JPH0830162B2 - Printing ink for plastics - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention is superior to plastics, especially plastic films such as polypropylene, polyester and nylon even when used in a one-pack type. The present invention relates to a printing ink having adhesiveness, printability, suitability for laminating, and boil / retort resistance.

(Prior Art) Printing inks for plastics, especially plastic films such as polypropylene, polyester, nylon, etc., include one-component type inks containing a linear polyurethane resin soluble in an organic solvent as a main binder, and organic solvent type inks. A two-component type in which a mixture of a soluble linear polyurethane resin and a polyisocyanate compound is used as a main binder is used, and it is properly used depending on the type and application of the material to be printed.

One-component printing ink has good adhesiveness to plastics and good laminating suitability for plastic films, but it is not sufficiently compatible with applications requiring high resistance such as boiling sterilization and retort sterilization. was there.

In addition, although the two-component type can sufficiently support applications requiring high resistance, from the viewpoint of storage stability, a polyisocyanate compound must be added to and mixed with the component containing the linear polyurethane resin immediately before use. However, there were drawbacks such as complicated work, lack of stability of residual meat, and difficulty of reuse of residual meat.

As a means for improving these drawbacks, Japanese Patent Laid-Open No. 14913/1982
No. 23, proposes a printing ink binder comprising a polyurethane resin formed from a polyol having an amide bond and an ester bond obtained from a polymerized fatty acid, an organic diamine and a polyhydric alcohol, and an organic diisocyanate. When such a printing ink binder is used as a one-pack type, although the residual thickness stability of the printing ink, the adhesion to the plastic film, the blocking resistance, and the lamination strength when used as a laminin ink are improved, The resistance to boiling and retort when used as a laminate ink were still insufficient.

(Problems to be Solved by the Invention) The present invention, even when used in a one-pack type, has excellent adhesiveness, printability, laminating suitability to plastics, especially plastic films such as polypropylene, polyester, and nylon. And a printing ink having boil / retort resistance.

[Structure of Invention]

(Means for Solving the Problem) The present invention relates to (A) a dimeryl diisocyanate derived from an amidated and reduced polymerized fatty acid, (B)
Printing for plastics using as a main binder a polymer polyol having no amide bond and not a polymerized fatty acid, and optionally a (C) chain extender and / or a terminal blocker It is ink.

In the present invention, (A) dimeryl diisocyanate is derived from a compound obtained by amidating and reducing a polymerized fatty acid. Polymerized fatty acids include C ₁₈ unsaturated fatty acids such as oleic acid and linoleic acid, drying oil fatty acids or semi-drying oil fatty acids, and lower monoalcohol esters of these fatty acids in the presence or absence of a catalyst. Molecularly polymerized products are listed, and various products are commercially available. Typical examples are C ₁₈ monocarboxylic acid 0 to 5% by weight, C ₃₆ dimer acid 70 to 98% by weight, and C ₅₄
Some consist of 0-30% by weight of trimeric acid. A part of (A) may be replaced with another organic polyisocyanate. When a part of (A) is replaced with another organic polyisocyanate, the isocyanate equivalent of (A) / (A)
It is preferable that the sum of isocyanate equivalents of the organic polyisocyanate other than (A) and (A) is 0.2 to 1.0.

In the present invention, as the polymer polyol (B) which does not have an amide bond and is not a polymerized fatty acid system, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1 Saturated or unsaturated low-molecular diols such as 1,4-butanediol, neopentyl glycol, pentanediol, hexanediol, octanediol, 1,4-butylenediol, diethylene glycol, triethylene glycol and dipropylene glycol, if necessary Glycerin, trimethylolpropane, trimethylolethane, 1,2,6-butanetriol,
Trifunctional or higher functional polyols such as pentaerythritol and sorbitol, adipic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, succinic acid,
Dicarboxylic acids such as oxalic acid, malonic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and their anhydrides, and, if necessary, trimellitic acid, pyromellitic acid, and other polyfunctional trifunctional compounds. Polyester polyols obtained by dehydration condensation or polymerization of divalent carboxylic acids or their anhydrides; polyester polyols obtained by ring-opening polymerization of cyclic ester compounds; polycarbonate polyols; polybutadiene glycols; bisphenol A with ethylene oxide or Examples thereof include polymer polyols that are usually used in the production of polyurethane resins, such as glygoles obtained by adding propylene oxide. Among these,
From the viewpoint of dispersion stability of the pigment and oil resistance when used as a laminate ink, it is preferable to use polycaprolactone polyol or polypropylene adipate as a main component. The (B) polymer polyol preferably has a molecular weight of about 500 to 3000. (B) When the molecular weight of the polymer polyol is less than 500, the adhesiveness with the plastic tends to be slightly decreased, and when it exceeds 3000, the viscosity of the obtained printing ink is high and the printability is slightly low. Tends to decline. However, a part of the high molecular weight polyol is replaced with ethylene glycol, 1,2-propanediol, 1,3-propanediol,
1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, hexanediol, octanediol, 1,4-butylenediol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerin, trimethylolpropane,
It does not prevent the use of low molecular weight polyols such as trimethylolethane, 1,2,6-butanetriol, pentaerythritol and sorbitol.

Examples of the chain extender (C) include ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4-diamine, and the like.
Amines having a hydroxyl group such as 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxypropylethylenediamine and di-2-hydroxypropylethylenediamine can also be used. Further, as the (D) terminal stopper, a dialkylamine such as di-n-butylamine can be used.

The polyurethane resin used in the present invention is
(A), if necessary, an organic polyisocyanate other than (A), (B), and if necessary, low molecular weight polyols are reacted at a ratio such that the isocyanate group becomes excessive to obtain a prepolymer having a terminal isocyanate group. , The obtained prepolymer in an appropriate solvent, that is, an aromatic solvent such as benzene, toluene, xylene, etc. which is usually used as a solvent for printing ink; an ester solvent such as ethyl acetate, butyl acetate; methanol, ethanol , Alcoholic solvents such as isopropyl alcohol, n-butanol; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone; or mixtures thereof,
Two-step method of reacting with (C) and / or (D) as required, or (A), if necessary, organic polyisocyanate other than (A), (B), and optionally low-molecular polyol It is produced by a one-step method in which the compounds and, if necessary, (C) and / or (D) are reacted at once in a suitable solvent. Among these methods, the two-step method is preferable to obtain a uniform polyurethane resin. Also, when polyurethane resin is manufactured by the two-step method,
The total (equivalent ratio) of isocyanate groups / (C) and / or (D) amino groups of the prepolymer is 1 / 0.90 with respect to the prepolymer of (C) and / or (D).
It is desirable to carry out the reaction in a ratio of ˜1.30, preferably 1.01 to 1.20. When the equivalent ratio of isocyanate group and amino group is less than 1 / 1.30, (C) and / or () remain unreacted, the polyurethane resin turns yellow, and odor is generated after printing. It may happen. The molecular weight of the polyurethane resin thus obtained is preferably in the range of 5,000 to 100,000. When the molecular weight of the polyurethane resin is less than 5000, the drying properties of the printing ink for plastics obtained, the strength of the printing film and the oil resistance tend to be slightly lower, and when it exceeds 100000, the printing for plastics obtained As the ink viscosity increases, the redissolvability decreases slightly, and the gloss of the printed film tends to decrease slightly.

In the printing ink for plastics of the present invention, in addition to the main binder made of the above polyurethane resin, if necessary,
Sub-binders such as nitrocellulose resin, polyvinyl chloride resin, vinyl chloride-vinyl acetate copolymer resin, polyamide resin, acrylic resin are mixed.

In the printing ink for plastics of the present invention, in addition to the above-mentioned binder, if necessary, a colorant such as a pigment, an organic solvent, a surface active agent for improving the fluidity and film state of the ink, an additive such as wax, etc. Appropriately blended, printed on a plastic such as a plastic film by a method such as gravure printing or flexographic printing, and dried. Printed plastics include cellophane, moisture-proof cellophane, olefin resins such as polyethylene and polypropylene,
Polyester such as polyethylene terephthalate, polybutylene terephthalate, vinyl chloride resin, vinylidene chloride resin, styrene resin, vinyl acetate resin, vinyl alcohol resin, polyamide, etc., uniaxially or biaxially stretched or stretched Film or sheet, a film or sheet that has or has not been surface-treated such as corona discharge treatment, low-temperature plasma treatment, or a laminate of these. Moreover, the drying temperature is usually about 40 to 60 ° C.

When the printing ink for plastics of the present invention is used as a laminating ink, the printing ink of the present invention is printed on the above-mentioned plastic film or sheet, and the printed surface of the printed film or sheet is an anchor coating agent or urethane type. Alternatively, another film or sheet or an aluminum foil is attached or extruded and laminated with or without a modified polyolefin-based adhesive to form a laminate. For retort sterilization applications, a laminate of polyester film / polypropylene film, polyamide film / polypropylene film, polyester film or aluminum foil / polypropylene film is suitable, and for boil sterilization applications polyester film / polyethylene film A laminate having a structure such as a polyamide film / polyethylene film is suitable. Anchor coat agents include organotitanium-based, polyisocyanate-based, polyethyleneimine-based, polybutadiene-based, etc., and resin for extrusion lamination is low density polyethylene, linear low density polyethylene,
Medium density polyethylene, high density polyethylene, ethylene-
Vinyl acetate copolymer or saponified product thereof, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer, polyethylene terephthalate, polyamide,
Examples include polymethylpentene-1, Iomer. Extrusion lamination is carried out by applying an extrusion coating on the printed surface of the film by heating the resin melted by heating at 120 to 310 ° C. and immediately cooling it with a cooling means such as a cooling roll. The laminate thus obtained is formed into a container shape such as a bag,
It is filled with medicines and medical equipment and sterilized by heating. The conditions for heat sterilization are usually 85 ℃ for 30 minutes for low temperature boiling sterilization, 100 ℃ for 30 minutes for high temperature boiling sterilization, 120 to 130 ℃ for 30 minutes for retort sterilization, and 140 for high retort sterilization.
It is about 145 ° C for about 10 minutes.

(Examples) Hereinafter, the present invention will be described with reference to Examples. In the examples, "parts" means "parts by weight" and "%" means "% by weight".

Synthesis Example 1 100 parts of poly (1,2-propylene adipate) glycol having an average molecular weight of 2000 and dimeryl diisocyanate "DDI-1410" (trade name, manufactured by Henkel Hakusui Co., Ltd.) 62.7
Parts at 100 ° C. for 6 hours to form a terminal isocyanate prepolymer, and 133 parts of toluene is further added to this,
A solvent solution of the terminal isocyanate prepolymer was obtained.

Next, to a mixture of 8.0 parts of isophorone diamine, 0.7 parts of di-n-butylamine, 133 parts of methyl ethyl ketone and 133 parts of isopropyl alcohol, 296 parts of the solvent solution of the obtained terminal isocyanate prepolymer was gradually added at room temperature, Next, react at 50 ° C for 3 hours to obtain solid content of 30%, 2
A polyurethane resin solution a having a viscosity of 250 cP at 5 ° C. was obtained.

Synthesis Example 2 From the following raw materials, in the same manner as in Synthesis Example 1, solid content 30
%, A polyurethane resin solution b having a viscosity of 400 cP at 25 ° C. was obtained.

Polycaprolactone glycol (average molecular weight 2000) 100 parts "DDI-1410" 62.7 parts Toluene 133 parts Isophoronediamine 8.0 parts Di-n-butylamine 0.7 parts Methyl ethyl ketone 133 parts Isopropyl alcohol 133 parts Synthesis Example 3 Synthesis Examples 1 and 1 from the following raw materials Similarly, solid content 30
%, A polyurethane resin solution c having a viscosity of 350 cP at 25 ° C. was obtained.

Polycaprolactone glycol (average molecular weight 1000) 100 parts Dimeryl diisocyanate 118 parts Toluene 183 parts Isophorone diamine 15.1 parts Di-n-butylamine 1.9 parts Methyl ethyl ketone 183 parts Isopropyl alcohol 183 parts Synthesis Example 4 Synthetic Example 4 Solid content 30
%, A polyurethane resin solution d having a viscosity of 250 cP at 25 ° C. was obtained.

Glycol used in Synthesis Example 1 100 parts Dimeryl diisocyanate 31.3 parts Isophorone diisocyanate 11.6 parts Toluene 118 parts Isophorone diamine 7.7 parts 2-Hydroxyethyl ethylenediamine 0.5 parts Di-n-butylamine 0.7 parts Methyl ethyl ketone 118 parts Isopropyl alcohol 118 parts Synthesis example 5 below From the raw material of
%, A polyurethane resin solution e having a viscosity of 300 cP at 25 ° C. was obtained.

Glycol used in Synthesis Example 1 100 parts Isophorone diisocyanate 18.1 parts Toluene 97 parts Isophorone diamine 6.0 parts Di-n-butylamine 0.5 parts Methyl ethyl ketone 97 parts Isopropyl alcohol 97 parts Synthesis Example 6 In the same manner as in Synthesis Example 1 from the following raw materials, Solid content 30
%, A polyurethane resin solution f having a viscosity of 400 cP at 25 ° C. was obtained.

Polycaprolactone polyol (average molecular weight 400) 100 parts Dimeryl isocyanate 296 parts Toluene 338 parts Isophorone diamine 37.8 parts Di-n-butylamine 1.2 parts Methyl ethyl ketone 338 parts Isopropyl alcohol 338 parts Synthetic example 7 Polymerized fatty acid "Versadym 216" (Henkel Hakusui (stock) ), Trade name) 1000 parts, azelaic acid 86 parts, hexamethylenediamine 183 parts and dibutyltin dilaurate 6.0 parts are reacted at 200 ° C. for 2 hours, cooled to 130 ° C., and then 1,6-hexanediol 126 Parts were added, and the mixture was reacted at 200 ° C. for 2 hours and further maintained at 200 ° C. for 1 hour under a vacuum of 200 mmHg to obtain a polyol having an amide bond and an ester bond.

To 100 parts of the obtained polyol, 138 parts of toluene and 80 parts of methyl ethyl ketone were added and dissolved by heating, 27.6 parts of dimeryl diisocyanate was added, and the mixture was reacted at 80 ° C. for 4 hours. Further, 80 parts of isopropyl alcohol was added to obtain a solid content of 30 parts.
%, Polyurethane resin solution with a viscosity of 6500 cP at 25 ℃ g
I got

Example 1 Composition of white printing ink Titanium white 30 parts Polyurethane resin solution a 50 parts Toluene 10 parts Isopropyl alcohol 10 parts Aiiro printing ink composition Phthalocyanine blue "Rionol Blue" (trade name, manufactured by Toyo Ink Mfg. Co., Ltd.) 10 parts Polyurethane resin solution a 40 parts Toluene 20 parts Isopropyl alcohol 10 parts Each mixture of the above composition was kneaded with a ball mill to obtain white printing ink and tinted printing ink, and for each 100 parts of the printing ink obtained, The viscosity was adjusted by adding 35 parts of toluene and 15 parts of isopropyl alcohol, and the two-color gravure rotary printing machine equipped with two gravure plates with a plate depth of 35 μm was used to print the white-colored printing ink in the first unit. The second unit is a 20 μm thick corona discharge treated polypropylene film “Pyrene 2161”
(Toyobo Co., Ltd., trade name, abbreviated as PP below) and 15 μm thick corona discharge treated nylon film “Emblem” (Unitika Co., Ltd., trade name, abbreviated as NY) discharge. Printed at a printing speed of 100 m / min on one side of the treated surface and polyethylene terephthalate film "Ester E5100" (trade name, manufactured by Toyobo Co., Ltd., abbreviated as PET hereinafter) with a thickness of 11 µm at 40 to 50 ° C. It was dried in a vacuum to obtain a printing film.

Table 1 shows the results of evaluations of the adhesiveness of the printing ink, the blocking resistance, and the temporal stability of the residual printing ink of the obtained printing film. The evaluation method and the display of the evaluation result are as follows.

Adhesiveness of printing ink The adhesiveness of the printing ink in the overprinted area of the white-colored printing ink and the white-colored printing ink of the obtained printing film was evaluated by the cellophane adhesive tape peel test. The display of the evaluation result is 5: No peeling.

4: Area ratio of more than 0% and less than 20% peeled.

3: More than 20% and 50% or less of the area ratio peeled.

2: More than 50% and 70% or less of the area ratio peeled.

1: More than 70% and 100% or less of the area peeled.

Blocking resistance Of the printing films obtained, using printing PP, the printed surfaces were superposed and the printed and non-printed surfaces were superposed, respectively, under a load of 1 kg / cm, 40 ° C, relative After storing at 80% humidity for 24 hours, they were peeled off and evaluated for blocking resistance. As for the display of the evaluation result, 5: no blocking was observed.

4: There was resistance during peeling.

3: A small area was peeled off in a part, and the gloss of the printed surface became large.

2: Blocking occurred in large area.

1: Blocking occurred on the entire surface.

Stability of Printing Ink Residue Over Time The printing ink residue was stored at room temperature for 1 week, and the fluidity of the printing ink residue and changes in the state were evaluated. The display of the evaluation result is ◯: No change.

Δ: A slight increase in viscosity was observed, but there was no problem in practical use.

X: Remarkably thickened, part or all gelled, or
The change in hue was remarkable.

Examples 2 to 4 and Comparative Examples 1 to 3 Instead of polyurethane resin solution a, polyurethane resin solution b (Example 2), polyurethane resin solution c (Example 3), polyurethane resin solution d (Example 4), Polyurethane resin solution e (Comparative Example 1), polyurethane resin solution f (Comparative Example 2), polyurethane resin solution g
In the same manner as in Example 1 except that (Comparative Example 3) was used, a printing film was obtained, and the results of evaluating the adhesiveness of the printing ink, the blocking resistance, and the temporal stability of the residual printing ink are shown in Table 1. Show.

Comparative Example 4 Triisocyanate curing agent 3 obtained by reacting 100 parts of each of the white printing ink and the light-colored printing ink obtained in Comparative Example 1 at a ratio of 3 mol of isophorone diisocyanate to 1 mol of trimethylolpropane.
Then, 35 parts of toluene and 15 parts of isopropyl alcohol were added to adjust the viscosity in the same manner as in Comparative Example 1.
Printing is performed to obtain a printing film, and the results of evaluating the adhesiveness of the printing ink, the blocking resistance, and the temporal stability of the residual printing ink are shown in Table 1.

Examples 5 to 8 and Comparative Examples 5 to 7 In Example 5, in Example 1, in Example 6, in Example 2, in Example 7, in Example 3, and in Example 8.
Then, in Example 4, in Comparative Example 5, in Comparative Example 1, in Comparative Example 6, in Comparative Example 2, and in Comparative Example 7, in Comparative Example 3, the print surface of each of the obtained print films was coated with polyethyleneimine-based anchor coat. Agent (AC agent) "EL-420" (trade name, manufactured by Toyo Morton Co., Ltd.) or polyisocyanate anchor coating agent (AC
Agent) "EL-443A and B" (trade name, manufactured by Toyo Morton Co., Ltd.) is applied, and low-density polyethylene "Yukaron LK-30" (trade name, manufactured by Mitsubishi Petrochemical Co., Ltd.) is applied on the coated surface. Extrusion lamination was performed to obtain a laminate. For each of the obtained laminates, the laminate strength of the overprinted portion of the white color printing ink and the white color printing ink was measured, and each of the laminates obtained using "EL-443A and B" was loaded at 130 ° C under load. The bag was heat-sealed at 2 kg / cm for 1 second, and the resulting bag was filled with water or vinegar / salad oil / tomato ketchup = 1/1/1 (weight ratio) soup, and the content was water. In the case of 100, the boiling point was 100 ° C for 30 minutes, and in the case of soup, it was boiled at 85 ° C for 30 minutes, and the appearance after the treatment was evaluated. The evaluation was performed using 5 bags each of the test samples. Table 2 shows the results of the laminate strength measurement and the appearance evaluation after the boiling test.

 In addition, the display of the appearance evaluation results after the boiling test was good in all of the 5 bags.

Δ: Delamination or blistering occurred in a part of 2 to 3 bags.

×: Delamination or blister occurred in all 5 bags.

Examples 9 to 12 and Comparative Examples 8 to 10 In Example 9, in Example 1, in Example 10, in Example 2, in Example 11, in Example 3, and in Example 12,
In Example 4, in Comparative Example 8, in Comparative Example 1, in Comparative Example 9, in Comparative Example 2, and in Comparative Example 10, the printed surfaces of printed NY and printed PET of the printed films obtained in Comparative Example 3 respectively. Adhesive "AD900 and RT-5" for polyurethane dry lamination
(Toyo Morton Co., Ltd., trade name, solid content 25%)
After coating using a 60μm gravure plate and drying, a polypropylene film with a thickness of 60μm “Trefan 37
01 "(trade name of Toray Industries, Inc.) is dry laminated,
A laminated body was obtained. The laminate strength of the obtained laminate was measured to evaluate the retort resistance. Table 3 shows the measurement results and evaluation results.

The unit of laminate strength is the same as in Table 2. For retort resistance, the obtained laminate was heat-sealed with "Torphan 3701" inside to make a bag,
Fill the resulting bag with soup of vinegar / salad oil / tomato ketchup = 1/1/1 (weight ratio) as contents and mix at 115 ° C for 3
Evaluation was performed outside after boiling treatment for 0 minutes. The evaluation was performed using 5 bags each of the test samples. The display of the evaluation result is the same as in the case of Table 2.

[Effects of the Invention] According to the present invention, plastics,
In particular, it has become possible to obtain printing inks having excellent adhesion to plastic films such as polypropylene, polyester, and nylon, printability, suitability for laminating, and boil retort resistance.

Claims (1)

[Claims] 1. A dimeryl diisocyanate derived from (A) amidated and reduced polymerized fatty acid, and (B).
The main binder is a polymer polyol having no amide bond and not a polymerized fatty acid system, and a polyurethane resin obtained by reacting (C) a chain extender and / or (D) a terminal terminator, if necessary. Printing ink for plastics.