KR20110002457A

KR20110002457A - Printing ink composition for seamless can

Info

Publication number: KR20110002457A
Application number: KR20107018057A
Authority: KR
Inventors: 신이치로 바바; 타쿠야 이와모토; 코우키찌 우시로다
Original assignee: 마츠이 가가쿠 가부시키가이샤
Priority date: 2008-04-02
Filing date: 2009-03-27
Publication date: 2011-01-07
Also published as: JP4897733B2; CN101981144B; RU2010144777A; CN101981144A; RU2496815C2; JP2009249435A; WO2009123053A1; KR101532809B1; MY157148A

Abstract

The present invention is a seamless printing ink composition for cans that has excellent printability and coating stability such as excellent transferability and mechanical stability, and imparts good film properties. The fatty acid modification amount is 35 to 65 mass%, and the hydroxyl value is 60 to 200 mgKOH /. Printing ink composition for seamless cans containing the polybasic acid addition fatty acid modified polyester (A) of g and styrene conversion weight average molecular weights of the acid value of 10-60 mgKOH / g, and the method of coating a seamless can using the ink To provide.

Description

Print ink composition for seamless cans {PRINTING INK COMPOSITION FOR SEAMLESS CAN}

TECHNICAL FIELD The present invention relates to a printing ink composition for seamless cans, and has a printability and coating stability such as excellent transferability and mechanical stability, and provides a seamless ink printing ink composition for ink and its ink. It relates to a method of coating a seamless can using

Seamless cans (seamless can) is widely used as packaging containers for juice drinks, soft drinks, carbonated drinks, alcoholic beverages such as beer, food. The outer circumferential surface of the seamless can is printed and coated on a metal can which is usually molded for the purpose of decoration, corrosion prevention, and the like, which increases product value.

In addition, the surface of seamless cans may be wet-coated with overcoat varnish after silver or white coating for decorative purposes. Thus, the inks used in seamless cans are often required to adhere to the underlying substrates.

However, in conventional seamless cans, wax is used when a metal material such as an aluminum plate or an iron plate is drilled in a cup form, and ironed thereon to make the fuselage part normal. For this reason, a washing | cleaning process is needed after shaping | molding, and a large amount of water is used.

In recent years, as a can container excellent in the global environment which does not require this washing process, a seamless can has been developed using a polyester coated steel sheet laminated with polyester on an iron plate or an aluminum plate, and printing on this new seamless can. Coating methods have been developed.

However, especially in printing coating systems using aqueous overprint varnishes in seamless cans using polyester coated steel sheets, metal printing inks containing conventional fatty acid-modified polyesters have good printability and good film properties. Was difficult to achieve.

That is, in a seamless can printing system using a polyester coated steel sheet as a metal substrate, ink agglomeration occurs during wet coating and baking of an aqueous overprint varnish after printing, resulting in uneven concentration. Phenomenon occurs.

For example, as a metal printing ink which has aptitude with respect to the varnish for aqueous overprint, as an example of obtaining compatibility with an aqueous overprint varnish with a diluent component, Patent Document 1, Patent Document 2, Patent Document 3 , Patent document 4, patent document 5, and patent document 6 are mentioned.

However, these are obtained by using a hydrophilic diluent component to obtain wettability with an aqueous overprint varnish, while inks using these diluents generate a large amount of mist during printing, causing contamination of the print coating can. Worsen the environment.

Moreover, patent document 7, patent document 8, etc. are mentioned as an example of obtaining affinity with respect to an aqueous varnish according to a resin component.

In Patent Document 7, the monohydric alcohol having 6 to 26 carbon atoms and the polycarboxylic anhydride are first made to react, and then reacted with the polyhydric alcohol to leave many hydroxyl groups, thereby making printability to the aqueous overprint varnish, improving misting).

In patent document 8, by using a monovalent branched saturated carboxylic acid, polyhydric alcohol, and polycarboxylic acid, many hydroxyl groups remain, making printability with respect to an aqueous overprint varnish, and improving misting. In these methods, the wettability to the aqueous overprint varnish is improved, but it is impossible to sufficiently stabilize the dispersion state of the pigment in the ink, and aggregation occurs depending on the use conditions.

Patent Document 1: Japanese Patent Application Laid-Open No. 62-295974

Patent Document 2: Japanese Patent Application Laid-Open No. 62-295975

Patent Document 3: Japanese Patent Application Laid-Open No. 62-295976

Patent Document 4: Japanese Patent Application Laid-Open No. 64-060670

Patent Document 5: Japanese Patent Application Laid-Open No. 03-273068

Patent Document 6: Japanese Patent Application Laid-Open No. 04-106166

Patent Document 7: Japanese Patent Application Laid-Open No. 02-127484

Patent Document 8: Japanese Patent Application Laid-Open No. 02-127485

MEANS TO SOLVE THE PROBLEM In the printing ink composition comprised mainly by a pigment, resin, and a solvent, the polybasic acid addition fatty acid modified polyester obtained by adding the intra-molecular anhydride of polybasic acid to the terminal of a fatty acid modified polyester. It was found that the terminal carboxyl group acts as an anchoring agent for pigments, improves pigment dispersion stability in ink, improves wettability with the underlying substrate, and improves adhesion to the substrate.

The present invention provides a seamless can printing system using a metal substrate such as a polyester coated steel sheet, which has excellent printability such as excellent transferability and mechanical stability and excellent suitability for overprint varnish wet coating, and provides good film properties. An object of the present invention is to provide a printing ink composition for a seamless can and a method of coating the seamless can.

That is, in the present invention, the weight average molecular weight in terms of styrene in terms of the amount of fatty acid modification is 35 to 65 mass%, the hydroxyl value is 60 to 200 mgKOH / g, and the acid value is 10 to 60 mgKOH / g. The printing ink composition for seamless cans containing the polybasic acid addition fatty acid modified polyester (A) of -30000.

As a polybasic acid addition fatty acid modified polyester (A), the polybasic acid addition fatty acid modified polyester obtained by adding the acid anhydride of a polybasic acid to the fatty acid modified polyester (B) whose acid value is less than 10 mgKOH / g acts as an anchor of a pigment. It is preferable at the point that the dispersion stability of a pigment is favorable.

The polybasic acid addition fatty acid modified poly (A) is a polybasic acid addition fatty acid modified poly (A) obtained by reacting an acid anhydride of a polybasic acid with a fatty acid modified polyester (B) having an acid value of less than 10 mgKOH / g at 100 ° C to 200 ° C. An ester is preferable at the point which can control the target acid value without substantially increasing the molecular weight of resin powder.

The ink composition of this invention contains a pigment component and a solvent component normally.

The present invention also forms a can body by drilling a metal substrate, and forms a print layer on the surface of the can body by the seamless can printing ink composition of the present invention, and applies a thermosetting overprint varnish on the print layer. Next, the present invention relates to a method for coating a seamless can that is heat cured.

As a metal base material, a polyester coating steel plate is mentioned suitably.

According to the present invention, a printing ink composition capable of suppressing agglomeration of ink even when an aqueous overprint varnish is used, and providing a stable wet coating aptitude and good film properties in a seamless can printing coating system, and an ink composition. The coating method of the metal base material by this can be provided.

The polybasic acid addition fatty acid modified polyester (A) used for this invention can be manufactured, for example by the following method.

First, fatty acid modified polyester (B) which uses a fatty acid or vegetable oil as a raw material is synthesize | combined using a well-known fatty acid method or transesterification method. By adding the intramolecular acid anhydride of a polybasic acid to the hydroxyl terminal of this raw material fatty acid modified polyester (B), a carboxyl group is introduce | transduced into the terminal of fatty acid modified polyester, and polybasic acid addition fatty acid modified polyester (A) is manufactured.

Next, a raw material fatty acid modified polyester (B) and a polybasic acid addition fatty acid modified polyester (A) are demonstrated concretely.

The raw material fatty acid modified polyester (B) can be produced, for example, by reacting a polyhydric alcohol with a polybasic acid and a fatty acid. It can also be produced by transesterifying a fatty acid ester to a polyester obtained by reacting a polyhydric alcohol with a polybasic acid.

As a polyhydric alcohol, For example, Dihydric alcohol, such as ethylene glycol, diethylene glycol, triethylene glycol, 1, 6- hexanediol, bisphenol A, hydrogenated bisphenol A; Trihydric alcohols such as glycerin, trimetholethane, and trimetholpropane; Tetrahydric or more alcohols such as pentaerythritol and dipentaerythritol can be used.

As a polybasic acid used for manufacture of a raw material fatty acid modified polyester (B), for example, anhydrous phthalic anhydride, isophthalic acid, telephthalic acid, succinic anhydride, adipic acid, tetrahydro phthalic anhydride, hexahydro phthalic anhydride, anhydrous Dibasic acids such as maleic acid; Tribasic acids, such as trimellitic anhydride and methylcyclohexene tricarboxylic anhydride, etc. can be used.

Denatured fatty acids include decanoic acid, lauric acid, myristic acid, octanoic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, and ricinoleic acid. ), Natural or synthetic fatty acids such as linolenic acid, eleostearic acid; Vegetable oil, such as a cow's milk, castor oil, palm oil, linseed oil, safflower oil, dehydrated castor oil, tall oil, and rice bran oil, etc. are mentioned. These fatty acids may be used independently and may use 2 or more types together. Moreover, monobasic acids other than these fatty acids, for example, benzoic acid, p-t-butyl benzoic acid, abienic acid, etc. can also be used together.

Fatty acid is added so that fatty acid modification amount in polybasic acid addition fatty acid modified polyester (A) may be 35-65 mass%, Preferably it is 40-60 mass%.

When the amount of fatty acid modification is less than 35% by mass, the transferability and mechanical stability of the resulting ink composition are lowered. If it exceeds 65% by mass, mechanical properties such as ink film hardness are lowered, and therefore, it is necessary to prepare other additives such as a curing agent, particularly an amino resin curing agent.

The raw material fatty acid-modified polyester (B) is blended so that the total hydroxyl group equivalent of the polyhydric alcohol is greater than the total acid equivalent (total carboxyl equivalent) of the monobasic acid and the polybasic acid containing the fatty acid, and the esterification reaction is carried out. do.

The amount of the polyhydric alcohol, the polybasic acid and the fatty acid is such that the hydroxyl value of the obtained raw fatty acid-modified polyester (B) is 70 to 250 mgKOH / g, and the weight average molecular weight in terms of styrene is 3000 to 30000.

When the hydroxyl value of the raw material fatty acid-modified polyester (B) is greater than 250 mgKOH / g, the hydroxyl group of the polybasic acid addition fatty acid-modified polyester (A) becomes too large, so that the adhesiveness to the polyester-coated steel sheet deteriorates, while 70 mgKOH Below / g, the wettability with the aqueous overprint varnish becomes insufficient, and wet coating of the aqueous overprint varnish causes agglomeration in the printing ink.

The weight average molecular weight in terms of styrene is preferably 3000 to 30000, more preferably 6000 to 16000. If the molecular weight is too small, the cohesive force of the target polybasic acid addition fatty acid-modified polyester (A) is too small, and the strength of the ink film is insufficient. On the other hand, when the molecular weight is too large, the viscosity of the polybasic acid addition fatty acid-modified polyester (A) is too high to prepare the ink in a predetermined shape.

Moreover, in this ester reaction, since there are many hydroxyl groups (polyhydric alcohol), the acid value of the raw material fatty acid modified polyester (B) obtained is small, and is less than 10 mgKOH / g. When this acid value uses less than 10 mgKOH / g fatty acid modified polyester (B) as it is in an ink composition, even if the hydroxyl value is 70-250 mgKOH / g, even if the weight average molecular weight in terms of styrene is 3000-30000, the aqueous overprint varnish Although wettability with is good, the dispersion stability of a pigment is inadequate and the objective of this invention cannot be achieved.

On the other hand, when the raw material fatty acid-modified polyester is produced with an excess of acid (polybasic acid and fatty acid), the acid value is increased, but the hydroxyl value is smaller than the above range, and even if the polybasic acid is reacted in the next step, Polybasic acid addition fatty acid modified polyester cannot be obtained.

It is also contemplated to control the acid value by stopping the esterification in the middle, but in practice it is difficult to control the reaction for the control of the acid value and the hydroxyl value.

A polybasic acid addition fatty acid modified polyester (A) can be manufactured by adding the intramolecular acid anhydride of polybasic acid to the terminal hydroxyl group of the said raw material fatty acid modified polyester (B).

In the case of the polybasic acid to be reacted and not the acidic anhydride in the molecule, the polybasic acid (the carboxyl group is all an acid of the free carboxyl group), the reaction of the raw fatty acid-modified polyester (B) with the terminal hydroxyl group is not an addition reaction but an esterification reaction accompanied with dehydration. It is not preferable because polybasic acids connect terminal hydroxyl groups of fatty acid-modified polyester (B) with each other, molecular weight increases rapidly, and introduction of a carboxyl group becomes difficult. On the other hand, when an intramolecular acid anhydride is used as the polybasic acid to be reacted, the reaction takes place at a lower temperature, so that the reaction with the terminal hydroxyl group of the raw material fatty acid-modified polyester (B) becomes only an addition reaction, so that the carboxyl group is easily increased without almost increasing the molecular weight. It is preferable at the point which can introduce easily.

As an intramolecular acid anhydride of polybasic acid, For example, dibasic acid anhydrides, such as a phthalic anhydride, a succinic anhydride, tetrahydro phthalic anhydride, a hexahydro phthalic anhydride, maleic anhydride; Tribasic acid anhydrides, such as trimellitic anhydride and methylcyclohexene tricarboxylic anhydride, etc. can be used. By adding the intramolecular acid anhydride, they hardly change the weight average molecular weight, and the acid value and the hydroxyl value, in particular, can adjust the acid value. Particularly preferred intramolecular acid anhydrides of polybasic acids are anhydrous trimellitic acid and anhydrous phthalic acid in view of good solubility in resins and ink misting.

It is preferable to perform reaction at 100 degreeC-200 degreeC. When the reaction temperature is lower than 100 ° C., the solubility of the polybasic acid in the molecular acid anhydride in the raw material fatty acid-modified polyester (B) is small, and the addition reaction with the terminal hydroxyl group of the raw material fatty acid-modified polyester (B) is less likely to occur. Some of the acid molecules in the molecule remain as solids.

When the reaction temperature exceeds 200 ° C, the carboxyl group produced by the addition reaction of the intramolecular acid anhydride of the polybasic acid or other carboxyl groups contained in the trivalent or higher intramolecular acid anhydride is again esterified with the hydroxyl group and the hydroxyl group of the raw material fatty acid-modified polyester (B). Reaction may occur, and the acid value and hydroxyl value of the polybasic acid addition fatty acid modified polyester obtained may decrease, and the target acid value and hydroxyl value may not be obtained, or the molecular weight may rise too much and gelatinization may occur.

The hydroxyl value of a polybasic acid addition fatty acid modified polyester (A) is 60-200 mgKOH / g, Preferably it is 80-180 mgKOH / g. When the hydroxyl value is larger than 200 mgKOH / g, the hydroxyl group becomes too large, so that the adhesiveness to the polyester coated steel sheet is deteriorated, while when the hydroxyl value is less than 60 mgKOH / g, the wettability with the aqueous overprint varnish becomes insufficient, and the aqueous overprint Wet coating of varnish causes coagulation in the printing ink.

The acid value of the polybasic acid addition fatty acid modified polyester (A) is 10-60 mgKOH / g, Preferably it is 15-40 mgKOH / g. When the acid value is too small, the dispersion stability of the pigment becomes insufficient, and in particular, when wet coating of the aqueous overprint varnish, the pigment in the ink may cause aggregation and become a problem depending on the kind thereof. If the acid value is too high, the polarity of the resin is too high, so the fluidity of the ink decreases and the transferability deteriorates.

The styrene reduced weight average molecular weight of polybasic acid addition fatty acid modified polyester (A) is 3000-30000, Preferably it is 6000-16000. If the molecular weight is too small, the cohesive force of the polybasic acid addition fatty acid-modified polyester (A) is too small, and the strength of the ink film is insufficient. On the other hand, when molecular weight is too big | large, the viscosity of polybasic acid addition fatty acid modified polyester (A) is too high, and ink cannot be prepared in a predetermined shape.

The polybasic acid addition fatty acid modified polyester (A) of this invention can be made into the seamless printing ink composition for cans by mixing with a pigment component and a solvent component, for example.

The printing ink composition for seamless cans of this invention is comprised by polybasic acid addition fatty acid modified polyester (A), and other components, for example, a pigment powder and a solvent component.

As a pigment, if it has heat resistance, light resistance, and retort treatment property, what is conventionally used for metal printing ink can be used without a restriction | limiting. For example, inorganic pigments, such as titanium oxide, a silica, and carbon black; Organic pigments such as phthalocyanine blue, watching red, quinacridone, diketopyrrolopyrrole, and quinophthalone.

Although the compounding quantity of a pigment changes with kinds and an objective, what is necessary is just to select within the range of 10-60 mass% in an ink composition normally.

A solvent can also use the well-known thing used for a metal printing ink. For example, aliphatic hydrocarbon, alicyclic hydrocarbon, aromatic hydrocarbons, such as alkylbenzene, higher alcohol, etc. of boiling point range 230 degreeC-about 400 degreeC are mentioned.

Moreover, it is also possible to use together the other resin normally used for a metal printing ink. As resin which can be used together, a petroleum resin, an epoxy resin, ketone resin, rosin modified maleic acid resin, an amino resin, benzoguanamine resin, oil-free polyester, rosin phenol resin etc. are mentioned, for example. Moreover, it is also possible to add usual additives, such as a lubricating agent, a hardening catalyst, and a dispersing agent, as needed.

The viscosity of the ink composition of this invention can be suitably selected by adjusting a solvent amount etc. according to a printing system. For example, for printing offset plates, for flat plates without water, adjusted in the range of tack value (JIS K5701-1) 4 to 12 and flow value (JIS K 5701-1) 27 to 47. It is preferable to adjust to higher viscosity than general ink, and it is preferable to set it as the adhesion value 6-15 and the flow value 25-45 range normally.

The ink composition of the present invention can be prepared according to a conventional method using a roll mill, a ball mill, a bead mill, or the like.

The seamless printing ink composition for cans of the present invention can be used in a dry offset method using a resin fan plate, which is a conventional printing method, or in an offset using a flat plate without water. Although the film thickness of ink is arbitrary, it is good to set it as the range of 0.5-6 micrometers.

The present invention also forms a can body by drilling a metal substrate, forms a printing layer on the surface of the can body by the seamless can printing ink composition of the present invention, and applies a thermosetting overprint varnish on the print layer. The present invention also relates to a method for coating a seamless can that is heat cured.

The seamless can to which the ink composition of this invention is apply | coated is what penetrated the metal base material in can shape, As a metal base material, the coating board which laminated | stacked the aluminum plate, the iron plate, these polyester films, etc. is used. In addition, chemical conversion treatment, plating treatment, size coating, white coating, silver coating or the like may be performed on these substrates.

The ink composition thus prepared can be used on the outer circumferential surface of the seamless can without limitation by the conventionally known printing method as described above.

In this invention, an effect is especially exhibited when applied to a polyester coating base material as a metal base material.

Subsequently, without printing the printed ink layer, the varnish for thermosetting overprint is applied and finally plastically cured to complete the printing of the seamless can. The firing conditions are not particularly limited, but in general, heating for 20 seconds to 10 minutes is preferable at a temperature of 160 ° C to 260 ° C.

There is no restriction | limiting in particular as a varnish for thermosetting overprint, A conventionally well-known thing can be used, Specifically, For example, A solvent type or an aqueous polyester melamine type, Polyester epoxy epoxy melamine type, Polyester acrylic melamine System varnish etc. can be illustrated.

Example

Next, the present invention will be described with reference to Production Examples, Examples, and Comparative Examples, but the present invention is not limited only to these Examples. In addition, below, both "part" and "%" are a "mass part" and the "mass%."

Preparation Example 1 (Preparation of Raw Fatty Acid Modified Polyester (B-1))

29.0 parts of phthalic anhydride. 18.0 parts of trimetholpropane, 18.0 parts of pentaerythritol, 42.0 parts of palm oil fatty acid, and 10.0 parts of cisylol were placed in a four-necked flask equipped with a stirrer, and the acid value was 2 at a temperature of 220 ° C. to 230 ° C. while returning cysilol under a nitrogen stream. The esterification reaction was carried out until it became mgKOH / g. After the reaction, the chisilol was distilled at 240 ° C. to obtain a starting fatty acid-modified polyester (B-1).

The fatty acid modification amount (%), acid value (mgKOH / g), and hydroxyl value (mgKOH / g) of this raw material fatty acid modified polyester are shown in Table 1.

Production Examples 2 to 12 (Production of Raw Fatty Acid Modified Polyester (B-2) to (B-12))

Raw material fatty acid-modified polyesters (B-2) to (B-12) were prepared under the same conditions as those for preparation of (B-1) using the intramolecular acid anhydride, polyhydric alcohol and fatty acids of the polybasic acids shown in Table 1.

Table 1 shows the fatty acid modification amount (%), acid value (mgKOH / g) and hydroxyl value (mgKOH / g) of these raw fatty acid-modified polyesters.

Production Example One 2 3 4 5 6 Reactive
Polybasic acid (part)
Phthalic anhydride
Polyhydric alcohol (part)
Trimethyrol Propane
Pentaerythritol
Fatty acid (part)
Palm oil fatty acid
Palmitic acid
Dehydration amount (part)
Total (part)

29.0

18.0
18.0

42.0
-
-7.0
100.0

21.1

28.3

58.0
-
-7.4
100.0

26.9

33.1

47.3
-
-7.3
100.0

26.7

21.0
12.3

47.3
-
-7.3
100.0

32.8

5.0
27.7

42.0
-
-7.5
100.0

29.6

17.5
17.5

-
42.0
-6.6
100.0 Fatty Acid Modified Polyester (B)
Fatty acid denaturation amount (%)
Acid value (mgKOH / g)
Hydroxyl value (mgKOH / g)
sign
42.0
2
196
B-1
58.0
2
158
B-2
47.3
2
88
B-3
47.3
2
144
B-4
42.0
2
164
B-5
42.0
2
194
B-6
Production Example 7 8 9 10 11 12 Reactive
Polybasic acid (part)
Phthalic anhydride
Polyhydric alcohol (part)
Trimethyrol Propane
Pentaerythritol
Fatty acid (part)
Palm oil fatty acid
Palmitic acid
Dehydration amount (part)
Total (part)

37.7

19.0
19.0

31.5
-
-7.2
100.0

12.3

-
24.7

70.3
-
-7.3
100.0

24.8

19.9
19.9

42.0
-
-6.6
100.0

32.0

33.4
-

42.0
-
-7.4
100.0

34.1

-
31.6

42.0
-
-7.7
100.0

12.6

15.7
15.7

63.0
-
-7.0
100.0 Fatty Acid Modified Polyester (B)
Fatty acid denaturation amount (%)
Acid value (mgKOH / g)
Hydroxyl value (mgKOH / g)
sign
31.5
2
186
B-7
70.3
2
133
B-8
42.0
2
281
B-9
42.0
2
69
B-10
42.0
2
155
B-11
63.0
2
198
B-12

Production Example 13 (Preparation of Polybasic Acid-Added Fatty Acid Modified Polyester (A-1))

95.2 parts of raw material fatty acid-modified polyester (B-1) were placed in a four-necked flask, and stirred at 170 ° C. with stirring, 4.8 parts of trimellitic anhydride were added for 10 minutes, and the amount of fatty acid modification was 40.0% and the hydroxyl value was 172 mgKOH /. g, acid value 27 mgKOH / g. A transparent liquid polybasic acid addition fatty acid modified polyester (A-1) having a weight average molecular weight of 6000 in terms of styrene was prepared.

Production Example 14 (Preparation of Polybasic Acid-Added Fatty Acid Modified Polyester (A-2))

91.4 parts of the raw material fatty acid-modified polyester (B-1) was placed in a four-necked flask, and stirred at 170 ° C., at an additional temperature of 8.6 parts of trimellitic anhydride for 10 minutes, and the amount of fatty acid modification was 38.4% and the hydroxyl value was 153 mgKOH / g, acid value 50 mgKOH / g. A transparent liquid polybasic acid addition fatty acid modified polyester (A-2) having a weight average molecular weight of 6200 in terms of styrene was prepared.

Production Example 15 (Preparation of Polybasic Acid-Added Fatty Acid Modified Polyester (A-3))

94.8 parts of the raw material fatty acid-modified polyester (B-2) was placed in a four-necked flask, and stirred at 170 ° C. with stirring, 5.2 parts of trimellitic anhydride was added for 10 minutes, and the amount of fatty acid modification was 55.0% and the hydroxyl value was 135 mgKOH /. g, acid value 30 mgKOH / g. A transparent liquid polybasic acid addition fatty acid modified polyester (A-3) having a weight average molecular weight of 6000 in terms of styrene was prepared.

Production Example 16 (Production of Polybasic Acid-Added Fatty Acid Modified Polyester (A-4))

95.2 parts of raw material fatty acid-modified polyester (B-3) were placed in a four-necked flask, and stirred at 170 ° C. with stirring, 4.8 parts of trimellitic anhydride were added for 10 minutes, and the amount of fatty acid modification was 45.0% and the hydroxyl value was 70 mgKOH /. g, acid value 26 mgKOH / g. A transparent liquid polybasic acid addition fatty acid modified polyester (A-4) having a weight average molecular weight of 6500 in terms of styrene was prepared.

Production Example 17 (Preparation of Polybasic Acid-Added Fatty Acid Modified Polyester (A-5))

95.2 parts of raw material fatty acid-modified polyester (B-4) were placed in a four-necked flask, and stirred at 170 ° C. with stirring, 4.8 parts of trimellitic anhydride were added for 10 minutes, and the amount of fatty acid modification was 45.0% and the hydroxyl value was 120 mgKOH /. g, acid value 27 mgKOH / g. A transparent liquid polybasic acid addition fatty acid modified polyester (A-5) having a weight average molecular weight of 6500 in terms of styrene was prepared.

Production Example 18 (Preparation of Polybasic Acid-Added Fatty Acid Modified Polyester (A-6))

95.2 parts of raw material fatty acid-modified polyester (B-5) were placed in a four-necked flask, and stirred at 170 ° C. with stirring, 4.8 parts of trimellitic anhydride were added and reacted for 10 minutes. The fatty acid modification amount was 40.0% and the hydroxyl value was 142 mgKOH / g, acid value 28 mgKOH / g. A transparent liquid polybasic acid addition fatty acid modified polyester (A-6) having a weight average molecular weight of 25000 in terms of styrene was prepared.

Preparation Example 19 (Preparation of Polybasic Acid-Added Fatty Acid Modified Polyester (A-7))

95.2 parts of raw material fatty acid-modified polyester (B-6) was placed in a four-necked flask, and stirred at 170 ° C. with stirring, 4.8 parts of trimellitic anhydride were added and reacted for 10 minutes, and the amount of fatty acid modification was 40.0% and the hydroxyl value was 168 mgKOH /. g, acid value 28 mgKOH / g. A transparent liquid polybasic acid addition fatty acid modified polyester (A-7) having a weight average molecular weight of 6500 in terms of styrene was prepared.

Production Example 20 (Preparation of Polybasic Acid-Added Fatty Acid Modified Polyester (A-8))

The reaction was carried out under the same conditions as those for the preparation of (A-1) except that 6.8 parts of anhydrous phthalic acid was added to 93.2 parts of the raw material fatty acid-modified polyester (B-1), and the amount of fatty acid modification was 39.1% and the hydroxyl value was 168 mgKOH / g, acid value 27 mgKOH / g. A transparent liquid polybasic acid addition fatty acid modified polyester (A-8) having a weight average molecular weight of 6100 in terms of styrene was prepared.

Production Example 13 14 15 16 17 18 19 20 Raw material fatty acid modified polyester (B)
Kinds
Quantity
Inorganic acid anhydrides of polybasic acids
Trimellitic anhydride (part)
Phthalic anhydride (part)
Sum
B-1
95.2

4.8
-
100.0
B-1
91.4

8.6
-
100.0
B-2
94.8

5.2
-
100.0
B-3
95.2

4.8
-
100.0
B-4
95.2

4.8
-
100.0
B-5
95.2

4.8
-
100.0
B-6
95.2

4.8
-
100.0
B-1
93.2

-
6.8
100.0 Polybasic acid addition fatty acid modification
Polyester (A)
Fatty acid denaturation amount (%)
Acid value (mgKOH / g)
Hydroxyl value (mgKOH / g)
Weight average molecular weight
sign

40.0
27
172
6000
A-1

38.4
50
153
6200
A-2

55.0
30
135
6000
A-3

45.0
26
70
6500
A-4

45.0
27
120
6500
A-5

40.0
28
142
25000
A-6

40.0
28
168
6500
A-7

39.1
27
168
6100
A-8

Comparative Production Examples 1 to 8 (production of polybasic acid addition fatty acid modified polyester (A-9) to (A-16))

It adds to the raw material fatty acid modified polyester (B-1) and (B-7)-(B-12) on the conditions similar to the manufacturing conditions of (A-1) except having added the phthalic anhydride in the ratio shown in Table 3. The reaction was carried out to prepare a transparent liquid polybasic acid addition fatty acid-modified polyester (A-9) to (A-16). Table 3 shows these fatty acid modification amounts, hydroxyl value, acid value, and styrene equivalent weight average molecular weight.

Production Example One 2 3 4 5 6 7 8 Raw material fatty acid modified polyester (B)
Kinds
Quantity
Inorganic acid anhydrides of polybasic acids
Trimellitic anhydride (part)
Sum
B-1
99.0

1.0
100.0
B-1
88.5

11.5
100.0
B-7
95.2

4.8
100.0
B-8
95.2

4.8
100.0
B-9
95.2

4.8
100.0
B-10
95.2

4.8
100.0
B-11
95.2

4.8
100.0
B-12
95.2

6.8
100.0 Polybasic acid addition fatty acid modification
Polyester (A)
Fatty acid denaturation amount (%)
Acid value (mgKOH / g)
Hydroxyl value (mgKOH / g)
Weight average molecular weight
sign

43.6
6
189
5900
A-9

37.2
65
141
6300
A-10

30.0
26
163
14000
A-11

67.0
26
113
3100
A-12

40.0
27
253
3200
A-13

40.0
27
51
12000
A-14

40.0
28
132
38000
A-15

60.0
27
174
2300
A-16

Comparative Production Example 9

The reaction was carried out under the same conditions as in (A-1) except that the reaction temperature was 80 ° C., but the solid unreacted substance remained even after 2 hours of reaction, and a transparent liquid ink composition could not be prepared. This is considered to be because an anhydrous trimellitic acid does not melt | dissolve in resin, and because it did not react.

Comparative Production Example 10

The reaction was carried out under the same conditions as in (A-1) except that the reaction temperature was 230 ° C. However, the carboxyl group of anhydrous trimellitic acid and the hydroxyl group of the raw material fatty acid-modified polyester (B-1) caused condensation reactions. It changed to rubber | gum phase and could not manufacture a normal ink composition.

Examples 1-8

Polybasic acid addition fatty acid modified polyester (A-1)-(A-8), carbon black (made by Cabot Specialty Chemicals, Inc .: REGAL 400) and high boiling point aromatic hydrocarbon (Japan oil) shown in Table 2 as binder resin Co., Ltd .: ALKENE L) was blended in the ratio shown in Table 4, and meat-dispersed with three rolls to prepare a printing ink composition.

Comparative Example 1

A printing ink composition was prepared in the same manner as in Example 1 except for using the raw material fatty acid-modified polyester (B-1) without adding an acid anhydride as the binder resin.

Comparative Examples 2-9

A printing ink composition was prepared in the same manner as in Example 1 except that the pigment and the high-boiling aromatic hydrocarbon were mixed in the proportion of the polybasic acid-added fatty acid-modified polyester (A-9) to (A-16) shown in Table 3 in Table 5. It prepared.

The printability (transferability, wet coating property), adhesiveness, and surface hardness of the printing ink compositions prepared in Examples 1 to 8 and Comparative Examples 1 to 9 were examined by the following methods. The results are shown in Tables 4 and 5.

(1) printability

(Transferability test)

The printing ink composition was applied to the test rubber roll uniformly so that the thickness of the ink film in wet was 2 µm using a high-speed printability tester (PM904PT manufactured by SMT Co., Ltd.), followed by aluminum 2 Using a piece can (seamless can, 50-100 μm in thickness), it is transferred at a printing speed of 8 m / s.

About this printed seamless can, the printing state (transition state of ink) is visually evaluated by the following reference | standard.

A: The transferability of the ink and the surface smoothness of the ink film are good.

B: A state in which the transferability of the ink and the surface smoothness of the ink film are slightly lower than those of A, making it difficult to reproduce the color tone, which is a problem in quality.

C: The transfer amount of the ink is small, and the surface smoothness of the ink film is significantly different from that of A, and cannot be used as a product.

(Wet coatability of overprint varnish)

The printing ink composition was applied to the test rubber roll uniformly so that the thickness of the ink film in wet was 1.5 µm using a high speed printability tester (manufactured by SMT Co., Ltd.), and then seamless silver coated cans. (Thickness 50 to 100 µm) was used to transfer at a printing speed of 8 m / s.

Immediately after transfer, with 55 parts of water-soluble acrylic resin (ALMATEX WA41 from Mitsui Chemicals Inc.), 15 parts of methylated melamine resin (Cymel 303 from Nihon Cytec Industries, Inc.), 20 parts of deionized water and 10 parts of ethylene glycol mono isopropyl ether The resulting aqueous overprint varnish is coated on the entire surface of the printing surface (coating amount 50 mg / 100 cm 2), and calcined at 220 ° C. for 2 minutes to produce a flat printed seamless can.

A: The surface of the ink film is not different from before wet coating the overprint varnish.

B: The agglomeration tendency was visually confirmed compared with the surface of the ink film before wet coating the overprint varnish and cannot be used as a product.

C: The surface of the ink film has a significant difference before and after wet coating the overprint varnish and cannot be used as a product.

(Adhesiveness)

It evaluates by the cross cut test prescribed | regulated to JISK5600-5-6 (surface hardness).

Gardner cross cut tester Cat. No. Using 5123, the printed test piece is cut in the cross section by the method specified in JIS, and then the adhesion test is performed using a transparent pressure-sensitive adhesive tape having a width of 25 mm.

Evaluation of adhesiveness was evaluated as follows according to JI K5600-5-6.

0: The line of cut is completely smooth, and there is no peeling in any lattice.

1: There is small peeling in the coating film at the intersection of cut. The influence on the cross section is clearly not more than 5%.

2: There is peeling along the edge of the coating cut and / or at the intersection. Affected by the cross section is clearly over 5% but not over 15%.

3: There is a large peeling partially or entirely along the rim of the coating cut, or several cross sections are peeled partially or fully. Affected by the cross section is clearly over 15% but not over 35%.

4: There is a large peeling partially or entirely along the coating film cut, and / or a part is peeled partially or fully. Clearly over 35% are affected in the transverse section.

(Pencil hardness)

It evaluates by JIS-A hardness (pencil hardness) prescribed | regulated to JISK5600-5-4. The hardness test of the hardened pencil which does not produce the defect by a scratch test is made so that a pencil core may contact 45 degree to the printed test piece by the method prescribed | regulated to JIS standard, and pencil hardness is called pencil hardness.

Example One 2 3 4 5 6 7 8 Print Ink Composition
Polybasic acid addition fatty acid modification
Polyester
A-1
A-2
A-3
A-4
A-5
A-6
A-7
A-8
Carbon black
High boiling aromatic hydrocarbon solvent

30
-
-
-
-
-
-
-
25
45

-
30
-
-
-
-
-
-
25
45

-
-
30
-
-
-
-
-
25
45

-
-
-
30
-
-
-
-
25
45

-
-
-
-
30
-
-
-
25
45

-
-
-
-
-
25
-
-
25
50

-
-
-
-
-
-
30
-
25
45

-
-
-
-
-
-
-
30
25
45 Printability
Metastatic
Wet coating
Adhesive
Surface hardness
A
A
0
4H
A
A
0
4H
A
A
0
4H
A
A
0
4H
A
A
0
4H
A
A
0
4H
A
A
0
4H
A
A
0
4H

Example One 2 3 4 5 6 7 8 9 Print Ink Composition
Fatty Acid Modified Polyester
B-1
A-9
A-10
A-11
A-12
A-13
A-14
A-15
A-16
Carbon black
High boiling aromatic hydrocarbon solvent

30
-
-
-
-
-
-
-
-
25
45

-
30
-
-
-
-
-
-
-
25
45

-
-
30
-
-
-
-
-
-
25
45

-
-
-
25
-
-
-
-
-
25
50

-
-
-
-
45
-
-
-
-
25
30

-
-
-
-
-
30
-
-
-
25
45

-
-
-
-
-
-
30
-
-
25
45

-
-
-
-
-
-
-
25
-
25
50

-
-
-
-
-
-
-
-
50
25
25 Printability
Metastatic
Wet coating
Adhesive
Surface hardness
A
C
3
4H
A
B
2
4H
C
A
One
4H
C
A
One
4H
A
B
0
HB
A
A
4
4H
A
B
One
3H
C
A
2
4H
A
B
3
2H

From the results in Tables 4 and 5, it can be seen that the effect of the present invention in the printing system of seamless cans is obvious and very advantageous industrially.

Claims

The polybasic acid addition fatty acid modified polyester (A) which has a weight average molecular weight of styrene conversion of 35-65 mass%, styrene value 60-200 mgKOH / g, and acid value 10-60 mgKOH / g in terms of styrene conversion weight average molecular weight is 3000-30000. Seamless printing ink composition for cans.

The polybasic acid-added fatty acid-modified polyester according to claim 1, wherein the polybasic acid-added fatty acid-modified polyester (A) is obtained by adding an acid anhydride of a polybasic acid to a fatty acid-modified polyester (B) having an acid value of less than 10 mgKOH / g. A printing ink composition for a seamless can, which is characterized by the above-mentioned.

The said polybasic acid addition fatty acid modified polyester (A) is obtained by making the acid value of less than 10 mgKOH / g of fatty acid modified polyester (B) react in-molecular acid anhydride of a polybasic acid at 100 to 200 degreeC. A printing ink composition for a seamless can, which is a polybasic acid addition fatty acid-modified polyester.

The printing ink composition for a seamless can according to any one of claims 1 to 3, further comprising a pigment component and a solvent component.

The can body is formed by drilling a metal substrate, and a printing layer is formed on the surface of the can body by the seamless printing ink composition for cans according to any one of claims 1 to 4, and the thermosetting on the print layer is used for overprinting. A method for coating a seamless can, wherein the varnish is applied and subsequently heat cured.

6. The method of covering a seamless can according to claim 5, wherein the metal substrate is a polyester coated steel sheet.