JPS58189272A - Printing ink composition - Google Patents

Abstract

PURPOSE:To provide an ink compsn. showing excellent durability, suitable for printing onto resin films, by incorporating as a binder a soluble polyurethane resin prepared by the reaction of a particular high-MW diol, org. diisocyanate, and chain extender. CONSTITUTION:A polycarbonatediol, number-average MW of 700-3,000, prepared by reacting diols with diaryl carbonates is used as a high-MW diol. By the reaction of said high-MW diol (A), an org. diisocyanate compd. (e.g., 1,5- naphthylene diisocyanate) (B) (wherein the molar ratio of the hydroxyl group in component A to the isocyanate group in component B is about 1:2-1:5), and a chain extender (e.g, 4,4-diaminodicyclohexylmethane) (C), a polyurethane resin having a stress at 100% elongation of about 20-100kg/cm<2> is formed, which is suitable for use as a binder of printing inks.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing ink composition having excellent durability and suitable for printing on plastic films.

Printing ink compositions containing a polyurethane solution as a whole vehicle are used industrially because they have excellent adhesion to various plastic films such as polyester, nylon, and polypropylene.

However, the printing ink compositions that have been used so far do not produce tackiness in the printed area when the printed film is treated in hot water or left under normal lighting for a long period of time. Also, there were problems such as the printed portion peeling off due to strong friction, staining the surface of the candy, and adhering to flakes, which deteriorated the appearance and reduced the commercial value.

These problems are caused by deterioration, hydrolysis, etc. of the polyurethane resin used in the vehicle of the printing ink composition, and improving the hydrolysis resistance and oxidation resistance of the vehicle can solve the problem. is necessary.

When a polyurethane resin containing a polyester-based polymer diol as a soft segment is used as a vehicle, there is no problem in terms of oxidative deterioration resistance, but there is a problem with hydrolyzability9; When the entire vehicle is a polyurethane resin, there is almost no problem in terms of hydrolysis resistance, but the oxidative deterioration resistance decreases. When these two types of polymer geo-)v are used in combination, the respective drawbacks can be reduced, but the printing ink composition has both of the drawbacks, resulting in insufficient durability.

Adding an oxidative deterioration inhibitor is one of the methods for preventing oxidative deterioration of vehicles, but it is effective from the viewpoint of deterioration prevention, but plastic films printed with printing ink compositions containing deterioration inhibitors Considering that it may be used in food packaging, there remains a problem in terms of safety.
Not the preferred method of problem solving.

The present invention addresses the above-mentioned problems, provides durability,
The present invention provides a printing ink composition for plastics having the following properties. That is, the present invention provides a printing ink composition having a vehicle μ as a main component of a polyurethane resin soluble in an organic solvent obtained by reacting a high molecular weight diol, an organic diisocyanate, and a chain extender, wherein the high molecular weight diol component of the polyurethane resin is A printing ink composition characterized in that it is a high molecular weight geo-μ containing polycarbonate (polycarbonate) V having a number average molecular weight of 700 to 5000.

The high molecular weight diol component of the polyurethane resin used in the present invention may be entirely composed of polycarbonate diol, but it is preferable to use the same high molecular weight diol in combination, since this improves adhesion.

From the viewpoint of durability, it is preferable that the high molecular weight diol component of the pond is 50% by weight or less, but if a high degree of durability is not required, the high molecular weight diol component of the pond should be 50% by weight or less.
The above may be used in combination. However, if it exceeds 80%, the durability improvement effect decreases, which is not preferable.

The polycarbonate diol used in the present invention includes:
For example, propane-1,3-diol, butane-1,4-
diol and/or chitin-1゜6-diol,
Diols such as diethylene glycol, triethylene glycol/l/or tetraethylene glycol,
Mention may be made, by way of example, of polycarbonates di-)v, which are prepared by reaction with diaryl carbonates, such as diphenyl carbonate, or with phosgene. If the number average molecular weight of the polycarbonate diol exceeds 3000'i, the resulting polyurethane resin will be soft and sticky, and will cause blocking as a printing ink composition, which is not preferred. On the other hand, when the number average molecular weight is less than 700, the resulting polyurethane resin is somewhat hard and non-tacky, but when used as a printing ink composition, the adhesion is low.

The viscosity of the ink composition also increases over time, causing problems such as decreased printability. Therefore, the number average molecular weight of the polycarbonate diol is preferably in the range of 700 to 3,000.

The high molecular weight diols used together with the polycarbonate diol in the present invention include polyether polyols such as polymers or copolymers of ethylene oxide, propylene oxide, tetrahydrofuran, ethylene glycol, glopylene glycol, 1° 5-butanediol, 1,4
-Butanediol, neohentyl glycol, bentanediol, hexanediol, octanedio-", L
Saturated and unsaturated compounds such as 4-butynediol, 2-ethyl-1,5-hexanedio-/L/, hispheno-/1/A', diethylene glycol, triethylene glycol-/I/, dipropylene glycol, etc. In addition to polyester polyols obtained by dehydration condensation reaction from molecular glycols and dibasic acids, polyester polyols obtained by ring-opening polymerization of cyclic ester compounds, polybutadiene glycols, etc., bisphenol) Examples include glycols obtained by adding ethylene oxide or propylene oxide to vA, and further known polyols generally used in the production of polyurethane. Among these high molecular weight diols, combination use with polycaprolactone diol is particularly preferred since the adhesion to the plastic film is improved. The ratio of polycarbonate diol and polycaprolactone diol is 80/20 to 80/20 on a heavy TT basis.
A ratio of 20/80 is preferable because it is superior to printing ink compositions using conventional polyurethane resins in terms of durability and adhesion.

Examples of organic diisocyanate compounds include aromatic, aliphatic, and alicyclic polyisocyanates, such as tba1,
5-naphthylene diisocyanate, 4.4'-diphenylmethane diisocyanate, 4.4'-diphenyldimethylmethane diisocyanate, di- and tetraphalkyldiphenylmethane diisocyanate, 4.4'-dibenzyl isocyanate, 1°6-phnynylene diisocyanate $ ? , 1,4-phenylene diisocyanate, toluene diisocyanate, butane-1,4-diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate $-1-, hexane-1,6-diisocyanate,
Lysine diisocyanate, cyclohexane-1,4-diisocyanate, xylene diisocyanate, isophorone diisocyanate (IPDI)% dicyclohexylmethane-4,4'-diisocyanate (H12MDI)
) etc. are cited as representative examples. When yellowing of the vehicle due to light is a problem, alicyclic diisocyanates such as isophorone diisocyanate and dicyclohexylmethane-4,4'-diisocyanate are preferably used as the organic diisocyanate compound. These diisocyanate compounds may be used alone or in combination of two or more diisocyanate compounds.

Examples of chain extenders include aliphatic glycols such as ethylene glycol and 1,4-butanediol, alicyclic glycols such as 1,4-cyclohexane glycol, xylylene glycol/l/% 1,4- Glyco-p such as aromatic glycols such as dihydroxyethylene oxybenzene, aliphatic diamines such as ethylene diamine and propylene diamine, diamines such as alicyclic diamines such as isophorone diamine, heptanoethanolamine, jetanolamine, etc. Examples include alkanolamines, hydrazines, and hydrazides. These chain extenders can be used alone or in combination. Although the physical properties of the resulting polyurethane resin vary depending on the type of chain extender, particularly preferred extenders include alicyclic diamines such as 4,4'-diaminodicyclohexylmethane (H12DAM) and isophorone diamine (IPDA).

In the polyurethane resin used in the present invention, the molar ratio of the hydroxyl group of the high molecular weight diol to the isocyanate group of the organic diisocyanate is preferably in the range of 1:2 to 1:5. When the amount of isocyanate groups decreases even at a molar ratio of 1:2, the chain length of the hard segment becomes shorter, and unless a low molecular weight high molecular weight diol is used, stickiness will occur and (9) blocking will become a problem. . On the other hand, if the molar ratio greatly exceeds 1:5, the chain length of the octad segments becomes long, the viscosity of the polyurethane solution changes over time, thickens, and fluidity decreases, and the resulting polyurethane resin Since it is also hard, it is not satisfactory as a printing ink composition (carrier).

The proportion of hard segments in the resulting polyurethane resin varies depending on the molecular weight of the high molecular weight diol, and even if the molar ratio of hydroxyl groups to isocyanate groups is within the above range,
The printing ink composition of the present invention can be obtained from extremely flexible to hard, but the stress at 100% elongation is 2.
Particularly preferred are polyurethane resins having a viscosity in the range of 0 to 110 degrees/cd. If the stress is less than 20 kg7c4, there will be problems with adhesive resistance and solvent resistance, and if the stress is less than 110 kg/d
If the weight exceeds -2, problems will occur in adhesion, flexibility, and dilutability, so if there is no particular need, it is best to use the polyurethane resin as a total vehicle in the range of 20 to 110 kg/d.

Solvents used in the present invention include alcohols such as ethanol and isopropano-μ, acetone, (10) ketones such as methyl ethyl ketone and cyclohequinanone, ethers such as dioxane and tetrahydrofuran, and aromatic carbonates such as toluene. Examples include hydrogen, halogenated hydrogen such as chlorobenzene, trichrene, and perchlorene, and esters such as ethyl acetate and butyl acetate. Preferred are isofuropanol, acetone, methyl ethyl ketone, ethyl acetate, and toluene from the viewpoint of solubility and economy.

The resin concentration and viscosity of the polyurethane resin solution of the present invention do not need to be particularly limited, but from the viewpoint of workability, economy, and physical properties, it should be within the range of 5 to 60% by weight, preferably 10 to 50% by weight and at 20°C. Viscosity is 1,000-500+0
A range of 00 cps is preferred.

In the present invention, the method for producing the polyurethane resin solution is not particularly limited, and any known method may be used. For example, a method in which a diisocyanate component and a diol component are reacted at a molar ratio with an excess of isocyanate groups to create a prepolymer with isocyanate groups at both ends and then extended with a chain extender; A two-step method, such as a method of reacting with a diisocyanate component, or a one-step method, such as a method of reacting all three components (diol component, diisocyanate component, and chain extender) in one step, can be carried out. In the above method, the polymerization is carried out in the presence or absence of a solvent. If polymerization is carried out in the absence of a solvent, a solvent is added afterwards, or after the entire solid resin has been produced, it is dissolved in a solvent to form a resin solution. A method of manufacturing is used.

Into the above polyurethane solution, a coloring agent such as a pigment, a solvent, a surfactant for improving ink fluidity and modifying a surface film as necessary, and additives for the same are added,
Printing ink can be manufactured by kneading using a common ink manufacturing apparatus such as a ball mill.

The printing ink composition of the present invention exhibits excellent adhesion to films of polyethylene, polypropylene, polyester, nylon, etc., and has better hydrolysis resistance than conventional printing ink compositions using polyurethane resin as a vehicle. It exhibits excellent durability and oxidative deterioration resistance. Furthermore, although this is an unexpected effect and the reason is not clear, the printing ink composition of the present invention has good dispersion stability of the pigment, and even when left standing for a long period of time, the printing ink composition does not remain at the bottom of the container. No pigment deposits occur, and the viscosity of the printing ink composition does not change and thicken over time. Therefore, it has become possible to safely produce a printing ink composition using only a polyurethane resin as a vehicle, which has conventionally had concerns about dispersion stability.

In the production of the printing ink composition, polymers such as nitrocellulose, polyvinyl chloride, vinyl chloride vinyl acetate copolymer, polyamide, and acrylic acid ester polymers may be mixed, if necessary.

Next, the present invention will be specifically explained with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Parts in Examples and Comparative Examples represent parts by weight unless otherwise specified.

In addition, in the examples, adhesiveness (15) among printability was evaluated using Sellotape adhesiveness. The ink compositions of Examples and Comparative Examples were completely printed on polyester film using a gravure proofing machine, and after being left for one day, Cellochive was attached to the printed area and when it was rapidly peeled off, it did not come off at all. Rabbits that were partially peeled off were classified as good, and those that were partially peeled off were classified as completely defective.

Blocking resistance was measured by folding each printed material so that the printed side was inward, tightly tightening it with a vacuum cleaner, leaving it in an air bath kept at 40°C overnight, then unfolding the sample again and visually judging the resistance at that time. Those with no resistance at all were judged as good, those with very slight resistance were judged as good, and those with obvious resistance or those in which peeling was difficult were judged as poor.

Of durability, hydrolysis resistance is measured by immersing a printed plastic film in hot water at 100°C.
After the elapse of time, the presence or absence of stickiness of the printed portion was examined, and those with stickiness were evaluated as having poor hydrolysis resistance. Heat deterioration resistance was determined by leaving a printed plastic film in an air bath at 120°C for 96 hours and checking whether the printed part was sticky. It was evaluated that If no stickiness was observed even after one week or more had passed, it was judged as good.

Those exhibiting intermediate durability were rated as good.

Example 1 300 parts of 1.6-hexanediol polycarbonate (PC) having an average molecular weight of 2,000 was placed in an 11-fourth 7-fusco equipped with a stirrer, thermometer, Dimroth, and N2 gas inlet tube.
Isophorone diisocyanate (IPDI) 66.7
The parts were mixed and reacted at 95°C for 10 hours to release the free NCO.
A urethane prepolymer with a percentage of 3.44% was obtained. Next, 244.5 parts of methyl ethyl ketone (MEK) was added to make a homogeneous solution, and then isophorone diamine (IPDA) was added.
25.5 parts and di-n-buty/l/7 as a reaction terminator
Mino 2j 6 parts iMEK 226.3 parts and isopropano/
To a solution of 117.7 parts of L dissolved in a mixed solvent, 611.2 parts of the solution was added dropwise to the ME of the urethane prepolymer at room temperature. After the dropwise addition, the temperature was raised and the mixture was reacted at 50°C for 3 hours. This polyurethane resin solution has a viscosity of 12,500 c
ps/20°C/40% (15) The stress at only 100 degrees of elongation was 50 kg/cd.

Next, titanium oxide (Ishihara Sangyo Co., Ltd., Thai Bake-820
) 25 parts of the polyurethane solution (polymer concentration 40%)
) 37.5 parts, and methyl ethyl ketone (reagent If&
) 25.0 parts Kneaded for 24 hours in a gold powder mill, and then subjected to ethyl acetate/l/29 parts k 1) iJ to obtain a printing ink composition. This ink composition was used to print on nylon and polyester films on a Gutsubia printing press. The printing results were as shown in Table 1.

This printing ink composition showed no change in viscosity even after long-term storage and had good dispersibility.

Example 2 150 parts of 1,6-hequitinedio-rubolycarbonate with an average molecular weight of 2000, polycaprolactone (PCL) i50s with an average molecular weight of 2000, and 66.7 parts of isophorone diisocyanate were mixed together and reacted at 95°C for 10 hours. A urethane prepolymer having a free NCO% of 3.44% was obtained. Next, 244.5 parts of methyl ethyl ketone was added to make a homogeneous solution, and then 23.5 parts of sophorone diamine (16) and 2 parts of di-n-butylamine were added.
．． 36 parts MEK 226.5 parts, isoproper tool 1
To a solution dissolved in 17.7 parts of a mixed solvent, 611.2 parts of the homogeneous solution of the urethane prepolymer was added dropwise at room temperature. After the dropwise addition, the temperature was raised to 50'C and the mixture was reacted for 5 hours.

The resulting polyurethane resin solution has a viscosity of 136P/20
°C/40%. The stress at 100% elongation is 45
kg, it was j.

A printing ink composition was prepared in the same manner as in Example 1, and the printability and durability were examined. Table 1 shows the results. There was almost no increase in the viscosity of the printing ink composition over time.

Example 3 200 parts of 1,6-hexanediol polycarbonate having a number average molecular weight of 2000, 50 parts of polycaprolactof having an average molecular weight of 2000, 50 parts of polytetramethylene glyco-IV (PTG) having an average molecular weight of 2000, and 66.0 parts of isophorone diisocyanate. Mix with 7 parts and heat to 95°C.
After reacting for 10 hours, a urethane prepolymer having a free NCO% of 5.44 was obtained. Next, 252.4 parts of methyl ether (17) and methyl ketone were added to make a homogeneous solution, and then 23.5 parts of isophorone diamine and di-lobe 4-
611 parts of the MEK solution of the urethane prepolymer was added dropwise to a solution dissolved in a mixed solvent of 2j/l/amine 2j6 parts (HMEK 232.7 parts and isopropanol 121j parts) at room temperature, and stirred at 50°C after the dropwise addition. This polyurethane resin solution had a viscosity of 150P/20°C.
/4Qwt%. The stress at 100% elongation is 4 y
kq,/cd.

A printing ink composition was prepared using the same formulation as in Example 1,
Printability and durability were investigated. The results are shown in Table 1. The viscosity of the printing ink composition was constant during storage, and the dispersion stability was good.

Examples 4 to 10 Various polyurethane solutions were prepared in the same manner as the polyurethane resin solution preparation method described in Example 1, and printing ink compositions were prepared from them, and the printability and durability were examined. Ta. Table 1 summarizes the results.

(18) Example 11 1,6-hexanediol polycarbonate (number average molecular weight 2ooo) and polycabrolactone di-/L/(
A mixture of isophorone diisocyanate and 4,4'-dicyclohexylmethane diisocyanate (7μ ratio 1 :1) was added at a ratio of 2.2 moles and reacted at 100°C for 9 hours to obtain a urethane prepolymer. After adding methyl ethyl ketone to this to make a prepolymer solution with a concentration of 60% by weight, isophoronediamine was added at 1.1 mol and di-n-butylamine was added at 0.1 mol per 1 mol of polymer di-/L.
An extender solution is prepared by dissolving amine mixed in a molar ratio, methyl ethyl ketone, and isopropyl alcohol in a mixed solvent with a weight ratio of 2:1, and this extender solution is added to the prepolymer solution that is being stirred vigorously to extend the chain. The polyurethane solution concentration was 40% and the viscosity was 150F (40%).
%, 20°C) was obtained.

(20) A printing ink composition was prepared in the same manner as in Example 1 using this polyurethane resin solution. This printing ink composition was superior to conventional products in terms of dispersibility, adhesion, and durability.

Comparative Example 1 Polytetramethylene glyco/with a number average molecular weight of 2000
Mix L/300 parts and 66.7 parts of isophorone diisocyanate and react at 95°C for 10 hours to reduce free NCO%.
A urethane prepolymer having a content of 3.44% was obtained. After adding 244.5 parts of methyl ethyl ketone (MEK) to this to make a homogeneous solution, 23.5 parts of isophorone diamine and 2.36 parts of di-n-butylamine i MEK 226.5 parts
611.2 parts of the MEK solution of the urethane prepolymer was added dropwise at room temperature to a solution of 117.7 parts of the urethane prepolymer in a mixed solvent of

After the dropwise addition, the temperature was raised to 50°C for 3 hours. The viscosity of this polyurethane resin solution is 12.500 cps/20
℃/40%. A printing ink composition was prepared in the same manner as in Example 1 using the above polyurethane resin, and its printability and durability were examined, and the results are shown in Table 121).

Comparative Example 2 Polybutylene adipate geo- with a number average molecular weight of 2000
/L/300 parts and 78.6 parts of 4,4'-dicyclohexylmethane diisocyanate were mixed at 95°C for 10 minutes.
A urethane prepolymer with a free NCO% of 3.32% was obtained after extensive time-spreading. Next, 244.5 parts of MEK was added to make a urethane prepolymer solution with a concentration of 60%, and 23.3 parts of isophoronediamine (!
f4-y7 mini y 2.36 parts and -q MEK 22
M E K of the urethane prepolymer was dissolved in a mixed solvent of 6 parts and 117.7 parts of Isoglobanol/I.
Solution 16519f was added dropwise at room temperature. After the dropwise addition, the temperature was raised to 50°C and the mixture was reacted for 3 hours. The viscosity of this polyurethane resin solution was 15,000 cps/20°C/40%. All printing ink compositions were prepared using the above polyurethane resin in the same manner as in Example 1, and the printability and durability were examined, and the results are summarized in Table 1.

Patent applicant: RiRashi Co., Ltd. Agent: Ken Honda (22)

Claims (1)

[Scope of Claims] 1. In a printing ink composition having as a main binder an organic solvent-soluble polyurethane resin obtained by reacting a high molecular weight diol, an organic diisocyanate, and a chain extender, the high molecular weight diol of the polyurethane resin A printing ink composition characterized in that the ink is a high molecular weight diol containing a polycarbonate diol having a number average molecular weight of 700 to 3,000. 2. The printing ink composition according to claim 1, wherein the 714 diisocyanate is an alicyclic diisocyanate. 3. The printing ink composition according to claim 1 or 2, wherein the chain extender is an alicyclic diamine. 4. The printing ink composition according to claim 2 or 3, wherein the molar ratio of the hydroxyl group of the high molecular weight diol to the isocyanate group of the organic diisocyanate is in the range of 1:2 to 1:5. 5. The printing ink composition according to claim 4, wherein the polyurethane resin film has a modulus of 20 to 110 kg/d at 100% elongation.