JPS6390583A - Vehicle for printing ink - Google Patents

Abstract

PURPOSE:To obtain the titled vehicle, by blending a polyamide resin prepared by subjecting a polyalkylenepolyamine, alkanolamine and polymerized fatty acid to condensation reaction with an alkyl titanate based chelating agent and having improved heat as well as rubbing resistance. CONSTITUTION:A vehicle obtained by blending (A) a polyamide resin prepared by subjecting (i) a polyalkylenepolyamine expressed by the formula H2N(RH)nH (R is 2-3C alkylene; n is 1-5), e.g. ethylenediamine, etc., (ii) an alkanolamine expressed by the formula R1NHR2 (R1 and R2 are H, 2-hydroxyethyl or 2- hydroxypropyl; at least one of R1 and R2 is 2-hydroxyethyl or 2-hydroxypropyl), e.g. monoethanolamine, etc., and (iii) a polymerized fatty acid [obtained by polymerizing a (semi)drying oil fatty acid, etc.] to condensation reaction with (B) an alkyl titanate based chelating agent, e.g. tetraisopropyl titanate, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a vehicle for printing ink. More specifically, the present invention relates to a printing ink vehicle with excellent heat resistance and rubbing resistance, which is made by blending an alkyl titanate chelating agent with a specific polyamide resin, for use in gravure printing inks useful for printing plastic films.

[Conventional technology and its problems]

In addition to using multi-layer laminates to package so-called dry foods such as rice crackers, arare, peanuts, biscuits, and even dried foods,
Relatively inexpensive, ink is printed on the surface of polyethylene, polypropylene, chlorinated vinylidene coated polypropylene, various moisture-proof cellophane, aluminum foil, etc., and the back side is left blank or coated with Bart coating agent or hot melt adhesive. Many packaging materials are also used.

In order to improve workability, high-temperature sealing for a short period of time has become common with the introduction of high-speed automatic bag making machines, and higher heat resistance inks have become required.

Currently, heat-resistant inks for surface printing used for these purposes include inks that use polyamide resin and nitrified cotton as the main binders, and use alkyl titanate-based chelating agents to further improve heat resistance. There is.

The main binder polyamide resin used in this product has gloss, which is the most necessary condition for surface printing ink, and has a wide adhesion range to various printing films, especially polyolefin films, moisture-proof cellophane, vinylidene chloride coated polypropylene, and aluminum foil. It also has good ink fluidity and pigment dispersibility, and has excellent printing effects. On the other hand, if the heat resistance is not sufficient and the seal bar hits the ink surface, the
In most cases, ink begins to adhere to the seal bar at around 80°C. This product is called a mixed solvent soluble polyamide, and its composition is a polycondensation metal of polyalkylene polyamine, polymerized fatty acid, and monocarboxylic acid, and the softening point of the resin is within the range of 110±10°C.

On the other hand, the nitrified cotton used in combination has high heat resistance and will not adhere to the seal bar even at temperatures above 210°C.

Heat resistance is improved by using this combination, but if the ratio of nitrified cotton is increased, the adhesion to the printing film will deteriorate and the gloss of the ink coating surface, which is a feature of polyamide resin, will be lost, so polyamide resin First of all, the ratio of nitrified cotton and nitrified cotton must be such that the first printing effect, which is good gloss, is not impaired.

Further, an alkyl titanate chelating agent that improves heat resistance improves heat resistance, but when added in excess, yellowing of the ink and poor ink stability occur. In particular, there is a limit to the amount that can be added because it gels or thickens in the form of ink.

Using a conventional ink that uses a combination of this polyamide resin and nitrified cotton and adds an alkyl titanate chelating agent, surface printing is performed on a printing film that can be made into bags by heat sealing.
When the heat seal bar hits the ink coating surface as a packaging material, the heat resistance is insufficient and the sealing time is 120
If the temperature exceeds ℃, the printing ink will be absorbed by the heat seal bar, leading to a negative image of the product.

To prevent ink from getting onto the heat seal bar,
If the heat-sealing temperature is lower than this, it is necessary to increase the heat-sealing time to obtain sufficient heat-sealing strength, which may lead to a decrease in work efficiency, or the temperature may sometimes fall below the sealing conditions, resulting in insufficient sealing strength. There are cases where something like that happens.

At present, ink compositions that have good gloss and adhesion, and that use a combination of conventional polyamide resin and nitrified cotton, as well as an alkyl titanate chelating agent, have a temperature of 130°C.
, none can withstand heat sealing conditions for more than 1 second.

[Purpose of the invention]

The purpose of the present invention is to improve bag manufacturing speed and work efficiency by developing an ink with excellent heat resistance, as well as to create designs that were previously impossible due to the lack of heat resistance of the ink. The objective is to make it possible to use materials with a high sealing temperature as packaging materials.

[Means for solving problems]

As a result of extensive studies to solve the above problems, the present inventor discovered that a specific polyamide resin blended with an alkyl titanate chelating agent has dramatically superior heat resistance. The invention was completed.

That is, the present invention provides: (A) a polyalkylene polyamine represented by the following general formula; (B) an alkanolamine represented by the following general formula;
and at least one of R2 is a 2-hydroxyethyl group or a 2-hydroxypropyl group) (C) For printing ink made by blending an alkyl titanate-based chelating agent with a polyamide resin subjected to a condensation reaction with a polymerized fatty acid It provides the vehicle.

An ink composition using the printing ink vehicle of the present invention can withstand heat sealing conditions of 140°C and 1 second.

Examples of the polyalkylene polyamine of component (A) used in the present invention include ethylenediamine, diethylenetriamine, triethylenetetramine, propylenediamine, dipropylenetriamine, tripropylenetetramine, etc. alone or in mixtures.

The polyalkylene polyamine of component (A) may be any one represented by the above general formula, or a mixture of several types may be used. In the general formula, n
If the polyamide resin is larger than 5, the resulting polyamide resin will have a low softening point, which will have an undesirable effect on the properties of the ink, etc., which is not preferable. Particularly preferred is (
A) This is the case where 50 equivalent % or more of components with n=1 are used.

The alkanolamine as component (B) used in the present invention includes monoethanolamine, jetanolamine,
Examples include monoisopropanolamine and diisopropanazoleamine.

The polymerized fatty acid as component (C) used in the present invention is obtained by polymerizing a dry or semi-drying oil fatty acid or an ester thereof. That is, polymerized fatty acids are monobasic fatty acids including polyunsaturated fatty acids or esters thereof, and have a molecular weight of 8 to 24%.
It is a polymerized product with a carbon number of It can also be obtained by heating using a catalyst such as a known acid clay or peroxide. Currently commercially available polymerized fatty acids have a carbon number of 1
Many of them are based on 8 unsaturated fatty acids, and typical ones have the following composition.

Monobasic acids with 18 carbon atoms: 0 to 5% by weight Dibasic acids with 36 carbon atoms: 60 to 100% by weight It means that the trimeric fatty acid includes a polymerized fatty acid that is more than four-walled.

The polyamide resin of the present invention basically has the above-mentioned polyalkylene polyamine (8) or alkanolamine, but the general formula Ra generally used for polyamide resin is
A monocarboxylic acid represented by COOH (in the formula, R represents a saturated or unsaturated alkyl group having 1 to 20 carbon atoms),
General formula HOOC-R. -COO)! (In the formula, R represents an aliphatic, aromatic, or ring group residue having 2 to 20 carbon atoms)
It goes without saying that the dicarboxylic acid represented by can be used depending on the case.

Generally, when synthesizing polyamide, it is preferable that the carboxyl equivalent and amine equivalent are not much different from each other in view of the physical properties of the resin. That is, if the equivalent of one is too large relative to the other, a desirable polyamide resin cannot be produced, but in the present invention, the carboxyl group and the hydroxyl group of the alkanolamine partially react to form an ester bond. , the ratio of the sum of carboxyl equivalent/amine equivalent of polymerized fatty acid (C) to the sum of polyalkylene polyamine (A) and alkanolamine (B) is 1.0 to 1.2.
It is preferable to set the carboxyl equivalent to a slightly larger range.

Further, the amine equivalent ratio of polyalkylene polyamine (A) and alkanolamine (B) is 50:50 to 90.
It is particularly preferable to carry out the reaction within a range of 10 to 10. If the amount of alkanolamine is too large, the softening point of the resulting polyamide will be low, which may have an unfavorable effect on the physical properties of the ink. The effect may not be as expected.

In the production of the polyamide of the present invention, the condensation reaction is carried out by a known method, that is, by mixing and heating an amine component and an acid component and reacting at 180 to 250 DEG C. until a low acid value is achieved.

In the present invention, in order to further enhance the effects of the invention, nitrified cotton can be blended with the polyamide resin, but this has a favorable effect on the physical properties of the ink. Considering heat resistance, gloss and adhesive properties required for surface printing ink, the amount of nitrified cotton to be added is 10 to 4 to the polyamide resin.
A range of 0% by weight is preferred.

Examples of the alkyl titanate chelating agent used in the present invention include tetraisopropyl titanate, tetra-n-butyl titanate, and tetra(2-ethylhexyl) titanate. The amount of the alkyl titanate chelating agent added is preferably within 5% by weight of the ink.

[For production]

In the present invention, excellent effects are obtained by using a specific polyamide resin and an alkyl titanate chelating agent in combination, but this is because the polyamide resin used in the present invention has a certain amount or more of hydroxyl groups at the molecular terminals. This is because this causes an appropriate crosslinking reaction with the alkyl titanate chelating agent.

〔Example〕

Next, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto.

Note that "parts" and "%" indicate parts by weight and % by weight, respectively, unless otherwise specified.

Polyamide resin production example 1 572 parts of Unidyme 22 (Union Camp Co., Ltd. trade name: about 3% monobasic acid of C18, about 75% of dibasic acid of C3, about 22% of tribasic acid of C54) as polymerized fatty acids and 48 parts of ethylene diamine Place the aliquot into a four-eye round bottom flask equipped with a thermometer, stirrer, dehydration tube and nitrogen sparging tube. The mixture is stirred, the temperature raised to 200°C, and kept at 200°C for 3 hours under a slight stream of nitrogen to prevent coloring of the contents. 22.5 parts of monoethanolamine was added thereto, and the mixture was further reacted at 200°C for 3 hours. After that, under reduced pressure at 200℃ (
Approximately 100 mmHg) for 1 hour, polyamide resin R
-1 was obtained. The composition of the raw materials and the properties of the resulting resin are shown in Table I.

Among the resin properties shown in Table ■, the softening point is JIS K253.
1-1960, and the solution viscosity was measured using a B-type viscometer at 25° C. of a 35% resin solution using a solvent of toluene/isopropanol=271.

Polyamide Resin Production Example 2 22,572 parts of Unidim, 48 parts of ethylenediamine, and 30 parts of monoisopropanolamine are placed in a four-eye round bottom flask similar to Production Example 1. After reacting at 230°C for 4 hours, the reaction was carried out for 1 hour under reduced pressure to obtain polyamide resin R-2. The composition of the raw materials and the properties of the resulting resin are shown in Table I.

Polyamide Resin Comparative Production Example 1 22,500 parts of Unidym, 40 parts of Etol FAX (tall oil fatty acid manufactured by Kanyo Kagaku Kogyo) as a monocarboxylic acid, and 56.6 parts of ethylenediamine were reacted in the same manner as in Production Example 2. Table I shows the properties of the resin T-1 obtained.

Table ■ Reference example of preparation composition and resin properties of polyamide resin [Ink preparation and ink performance] The polyamide resin obtained in Production Example 1.2 and Comparative Production Example 1 was dissolved in a mixed solvent of toluene/isopropanol-2-1. Then, solutions (G) each having a resin concentration of 35% were prepared.

On the other hand, in order to prevent blocking and improve heat resistance, nitrified cotton RS'A was dissolved in ethyl acetate to prepare a solution (H) with a non-volatile content of 25%. A mixture containing these (G) and (H) and having the following composition: 53 parts of resin solution (G), 8 parts of nitrified cotton solution (H), 100 parts was charged into a ball mill and dispersed for 16 hours.
The resulting white ink was applied to treated polyethylene and treated stretched polypropylene films using a wire coater I! Print 1 at 15
After drying overnight at room temperature, the prints were examined for adhesion, water resistance, oil resistance, and heat resistance.

The test results are shown in Table ■.

The test method and criteria are as follows.

i) Adhesiveness: Adhesiveness using pressure-sensitive tape using Chiban Cellotape) Items in which the printed surface is not removed at all by the Sellotape side -----○ Items in which part of the printed surface is removed by the Sellotape side ------ --△ii)
Water resistance: immerse the printed surface in tap water for 4 hours,
Those with a perfect printed surface after kneading - those whose 0th side has fallen off... ×111) Oil resistance: Soak the printed matter in salad oil for 1 hour, take it out, wipe off the salad oil with paper, and rub it together. The ink coating on the printed surface is complete after rubbing 10 times. -------〇 There are cracks but no ink has fallen off.------△ The ink has fallen off.------- xiv) Heat resistance: Table - ■ using a thermal gradient tester (Toyo Seiki Seisakusho)
2 kg/cm” at the specified temperature shown in the table for A seconds, peeled off immediately, and judged the printed matter with the naked eye.The printed matter is perfect at the specified temperature.
Example 1.2 without addition of chelating agent, Comparative Example 11 A chelating agent (
A white ink containing 1 part (4 parts of tetraisopropyl titanate dissolved in 6 parts of acetylacetone) was printed in the same manner as in the reference example, and the adhesion, water resistance, oil resistance, and heat resistance of the printed matter were examined. The test results are shown in Table ■.

Table 2: Chelating agent addition system - Effects of the invention As is clear from the above explanation, the gravure ink using the printing ink vehicle using the polyamide resin of the present invention has significantly improved heat resistance. Furthermore, the ink containing the chelating agent is also satisfactory in terms of adhesion, kneading resistance, water resistance, and oil resistance required of printing inks.

Claims (1)

[Scope of Claims] 1(A) A polyalkylene polyamine represented by the following general formula, H_2N(RNH)_nH (wherein R is an alkylene group having 2 to 3 carbon atoms, and n is an integer of 1 to 5) (B) An alkanolamine represented by the following general formula, R_1NHR_2 (wherein R_1 and R_2 each represent a hydrogen atom, a 2-hydroxyethyl group, or a 2-hydroxypropyl group,
At least one of R_1 and R_2 is a 2-hydroxyethyl group or a 2-hydroxypropyl group) (C) Printing ink made by blending an alkyl titanate-based chelating agent with a polyamide resin subjected to a condensation reaction with a polymerized fatty acid. vehicle. 2 The amine equivalent ratio of polyalkylene polyamine (A) and alkanolamine (B) is 50:50 to 90:1
A vehicle for printing ink according to claim 1, wherein the vehicle is 0.0. 3 (C) relative to the sum of amine equivalents of (A) and (B)
The vehicle for printing ink according to claim 1, wherein the ratio of the carboxyl equivalents of is from 1.0 to 1.2. 4 At least 50 equivalent % of the polyalkylene polyamine (A) is a compound in which n=1, Claim 1
Vehicles for printing inks as described in Section. 5. The vehicle for printing ink according to claim 1, wherein the polymerized fatty acid (C) has the following composition. Monobasic acid with 18 carbon atoms 0-5% by weight Dibasic acid with 36 carbon atoms 60-100% by weight Tribasic acid with 54 carbon atoms or higher 0-30% by weight