JPH04283274A - Ink composition for gravure printing - Google Patents

Abstract

PURPOSE:To prepare the title compsn. excellent in stability of pigment dispersion, drying properties, stickiness, heat resistance, and coating film appearance by using a specific nitrocellulose. CONSTITUTION:The title compsn. is prepd, by mixing nitrocellulose having a wt. average mol.wt. by GPC of 20,000 or lower and a carboxyl group content of 9mmol/100g or higher, a thermoplastic resin such as a polyamide resin, a plasticizer such as dibutyl phthalate, a pigment such as titanium oxide, and an org. solvent such as ethyl acetate, isopropyl alcohol, or toluene in a specified ratio.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gravure printing ink composition used for cellophane, paper, plastic films, metal foils, etc. for packaging foods, medicines, clothing, etc. More specifically, the present invention comprises nitrocellulose having a weight average molecular weight of 20,000 or less and a carboxyl group content of 9 mmol/100 g or more as measured by gel permeation chromatography, a thermoplastic resin, a plasticizer, The present invention relates to a composition for gravure printing ink, which is composed of a specific ratio of pigment and organic solvent, has favorable pigment dispersion stability and drying properties, and is capable of forming an ink film with excellent adhesion, heat resistance, and film appearance. .

0002

BACKGROUND OF THE INVENTION Various nitrocelluloses specified in JIS-K6703 have been widely used as film-forming agents for gravure printing inks due to their excellent drying properties, heat resistance, and pigment dispersibility. The printing materials for gravure printing are mainly cellophane, paper, plastic film, metal foil, etc. In the case of cellophane and paper, nitrocellulose itself has suitable adhesive properties, so it is possible to use a combination of nitrocellulose, pigments, and organic solvents. Alternatively, printing inks with practical performance have been produced and used by combining these with small amounts of plasticizers.

However, plastic films such as low-density polyethylene, high-medium density polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride,
Polyvinyl acetate, polyester, nylon, etc., and
Since the adhesion is insufficient for printing on metal foils such as aluminum foil and tin foil, other thermoplastic resins such as polyamide resins, alkyd resins, polyurethane resins, acrylic resins, chlorinated rubber, cyclized rubber, and maleic acid resins are used. , phenolic resin, rosin or its derivatives were used in combination. However, because it was necessary to use a large amount to obtain practical adhesion, pigment dispersion stability, drying properties, heat resistance, etc. were sacrificed.

[0004] Japanese Patent Publication No. 61-29396 proposes a printing ink composition characterized by containing 15% or more of nitrocellulose having an average degree of polymerization of 30 or less in the coating film forming element. . The average degree of polymerization referred to in this publication is a value calculated from the intrinsic viscosity using the following formula: DP=[η]/Km DP: Average degree of polymerization [η]: Intrinsic viscosity Km: Constant (1.1× 10-4) Nitrocellulose, which has an average molecular weight of 30 by this method, has a weight average molecular weight of 27,000 by gel permeation chromatography according to the present invention. According to this publication, a printing ink composition that has good adhesion to plastic films and metal foils and excellent drying properties is obtained. However, the nitrocellulose used in this publication essentially does not have sufficient interaction with pigments, and has an average molecular weight of JIS-K6703.
Since it is much smaller than the described nitrocellulose, there was a problem with pigment dispersion stability and a problem that the appearance of the ink film deteriorated.

Furthermore, Japanese Patent Publication No. 61-45641 proposes a method for producing modified nitrocellulose using partially oxidized cellulose containing at least 15 mmol of carboxyl groups per 100 g of cellulose. It has been shown that the nitrocellulose prepared by this method can be used in printing inks with good adhesion to plastic films and metal foils, and improved pigment dispersibility, drying properties, and heat resistance. however,
The nitrocellulose prepared in this publication not only has insufficient adhesion to plastic films and metal foils, but also has a high molecular weight despite the large interaction between carboxyl groups and pigments.
The viscosity of the printing ink composition is high, and the appearance of the resulting ink film is impaired.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a gravure printing ink composition that has good pigment dispersion stability and drying properties, and provides an ink film that has excellent adhesion to plastic films and metal foils, heat resistance, and film appearance. It's about providing things.

[0007]

[Means for Solving the Problems] As a result of intensive studies regarding the above problems, the present inventors have found that (a) the weight average molecular weight is 20,000 or less and the carboxyl group content is 9 mmol/100 g or more; Nitrocellulose, (
b) thermoplastic resin, (c) plasticizer, (d) pigment, (e)
It consists of an organic solvent, and the ratio of each component is a/b on a weight basis.
is 5/95 to 60/40, (a+b)/c is 70/3
It was discovered that a gravure printing ink composition having a ratio of 0 to 100/0, a ratio of (a+b+c)/d of 50/50 to 95/5, and a ratio of (a+b+c+d)/e of 20/80 to 50/50 is excellent, and the present invention was developed. It is completed.

The nitrocellulose used in the present invention has a weight average molecular weight of 20,000 or less, preferably 15,000
0 or less, and the carboxyl group content is 9 mmol/
The amount is 100 g or more, preferably 12 mmol/100 g or more. If the weight average molecular weight exceeds 20,000, adhesion to plastic films and metal foils will be insufficient, and the viscosity of the gravure printing ink composition will increase, resulting in poor film appearance. The lower limit of the weight average molecular weight is determined by the heat resistance required of the printing ink and pigment dispersion stability. In addition, the carboxyl group content is 9mm
If it is less than ol/100g, the pigment dispersion stability will be insufficient and the appearance of the film will deteriorate. The upper limit of the carboxyl group content is determined by the degree of film appearance required for the printing ink and the viscosity, but is usually about 50 mmol/100 g.

[0009] The weight average molecular weight here refers to the value measured by gel permeation chromatography as mentioned above, but to explain in more detail, the device is manufactured by Co., Ltd.
It refers to the value measured as a 0.3% tetrahydrofuran solution of nitrocellulose using Tosoh's HLC-8020, two GNHXL columns and one G2000HXL column in series. In addition, carboxyl group content refers to the value measured by the following method, and the amount of carboxyl groups per 100 g of nitrocellulose is mm.
It is expressed in ol number. That is, approximately 1.5 g of sample
Accurately weigh out 0.1 in a 100ml Erlenmeyer flask.
Add about 50 ml of N hydrochloric acid aqueous solution and shake for about 2 hours.
Let stand for a while. The contents are then filtered on a glass filter and washed with ion-exchanged water until the washing solution is completely neutral. The sample and attached water are weighed, placed in a 100 ml beaker together with 50 ml of a 0.05 M aqueous calcium acetate solution, shaken, and left overnight. Take 20 ml of the supernatant liquid from the beaker and titrate it with a 0.01N aqueous sodium hydroxide solution using phenolphthalein as an indicator. A blank test is performed using 20 ml of a 0.05M calcium acetate aqueous solution, and the carboxyl group content is calculated using the following formula.

Carboxyl group content={Amount of sodium hydroxide aqueous solution dropped (ml)-Blank test sodium hydroxide amount dropped (ml)}/20×{Amount of adhering water (g)+50
}/sample weight (g)} The nitrogen content of the nitrocellulose used in the present invention is 10.0 to 12.5% by weight.
, preferably 10.5 to 12.2% by weight, more preferably 10.7 to 11.5% by weight. If the nitrogen content of nitrocellulose is less than 10.0% by weight, it will lack affinity with organic solvents, especially esters and ketones, and if it exceeds 12.5% by weight, it will have poor affinity with organic solvents, especially alcohols. In addition to shortages, safety issues also arise.

An example of a method for preparing nitrocellulose used in the present invention will be described below, but the present invention is not limited to this method. That is, low molecular weight nitrified cotton prepared by nitrifying and depolymerizing cellulose raw materials such as wood pulp, cotton linter pulp, and cotton linters by known methods is mixed with nitrogen oxide, hydrogen peroxide, calcium chlorate, and hypochlorite. It can be prepared by oxidizing with an oxidizing agent such as calcium acid. Another method, as disclosed in Japanese Patent Publication No. 61-45641, is to pre-mix cellulose raw materials such as wood pulp, cotton linter pulp, and cotton linters with nitrogen oxide, hydrogen peroxide, calcium chlorate, and hypochlorite. There is a method of preparing a carboxyl group-containing cellulose raw material prepared by oxidizing it with an oxidizing agent such as calcium chloride, by nitrification and depolymerization using a known method, and nitrocellulose prepared by either method can be used.

[0012] In the present invention, thermoplastic resins can be used, the ratio of nitrocellulose/thermoplastic resin being from 5/95 to 60/40 by weight, preferably 10
/90 to 50/50. If the ratio of nitrocellulose/thermoplastic resin is less than 5/95, only a gravure printing ink composition with insufficient drying properties and heat resistance will be obtained. Moreover, when the ratio exceeds 60/40, the adhesion of the coating film decreases.

Examples of the thermoplastic resin used in the present invention include one or two of polyamide resins, polyurethane resins, alkyd resins, chlorinated rubbers, cyclized rubbers, maleic acid resins, phenolic resins, rosins or derivatives thereof.
Combinations of more than one species can be used. In the present invention,
A plasticizer can be used, and the ratio of the total amount of nitrocellulose and thermoplastic resin to the plasticizer is from 70/30 to 100/0, preferably from 80/20 to 95/5, by weight. If this ratio is less than 70/30, only a gravure printing ink composition with insufficient drying properties and heat resistance will be obtained. Examples of the plasticizer used in the present invention include phthalic acid esters such as dibutyl phthalate, dioctyl phthalate, and dicyclohexyl phthalate; phosphoric acid esters such as tricresyl phosphate and trichloroethyl phthalate; dioctyl adipate, diisobutyl adipate, and acetyl tributyl phthalate; One or a combination of two or more of castor oil and the like can be used.

In the present invention, a pigment is used, and it is essential that the ratio of the total amount of nitrocellulose, thermoplastic resin, and plasticizer to the pigment is from 50/50 to 95/5 on a weight basis. This ratio must be determined depending on the type of pigment used, but if it is less than 50/50, the elongation of the film will decrease, resulting in a gravure printing ink composition with insufficient adhesion to plastic films and metal foils. , 95/5 or more, the tinting power is reduced and only a gravure printing ink composition with an insufficient film appearance is obtained. The pigment used in the present invention may be any pigment that is generally used in printing inks, but examples include inorganic pigments such as titanium oxide and iron oxide, phthalocyanine blue,
There are organic pigments such as Wachan Red, carbon black, etc., and combinations of these and inorganic extender pigments such as barium hydroxide and calcium carbonate.

In the present invention, an organic solvent is essential, and the ratio of the total amount of nitrocellulose, thermoplastic resin, plasticizer, and pigment to the organic solvent is from 20/80 to 5 on a weight basis.
0/50, preferably 25/75 to 35/65. If this ratio is less than 20/80, only a gravure printing ink composition with insufficient drying properties and film appearance will be obtained;
When it exceeds 50, the fluidity of the ink decreases and only a gravure printing ink composition with an insufficient film appearance is obtained. The organic solvent used in the present invention may be any organic solvent that is generally used in gravure printing inks, but examples include esters such as methyl acetate, ethyl acetate, butyl acetate, methyl propionate, and ethyl propionate. Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, alcohols such as methanol, ethanol, isopropanol, ether alcohols such as methyl cellosolve, ethyl cellosolve, aromatics such as toluene, xylene, methylbenzene, etc. There are species or combinations of two or more species.

Further, in the present invention, titanium chelate,
Additives such as crosslinking agents such as polyisocyanates and surfactants can be used. The use of these additives increases the usefulness of the gravure printing ink compositions of the present invention.

[0017]

EXAMPLES The effects of the present invention will be explained in detail below using examples. The test and evaluation methods used in the Examples are shown below. (Testing and evaluation method of gravure printing ink composition) Preparation method of gravure printing ink 200 m
The mixture was weighed into a 1-liter UM-sample bottle, sealed, and shaken for 1 hour using a paint shaker (manufactured by Toyo Seiki Co., Ltd.) to obtain a uniform vehicle. Next, a portion of this vehicle and the test pigment were mixed in a 200 m
Weigh into a lUM-sample bottle, add 100 g of glass beads with a diameter of 2 to 3 mm, and seal it. After shaking this in a paint shaker for 2 hours, it is filtered through a bleached cloth to prepare a gravure printing ink composition for testing. Test method for pigment dispersion stability The above-mentioned gravure printing ink composition
The mixture was placed in a 0 mm test tube and allowed to stand at room temperature for one week, and the presence or absence of separation of the pigment was determined.

○: No separation is observed △: Slight floating of varnish is observed on the surface ×: Sedimentation of pigment is observed Drying test method The above-mentioned gravure printing ink was applied on a glass plate with a smooth surface. Approximately 1 g of the composition is dropped, a film is formed using a 2 mil film applicator (manufactured by Toyo Seiki Co., Ltd.), and the surface is lightly touched with a fingertip to measure the time until the tackiness disappears. however,
Test temperature is 20±0.5℃, test humidity is 65±3%RH
shall be. (Testing and evaluation method of gravure printing ink composition film) Preparation method of gravure printing ink composition film Surface treated polypropylene film (Pylene P2161; Toyobo Co., Ltd.)
Approximately 1 g of the gravure printing ink composition described above is dropped onto the gravure printing ink composition, and a film is formed using a 2 mil film applicator (described above), and dried for approximately 10 to 20 seconds with a hair dryer. Thereafter, it is cured at room temperature for one day or more and then tested. Test method for adhesion A cellophane adhesive tape (No. 405; manufactured by Nichiban Co., Ltd.) is attached to the film of the gravure printing ink composition prepared by the method described above, and rubbed strongly five times with the tip of the thumb. Then, hold the sample surface and quickly peel off the adhesive tape to observe how the film peels off.

◎: No peeling at all ○: Peeling area is 20% or less △: Peeling area is 20-50% ×: Peeling area is 50% or more XX: Complete peeling Heat resistance test method Prepared by the method described above Layer the gravure printing ink film and aluminum foil (manufactured by Toyo Aluminum Co., Ltd.) and heat seal tester (manufactured by Toyo Seiki Co., Ltd.) at 100°C x 1 kg.
A heat seal test is conducted under the condition of /cm2 x 2 seconds.

◎: No sticky feeling at all ○: Slight sticky feeling, but easily peeled off, no ink transfer at all △: Sticky feeling, ink transfer observed after peeling ×:
Testing and judging the appearance of a film that is completely adhesive and cannot be peeled off.The appearance of the film is measured by measuring the gloss and visually observing the film. Gloss measurement The gravure printing ink film prepared by the method described above was fixed on a glass plate with a smooth surface, and a variable angle gloss meter (Suga Test Instruments) was used.
60/60 specular gloss is measured with a 60/60 specular gloss. Visual Observation In the method for preparing the gravure printing ink film described above, only the treated polypropylene film was tested using hiding power test paper (JIS
K5400) was used to prepare a gravure printing ink film for evaluation, and the evaluation was performed according to the following criteria. ◎: No color unevenness and good smoothness ○: Slight color unevenness or poor smoothness △: Color unevenness and/or coating streaks ×: Color unevenness and/or coating streaks are noticeable

[0021]

[Reference Example 1] Nitrocellulose HI manufactured by Asahi Kasei Industries, Ltd.
G1/16 (containing 30% isopropyl alcohol) 1
Pour into 0 times the volume of water, stir well, and then dehydrate using a centrifuge. After repeating this operation 5 times, 5 times the amount of 24
% aqueous sodium hydroxide solution was added and heated at 50° C. for 60 minutes. This reaction solution was filtered, and nitrocellulose was added to
After washing once with 0 times the amount of water, add 5 times the amount of water and adjust the pH.
= 9, added 4 times the amount of 12% sodium hypochlorite, and heated at 50° C. for 60 minutes. The obtained nitrocellulose was sampled as Sample No. Set to 1. As a result of measuring the weight average molecular weight and carboxyl group content of this nitrocellulose by the above-mentioned method, the weight average molecular weight was 6,
800, carboxyl group content is 18.6 mmol/1
It was 00g.

[0022]

[Reference Example 2] Reference Example 1 except that the amount of the 24% sodium hydroxide aqueous solution was increased to 3/4 times the amount and the amount of the 12% sodium hypochlorite aqueous solution was increased to 1.5 times the amount of Reference Example 1.
It was tested in the same way. The obtained nitrocellulose was
ple No. Set it to 2. When this nitrocellulose was measured, it had a weight average molecular weight of 15,500 and a carboxyl group content of 9.6 mmol/100 g.

[0023]

[Comparative Reference Example 1] Nitrocellulose HIG1/16 manufactured by Asahi Kasei Kogyo Co., Ltd. (contains 30% isopropyl alcohol)
was poured into 10 times the volume of water, stirred thoroughly, and then dehydrated using a centrifugal separation system. After repeating this 5 times, 5 times the amount of water was added and heated at 150° C. for 30 minutes in an autoclave. The obtained nitrocellulose was sampled as Sample No. 3
shall be. When this nitrocellulose was measured, the weight average molecular weight was 25,300, and the carboxyl group content was 0.
It was 2 mmol/100g. Furthermore, when the average degree of polymerization of this nitrocellulose was measured by the intrinsic viscosity method, it was 28
Met.

[0024]

[Comparative Reference Example 2] Tests were carried out in the same manner as in Comparative Reference Example 1, except that only the autoclave treatment time was changed to 90 minutes. The obtained nitrocellulose was
Ample No. Set it to 4. When this nitrocellulose was measured, it had a weight average molecular weight of 17,000 and a carboxyl group content of 0.1 mmol/100 g. The average degree of polymerization of this nitrocellulose was 20 when measured by intrinsic viscosity method.

[0025]

[Comparative Reference Example 3] In Reference Example 1, HIG1/16 was replaced with HIG1/16 as the nitrocellulose.
The test was conducted in the same manner as in Reference Example 1, except that IG1/8 (containing 30% isopropyl alcohol) was used. The obtained nitrocellulose was sampled as Sample No. 5. When this nitrocellulose was measured, the weight average molecular weight was 21,200, and the carboxyl group content was 9.6 mmol.
/100g.

[0026]

[Comparative Reference Example 4] A test was carried out in the same manner as in Reference Example 2, except that only the amount of the 12% sodium hypochlorite aqueous solution was changed to 1.2 times the amount. The obtained nitrocellulose was sampled as Sample No. Set it to 6. When this nitrocellulose was measured, the weight average molecular weight was 17,900.
, carboxyl group content was 8.2 mmol/100 g.

[0027]

[Comparative Reference Examples 5 to 7] The weight average molecular weight and carboxyl group content of commercially available nitrocellulose SL-1, HIG1/16, and HIK1/8 manufactured by Asahi Kasei Industries, Ltd. were measured. The results are as follows. Nitrocellulose weight average molecular weight
Carboxyl group content SL-1
24,000 0.
1mmol/100g HIG1/16
36,000 0.1 〃HI
K1/8 45,000
5.3 〃

[0028]

[Examples 1 and 2 and Comparative Examples 1 to 7] Nitrocellulose Sample No. prepared in Reference Examples 1 and 2. 1,N
o. 2. Nitrocellulose Sample No. 2 prepared in Comparative Reference Examples 1 to 4. 3 to 6 and comparative reference examples 5 to 7
Using commercially available nitrocellulose, a gravure printing ink composition having the composition shown below was prepared by the method described above, and tested by the method described above. The test results are shown in Tables 1 and 2. (Composition of printing ink) Nitrocellulose (contains 30% isopropyl alcohol) 15.0% by weight Polyamide resin a)

18.0 Dibutyl phthalate b)

0.8 Titanium oxide c)

12.1 Organic solvent d)

54.1 Total

100.0
Weight% a) Versamide 754; Henkel Hakusui Co., Ltd.
b) Made by Daihachi Kagaku Co., Ltd. c) Thai Coupe R820; Made by Ishihara Sangyo Co., Ltd. d) Organic solvent composition: Ethyl acetate/isopropyl alcohol/toluene = 43/24/33 (weight ratio)

[0029]

[Examples 3 and 4] In Example 1, Sample No. 2 was used, and the total amount of nitrocellulose/polyamide resin remained the same, except that only the ratio was changed to 55/45 and 10/90 by weight.
It was carried out in the same manner as in Example 1. The test results are shown in Tables 1 and 2.

[0030]

[Comparative Examples 8 and 9] In Example 1, Sample No. 1 was used as the nitrocellulose. 2, the weight ratio of nitrocellulose/polyamide resin is 65/35,
The same procedure as in Example 1 was carried out except that the temperature was changed to 3/97. The test results are shown in Tables 1 and 2.

[0031]

[Example 5] In Example 1, Sample No. 2, the weight ratio of (nitrocellulose + polyamide resin)/plasticizer alone is 75.
The same procedure as in Example 1 was carried out except that the temperature was changed to /25. The test results are shown in Tables 1 and 2.

[0032]

Comparative Example 10 The same procedure as in Example 5 was carried out except that only the ratio of (nitrocellulose + polyamide resin)/dibutyl phthalate was changed to 65/35 by weight. The test results are shown in Tables 1 and 2.

[0033]

[Example 6] In Example 1, Sample No. The following procedure was carried out in the same manner as in Example 1 except that only the ratio of (nitrocellulose + polyamide resin + dibutyl phthalate)/titanium oxide was changed to 55/45 by weight. The test results are shown in Tables 1 and 2.

[0034]

[Comparative Example 11] In Example 1, Sample No. Example 1 was carried out in the same manner as in Example 1, except that only the ratio of (nitrocellulose + polyamide resin + dibutyl phthalate)/titanium oxide was changed to 40/60 by weight. The test results are shown in Tables 1 and 2.

[0035]

[Example 7] As nitrocellulose, Sample
No. A gravure printing ink composition having the composition shown below was prepared by the above-mentioned method using No. 2, and was tested using the above-mentioned test method. The results are shown in Tables 1 and 2. (Composition of printing ink) Nitrocellulose (contains 30% isopropyl alcohol) 19.7% by weight Polyamide resin a)

23.6 Dibutyl phthalate b
)
1.1 Carbon black
c)
3.0 〃Organic solvent d)

52.6 〃
total
1
00.0% by weight a) Versamide 754; manufactured by Henkel Hakusui Co., Ltd. b) manufactured by Daihachi Chemical Co., Ltd. c) MA-100; manufactured by Mitsubishi Chemical Corporation d) Organic solvent composition; ethyl acetate/isopropyl alcohol/ Toluene = 43/24/33 (weight ratio)

[0036]

[Comparative Example 12] The following procedure was carried out in the same manner as in Example 7 except that only the ratio of (nitrocellulose + polyamide resin + dibutyl phthalate)/carbon black was changed to 97/3 by weight. The test results are shown in Tables 1 and 2.

[0037]

[Example 8] In Example 1, Sample No. 1 was used as the nitrocellulose. 66 g of the mixed organic solvent used in Example 1 was added to 100 g of the gravure printing ink composition prepared using Example 2, and the mixture was shaken for 30 minutes with a paint shaker to prepare a gravure printing ink composition. It was carried out in the same manner as in 1. The results are shown in Tables 1 and 2.

[0038]

Comparative Example 13 The same procedure as in Example 8 was carried out except that only the amount of mixed organic solvent added was changed to 176 g. The results are shown in Tables 1 and 2.

[0039]

[Comparative Example 14] In Example 1, Sample No. 1 was used as the nitrocellulose. Example 1 was carried out in the same manner as in Example 1, except that Example 2 was used and the composition was changed as shown below. Table 1 shows the results.
, 2. (Composition of printing ink) Nitrocellulose (contains 30% isopropyl alcohol) 19.9% by weight Polyamide resin a)

23.9 Dibutyl phthalate b
)
1.1 Titanium oxide c)

16.1 Organic solvent d)

39.0 Total
10
0.0% by weight a) Versamide 754; made by Henkel Hakusui Co., Ltd. b) Made by Daihachi Kagaku Co., Ltd. c) Thai Coupe R820; made by Ishihara Sangyo Co., Ltd. d) Organic solvent composition: Ethyl acetate/isopropyl alcohol/toluene = 43/24/33 (weight ratio)

[0040]

[Table 1]

[0041]

[Table 2]

[0042]

Effects of the Invention The gravure printing ink composition of the present invention has excellent pigment dispersion stability, drying properties, adhesion to plastic films, heat resistance, and good film appearance. Therefore, it can be used for gravure printing of foods, medicines, clothing, etc., and the printing effect can be dramatically improved.

Claims (1)

[Claims] Claim 1: (a) Weight average molecular weight is 20.0
00 or less, and the carboxyl group content is 9 mmol
/100g or more of nitrocellulose (b), thermoplastic resin (c), plasticizer (d), pigment (e), and organic solvent, and the ratio of each component is a/b on a weight basis.
from 5/95 to 60/40 (
a+b)/c is 70/30 to 1
00/0(a+b+c)/d is 50/50
to 95/5(a+b+c+d)/e is 20/80
A gravure printing ink composition characterized in that it is 50/50 from