JPS586756B2 - printing ink - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel printing ink, and more particularly to a printing ink comprising a polyurethane solution and a pigment that has excellent adhesion to non-absorbent substrates such as various plastic films. It is something.

Printing inks using polyurethane solutions as vehicles have been used industrially for some time, but they have insufficient adhesion to plastic films such as polyethylene, polypropylene, polyester, and nylon, or only adhere to certain films. This has caused major problems in the industry, as many of the printed materials lack versatility due to their good properties, or have inferior properties such as surface strength, non-adhesiveness, water resistance, oil resistance, acid resistance, and alkali resistance.

In order to solve these problems, the present inventors conducted extensive research and found that at least two urea bonds and A polyurethaneurea polyamine having at least two amino groups, or an alkyl isocyanate having a C12-C22 alkyl group or an α-olefin epoxide having a C12-C22 alkyl group is partially reacted with the amino group of the polyurethaneurea polyamine. It has been discovered that a printing ink comprising a polyurethaneurea polyamine having a long-chain alkyl group, at least two urea bonds, and at least two amine groups produced by the above method, a pigment, and an organic solvent exhibits excellent properties. , completed the present invention.

Since the polyurethaneurea polyamine solution used in the printing ink of the present invention has at least two urea bonds and at least two amine groups in one polymer molecule, It has excellent adhesion to films and can be diluted with solvents commonly used in printing inks, such as lower alcohols, acetic esters, toluene, etc., and is printed with a printing ink obtained from the polyurethaneurea polyamine solution and pigment. The resulting printed matter has excellent surface strength, non-stick properties, water resistance, oil resistance, acid resistance, and alkali resistance.

Furthermore, the solution of the polyurethaneurea polyamine having C12 to C22 long-chain alkyl groups used in the printing ink of the present invention has at least two urea bonds and at least two amine groups in one polymer molecule. At the same time, the long-chain alkyl group acts as an internal plasticizer that gives flexibility to the polymer, and also to increase the hydrophobicity and lubricity of the printed surface, increasing the flexibility of the printed material. , greatly contributes to improving properties such as water resistance, abrasion resistance, and blocking resistance.

The polyurethane urea polyamine used in the printing ink of the present invention is produced by reacting a polyalkylene polyamine with a urethane prepolymer having incyanate groups at both ends obtained from a polyhydroxyl compound and an excess polyfunctional isocyanate in an organic solvent. Ru.

Polyfunctional incyanates include aromatic, aliphatic and alicyclic polyisocyanates, such as 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate. , di- and tetraalkyldiphenylmethane diisocyanate, 4,4'-dibenzyl isocyanate, 1,3-phenylene diisocyanate, 1,4
-Phenylene diisocyanate, toluene diisocyanate, butane-1,4-diisocyanate, 2,2,4
-trimethylhexamethylene diisocyanate, hexane-1,6-diisocyanate, lysine diisocyanate, cyclohexane-1,4-diisocyanate, xylene diisocyanate, inphorone diisocyanate,
Dicyclohexylmethane-4,4'-diisocyanate, 1-methylbenzole-2,4,6-triisocyanate, methylcyclohexylene diisocyanate, biphenyl-2,4,4'-triisocyanate, isopropylidene dicyclohexyl-4,4'- Typical examples thereof include diisocyanate and triphenylmethane triisocyanate.

As the polyhydroxy compound, oligomer polyols and monomer polyols with a molecular weight of 62 to 2,000 are used, and as the oligomer polyols, polyether polyols such as polymers or copolymers of ethylene oxide, propylene oxide, tetrahydrofuran, etc., ethylene glycol, Propylene glycol, 1,3-butanediol,
1,4-butanediol, neopentyl glycol, pentanediol, hexanediol, octanediol, 1,4-butynediol, 2-ethyl-1,3-hexanediol, bisphenol A, diethylene glycol, triethylene glycol, dipropylene glycol Polyester polyols obtained by dehydration condensation reaction from saturated and unsaturated low-molecular-weight glycols such as dibasic acids and dibasic acids, polyester polyols obtained by ring-opening polymerization of cyclic ester compounds, polyester amides, In addition to polyacetals, polythioethers, polybutadiene glycols, etc., glycols made by adding ethylene oxide and propylene oxide to bisphenol A, etc.
Known polyols that are generally used in the production of polyurethane can be used, while typical examples of monomer polyols include low molecular weight glycols that are used as raw materials for the above-mentioned polyester polyols. Monomeric polyols are used in admixture with oligomeric polyols.

As the polyalkylene polyamine, various polyalkylene polyamines including polyethylene polyamine, polypropylene polyamine, polybutylene polyamine, etc. can be used, and more specifically, nitrogen is a group of the formula -CnH2n- where n is an integer greater than 1. , and there are in the range of 2 to about 4 such groups in the molecule.

The nitrogen atom is bonded to an adjacent carbon atom in the group CnH2n, but not to the same carbon atom.

Specifically, the use of polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentane, and dipropylenetriamine is contemplated, as well as mixtures and various purified polyamine materials, and hydroxyalkyl-substituted polyamines may also be used in combination.

In some cases, it is possible to improve the adhesion of the printing ink of the present invention to various plastic films, or to improve the properties of the printed matter such as surface strength, non-stickiness, water resistance, oil resistance, acid resistance, alkali resistance, etc. Therefore, it is desirable to widen the spacing between the amine groups in the polyurethaneurea polyamine molecule.

For this purpose, it is effective to replace a part of the polyalkylene polyamine used with ethylene diamine, propylene diamine, hexamethylene diamine, and alkylene oxide adducts, acrylonitrile adducts, acrylic ester adducts, etc. of these diamines. Yes, usually 5
Substitutions of 0 mole % or less are suitable for the purpose.

The production of the urethane prepolymer having isocyanate groups at both ends used in the present invention is carried out in the presence or absence of a solvent, and the amount of polyfunctional isocyanate is determined such that all the OH groups that react with the isocyanate groups react. It is preferable to select the

That is, the ratio of the total number of isocyanate groups in the polyfunctional isocyanate to the total number of hydroxyl groups in the polyhydroxy compound is 1.1:
1.0 to 5.0:1.0 is preferred.

The reaction between the urethane prepolymer having isocyanate groups at both ends and the polyalkylene polyamine is preferably carried out at -20°C to 70°C in a ketone solvent or tertiary alcohol, and the solvent may be acetone, methyl ethyl ketone, Diethyl ketone, dipropyl ketone, methyl isobutyl ketone, methyl isopropyl ketone, tertiary butanol, etc. are preferred, but also ethyl acetate, toluene, ethanol, isopropanol, dioxane, tetrahydrofuran, trichlene, which are commonly used in printing inks. It is also possible to use a mixture of a portion of a solvent such as perchlorine, chlorobenzene, or the like.

In the reaction between a urethane prepolymer and a polyalkylene polyamine, it is necessary that the total number of moles of amine groups in the polyalkylene polyamine is in excess of the total number of moles of isocyanate groups, but unreacted polyalkylene polyamine should not be so excessive that it remains.

That is, as the total number of moles of amine groups approaches the total number of moles of isocyanate groups, higher molecular weight polyurethaneurea polyamines are produced, but gelled products or polymer solutions with a marked tendency to gel are produced; If the ratio of the number of moles of amine groups is increased too much, a low molecular weight polyurethaneurea polyamine may be generated, or unreacted polyalkylene polyamine may remain, making the printing ink composed of such a polyurethaneurea polyamine solution and pigment unstable. Otherwise, the adhesion to various plastic films deteriorates, and the properties of the printed matter such as surface strength, non-adhesiveness, water resistance, oil resistance, acid resistance, and alkali resistance become extremely poor.

Therefore, the ratio of the number (B) of active hydrogen-containing amine groups in the polyalkylene polyamine to the number (8) of isocyanate groups in the urethane prepolymer having isocyanate groups at the ends is 1<B/A≦5. Yes, more preferably 1
<B/A≦3, and the molecular weight of the polyurethaneurea polyamine is preferably 5,000 to 100,000.

Typical examples of alkyl isocyanates having a C12 to C22 alkyl group include dodecyl isocyanate, tetradecyl isocyanate, hexadecyl isocyanate, heptadecyl isocyanate, octadecyl isocyanate, and alkyl isocyanates obtained from 1 mol of long-chain alcohol and 1 mol of diisocyanate. can be,
Further, examples of the α-olefin epoxide having a C12 to C22 alkyl group include dodecene oxide,
Tetradecene oxide, hexadecene oxide, octadecene oxide, eicosene oxide, docosene oxide and mixtures thereof are preferred.

The alkyl isocyanate or α-olefin epoxide having a C12 to C22 alkyl group has a concentration of 0.1 to 6 with respect to the amine group in the polyurethaneurea polyamine molecule.
It is preferable to carry out the reaction in an equivalent amount of 0 mol %; if it is more than 60 mol %, the strength of the polymer and the adhesion of the polymer ink to various plastic films will decrease, and if it is less than 0.1 mol %, it will cause long-chain alkyl The above-mentioned properties such as flexibility, abrasion resistance, and water resistance that can be obtained by introducing groups are not exhibited.

Another method for introducing long-chain alkyl groups into polyurethane urea polyamine molecules is the reaction of a urethane prepolymer with polyamines having long-chain alkyl groups, but it is difficult to produce a polymer with a high molecular weight. However, as in the present invention, after producing the polyurethaneurea polyamine, reacting it with a compound containing a long-chain alkyl group having high reactivity such as an incyanate group or an epoxy group is more likely to achieve the objective. I can do it.

The resin concentration of the polyurethaneurea polyamine solution used in the present invention is not particularly limited, but is preferably 151% to 60%, and the viscosity is 100 to 100,000 cps (2
5° C.) is practically suitable.

The printing ink obtained by diluting the polyurethaneurea polyamine solution produced as described above with a solvent commonly used in printing inks as necessary and mixing it with a pigment using a kneader such as a ball mill is as follows: It exhibits excellent adhesion to films such as polyethylene, polypropylene, polyester, and nylon, and prints have excellent properties such as surface strength, non-adhesiveness, water resistance, oil resistance, acid resistance, and alkali resistance. Excellent printability in gravure printing,
In addition to the printing effect, the adhesion between the printed surface and other plastic films (appropriate lamination) is also good.

In addition, when producing the printing ink, if necessary, the polyurethaneurea polyamine solution used in the present invention is mixed with a known ink resin such as nitrocellulose, polyvinyl chloride, polyamide, or (meth)acrylic acid polymer. I can do it.

In addition to being used as a printing ink vehicle, the polyurethaneurea polyamine solution used in the present invention can also be impregnated into textile materials, paper, leather, rubber, wood, metal concrete, plaster, glass, glass fibers, plastics, etc. Alternatively, it can be applied to these surfaces to improve performance such as surface modification, adhesion, and texture improvement, and is also useful as a binder, adhesive, etc. for civil engineering, construction, and various ceramic industries. It is.

Next, the present invention will be specifically explained with reference to Examples and Comparative Examples, but it goes without saying that the present invention is not limited to these.

In addition, all parts and percentages in the examples are based on weight unless otherwise specified.

Example 1 646.1 parts of dehydrated and dried polyoxytetramethylene glycol (molecular weight, approximately 2000), 149.1 parts of 1,4-butanediol, and 405 parts of toluene diisocyanate.
6 parts of methyl ethyl ketone and 300 parts of methyl ethyl ketone were placed in a round bottom flask equipped with a stirrer and a thermometer and reacted at 75°C for 6 hours to obtain a urethane prepolymer solution (concentration 80%) having 1.85% free isocyanate groups. However, since it was viscous at room temperature, it was diluted with methyl ethyl ketone to give a concentration of 60%.

In a separate round bottom flask, mix 19.2 parts of diethylene triamine and 823 parts of methyl ethyl ketone, and at room temperature add 978 parts of the above urethane prepolymer solution.
The solution was added dropwise, and after reacting at 50°C for 30 minutes, it was diluted by adding 200 parts of methyl ethyl ketone to obtain a polyurethaneurea polyamine solution with a concentration of 30% (total amine value 6.6, viscosity 10,640 cps (25°C)). .

This polyurethaneurea polyamine solution was cast onto a polyfluoroethylene resin plate with a smooth surface, dried at room temperature,
A uniform transparent film with a thickness of about 1 mm was obtained.

The mechanical properties (tensile test results) of this film were as follows.

100% modulus tensile strength elongation rate 97kg/
cm2 422 kg/cm2 540% Using the polyurethaneurea polyamine solution obtained here as a vehicle, a printing ink was prepared according to the following formulation.

Polyurethaneurea polyamine solution 110 parts (concentration 30%) Pigment (titanium oxide) 55 parts Methyl ethyl ketone 17.5 parts Ethyl acetate
10.5 parts toluene
7 parts total
200 parts of the above ingredients to an internal volume of 500 parts
ml hexagonal ball mill and kneaded for 16 hours to obtain a uniform and stable printing ink.

Example 2 Polyoxytetramethylene glycol (hydroxyl value 55.
3) 101 parts of methyl ethyl ketone and 348 parts of toluene diisocyanate were added to 202 parts and reacted at 70° C. for 3 hours with stirring to obtain a urethane prepolymer solution having 2.50% free isocyanate groups.

In another flask, 142 parts of methyl ethyl ketone and 383 parts of diethylene triamine were placed and mixed uniformly. 100 parts of the above urethane prepolymer solution was gradually added dropwise to this, and the mixture was reacted at 50°C for 30 minutes to achieve a concentration of 30
% polyurethaneurea polyamine solution was obtained.

A uniform and stable printing ink was obtained in the same manner as in Example 1 using this polyurethaneurea polyamine solution as a vehicle.

Example 3 A solution prepared by dissolving 4.44 parts of octadecyl isocyanate in 10.36 parts of methyl ethyl ketone was added to 245.8 parts of a polyurethaneurea polyamine solution produced in exactly the same manner as in Example 2, and the mixture was heated at 50°C. The reaction was carried out for 30 minutes to obtain a solution (30% concentration) of polyurethaneurea polyamine containing a long-chain alkyl group.

A uniform and stable printing ink was obtained in the same manner as in Example 1 using this polymer solution as a vehicle.

Example 4 3.90 parts of NEDOX 1518 olefin ox was used in place of the octadecyl isocyanate used in Example 3.
ide (ADM Chemicals, Ashlan
dOil & Refining Co. ) (α-olefin epoxide having 15 to 18 carbon atoms) to 9.1
A polyurethaneurea polyamine solution containing long-chain alkyl groups having a concentration of 30% was obtained in exactly the same manner as in Example 3, except that a solution dissolved in methyl ethyl ketone was used.

A uniform and stable printing ink was obtained in the same manner as in Example 1 using this polymer solution as a vehicle.

Comparative Example Using the same main raw materials as in Example 1, a polyurethane solution containing no amino groups or urea bonds was prepared as follows.

That is, 646.1 parts of dehydrated and dried polyoxytetramethylene glycol (molecular weight approximately 2000), 149.1 parts of 1,4-butanediol. 1 part, methyl ethyl ketone 26
Add 47 parts to a round bottom flask equipped with a stirrer and a thermometer and mix uniformly, then add 339 parts of toluene diisocyanate.
．． 4 parts and reacted at 75°C for 50 hours to give a concentration of
% homogeneous clear polyurethane solution was obtained.

In producing this polyurethane solution, a polyalkylene polyamine such as diethylenetriamine used in Example 1 was not used as a reaction raw material, so the polyurethane chain contained neither urea bonds nor amino groups.

A uniform printing ink was obtained in the same manner as in Example 1 using this polyurethane solution as a vehicle.

Example 5 The printing inks obtained in Examples 1 to 4 and Comparative Examples were used to print on corona discharge-treated polypropylene film, polyethylene film, polyester film, and nylon film using a bar coater, and dried at room temperature for 24 hours. Thereafter, the following tests were conducted on the obtained printed matter, and the results shown in Tables 1 to 3 were obtained.

(i) Sekisui Cellotape #3 manufactured by Sekisui Chemical Co., Ltd. on the adhesive printing surface
00 (width 24 mm) was applied, and one end of this cellophane tape was rapidly peeled off in a direction perpendicular to the printed surface, and the state of the printed surface was observed.

(ii) Surface Strength The state of the printed surface was observed when the film was scratched with a fingernail to the extent that the film did not tear.

(iii) Non-adhesive The presence or absence of stickiness of the printed surface due to finger contact was checked.

(iv) Water resistance After immersing the printed matter in water at 30° C. for 24 hours, the surface condition was observed.

(v) Oil resistance After immersing the printed matter in rapeseed oil for 24 hours at room temperature (approximately 25° C.), the surface condition was observed.

(vi) Acid resistance After immersing the printed matter in a 5% acetic acid aqueous solution at room temperature for 24 hours, the surface condition was observed.

(vii) Alkali resistance After the printed matter was immersed in a 5% caustic soda aqueous solution for 24 hours at room temperature, the surface condition was observed.

(vii) Resistance to kneading The surface condition of the printed matter was observed when it was hand-kneaded at room temperature with enough force to prevent the film from tearing.

Judgment ◎...Extremely good, no abnormalities at all ○...Good, almost no abnormalities, practical △...
...Slightly poor × ...Poor

Claims (1)

[Scope of Claims] 1. A polyurethaneurea polyamine obtained by reacting an excess amount of polyalkylene polyamine with a urethane prepolymer having isocyanate groups at both ends of the molecule, or partially converting the amine groups in the polyurethaneurea polyamine into C12 A printing ink comprising a long-chain alkyl group-containing polyurethaneurea polyamine obtained by reacting with an alkyl isocyanate having a C22 alkyl group or an α-olefin epoxide having a C12 to C22 alkyl group, a pigment, and an organic solvent.