JPH07126564A - Binder for printing ink - Google Patents

Abstract

PURPOSE:To provide a binder for a printing ink having excellent adhesion to various plastic films, suitability for lamination, suitability for boiling, suitability for retorting and long-term stability. CONSTITUTION:A binder for a printing ink, containing a polyurethane prepared by reacting a polymer polyol with a diisocyanate compound, a chain extender and optionally a chain terminator, wherein 3-70wt.%, based on the polyurethane solid content, hydrogenated polyisoprene having a degree of hydrogenation of C-C double bonds of 80% or above, a number-average molecular weight in the range of 400-10000 and having at least one hydroxyl group or amino group is used as the constituent of the polyurethane, is provided.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a binder for printing inks. More specifically, it relates to a binder for printing ink useful as a coating agent for plastic films, plastic sheets or synthetic resin molded products.

[0002]

2. Description of the Related Art In recent years, various plastic films have come to be used as packaging materials in accordance with the diversification of objects to be packaged and the sophistication of packaging technology, and printing inks for such plastic films have various performances. It is being requested. In particular, in the field where various plastic films are laminated and used to make packaging materials more beautiful and sophisticated, a wide range of adhesion of printing inks, as well as various post-processing such as laminating processing suitability, boil suitability, retort suitability, etc. Aptitude is needed.

In particular, a laminated film having an aluminum foil in the middle is required to have boil suitability and retort suitability. In the field of packaging materials based on transparent base materials, base film, oriented polypropylene (OPP)
Is also required to be suitable for laminating (normally referred to as PP direct laminating suitability), which can be directly coated with molten polypropylene without using an anchor coating agent.

Conventionally, polyurethane has been widely used as a binder for printing inks in such fields because of its wide suitability for base films such as nylon and polyester. However, although polyurethane has an excellent adhesive force alone to a polyester film or a nylon film, it does not have sufficient adhesive force to a polyolefin film such as a polyethylene film or a polypropylene film, which is a general-purpose film, and is suitable for laminating, especially PP. The direct laminating suitability was insufficient. Further, when the polyurethane is used as a so-called two-pack type, the pot life is short and there are various restrictions on work. On the other hand, a chlorinated polyolefin having a relatively low degree of chlorination such as chlorinated polypropylene is used as a binder for a printing ink of a polyolefin to which PP direct lamination is applied. However, although the chlorinated polyolefin exhibits a good adhesive force to a polyolefin film, it does not have a sufficient adhesive force to a polyester film or a nylon film, and has insufficient boiling suitability and retort suitability. Further, the compatibility of chlorinated polyolefin and polyurethane is poor and it is difficult to use a mixture of the two. Therefore, depending on the application such as various base film, various laminating or retort processing,
Binders for printing inks had to be manufactured.

As a binder for a printing ink that solves these problems, JP-A-5-209146 proposes polyurethane having a polyisoprene skeleton.
However, the suitability for PP direct laminating of the polyurethane having the polyisoprene skeleton has not been sufficiently improved. Furthermore, since the polyisoprene skeleton has a double bond, it is inferior in light resistance, heat resistance, oxygen resistance, etc., and physical properties such as adhesive strength, suitability for laminating, suitability for boil, suitability for retort, etc. are deteriorated with time, and a printed film is formed. It had the drawback of being colored.

[0006]

The present invention has excellent adhesiveness and suitability for laminating (in particular, PP direct laminating suitability) for any of various plastic films such as polyester, nylon, polyethylene and polypropylene as a material to be printed, It is an object of the present invention to provide a one-pack type printing ink binder which has boilability and retort ability and is stable over time.

[0007]

Means for Solving the Problems As a result of intensive investigations by the present inventors to provide a binder for a printing ink that can solve the above problems, a specific hydrogenated polyisoprene containing a hydroxyl group or an amino group is formed. It has been found that the polyurethane used as a component can solve such a problem. The present invention has been completed based on such new knowledge.

That is, the present invention relates to a polymer polyol,
In a binder for a printing ink, which comprises a polyurethane obtained by reacting a diisocyanate compound, a chain extender and optionally a chain length terminating agent, a hydrogenation rate of a carbon-carbon double bond as a constituent of the polyurethane. Is 80% or more and the number average molecular weight is 400 to 1,000.
It relates to a binder for a printing ink, which comprises using hydrogenated polyisoprene in the range of 0 and having one or more hydroxyl groups or amino groups per molecule in an amount of 3 to 70% by weight of the polyurethane solid content.

In the present invention, as a constituent of polyurethane, the hydrogenation rate of carbon-carbon double bonds is 80% or more, the number average molecular weight is in the range of 400 to 10,000, and one or more per one molecule. It is essential to use hydrogenated polyisoprene having the hydroxyl groups or amino groups of Since the hydrogenated polyisoprene has the same structure as the alternating copolymer of ethylene and propylene and has a higher chemical affinity for polypropylene than polyisoprene, the hydrogenated polyisoprene skeleton is introduced into polyurethane. By doing so, it is intended to further improve the adhesiveness of the binder for printing ink, particularly the PP direct laminating suitability. Furthermore, by hydrogenating the double bonds of polyisoprene, it is attempted to improve the deterioration of physical properties such as adhesive strength of printing ink binder, suitability for laminating, suitability for boil, suitability for retort, etc., and coloring of the printing film. To do.

Therefore, in the present invention, it is essential to use hydrogenated polyisoprene having a hydroxyl group or an amino group, which has a hydrogenation rate of carbon-carbon double bond of 80% or more. It is preferably 90% or more. If the hydrogenation rate is less than 80%, the PP direct laminating suitability cannot be sufficiently improved.

In the present invention, the number average molecular weight is 400 to
Hydrogenated polyisoprene having hydroxyl or amino groups in the range of 10,000 is used. Number average molecular weight is 4
If it is less than 00, the adhesiveness, particularly suitability for PP direct lamination, is insufficient, and if it exceeds 10,000, the resulting polyurethane resin solution tends to be poor in stability over time. Generally, when hydrogenated polyisoprene having a hydroxyl group or an amino group is used as the polymer polyol component, the number average molecular weight is 700 to 10,000,
It is preferable to use one in the range of 1000 to 5000, and 400 to 70 when used as a chain extender component.
Those within the range of less than 0 are used, and those used within the range of 400 to 10,000 when used as the extension terminator component.

It is essential that the hydrogenated polyisoprene has one or more hydroxyl groups or amino groups per molecule. This is because hydrogenated polyisoprene having no hydroxyl group or amino group per molecule remains in the polyurethane unreacted, so that the stability of the resin solution of the polyurethane with time becomes insufficient. The hydrogenated polyisoprene having a hydroxyl group or an amino group is used as a polymer polyol component or a chain extender component when it has two or more hydroxyl groups or amino groups in the molecule,
When it has one hydroxyl group or amino group in the molecule, it is used as an extension terminator component.

The hydrogenated polyisoprene having a hydroxyl group or an amino group can be easily produced by a method of producing a polyisoprene having a hydroxyl group or an amino group and then hydrogenating it by a known means, as shown below. You can

For example, polyisoprene having a hydroxyl group or an amino group is an azo compound having hydrogen peroxide, a hydroxyl group or an amino group (for example, 2,2'-azobis [2-methyl-N- (2-hydroxyethyl)). -Propionamide] or the like) or a peroxide having a hydroxyl group or an amino group (for example, cyclohexanone peroxide or the like) as a polymerization initiator, and isoprene monomers can be radically polymerized. The amount of the polymerization initiator used is 100 parts by weight of the isoprene monomer,
The amount of hydrogen peroxide is about 1.2 to 12 parts by weight, the amount of azo compound is about 9.2 to 92 parts by weight, and the amount of peroxide is about 7.6 to 76 parts by weight. Although the polymerization can be carried out in the absence of a solvent, it is preferable to carry out the polymerization in the presence of a solvent such as ethanol or isopropanol because the reaction can be easily controlled. The reaction temperature is usually about 100 to 150 ° C, and the reaction time is about 5 to 15 hours.

The polyisoprene having a hydroxyl group or an amino group is prepared by anionically polymerizing an isoprene monomer using a catalyst such as naphthalene dilithium to prepare an isoprene living polymer, and further reacting with a monoepoxy compound or a monoaziridinyl compound. Can also be manufactured. The polymerization can be carried out in the absence of a solvent as in the radical polymerization, but it is preferable to carry out the polymerization in the presence of a solvent such as hexane or cyclohexane because the reaction can be easily controlled. The reaction temperature is usually about 50 to 100 ° C., and the reaction time is 1
It is about 10 hours.

As a method for hydrogenating the obtained polyisoprene having a hydroxyl group or an amino group, known means using a homogeneous catalyst or a heterogeneous catalyst can be adopted.

When a homogeneous catalyst is used, saturated hydrocarbons such as hexane and cyclohexane, benzene, toluene,
Aromatic hydrocarbon such as xylene is used as a solvent at room temperature to 150
The hydrogenation reaction is carried out for about 1 to 24 hours at a reaction temperature of about C and a hydrogen pressure of atmospheric pressure to 50 kg / cm ² . Examples of homogeneous catalysts include Ziegler catalysts which are a combination of a transition metal halide and aluminum, or an alkyl compound such as an alkaline earth metal or an alkyl metal, and the amount of the catalyst used is 0.1 per double bond of the polyisoprene. It is about 01 to 0.1 mol%.

When a heterogeneous catalyst is used, hexane,
Saturated hydrocarbons such as cyclohexane, aromatic hydrocarbons such as benzene, toluene and xylene, diethyl ether,
Using ethers such as tetrahydrofuran and dioxane, alcohols such as ethanol and isopropanol as a solvent, and a reaction temperature of normal temperature to 200 ° C. and normal pressure to 100 kg.
The hydrogenation reaction is performed under a hydrogen pressure of / cm ² for about 1 to 48 hours. Examples of the heterogeneous catalyst include catalysts such as nickel, cobalt, palladium, platinum, rhodium, and ruthenium, or a carrier of these catalysts on a carrier such as silica, alumina, diatomaceous earth, and activated carbon. It is about 0.5 to 10% by weight with respect to 100 parts by weight of isoprene.

The hydrogenated polyisoprene having a hydroxyl group or an amino group used in the present invention may be the one produced by the above-mentioned method as it is, and it is a commercially available product.
For example, "TH-1", "TH-21", "TH-3"
1 ”(both manufactured by Kuraray Co., Ltd.) and the like may be used as they are.

The hydrogenated polyisoprene having a hydroxyl group or an amino group must be used as a constituent of polyurethane in an amount of 3 to 70% by weight of the solid content of the polyurethane. It is preferably 5 to 50% by weight. When the amount of hydrogenated polyisoprene having a hydroxyl group or amino group is less than 3% by weight, the adhesiveness, particularly PP direct laminating suitability, is insufficient, and when it exceeds 70% by weight, a polyurethane resin obtained is obtained. The stability of the solution over time tends to be poor.

Next, the constituent components of the polyurethane of the present invention will be described. In the present invention, hydrogenated polyisoprene having a specific hydroxyl group or amino group is used as an essential constituent component of the polyurethane as described above, but in the production of the polyurethane of the present invention, a known polymer polyol, chain extension The agent and the chain length terminating agent can be used within the range where the hydrogenated polyisoprene having a hydroxyl group or an amino group is in the above-mentioned usage amount.

As the polymer polyol component, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol is used. , Pentanediol,
Various known saturated or unsaturated glycols such as 3-methyl-1,5-pentanediol, hexanediol, octanediol, 1,4-butynediol, dipropylene glycol or n-butylglycidyl ether,
Alkyl glycidyl ethers such as 2-ethylhexyl glycidyl ether, monocarboxylic acid glycidyl esters such as versatic acid glycidyl ester, and adipic acid, maleic acid, fumaric acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, oxalic acid Polyester diols obtained by dehydration condensation of dibasic acids such as acids, malonic acid, glutaric acid, pimelic acid, azelaic acid, sebacic acid and suberic acid, or acid anhydrides or dimer acids corresponding thereto; cyclic esters Polyester polyols obtained by ring-opening polymerization of compounds; polyether polyols such as polymers or copolymers of ethylene oxide, propylene oxide, tetrahydrofuran, etc .; other, polycarbonate polyols, polybutadiene glycols, bispheno In general the various known polymer polyols used in the production of polyurethane, such as glycols, which are E by adding ethylene oxide or propylene oxide Le A can be mentioned. In the case of a polymer polyol obtained from the above low molecular glycols and dibasic acid, up to 5 mol% of the low molecular glycol component is glycerin, trimethylolpropane, trimethylolethane, 1,2,6. It can be substituted with various low-molecular-weight polyols such as -hexanetriol, 1,2,4-butanetriol, sorbitol and pentaerythritol.

The number average molecular weight of the polymer polyol is
It is appropriately determined in consideration of the solubility, drying property, blocking resistance, etc. of the resulting polyurethane, and usually 700 to 100.
It is about 00, preferably within the range of 1000 to 5000. When the number average molecular weight is less than 700, the printability tends to be poor due to the decrease in solubility.
If it exceeds 00, the drying property and blocking resistance tend to be lowered.

Aromatic diisocyanate compounds,
Various known aliphatic or alicyclic diisocyanates can be used. For example, 1,5-naphthylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-diphenyldimethylmethane diisocyanate, 4,4′-dibenzyl isocyanate,
Dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-
Phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-
1,4-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, lysine diisocyanate, Typical examples thereof include dicyclohexylmethane-4,4-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane diisocyanate, m-tetramethylxylylene diisocyanate, and dimerisocyanate obtained by converting a carboxyl group of dimer acid into an isocyanate group. Can be given as.

Examples of the chain extender include ethylenediamine, propylenediamine, hexamethylenediamine,
Triethylenetetramine, diethylenetriamine, isophoronediamine, dicyclohexylmethane-4,4'-
Examples include diamines. In addition, 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2
-Hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, and other diamines having a hydroxyl group in the molecule, and low-molecular glycols and dimerdiamines obtained by converting the carboxyl group of dimer acid to an amino group described in the section of the polyester diol. Is also a representative example.

Furthermore, examples of the chain length terminator used as necessary include dialkylamines such as di-n-butylamine and alcohols such as ethanol and isopropyl alcohol.

The method for producing the polyurethane of the present invention is not particularly limited. For example, a polymer polyol component and a diisocyanate compound are reacted under conditions of excess isocyanate groups, and a prepolymer having an isocyanate group at both ends is used. A two-step process of preparing a polymer (preferably an isocyanate content of 0.5-10%) and then reacting it in a suitable solvent with a chain extender and optionally a chain terminator, and a polymeric polyol component, Although any one-step method in which a diisocyanate compound, a chain extender and, if necessary, a chain length terminating agent are reacted at once in a suitable solvent can be adopted, it is easy to obtain a uniform polymer solution. It is preferable to adopt the method. During production of these polyurethanes, various known catalysts such as tin-based catalysts such as stannous octylate may be added.

When the polyurethane used in the present invention is produced by the two-step method, the conditions for reacting the polymer polyol component and the diisocyanate compound are not particularly limited, except that the isocyanate groups are excessive.
Equivalent ratio of hydroxyl group / isocyanate group is 1 / 1.2-1 to 1/1
It is preferable that the reaction is performed within the range of 3. Also,
The conditions for reacting the obtained prepolymer with a chain extender and optionally a chain length terminating agent are not particularly limited, but when the free isocyanate group at both ends of the prepolymer is 1 equivalent In addition, the total equivalent of active hydrogen capable of reacting with the isocyanate group in the chain extender is 0.5 to
It is preferably in the range of 2.0 equivalents (particularly in the range of 0.5 to 1.3 equivalents when the active hydrogen-containing group is an amino group). When the amount of active hydrogen is less than 0.5 equivalent, the drying property, blocking resistance and film strength are not sufficient, and when the amount of active hydrogen is more than 2.0 equivalents, the chain extender is unreacted. It remains as it is, and the odor tends to remain on the printed matter.

As the solvent used in these production methods, aromatic solvents such as benzene, toluene, xylene and the like which are well known as solvents for printing inks; methanol, ethanol, isopropanol, n-butanol and the like are usually used. Examples thereof include alcohol solvents; ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate. These solvents may be used alone or as a mixture of two or more kinds.

The number average molecular weight of the polyurethane of the present invention thus obtained is usually in the range of about 5,000 to 150,000. When the number average molecular weight is less than 5,000, the drying property, blocking resistance, film strength, oil resistance, etc. of the printing ink using this as a vehicle are apt to decrease, while when it exceeds 150,000, the polyurethane resin The viscosity of the solution (binder) increases,
The gloss of printing ink tends to decrease. Further, the resin solid content concentration of the polyurethane solution is not particularly limited and may be appropriately determined in consideration of workability at the time of printing, but is usually 1
5-60% by weight, viscosity is 50-100,000 cP / 25
It is practically preferable to adjust the temperature within the range of ° C.

Further, in the present invention, chlorinated polyolefins such as polyurethane, nitrified cotton, chlorinated polyethylene, chlorinated polypropylene and chlorinated ethylene / propylene other than those of the present invention may be used, if necessary, unless the performance of the binder of the present invention is deviated. Further, resins such as chlorosulfonated polyolefin, ethylene / vinyl acetate copolymer or its chloride, chlorosulfonate, maleic acid resin or vinyl chloride / vinyl acetate copolymer can be used in combination.

The binder for printing ink of the present invention thus obtained is appropriately blended with a colorant, a solvent, and if necessary, a surfactant, a wax and other additives for improving the ink fluidity and the ink surface film. Ball mill,
The printing ink composition of the present invention can be produced by kneading with a conventional ink producing device such as an attritor or a sand mill.

[0033]

INDUSTRIAL APPLICABILITY According to the present invention, excellent adhesiveness, laminating processability (particularly PP direct laminating processability), and boiling process can be applied to any of various plastic films such as polyester, nylon, polyethylene, and polypropylene as printed materials It is possible to provide a one-pack type printing ink binder which is suitable for retort processing and is stable over time. In addition, the printing ink binder of the present invention does not deteriorate in physical properties such as adhesive strength, suitability for laminating, suitability for boil, suitability for retort, and the like, and the film is not colored over time.

[0034]

The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. In addition, in each example, a part represents a weight part.

Example 1 A hydroxyl group-containing hydrogenated polyisoprene (number average molecular weight 3000, hydrogenation rate 98%, hydroxyl group number 2 was placed in a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube. 19) 500 parts, adipic acid and 3-methyl-1,5
Charging 500 parts of a polyester polyol (number average molecular weight 3000, hydroxyl group number 2.0) obtained from pentanediol and 155 parts isophorone diisocyanate,
After reacting at 120 ° C. for 6 hours under a nitrogen stream, it was cooled to 50 ° C. Then add isophorone diamine 51
Parts, 13 parts of di-n-butylamine, 1896 parts of toluene and 948 parts of isopropyl alcohol were added, and the mixture was reacted at 50 ° C. for 3 hours with stirring. The obtained polyurethane resin solution (hereinafter referred to as resin solution A) had a resin solid content concentration of 30% and a viscosity of 1000 cP / 25 ° C. The number average molecular weight of the polyurethane resin was 25,000. The proportion of hydrogenated polyisoprene in the solid content of polyurethane was 41%.

Example 2 1000 parts of a polyester polyol (a number average molecular weight of 2000 and a number of hydroxyl groups of 2.0) obtained from adipic acid and 1,4-butanediol and 222 parts of isophorone diisocyanate were placed in the same reactor as in Example 1. Was charged and reacted at 120 ° C. for 6 hours under a nitrogen stream. Further, a hydroxyl group-containing hydrogenated polyisoprene (number average molecular weight 50
0, hydrogenation rate 98%, hydroxyl group number 2.2) 184 parts and toluene 352 parts were added, and the mixture was reacted at 120 ° C. for 12 hours with stirring and then cooled to 50 ° C. Next, this was added with 1853 parts of toluene and 111 of isopropyl alcohol.
Diluted with 4 parts. The obtained polyurethane resin solution (hereinafter referred to as resin solution B) has a resin solid content concentration of 30%,
The viscosity was 270 cP / 25 ° C. The number average molecular weight of the polyurethane resin was 15,000. The ratio of hydrogenated polyisoprene in the solid content of polyurethane is 1
3%.

Example 3 In the same reactor as in Example 1, 1000 parts of polyester polyol (number average molecular weight 2000, hydroxyl group number 2.0) obtained from adipic acid and 1,4-butanediol and 222 parts of isophorone diisocyanate were used. Was charged and reacted at 120 ° C. for 6 hours under a nitrogen stream. Furthermore, a hydroxyl group-containing hydrogenated polyisoprene (number average molecular weight 180
0, hydrogenation rate 96%, number of hydroxyl groups 1.3) 246 parts, 1,
After adding 38 parts of 4-butanediol and 367 parts of toluene and reacting at 120 ° C. for 12 hours with stirring, 50
Cooled to ° C. It was then diluted with 1977 parts toluene and 1172 parts isopropyl alcohol. Obtained polyurethane resin solution (hereinafter referred to as resin solution C)
Has a resin solid content of 30% and a viscosity of 500 cP / 25
It was ℃. The number average molecular weight of the polyurethane resin was 20,000. The proportion of hydrogenated polyisoprene in the solid content of polyurethane was 16%.

Example 4 In a reactor similar to Example 1, 250 parts of hydroxylated hydrogenated polyisoprene (number average molecular weight 3000, hydrogenation rate 98%, number of hydroxyl groups 2.19), adipic acid and 3-methyl-
Polyester polyol obtained from 1,5-pentanediol (number average molecular weight 3000, hydroxyl group number 2.0) 7
After charging 50 parts and 152 parts of isophorone diisocyanate and reacting at 120 ° C. for 6 hours in a nitrogen stream, 5
Cooled to 0 ° C. Next, 50 parts of isophoronediamine, 13 parts of di-n-butylamine and 189 of toluene were added to this.
0 part and 945 parts of isopropyl alcohol were added, and the mixture was reacted at 50 ° C. for 3 hours while stirring. The obtained polyurethane resin solution (hereinafter referred to as resin solution D) had a resin solid content concentration of 30% and a viscosity of 1200 cP / 25 ° C. The number average molecular weight of the polyurethane resin was 24,000. The proportion of hydrogenated polyisoprene in the solid polyurethane content was 20%.

Comparative Example 1 In the same reactor as in Example 1, 500 parts of hydroxylated hydrogenated polyisoprene (number average molecular weight 2700, hydrogenation rate 61%, number of hydroxyl groups 2.19), adipic acid and 3-methyl-
Polyester polyol obtained from 1,5-pentanediol (number average molecular weight 3000, hydroxyl group number 2.0)
After charging 500 parts and 156 parts of isophorone diisocyanate and reacting under a nitrogen stream at 120 ° C. for 6 hours,
Cooled to 50 ° C. Then, 47 parts of isophoronediamine, 14 parts of di-n-butylamine and 18 parts of toluene
94 parts and 947 parts of isopropyl alcohol were added, and the mixture was reacted under stirring at 50 ° C. for 3 hours. The obtained polyurethane resin solution (hereinafter referred to as resin solution E) had a resin solid content concentration of 30% and a viscosity of 800 cP / 25 ° C. The number average molecular weight of the polyurethane resin was 22,000. The proportion of hydrogenated polyisoprene in the solid content of polyurethane was 41%.

Comparative Example 2 A polyester polyol (number average molecular weight 3000, hydroxyl group 2.0) obtained from adipic acid and 3-methyl-1,5-pentanediol was placed in the same reactor as in Example 1.
After 1,000 parts and 222 parts of isophorone disiocyanate were charged, the mixture was reacted at 120 ° C for 6 hours under a nitrogen stream, and then cooled to 50 ° C. Then, 74 parts of isophoronediamine, 17 parts of di-n-butylamine, 2042 parts of toluene and 1021 parts of isopropyl alcohol were added thereto, and the mixture was reacted at 50 ° C. for 3 hours while stirring. The obtained polyurethane resin solution (hereinafter referred to as resin solution F) had a resin solid content concentration of 30% and a viscosity of 900 cP / 25 ° C. The number average molecular weight of the polyurethane resin is 2000.
It was 0.

Comparative Example 3 Hydroxyl group-containing hydrogenated polyisoprene (number average molecular weight 300
0, hydrogenation rate 98%, hydroxyl group number 2.19) 500 parts, polyester polyol obtained from adipic acid and 3-methyl-1,5-pentanediol (number average molecular weight 300
0, hydroxyl group number 2.0) 500 parts, isophorone diisocyanate 81 parts and toluene 2522 parts were mixed at room temperature to obtain a polyurethane resin solution (hereinafter referred to as resin solution G). The proportion of hydrogenated polyisoprene in the solid content of polyurethane was 46%.

(Preparation of Ink) 40 parts of the resin solutions A to G obtained in Examples 1 to 4 or Comparative Examples 1 to 30, 30 parts of titanium oxide, 15 parts of toluene and 15 parts of methyl ethyl ketone.
A part of the mixture was kneaded to prepare a white printing ink. For the resin solutions A to F, a white printing ink that can be used for printing could be prepared, but for the resin solution G, immediately after the white printing ink was prepared, separation and gelation occurred, and a white printing that could be used for printing. No ink was obtained.

(Preparation of Printing Film) The viscosity of the obtained printing ink was adjusted with a mixed solvent of toluene, methyl ethyl ketone and isopropyl alcohol (weight ratio 60:30:10), and then a gravure plate having a plate depth of 35 μm was provided. A corona-treated stretched polypropylene film (OPP), a corona-treated polyethylene terephthalate (PET) and a corona-treated nylon film (NY) were printed by gravure proofing and dried at 40 to 50 ° C to prepare a printing film.

(Evaluation of Performance of Printing Film) The obtained printing film was evaluated for adhesion, extrusion laminating strength, dry laminating strength, boil suitability, retort suitability and PP direct laminating suitability by the following test methods. The evaluation results are shown in Table 1.

(1) Adhesiveness After leaving the printing film for 1 day, a cellophane tape was attached to the printing surface, and the appearance of the printed film which was rapidly peeled off was visually judged according to the following criteria. ◎ ---- The printed film did not peel off at all. ○ --- 80% or more of the printed film remained on the film. Δ --- 50% to less than 80% of the printed film remained on the film. X ---- Less than 50% of the printed film remained on the film.

(2) Extrusion Laminate Strength Polyethyleneimine-based anchor coating agents for OPP and isocyanate-based anchor coating agents for PET and NY were used for printing films, and molten polyethylene was laminated by an extrusion laminating machine. Further PET and N
Y was aged at 40 ° C. for 2 days. On the third day after laminating, the sample was cut into a width of 15 mm, and a T-type peel strength (unit g / 15
mm) was measured.

(3) Dry Lamination Strength A urethane adhesive was used for the printing film, a CPP (unstretched polypropylene) film was laminated by a dry laminating machine, and aged at 40 ° C. for 3 days. Immediately after aging or after being left for 6 months after aging, the sample was cut into a width of 15 mm, and the T-type peel strength was measured by the same method as the extrusion laminate strength.

(4) Suitability for boil and suitability for retort Immediately after dry-laminating the NY printing film or after leaving it for 6 months for dry-laminating, the laminate is made into a bag, and a mixture of water / salad oil is put in as a content, and after sealing, After heating at 100 ° C. for 30 minutes for boiling suitability and at 120 ° C. for 30 minutes for retort suitability, the appearance change of the laminate film was observed. ○ --- There is no abnormality in the film. Δ --- A small part of the film is delaminated or slight blisters occur. X --- A part of the film is delaminated or blisters are generated.

(5) PP direct laminating suitability The OPP printing film was laminated by a laminating machine.
The molten polypropylene was directly laminated, left for half a day, and then the T-type peel strength was measured by the same method as the extrusion laminate strength.

[0050]

[Table 1]

Claims (4)

[Claims] 1. A binder for a printing ink, comprising a polyurethane obtained by reacting a polymer polyol, a diisocyanate compound, a chain extender and, if necessary, a chain length terminating agent, carbon as a constituent of the polyurethane. A hydrogenated polyisoprene having a hydrogenation rate of carbon double bonds of 80% or more, a number average molecular weight of 400 to 10,000, and one or more hydroxyl groups or amino groups per molecule; A binder for printing ink, characterized in that 3 to 70% by weight of the polyurethane solid content is used. 2. The hydrogenated polyisoprene having a number average molecular weight in the range of 700 to 10,000 and having two or more hydroxyl groups or amino groups per molecule is used as the polymer polyol component. Binder for printing ink. 3. A chain extender component having a number average molecular weight of 4
The printing ink binder according to claim 1 or 2, wherein hydrogenated polyisoprene having a hydroxyl group or an amino group in the range of 0 to less than 700 is used. 4. A hydrogenated polyisoprene having a number average molecular weight in the range of 400 to 10,000 and having one hydroxyl group or amino group per molecule is used as the chain length terminator component. Or the binder for printing ink according to the item 3.