of the printed material was measured using a spectral densitometer manufactured by X-Rite, and the L ^* value was measured and evaluated according to the following evaluation criteria. The results are shown in Table 2.
(Evaluation criteria)
A: L ^* value is 75 or more and excellent B: L ^* value is 50 or more and less than 75, and there is no practical problem C: L ^* value is less than 50, and there is a practical problem thing

[Abrasion resistance]
The film strength of the printed material against rubbing was measured using a Gakushin type friction fastness tester manufactured by Tester Sangyo Co., Ltd., evaluated according to the following evaluation criteria, and the results are shown in Table 2. The measurement conditions were a test piece width of 20 mm, a load of 0.2 gf, 20 reciprocations, and Kanakin No. 3.
(Evaluation criteria)
A: The ink film is not removed at all, and it is very excellent. B: The area where the ink film is removed is less than 10%, and there is no practical problem. C: The area where the ink film is removed is 10% or more. Those that impede practical use

[PVC blocking resistance]
A soft vinyl chloride sheet cut to the same size as the printed material and the printed surface are overlaid, applied with a load of 0.5 kg / cm ² , and allowed to stand in an atmosphere of 40 ° C. and 80% RH for 24 hours. The sheet was peeled off, the degree of ink peeling was evaluated, and the following evaluation criteria were evaluated. The results are shown in Table 2.
(Evaluation criteria)
A: The ink does not peel at all and is very excellent. B: It feels peeling resistance but the ink does not peel off and is excellent. C: The ink film is slightly peeled, but there is no practical problem. D: The area where the ink film is removed is 10% or more, and there are practical problems

[Heat-resistant]
Using a heat sealer manufactured by Sentinel, the aluminum foil cut into the same size as the printed material and the printed surface are overlapped, and the aluminum foil is pressed at 120 ° C. for 1 second at a pressure of 2 × 9.8 N / cm ^{2 to} obtain ink. The degree of peeling was evaluated and evaluated according to the following evaluation criteria. The results are shown in Table 2.
(Evaluation criteria)
A: The ink does not peel off at all and is very excellent. B: The ink film is slightly peeled off, but there is no practical problem. C: The ink film of 10% or more of the printing area peels off, and there is a practical problem. some stuff

[Oil resistance]
A commercially available margarine was applied to the entire surface of the print, and allowed to stand at 30 ° C. or lower for 1 hour, and then rubbed 10 times with a Gakushoku type friction fastness tester manufactured by Tester Sangyo Co., Ltd. Evaluation is performed according to the following evaluation criteria, and the results are shown in Table 2.
(Evaluation criteria)
A: The ink does not peel at all and is very excellent. B: The ink film is slightly peeled off, but there is no practical problem. C: The area where the ink film is taken is 20% or more, and there is a practical problem. some stuff

[Print quality]
Gravure helio engraving plate making 175 lines / inch, the quality of the printed matter printed by a cylinder having a dot percentage of 100% to 3% was evaluated, and evaluated according to the following evaluation criteria. The results are shown in Table 2.
(Evaluation criteria)
A: Gradation reproducibility up to the highlight part (3%), very excellent B: Gradation reproducibility of the highlight part (3%) is slightly inferior, but no problem in practical use C: Gradation reproducibility There is no practical problem

[Resolubility]
The prepared ink was applied to a gravure ballad plate with a squeegee and allowed to air dry for 5 minutes, then immersed in a mixed solvent (toluene: ethyl acetate: isopropyl alcohol = 60: 30: 10) until the ink film was completely eluted. The time was evaluated and evaluated according to the following evaluation criteria. The results are shown in Table 2.
(Evaluation criteria)
A: Less than 30 seconds until the ink film completely elutes, and excellent B: It takes 30 seconds or more until the ink film completely dissolves, but there is no practical problem C: The ink film does not elute, Those that impede practical use

[Ink storage stability]
The test ink is allowed to stand at 40 ° C. for 7 days, and the viscosity stability with time is evaluated from the viscosity measurement data before and after aging (measured by Zoan Co., Ltd.), and evaluated according to the following evaluation criteria. It is shown in 2.
(Evaluation criteria)
A: Viscosity with time is less than 1.5 times immediately after finishing and excellent B: Viscosity with time is 1.5 times or more immediately after finishing and less than 2 times, and there is no practical problem C: Viscosity with time 2 times or more immediately after finishing, or causing precipitation or separation, which hinders practical use. D: Solidified (gelled) over time, and not a product as ink

<Results of physical property evaluation of white ink>
Reference Examples 1 to 3 were blended so that the ratio of the dammar resin varnish to the polyamide resin varnish would be a ratio of 5/95 to 50/50 in terms of weight. All items have practically no problem.

Further, in Reference Example 4, when Reference Example 3 was further used with nitrocellulose resin varnish, the blocking resistance and heat resistance were improved.

Furthermore, Example 5 used the fatty acid amide in Reference Example 3, and Example 6 used the fatty acid amide in Reference Example 4 resulted in further improved blocking properties.

Further, in Comparative Example 1, a varnish having a polyamide resin weight average molecular weight of 2000 or less is inferior in frictional resistance, blocking property, and heat resistance due to the brittleness of the film strength as compared with Reference Example 4. Since the viscosity of the ink was low, precipitation and separation resulted in poor ink storage stability.

Further, in Comparative Example 2, a varnish having a polyamide resin weight average molecular weight of 50000 or more has a very high ink viscosity as compared with Reference Example 4, and an appropriate viscosity during printing (Zahn Cup N0. 3-15 seconds), the solvent dilution rate increases, the film and density of the printed matter decreases, the tackiness, blocking properties, solidification due to thickening (gelation) results in poor ink storage stability It became.

  Moreover, Comparative Examples 3-4 use nitrocellulose resin varnish and fatty acid amide for Comparative Examples 1-2, and as compared with Comparative Examples 1-2, the blocking property and heat resistance are inferior to the level of practical use. Has not reached.

Furthermore, in Comparative Example 5, Comparative Example 5 in which the dammar resin was not blended was inferior in adhesion to the weakly treated film and inferior in heat resistance and oil resistance as compared with Reference Examples 1 to 3.

  In addition, when the blending ratio of the dammar resin varnish is increased as in Comparative Examples 6 to 8, the adhesion to the weakly processed film is improved, but the tackiness peculiar to dammar becomes stronger, the blocking property is lowered, and the ink viscosity As a result, the ink storage stability was poor. Thus, when the balance of adhesiveness, polyvinyl chloride blocking property, ink storage stability, etc. is taken into consideration, it can be confirmed that the blending ratio of the dumale resin and the polyamide resin is in the range of 5/95 to 50/50 in terms of weight.

As described above, as specifically described with reference to Examples 5 and 6 and Reference Examples 1 to 4 , the surface printing gravure printing ink composition of the present invention has good adhesion to the film, and excellent print quality. Gravure printing ink composition for surface printing, which can store ink for a long period of time, and also has good anti-vinyl chloride blocking property to prevent the printed material from adhering to the soft vinyl chloride sheet used for table cloth, etc. Moreover, the printed matter obtained by printing with a gravure printing machine is slit and bag-made, and can be used practically for packaging of goods such as food.

Claims (3)

In a gravure printing ink composition for surface printing comprising a pigment, a binder resin , a fatty acid amide and an organic solvent,
Binder resin
Including dammar resin and polyamide resin,
Polyamide resin
Softening point 100-135 ° C
And weight average molecular weight 2,000-50,000
And
The ratio of dammar resin and polyamide resin is
5/95 to 50/50 by weight ratio of solids
A gravure printing ink composition for surface printing, characterized in that
However, the gravure printing ink composition for surface printing is used for a weakly processed film.   The gravure printing ink composition for surface printing according to claim 1, wherein the binder resin further contains a nitrocellulose resin. A printed material obtained by printing the gravure printing ink composition for surface printing according to claim 1 or 2 on a weakly treated film.