JPS588772A - Binder for water-based coating - Google Patents

Abstract

PURPOSE:To provide the titled binder consisting of a polyamide resin made from a trimer acid, a monocarboxylic acid and a polyamine, having good adhesion to non-absorptive substrate such as metal foil and forming a coating film with high gloss and excellent resistance to water and blocking. CONSTITUTION:A polyamide resin with an acid value of 20-250 is prepared by interaction of (A) an acid component consisting of at least 30eq.% trimer acid (e.g., a trimer of oleic or linoleic acid), a monocarboxylic acid (e.g., acetic acid) and, if necessary, a dimer acid (e.g., linoleic acid dimer) and (B) polyamine (e.g., ethylenediamine) in an eq. ratio of 1:0.35-1:0.9. The binder is obtained by neutralizing the polyamide resin with a basic substance (e.g., ammonia) and dissolving it in an aqueous solvent. USE:The binder is suitable for coating plastic film, cellophane, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to binders for aqueous coatings. For more details, see various plastic films.

This invention relates to a water-based coating binder that has good adhesion to non-absorbent materials such as metal foil and cellophane, and provides a film with excellent gloss, water resistance, anti-blocking properties, and other properties.

Organic solvent-soluble resins (polyamide, polyurethane, polyester, polyvinylidene chloride, polyvinyl chloride, polyvinyl acetate, alkyd resins, etc. Nitrocellulose, etc.) are used alone or in combination, but from the viewpoint of preventing fires and air pollution caused by organic solvents and saving resources, there is a strong desire to develop a water-based coating binder that can replace these binders.

Styrene-maleic acid copolymer resin, Styrene 7-7 IJ, is commonly used as a binder for water-based coatings.
Water-based coating agents using these resins are suitable for coating absorbent materials such as paper, but are not suitable for coating various plastic films, metal foils, etc. It had a fatal flaw: poor adhesion to non-absorbent materials such as cellophane.

On the other hand, an aqueous resin composition in which an unsaturated carboxylic acid is grafted to an alcohol-soluble polyamide resin and neutralized with a basic substance has been proposed to improve the adhesion to Li plastic film (Japanese Patent Application Laid-Open No. 55-5
No. 8244) Although this composition has improved adhesion to various plastic films, it has the disadvantage that the film has poor water resistance and gloss. In addition, rosin acid-dicarboxylic acid or its anhydrous adduct and polymerized fatty acid are added to
A water-based polyamide resin type ink binder reacted with a 0-equivalent polyamine has also been proposed (Japanese Patent Publication No. 55
-4788) Although this product also had improved adhesion to various plastic films, it had drawbacks of poor water resistance, blocking resistance, and gloss.

The present inventors have further improved the adhesion to non-absorbent materials, as well as water resistance and blocking resistance.

As a result of intensive research into a binder for water-based coatings that provides a film with excellent gloss, the present invention was achieved. That is, the present invention consists of a polyamide resin with an acid value of 20 to 250 made of an acid component consisting of a trimer acid, a monocarboxylic acid, and if necessary a dimer acid (however, the trimer acid has an equivalent weight of 30 or more in the acid component) and a polyamine. A binder for water-based coatings.

Trimer acids used in the present invention include C1g unsaturated fatty acids such as oleic acid and linoleic acid, drying oil fatty acids, semi-drying oil fatty acids, and lower alkyl esters of these fatty acids in the presence or absence of a catalyst. Examples include those obtained by trimolecular polymerization. The trimer acid may be a trimer acid ester obtained by polymerizing a lower alkyl ester instead of the above fatty acid. This trimer acid usually contains a small amount of monomer acid, dimer acid, etc. in addition to the main component, trimer acid. The composition of this trimer acid is usually C
54) ') 70-98% by weight of mer acid, (preferably 7
5-95 weight), C36 dimer monoacid 2-30 weight,
(preferably 5 to 25% by weight) and C18 monocarboxylic acid 0 to 10% by weight (preferably 0 to 5% by weight). Trimer acid is Mball 1040) Limer acid (manufactured by Emery; trimer acid 80% by weight, dimer acid 20% by weight)
, Empol 104] trimer acid (same; trimer acid 9
0 weight ratio, dimer acid 10 weight ratio). The approximate structure of trimer acid can be shown as follows.

, (CH2)y Co21( (where R+, &, R3 is an alkyl group, X is an undeterminable ring produced by polymerization of three unsaturated fatty acids forming a trimer acid. (An integer of 1 or more.) Monocarboxylic acids used in the present invention include C1-3o linear or side-chain saturated fatty acids (formic acid, acetic acid, etc.).

propionic acid, butyric acid, valeric acid, caprylic acid, lauric acid, palmitic acid, stearic acid, 2-ethylhexanoic acid, iristearic acid, etc.), 01-3° unsaturated fatty acids (oleic acid, linoleic acid, lylunic acid, etc.) ), mixed fatty acids obtained from natural fats and oils (tall oil fatty acids, rice bran oil fatty acids, beef tallow fatty acids.

rosin, etc.), aromatic monocarboxylic acids (benzoic acid, etc.).

toluic acid, etc.) Aliphatic or aromatic oxymonocarboxylic acids [lysirucic acid, salicylic acid, p-oxybenzoic acid, diphenolic acid (4,4-bis(hydroxyaryl)butyric acid, 44-bis(hydroxyaryl)valeric acid) etc.] and mixtures of two or more of these. Preferred monocarboxylic acids are Cl--H saturated aliphatic monocarboxylic acids, and particularly preferred is acetic acid.

Dimer acids that may be used as necessary include C+8 unsaturated fatty acids such as oleic acid and linoleic acid.

Examples thereof include drying oil fatty acids, semi-drying oil fatty acids, or lower alkyl esters of these fatty acids, which are bimolecularly polymerized in the presence or absence of a catalyst, and are generally referred to as polymerized fatty acids (which may also be esters). Polymerized fatty acids usually contain monomer acids and trimer acids in addition to dimer acids. The composition of this dimer acid is usually C1
8 monomer acid 0-5% by weight (preferably 0-4% by weight)
), C! 16 dimer acid 60-99% by weight (preferably 70-98% by weight), C44) IJ dimer acid 2-35
% by weight (preferably 3 to 30% by weight).

Other tricarboxylic acids (such as trimellitic acid) can be used along with the trimer acid if necessary. In this case, the amount is usually 40 equivalents or less in the acid component, preferably 3
It is below 0 equivalent ratio. If necessary, aliphatic or aromatic dicarboxylic acids (adipic acid, sebacic acid, azelaic acid, isophthalic acid, terephthalic acid, etc.) other than dimer acid can also be used. The amount thereof is usually 40 equivalents or less, preferably 30 equivalents or less in the acid component.

In the acid component consisting of trimer acid, monocarboxylic acid, and optionally dimer acid, the amount of trimer acid (when tricarboxylic acid is used, it is included in l.lmer acid) is 30 equivalents or more in the acid component. 7 Usually 30 to 70 equivalents, preferably 34 to 55 equivalents, the amount of monocarboxylic acid is usually 10 to 50 equivalents, preferably 15 to 45 equivalents,
Amount of dimer acid (when using other dicarboxylic acids, the amount included in the dimer acid is usually 0 to 40 equivalents, preferably 3
~30 equivalents. When the amount of trimer acid is less than 30 equivalents, the resulting polyamide resin has a low melting point and is unsuitable as a coating binder due to poor blocking resistance and scratch resistance. Monocarboxylic acid is 10
If it is less than 50 equivalents, it will gel during the reaction, and if it is more than 50 equivalents, the resulting resin will have a low melting point.

The polyamines used in the present invention include aliphatic polyamines (ethylenediamine, propylenethiabene, hexamethylenediamine, diethylenetriamine, triethylenetetramine, etc.), alicyclic polyamines (isophoronediamine, etc.), aromatic polyamines (xylylenediamine, diaminophenyl methane, etc.) and mixtures of two or more of these. Preferred among these are ethylenediamine and a mixture of ethylenediamine and diethylenetriamine, and particularly preferred is ethylenediamine.

When producing polyamide resin, the ratio of acid component and amine component is usually on an equivalent basis, acid:amine = 1 + 0.
．． 35~1go09. Preferably 1:04 to 1:08
It is.

The method for producing polyamide resin by reacting an acid component with an amine component may be the same as the conventional method. For example, all the acid components are charged into a reactor, the air is completely replaced with an inert gas such as nitrogen gas, and then the mixture is stirred. While adding polyamine, 16
Raise the temperature to 0-250°C. The reaction temperature is usually 160-2
50°C1 Preferably kept at 180-230°C Usually 3
A method of carrying out the amidation reaction for 10 hours, preferably 4 to 8 hours is exemplified.

At the end of the reaction, if necessary, the reaction may be carried out under reduced pressure to facilitate the removal of volatile components.

The polyamide resin obtained in (-) is a light brown solid resin with an acid value of 20 to 250, preferably 40 to 200. If the acid value is lower than 20, salt formation due to neutralization of basic substances On the other hand, if the water solubility is insufficient, and the acid value is higher than 250, the water solubility of the salt is good due to neutralization of basic substances, but the melting point of the polyamide resin becomes low, and it has poor blocking resistance and scratch resistance as a coating binder. It is inferior and inappropriate.

The melting point is usually 90-120°C.

The polyamide resin in the present invention can be made into a salt by being neutralized with a basic substance and can be dissolved in an aqueous solvent. Basic substances include ammonia, alkali metal hydroxides (potassium hydroxide, sodium hydroxide, etc.) or amines (dimethylamine, trimethylamine, triethylamine,
dimethylethanolamine, diethylethanolamine, etc.). Among these, preferred are ammonia, dimethylamine, and trimethylamine.

The amount of the basic substance used to form a salt is usually 09 to 1.2 equivalents, preferably 1 to 1.1 equivalents, relative to the carboxylic acid in the polyamide resin.

Aqueous solvents include water-based solvents or water and water-soluble solvents such as lower alcohols (methanol, ethanol).

n or isonopropanol, etc.). Among these, preferred is a mixed solvent of water and lower alcohol. The mixing ratio of water and lower alcohol is usually 9:1 to 4:6, preferably 8:2 on a weight basis.
~5:5.

The solution viscosity of the water-soluble salt of polyamide resin is usually 100-1
000 cps (concentration: 30 parts, solvent: water/iriprohyal: 7-l=/2 heavy it ratio: 1 salt haammonium salt).

The polyamide resin of the present invention can be used as a binder for aqueous coatings, and the method of use is to prepare a basic substance neutralized aqueous solution (or water-alcohol mixed solution) of this resin alone or, if necessary, add a coloring agent to it. (dye or pigment) and other additives can be used as an aqueous coating agent. In addition to the above, other additives include oxidized polyethylene wax emulsions, rosin, maleated rosin, antifoaming agents, and the like.

Examples of formulations of such aqueous coating agents include polyamide resin 15 to 30% by weight and 28% ammonia aqueous solution 1 to 30% by weight.
5 weight percent, water/isopropanol % (weight ratio) mixed solvent, 30-84 weight %, 9 colorant O-20 weight %, and other compounding agents 0-15 weight %. The manufacturing method of the coating agent may be the same as that for conventional aqueous coating agents or aqueous printing inks.

The polyamide resin, which is the binder for water-based coatings of the present invention, can be used as a coating agent for processing polyethylene, plastic films such as polyester, metal foils such as aluminum foil, and cellophane.

Applicable to non-absorbent materials such as moisture-proof cellophane and absorbent materials such as paper. The film thickness can be varied depending on the application, but in the case of printing ink, it is usually 1 to 2.
0 micron, preferably 5 to 10 micron. The coating agent may be applied by conventional methods such as coating or dipping, and if the coating agent is printing ink, it can be applied to the object using a printing machine or the like, and gravure printing and flexible printing are preferred.

The aqueous coating binder of the present invention has the following effects.

(1) Provides a film with excellent water resistance, blocking resistance, and gloss.

(2) Non-absorbent materials (various plastic films).

Good adhesion to metal foil, cellophane, etc.).

(3) Good solubility in aqueous solvents.

The binder for aqueous coatings of the present invention is useful as a binder for aqueous coatings, especially aqueous printing inks (gravure or flexo).

The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited thereto.

Example 1 Empol 1022 (dimer acid manufactured by Emery, USA; monomer acid 3%, dimer acid 7s%,
(22% product) 57.69 (0.20 equivalent).

Empol 1040 (same trimer acid; dimer acid 20
%.

80% trimer acid product) 172.8g (0.60 equivalent)
, and 12 g (0.20 equivalents) of acetic acid were added, stirred, and 21.6 g (0.72 g
equivalent amount) was added and reacted at 200°C for 5 hours to obtain polyamide resin (a). The physical property values are shown in Table 1.

Example 2 172.8 g (0.60 equivalent) of Empol 1040
, acetic acid 24.9 (0,4 eq.) and ethylenediamine 21.6. ! 9 (0.72 equivalents) and the same method as in Example 1 to obtain polyamide resin (b). The physical property values are shown in Table 1.

Example 3 Empol 1o4o 115.2,! 9 (0,40
equivalent), Enhol 1022 at 57.61I (0,2
Cibolyamide resin (C) was prepared by the same method as in Example 1 using acetic acid 1817 (0,30 equivalents), rice bran oil fatty acid 28 i (0,10 equivalents), and ethylenediamine (O, SO equivalents). I got it. The physical property values are shown in Table 1.

Example 4 86.4 g (0,30 equivalents) of Empol 1040, 2iy (o, 3o equivalents) of trimellitic acid, 24.9 g (0,30 equivalents) of acetic acid (
18 g (0,40 equivalents) of ethylenediamine (0,40 equivalents)
60 equivalents), and the same method as in Example 1 was used to obtain cibolyamide resin (d). The physical property values are shown in Table 1.

Comparative Example 1 230.4 g (0.8 equivalents, of which 0.176 equivalents are trimer acid) of Empol 1022, 12 g (0.2 equivalents) of acetic acid, and 21.6 g of ethylenediamine! 9 (0,
Polyamide resin (a') was obtained by the same method as in Example 1 using 72 equivalents). The physical property values are shown in Table 1.

Comparative Example 2 57.6 g (o, 2o equivalent) of Empol 1022, 172.8 g (0,60 equivalent) of Empol 1040, 12 g (0,20 equivalent) of acetic acid and 27 g of ethylenediamine
．． ! 9 (0.90 equivalents) and the same method as in Example 1 to obtain a polyamide resin ω'). The physical property values are shown in Table 1.

Comparative Example 3 86.4jj (0.30 equivalent) of Enpol 1040,
trimellitic acid 35.5 g (0.50 equivalents) acetic acid 12
Polyamide resin (C') was obtained in the same manner as in Example 1 using 9.9 g (0.20 equivalents) and 9.9 g (0.30 equivalents) of ethylenediamine.

The physical property values are shown in Table 1.

Comparative Example 4 As a styrene-maleic acid copolymer resin, SMA-17
352A (manufactured by Arco, USA, acid value 250, softening point 170)
°C) was used.

Comparative Example 5 As a styrene-acrylic acid copolymer resin, Joncryl 67 (manufactured by Johnson Company, USA, acid value 210, 4E point 14) was used.
7°C) was used.

Test Example 1 Examples 1 to 4. and Comparative Examples 1 to 5 (2 is excluded because it is insoluble).Coach-in Blonde No.
, 6 and left to dry at room temperature for 3 hours, cellophane tape resistance, blocking resistance, water resistance, kneading resistance, and gloss tests were conducted.The test results are shown in the second coating.

Test Example 2 Examples 1 to 4. and 90 parts of the solutions listed in Table 1 of Comparative Examples 1 to 5 (2 is excluded because it is insoluble), and phthalocyanine blue (FA8TBGN manufactured by Inu Nippon Ink Chemical) was used as a coloring agent.
BLUE) was placed in a ball mill and kneaded for 15 hours to prepare an ink. The created ink was applied to various plastic films, aluminum foil, and cellophane with Coach In Blonde No. 6, and after drying at room temperature for 3 hours,
Resistant to cellophane tape.

Blocking resistance, water resistance, kneading resistance, and gloss tests were conducted. The test results are shown in the third column.

(Note) Explanation for the second and third coatings (1) Evaluation symbol A...good, B...fair, C...unsatisfactory (2) Cellophane tape resistance 1800 peel test with cellophane adhesive tape ( 3) Blocking resistance The printed surfaces were overlapped and pressed together at a temperature of 40° C. and under two loads for 24 hours.

(4) Rub resistance I rubbed it with my hands 10 times.

(5) Water resistance After soaking in tap water at room temperature for 1 hour, it was kneaded by hand in water 10 times.

(6) Shine The gloss of the applied product was visually observed.

(7) Explanation of symbols *1) PA: Polyamide resin *2) Polyethylene: Treated polyethylene *3) Ester, polyester *4) Aluminum Mini aluminum foil 473-

Claims (1)

[Claims] 1. An acid component consisting of a trimer acid, a monocarbo/acid, and optionally a dimer acid (however, the trimer acid has an equivalent weight of 30 or more in the acid component) and a polyamine with an acid value of 20
Aqueous coating binder consisting of ~250 polyamide resin.