JP5918323B2 - Binder for printing ink and printing ink using the same - Google Patents

Description

  The present invention relates to a printing ink binder and printing ink. More specifically, it does not contain toluene, has excellent resolubility and anti-blocking properties, is non-chlorine, and is suitably used for any of various plastic films such as polyester, nylon, polyethylene, and polypropylene as printed materials. The present invention relates to a printing ink binder and printing ink.

  Conventionally, solvents such as toluene, methyl ethyl ketone, and ethyl acetate have been mixed and used as solvents for printing inks for plastic films. Among these, toluene is an inexpensive and relatively high boiling point solvent that suppresses drying of the ink on the gravure plate during printing, and the ink in the cells of the gravure plate remaining without transferring to the film contacts the new ink in the ink pan. Thus, since it is sufficiently re-dissolved, it is suitable for preventing cell clogging and has been used as a main solvent for printing ink. A polyurethane resin using 3-methylpentane adipate diol is known as a binder having good re-solubility in printing inks using a solvent containing toluene (see, for example, Patent Document 1).

  However, in recent years, revisions to the Industrial Safety and Health Act have tightened the environmental concentration regulations for toluene, and it has become necessary to improve the printing work environment. In addition, the implementation of the PL Act requires a reduction in residual solvent, which is a relatively high boiling point. In particular, there has been a growing demand for solvent-based printing inks that do not contain toluene, which tends to remain in the printed matter. However, printing inks that use only polyester-based polyurethane resins as binders without using toluene and only solvents such as MEK and ethyl acetate are inks that remain in the gravure plate cells because the solvent dries quickly. However, there is a problem that the ink is dried until it comes into contact with the new ink in the ink pan, is not sufficiently re-dissolved, and the plate is clogged, and printing cannot be performed with a plate having a shallow depth. A polyurethane resin using a polyester diol in which a linear diol and a branched diol are used together is known as a binder having good resolubility in a printing ink not containing toluene (for example, see Patent Document 2). However, in recent years, further increase in printing speed has been demanded, and further improvement in re-dissolvability is required. However, there is a problem in coexistence with re-dissolvability and blocking resistance in a trade-off relationship. ing.

  In addition, printing inks that use polyurethane resin as a binder have excellent adhesion to polyester films and nylon films alone, but are sufficient for polyolefin films such as general-purpose films such as polyethylene films and polypropylene films. Printing ink with chlorinated polyolefin as a binder shows good adhesion to polyolefin film, but there is not enough adhesion to polyester film or nylon film. There is a problem of being restricted.

  It has been proposed to use a mixture of polyurethane resin and chlorinated polyolefin for the purpose of improving the adhesion to polyester film, nylon film and polyolefin film and for general use in various plastic films (for example, patents) Reference 3).

  However, in recent years, efforts to address environmental issues have become important, and it is strongly desired to suppress the generation of harmful substances in the disposal of used products. Chlorinated polyolefins contain chlorine. Therefore, there is a problem that harmful substances are generated during incineration and there is a risk of polluting the environment.

Japanese Unexamined Patent Publication No. 63-161065 Japanese Patent No. 2976291 JP-A-10-251594

  The object of the present invention is excellent in re-solubility in solvent and blocking resistance even when used in printing inks that do not contain toluene as a solvent, does not contain chlorine, and is suitable for various plastic films such as polyester, nylon and polyolefin. An object of the present invention is to provide a printing ink binder that has excellent adhesiveness and can be used for various plastic films.

  The inventors of the present invention have arrived at the present invention as a result of intensive studies to achieve the above object. That is, the present invention is a printing ink binder comprising a polyurethane resin (U) obtained by reacting an active hydrogen component (A) and an organic polyisocyanate component (B), wherein the active hydrogen component (A) is A printing ink binder comprising the polylactone polyether polyol (a1), the polyester polyol (a2) and the polyether polyol (a3) represented by the general formula (1); It is a printing ink formed.

［式中、Ｒ^１は炭素数３〜１１のアルキレン基であり、複数個あるＲ^１はそれぞれ同一でも異なっていてもよく、Ｒ^２は炭素数２〜１２のアルキレン基であり、複数個あるＲ^２はそれぞれ同一でも異なっていてもよく、ａ及びｃはそれぞれ０以上の整数で、かつ５≦ａ＋ｃ≦１６を満たし、ｂは５〜２５０の整数である。］

[Wherein, R ¹ is an alkylene group having 3 to 11 carbon atoms, a plurality of R ¹ may be the same or different, and R ² is an alkylene group having 2 to 12 carbon atoms, and there are a plurality of R ¹ R ² may be the same or different, a and c are each an integer of 0 or more, 5 ≦ a + c ≦ 16 is satisfied, and b is an integer of 5 to 250. ]

  The binder for printing inks of the present invention is excellent in re-dissolvability and blocking resistance even when an ink solvent not containing toluene is used, and the ink remaining in the gravure plate cell during printing is re-dissolved. Since there is very little clogging of the material and it is non-chlorine, there is no risk of generating harmful substances during incineration and polluting the environment, and it has excellent adhesion to various plastic films such as polyester, nylon and polyolefin. And it can be used universally as a binder for printing ink for various plastic films.

  The binder for printing ink of the present invention comprises a polyurethane resin (U) obtained by reacting an active hydrogen component (A) with an organic polyisocyanate component (B), and the active hydrogen component (A) is represented by the general formula (1). ), A polyester polyol (a2) and a polyether polyol (a3).

R ¹ in the general formula (1) is an alkylene group having 3 to 11 carbon atoms, are preferred from the viewpoint of blocking resistance are 1,5-pentylene group, also in each of R ¹ when there are a plurality of identical May be different.

R ² is an alkylene group having 2 to 12 carbon atoms, preferably an alkylene group having 2 to 5 carbon atoms, more preferably an ethylene group, 1,2-propylene group, 1,2- 1,3- or 2,3-butylene group and 2-methyl-1,4-butylene group, particularly preferred are ethylene group and 1,2-propylene group, and when there are a plurality of R ² groups, Each may be the same or different.

  a and c are each an integer of 0 or more, satisfy 5 ≦ a + c ≦ 16, satisfy 6 ≦ a + c ≦ 14, and satisfy 7 ≦ a + c ≦ 12 from the viewpoint of blocking resistance and re-solubility. More preferably.

  b is usually from 5 to 250, preferably from 10 to 200, more preferably from 15 to 100, from the viewpoint of resolubility and blocking resistance.

  The polylactone polyether polyol (a1) is obtained by ring-opening addition of a lactone monomer to the polyether polyol. Examples of the polyether polyol include those similar to the polyether polyol (a3) described later, and polyoxypropylene glycol, polyoxyethylene glycol and poly (oxyethylene / oxypropylene) glycol are preferable from the viewpoint of re-solubility. [The bonding mode of poly (oxyethylene / oxypropylene) may be random or block, but is preferably random. More preferred is polyoxypropylene glycol. (A1) may be used individually by 1 type, and may use 2 or more types together.

  Examples of the lactone monomer include lactones having 4 to 12 carbon atoms (γ-butyrolactone, ε-caprolactone, γ-valerolactone, and the like). Among the lactone monomers, ε-caprolactone is preferable from the viewpoint of blocking resistance. A lactone monomer may be used individually by 1 type, or may use 2 or more types together.

  Examples of the polyester polyol (a2) include condensed polyester polyols, polylactone polyols, and polycarbonate polyols having a number average molecular weight (hereinafter abbreviated as Mn) of 500 or more. Mn in the present invention is measured by gel permeation chromatography (hereinafter abbreviated as GPC) using polyethylene glycol as a molecular weight standard and tetrahydrofuran as a solvent.

  Condensation-type polyester polyols can be obtained by condensing a polyol having a chemical formula amount or Mn of less than 500 and a polycarboxylic acid or an ester-forming derivative thereof [an acid anhydride, a lower (carbon number 1 to 4) alkyl ester, an acid halide, etc.]. What is obtained is mentioned.

  The polyol having a chemical formula amount or Mn of less than 500 includes an aliphatic dihydric alcohol having 2 to 8 carbon atoms [linear diol (ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5 -Pentanediol and 1,6-hexanediol), diol having a branched alkylene chain (1,2-propanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2-diethyl-1, 3-propanediol, 1,2-, 1,3- or 2,3-butanediol, etc.]]; C6-C10 alicyclic group-containing dihydric alcohol [1,4-bis (hydroxymethyl) cyclohexane And 2,2-bis (4-hydroxycyclohexyl) propane and the like]; an aromatic ring-containing dihydric alcohol having 8 to 20 carbon atoms [m- Is p-xylylene glycol, bis (hydroxyethyl) benzene, bis (hydroxyethoxy) benzene or bisphenol (bisphenol A, bisphenol S, bisphenol F, etc.) alkylene oxide having 2 to 12 carbon atoms (hereinafter abbreviated as AO) Adduct, AO adduct of dihydroxynaphthalene and bis (2-hydroxyethyl) terephthalate, etc.]; aliphatic trihydric alcohol [glycerin, trimethylolpropane, trialkanolamine, etc.] and aliphatic tetravalent or higher alcohol [pentaerythritol, Diglycerin, triglycerin, dipentaerythritol, sorbit, sorbitan, sorbide and the like]; and the like.

  Examples of AO having 2 to 12 carbon atoms include ethylene oxide (hereinafter abbreviated as EO), 1,2-propylene oxide (hereinafter abbreviated as PO), 1,3-propylene oxide, 1,2-, 2,3- Or 1,3-butylene oxide, tetrahydrofuran (hereinafter abbreviated as THF), 3-methyl THF, styrene oxide, α-olefin oxide, and the like. AO may be used individually by 1 type, or may use 2 or more types together.

  Examples of polycarboxylic acids or ester-forming derivatives thereof include aliphatic dicarboxylic acids having 2 to 15 carbon atoms (such as oxalic acid, succinic acid, adipic acid, sebacic acid, glutaric acid, azelaic acid, maleic acid, and fumaric acid), carbon Aromatic dicarboxylic acids of 8 to 12 [terephthalic acid, isophthalic acid, etc.], trivalent or higher polycarboxylic acids (trimellitic acid, pyromellitic acid, etc.) and ester-forming derivatives thereof [acid anhydride, lower Alkyl esters (such as dimethyl esters and diethyl esters), acid halides (such as acid chlorides), and the like]. Polycarboxylic acid may be used individually by 1 type, or may use 2 or more types together.

  Specific examples of the condensed polyester polyol include polyethylene adipate diol, polybutylene adipate diol, polyhexamethylene adipate diol, polyhexamethylene isophthalate diol, polyneopentyl adipate diol, polyethylene propylene adipate diol, polyethylene butylene adipate diol, poly Butylene hexamethylene adipate diol, poly (polyoxytetramethylene) adipate diol, poly (3-methylpentylene adipate) diol, polyethylene azelate diol, polyethylene sebacate diol, polybutylene azelate diol, polybutylene sebacate diol and poly And neopentyl terephthalate diol.

  As the polylactone polyol, a lactone monomer (γ-butyrolactone, γ-valerolactone, ε-caprolactone and a mixture of two or more thereof) is subjected to ring-opening polymerization using a polyol having the above chemical formula amount or Mn of less than 500 as an initiator. And the like. Specific examples of the polylactone polyol include polycaprolactone diol, polyvalerolactone diol, and polycaprolactone triol.

  The polycarbonate polyol includes a polyol having a chemical formula amount or Mn of less than 500, a low-molecular-weight carbonate compound (for example, an alkylene carbonate having an alkyl group having 1 to 6 carbon atoms, an alkylene group having 2 to 6 carbon atoms, and carbon). And polycarbonate polyols produced by condensing a diaryl carbonate having an aryl group of several 6 to 9 with a dealcoholization reaction.

  Specific examples of the polycarbonate polyol include polyhexamethylene carbonate diol, polypentamethylene carbonate diol, polytetramethylene carbonate diol, and poly (tetramethylene / hexamethylene) carbonate diol (for example, 1,4-butanediol and 1,6-hexane). And a diol obtained by condensing a diol with a dialkyl carbonate while causing a dealcoholization reaction).

Among the polyester polyols (a2), those having a branched alkylene chain are preferable from the viewpoint of resolubility, that is, those using a diol having a branched alkylene chain in a polyol having a chemical formula amount or Mn of less than 500 as a raw material. And those using PO, 1,2-, 2,3- or 1,3-butylene oxide, 3-methyl THF, etc. as AO in the AO adduct, more preferably a condensed type having a branched alkylene chain Polyester diols, particularly preferred are polyneopentylene adipate diol, polyethylene propylene adipate diol and poly (3-methylpentylene adipate) diol, most preferred are polyneopentylene adipate diol and poly (3-methyl Pentylene adipate) diol.
(A2) may be used alone or in combination of two or more.

  Examples of the polyether polyol (a3) include aliphatic polyether polyols and aromatic ring-containing polyether polyols.

  As the aliphatic polyether polyol, the aliphatic dihydric alcohol having 2 to 8 carbon atoms, the alicyclic group-containing dihydric alcohol having 6 to 10 carbon atoms, the aliphatic trihydric alcohol, or the aliphatic tetravalent or higher. Examples include an AO adduct of alcohol and an AO adduct of a compound having a primary or secondary amino group.

  Examples of the compound having a primary or secondary amino group include alkyl (C1-12) amine (monomethylamine, monoethylamine, monobutylamine, dimethylamine, diethylamine, dibutylamine, etc.) and poly (n = 2 to 6). Alkylene (2 to 6 carbon atoms) poly (n = 3 to 7) amine (diethylenetriamine, dipropylenetriamine, dihexylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, etc.) It is done.

  Specific examples of the aliphatic polyether polyol include polyoxyethylene polyol (polyoxyethylene glycol and the like), polyoxypropylene polyol (polyoxypropylene glycol and the like), poly (oxyethylene / oxypropylene) polyol [poly (oxyethylene / Oxypropylene) glycol and the like] and polyoxytetramethylene glycol (hereinafter abbreviated as PTMG).

  Aromatic ring-containing polyether polyols include aromatic low molecular weight active hydrogen atom-containing compounds [having 2 to 8 or more valences having a hydroxyl equivalent weight of 30 to less than 150, such as araliphatic alcohol {m- or p-xylylene Glycol, bis (hydroxyethyl) benzene and bis (hydroxyethoxy) benzene}, phenols (hydroquinone, catechol, resorcin, bisphenol A, bisphenol S, bisphenol F, etc.) and aromatic amines (aniline, phenylenediamine, etc.)] AO adduct is mentioned.

  Specific examples of the aromatic ring-containing polyether polyol include polyols having a bisphenol skeleton, such as an EO adduct of bisphenol A (an EO2 mol adduct of bisphenol A, an EO4 mol adduct of bisphenol A, an EO6 mol adduct of bisphenol A). Bisphenol A EO 8 mol adduct, bisphenol A EO 10 mol adduct, bisphenol A EO 20 mol adduct, etc.), bisphenol A PO adduct (PO2 mol adduct of bisphenol A, PO3 mol adduct of bisphenol A and Bisphenol A PO5 molar adducts, etc.) and resorcin EO or PO adducts.

Among the polyether polyols (a3), those having a branched alkylene chain are preferable from the viewpoint of resolubility, that is, a diol having a branched alkylene chain in a polyol having a chemical formula amount or Mn of less than 500 is used as a raw material. And those using PO, 1,2-, 2,3- or 1,3-butylene oxide, 3-methyl THF, etc. as AO in the AO adduct, more preferably 2 having a branched alkylene chain Fatty alcohol aliphatic polyether polyols, particularly preferred are polyoxypropylene glycol and polyoxyethylene / oxypropylene glycol, and most preferred are polyoxypropylene glycol.
(A3) may be used individually by 1 type, and may use 2 or more types together.

  The Mn of the polyester polyol (a2) and the polyether polyol (a3) is preferably 300 to 10,000, more preferably 400 to 4,000, respectively, from the viewpoint of adhesiveness.

  The ratio of the weight of the polylactone polyether polyol (a1) and the total weight of the polyester polyol (a2) and the polyether polyol (a3) [(a1) :( a2) + (a3)] From the viewpoint of solubility, 2: 8 to 8: 2 is preferable, and 3: 7 to 7: 3 is more preferable.

  The active hydrogen component (A) can further contain a chain extender (a4), a reaction terminator (a5), and the like.

  Examples of the chain extender (a4) include diamines having 2 to 12 carbon atoms, poly (n = 2 to 6) alkylene (2 to 6 carbon atoms) poly (n = 3 to 7) amines (diethylenetriamine, dipropylenetriamine, dihexane). Xylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, etc.), hydrazine and its derivatives (dibasic acid dihydrazide such as adipic acid dihydrazide) and aliphatic diols having 2 to 16 carbon atoms, etc. Is mentioned. (A4) may be used individually by 1 type, and may use 2 or more types together.

  Examples of the diamine having 2 to 12 carbon atoms include ethylene diamine, propylene diamine, hexamethylene diamine, isophorone diamine, toluene diamine, and piperazine, and isophorone diamine is preferable from the viewpoint of resolubility.

  Examples of the aliphatic diol having 2 to 16 carbon atoms include ethylene glycol, 1,2- or 1,3-propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,2-, 1,3-, 2,3. -Or 1,4-butanediol, 3-methyl-1,2-butanediol, 1,2-, 1,4-, 1,5- or 2,4-pentanediol, 3-methyl-1,5-pentane Diol, 2,3-dimethyltrimethylene glycol, 3-methyl-4,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-, 1,5-, 1,6 -Or 2,5-hexanediol, 2- or 3-methylpentanediol, 1,7-heptanediol, 2- or 3-methylhexanediol, 2-, 3- or 4-methyl Examples include butanediol, 1,8-octanediol, 2-, 3- or 4-methyl 1,8-octanediol, 1,9-nonanediol, 1,12-dodecanediol, and neopentyl glycol. From the viewpoint of properties, 1,3-butanediol and 1,3-propylene glycol are preferred.

  Examples of the reaction terminator (a5) include monoalcohols having 1 to 10 carbon atoms (such as methanol, propanol, butanol and 2-ethylhexanol) and monoamines having 2 to 8 carbon atoms [mono or dialkylamines having 2 to 8 carbon atoms ( n-butylamine and di-n-butylamine) and mono- or dialkanolamines having 2 to 6 carbon atoms (monoethanolamine, diethanolamine, propanolamine, etc.)] and the like. Of these, preferred are mono- or dialkanolamines having 2 to 6 carbon atoms. As the reaction terminator (a5), one type may be used alone, or two or more types may be used in combination.

  As an organic polyisocyanate component (B), what is conventionally used for manufacture of a polyurethane can be used, C2-C22 aliphatic polyisocyanate (b1) which has 2-3 or more isocyanate groups, C8-C18 alicyclic polyisocyanate (b2), C8-C26 aromatic polyisocyanate (b3), C10-C18 araliphatic polyisocyanate (b4), and modification of these polyisocyanates A thing (b5) etc. are mentioned.

  Examples of the aliphatic polyisocyanate (b1) having 4 to 22 carbon atoms include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (hereinafter abbreviated as HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2 , 2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethylcaproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate and 2-isocyanatoethyl- 2,6-diisocyanatohexanoate is mentioned.

  Examples of the alicyclic polyisocyanate (b2) having 8 to 18 carbon atoms include isophorone diisocyanate (hereinafter abbreviated as IPDI), 4,4′-dicyclohexylmethane diisocyanate (hereinafter abbreviated as hydrogenated MDI), cyclohexylene diisocyanate, Mention may be made of methylcyclohexylene diisocyanate, bis (2-isocyanatoethyl) -4-cyclohexene-1,2-dicarboxylate and 2,5- or 2,6-norbornane diisocyanate.

  Examples of the aromatic polyisocyanate having 8 to 26 carbon atoms (b3) include 1,3- or 1,4-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate (hereinafter abbreviated as TDI), and crude TDI. 4,4′- or 2,4′-diphenylmethane diisocyanate (hereinafter abbreviated as MDI), crude MDI, polyarylpolyisocyanate, 4,4′-diisocyanatobiphenyl, 3,3′-dimethyl-4,4 '-Diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, 4,4', 4 "-triphenylmethane triisocyanate and m- or p -Isocyanatophenylsulfonyl isocyanate.

  Examples of the araliphatic polyisocyanate (b4) having 10 to 18 carbon atoms include m- or p-xylylene diisocyanate and α, α, α ′, α′-tetramethylxylylene diisocyanate.

  As the modified polyisocyanate (b5) of (b1) to (b4), the modified polyisocyanate (urethane group, carbodiimide group, allophanate group, urea group, burette group, uretdione group, uretoimine group, isocyanurate group) Or modified product containing oxazolidone group, etc .; free isocyanate group content is usually 8 to 33% by weight, preferably 10 to 30% by weight, especially 12 to 29% by weight), such as modified MDI (urethane modified MDI, carbodiimide modified MDI) And modified products of polyisocyanates such as urethane-modified TDI, burette-modified HDI, isocyanurate-modified HDI, and isocyanurate-modified IPDI.

Among these, from the viewpoint of adhesiveness and re-solubility of the polyurethane resin (U), an alicyclic polyisocyanate (b2) having 8 to 18 carbon atoms is preferred, and IPDI is more preferred.
An organic polyisocyanate (B) may be used individually by 1 type, and may use 2 or more types together.

  The method for producing the polyurethane resin (U) by reacting the active hydrogen component (A) with the organic polyisocyanate (B) is not particularly limited, and the one-shot method or step in which (A) and (B) are reacted at a time. Multistage method of reacting [for example, a method in which (B) and a part of (A) are reacted to form an isocyanate group-terminated prepolymer, then the remaining amount of (A) is added and further reacted, etc. However, from the viewpoint of adhesiveness, after forming an isocyanate group-terminated prepolymer, the diamine having 2 to 12 carbon atoms as the chain extender (a4) is used in excess to form a polyurethane molecular chain. A method of introducing an amino group at the terminal is preferred.

  In the production of the polyurethane resin (U), the equivalent ratio (isocyanate group: active hydrogen-containing group) of the isocyanate group of the organic polyisocyanate (B) and the active hydrogen-containing group of the active hydrogen component (A) is usually 0.7: 1 to 0.99: 1, preferably 0.8: 1 to 0.98: 1.

  The reaction between the active hydrogen component (A) and the organic polyisocyanate (B) is usually performed at a temperature of 20 to 140 ° C, preferably 40 to 120 ° C. However, when making an amine react, it is 100 degrees C or less normally, Preferably it is 0-80 degreeC.

  In the reaction, in order to promote the reaction, if necessary, a catalyst used in a usual urethane reaction [amine catalyst (triethylamine, N-ethylmorpholine, triethylenediamine, etc.), tin-based catalyst (dibutyltin dilaurate, dioctyltin dilaurate and Tin octylate, etc.) and titanium catalysts (tetrabutyl titanate, etc.)] and the like may be used. The amount of the catalyst used is usually 0.1% by weight or less based on the polyurethane resin.

The reaction may be performed in an organic solvent, or an organic solvent may be added during or after the reaction. Organic solvents include ester solvents (such as ethyl acetate, butyl acetate and ethyl cellosolve acetate), ketone solvents (such as acetone, methyl isobutyl ketone and methyl isobutyl ketone), ether solvents (dioxane, THF and propylene glycol monomethyl ether, etc.) ), Hydrocarbon solvents (such as n-hexane, n-heptane and cyclohexane) and alcohol solvents (such as ethanol, methanol, n-propyl alcohol, isopropyl alcohol and n-butanol). Of these, ethyl acetate, butyl acetate, propylene glycol monomethyl ether, methyl isobutyl ketone, n-propyl alcohol and isopropyl alcohol are preferred from the viewpoint of re-solubility of the polyurethane resin (U), and acetic acid is more preferred. Ethyl, methyl isobutyl ketone and isopropyl alcohol.
An organic solvent may be used individually by 1 type, and may use 2 or more types together.

  The weight average molecular weight (hereinafter abbreviated as Mw) of the polyurethane resin (U) in the present invention is preferably 20,000 to 100,000, more preferably 30,000 to 80, from the viewpoint of the resin physical properties of the polyurethane resin (U). , 000. Mw in the present invention is measured by GPC using dimethylformamide as a solvent and polystyrene as a molecular weight standard.

  The binder for printing ink of the present invention comprising the polyurethane resin (U) of the present invention is preferably used as a solution (varnish) in which the polyurethane resin (U) is dissolved in the above organic solvent from the viewpoint of handling properties. The resin concentration of the organic solvent solution (U) is preferably 10 to 60% by weight, more preferably 20 to 50% by weight from the viewpoint of handling properties. Moreover, the viscosity at 20 ° C. of the organic solvent solution (U) is preferably 50 to 100,000 mPa · s, more preferably 100 to 10,000 mPa · s from the same viewpoint.

  The printing ink of the present invention contains the printing ink binder, pigment and solvent of the present invention as essential components. There is no restriction | limiting in particular as a pigment, The inorganic pigment, organic pigment, etc. which are used for normal printing ink can be used.

  If necessary, other resins usually used in printing inks and additives such as pigment dispersants can be blended. Each of the other resins and additives may be used alone or in combination of two or more.

  Examples of other resins include polyamide resin, nitrocellulose, acrylic resin, vinyl acetate resin, styrene maleic acid copolymer resin, epoxy resin, and rosin resin. The addition amount of these other resins is usually 30% by weight or less, preferably 20% by weight or less, based on the weight of the printing ink.

  The production method of the printing ink is not particularly limited, and the printing ink can be produced using a known method such as a normal ink production apparatus such as a three-roll, ball mill, and sand grinder mill.

An example of the formulation of the printing ink of the present invention is as follows.
Binder of the present invention (resin solid content): 5 to 40% by weight (preferably 10 to 30% by weight)
Pigment: 5 to 40% by weight (preferably 10 to 30% by weight)
Other resins: 0 to 30% by weight (preferably 0 to 20% by weight)
Solvent: 30 to 80% by weight (preferably 40 to 70% by weight)

  Although the printing ink using the binder for printing inks of the present invention may be used as a one-component printing ink, it can also be used as a two-component printing ink in combination with, for example, a polyisocyanate curing agent. As the polyisocyanate curing agent in this case, for example, an adduct formed from 1 mol of trimethylolpropane and 3 mol of 1,6-hexamethylene diisocyanate, TDI or IPDI; an isocyanate group of 1,6-hexamethylene diisocyanate or IPDI Preferred are isocyanurate group-containing trimers synthesized by cyclic trimerization; partial burette reactants derived from 1 mole of water and 3 moles of 1,6-hexamethylene diisocyanate and mixtures of two or more thereof. . When used as a two-component printing ink, the amount of polyisocyanate curing agent used is usually 0.5 to 10% by weight based on the weight of the printing ink binder of the present invention.

  Examples of the printing method using the printing ink of the present invention include printing methods such as special gravure printing, ink jet printing, offset printing, and thermal transfer printing used for printing of conventional plastic films.

  The printing ink of the present invention includes various plastics such as polyester film, nylon film, surface-treated or untreated polypropylene film, polyethylene film, polyvinyl acetal film, acetate film, polyvinyl chloride film, and films obtained by depositing aluminum on these films. It can be suitably used for printing a film.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to this. In the following, “part” means part by weight.

Production Example 1
A reactor equipped with a stirrer was charged with 100 parts of polyoxypropylene glycol [Sanix Kasei PP-1000 manufactured by Sanyo Chemical Co., Ltd .: Mn = 1000] and 114 parts of ε-caprolactone at 12O 0 C under a nitrogen atmosphere. By reacting for a period of time, polylactone polyether polyol (a1-1) in which 10 mol of ε-caprolactone was added to polyoxypropylene glycol was obtained.

Production Example 2
Polylactone polyether polyol (a1-2) in which 6 mol of ε-caprolactone was added to polyoxypropylene glycol in the same manner as in Production Example 1 except that 68 parts of ε-caprolactone was used instead of 114 parts of ε-caprolactone. Got.

Production Example 3
A polylactone polyether polyol (a1-3) in which 15 mol of ε-caprolactone was added to polyoxypropylene glycol in the same manner as in Production Example 1, except that 171 parts of ε-caprolactone was used instead of 114 parts of ε-caprolactone. Got.

Production Example 4
Polyoxypropylene glycol [Sanyo Chemicals Co., Ltd. “Sanniks PP-1000”: Mn = 1000] Instead of 100 parts polyoxypropylene glycol [Sanyo Chemicals Co., Ltd. “Sanniks PP-400”: Mn = 400 A polylactone polyether polyol (a1-4) in which 10 mol of ε-caprolactone was added to polyoxypropylene glycol was obtained in the same manner as in Production Example 1 except that 40 parts were charged.

Production Example 5
Instead of 100 parts of polyoxypropylene glycol [Sanix Kasei Co., Ltd. “Sanix PP-1000”: Mn = 1000], polyoxypropylene glycol [Sanyo Kasei Co., Ltd. “Sanniks PP-2000”: Mn = 2000 A polylactone polyether polyol (a1-5) in which 10 mol of ε-caprolactone was added to polyoxypropylene glycol was obtained in the same manner as in Production Example 1 except that 200 parts were charged.

Production Example 6
Instead of 100 parts of polyoxypropylene glycol [Sanix Kasei Co., Ltd. “SANNICS PP-1000”: Mn = 1000], polyoxyethylene glycol [Sanyo Kasei Co., Ltd. “PEG-1000”: Mn = 1000] 100 A polylactone polyether polyol (a1-6) in which 10 mol of ε-caprolactone was added to polyoxyethylene glycol was obtained in the same manner as in Production Example 1 except that the parts were charged.

Production Example 7
Instead of 100 parts of polyoxypropylene glycol [Sanix Kasei Co., Ltd. “SANNICS PP-1000”: Mn = 1000], poly (oxyethylene / oxypropylene) glycol [manufactured by Sanyo Kasei Co., Ltd. “New Pole 80-4000” “: Mn = 4000, poly (oxyethylene / oxypropylene) is randomly bonded”] In the same manner as in Production Example 1 except that 100 parts were charged, ε-caprolactone was added to poly (oxyethylene / oxypropylene) glycol. A polylactone polyether polyol (a1-7) added with 10 mol was obtained.

Comparative production example 1
A polylactone polyether polyol (a1′-1) obtained by adding 4 mol of ε-caprolactone to polyoxypropylene glycol in the same manner as in Production Example 1 except that 45 parts of ε-caprolactone was used instead of 114 parts of ε-caprolactone. )

Comparative production example 2
A polylactone polyether polyol (a1′-2) obtained by adding 20 mol of ε-caprolactone to polyoxypropylene glycol in the same manner as in Production Example 1, except that 228 parts of ε-caprolactone was used instead of 114 parts of ε-caprolactone. )

Example 1
In a reactor equipped with a stirrer, 200 parts of (a1-1) as polylactone polyether polyol (a1) and polyneopentylene adipate diol as polyester polyol (a2) [Sanester, manufactured by Sanyo Kasei Co., Ltd. 5620 ": Mn = 2000] 100 parts, polyoxypropylene glycol as polyether polyol (a3) [" SANNICS PP-2000 "manufactured by Sanyo Chemical Co., Ltd .: Mn = 2000] 100 parts and organic polyisocyanate component (B 80 parts of IPDI was prepared and reacted at 110 ° C. for 10 hours in a nitrogen atmosphere to obtain a urethane prepolymer having an isocyanate group content of 2.9% by weight. After cooling to 40 ° C., 795 parts of ethyl acetate as an organic solvent was added to obtain a uniform solution. Next, after adding 390 parts of isopropyl alcohol as an organic solvent and stirring until uniform, 26.4 parts of isophoronediamine as a chain extender (a3) and 1.9 parts of monoethanolamine as a reaction terminator (a5) And reacted at 40 ° C. for 1 hour to obtain a solution of a polyurethane resin (U-1) which is a binder for printing ink of the present invention. Mw of the polyurethane resin (U-1) was 41,000.

Examples 2-9 and Comparative Examples 1-5
A solution of polyurethane resins (U-2) to (U-9) and polyurethane resins (U′-1) to (U′−) of comparative examples were the same as in Example 1 except that the raw materials listed in Table 1 were used. A solution of 5) was obtained. In Comparative Example 3, the polylactone polyether polyol (a1) was not used, in Comparative Example 4, the polyether polyol (a3) was not used, and in Comparative Example 5, the polyester polyol (a2) was not used.

  Table 1 shows the structures of the polylactone polyether polyols (a1) used in the production of Examples 1 to 9 and Comparative Examples 1 to 5 and the polyurethane resins obtained in Examples 1 to 9 and Comparative Examples 1 to 5. Show.

In addition, the composition of the raw material represented by the trade name in Table 1 is as follows.
"Sanester 5620": Polyneopentylene adipate diol with Mn = 2,000 [manufactured by Sanyo Chemical Industries, Ltd.]
“Sanix PP-2000”: polyoxypropylene glycol with Mn = 2,000 [manufactured by Sanyo Chemical Industries, Ltd.]

Example 10
100 parts of a solution of polyurethane resin (U-1), 30 parts of pigment (β-type phthalocyanine blue), 30 parts of isopropyl alcohol, 70 parts of ethyl acetate and 150 parts of glass beads are mixed with a paint conditioner (manufactured by Red Devil). The mixture was kneaded for a time, and the glass beads were removed by filtration to obtain a printing ink (I-1).

Examples 11-18 and Comparative Examples 6-10
Implemented except changing the solution of the polyurethane resin (U-1) to the solution of the polyurethane resins (U-2) to (U-9) or (U'-1) to (U'-5) shown in Table 2. In the same manner as in Example 10, printing inks (I-2) to (I-9) and comparative printing inks (I′-1) to (I′-5) were obtained.

  Table 2 shows the results of the following performance tests using the obtained printing ink.

[Adhesion test method]
Surface-treated polypropylene film (OPP) [“Pyrene P-2161” manufactured by Toyobo Co., Ltd. (thickness 30 μm)], surface-treated polyester film (PET) [“Espet E-5102” manufactured by Toyobo Co., Ltd. (thickness 12 μm) )] And a surface-treated nylon film [“Harden N-1130” (thickness: 15 μm) manufactured by Toyobo Co., Ltd.] with a bar coater so as to have a solid content of 2 to 3 μm, and at 60 ° C. After drying for 1 minute, a cellophane tape (made by Nichiban, 12 mm width) is applied to the coated surface, and the coated surface state when one end of this cellophane tape is rapidly peeled in a direction perpendicular to the coated surface is as follows. Evaluation based on the criteria.
<Evaluation criteria>
A: The ink does not peel off at all.
○: Ink remains 80% or more.
X: Remaining ink is less than 80%.

[Resolubility test method]
Using a gravure printing test machine (TS-1 type printing machine; manufactured by Higashitani Iron Works), using a gravure plate with a depth of 35 μm, printing 100 m of printing ink on an OPP film at a speed of 30 m / min. After the excess ink adhered was washed off with a mixed solvent of isopropyl alcohol and ethyl acetate (weight ratio 3: 7), the clogged state of the cells was observed.
<Evaluation criteria>
◯: Less than 30% of ink remaining in the cell.
X: 30% or more of the ink in the cell remains.

[Testing method for blocking resistance]
A coated test piece (coated with PET) obtained by the same method as in the adhesion test is overlapped with a coated surface and a non-coated surface, and a load of 1.0 kgf / cm 2 is applied to a temperature of 40 ° C. and a humidity of 60% RH. After standing for 24 hours in a thermo-hygrostat, it was peeled off and the surface condition was observed.
<Evaluation criteria>
A: The ink does not peel off at all.
○: Ink remains 80% or more.
X: Remaining ink is less than 80%.

The binder of the present invention is particularly suitable as a binder for special gravure inks for various plastic films (polyester film, nylon film, polypropylene film, cellophane film, etc.) because it is excellent in re-solubility in solvents, adhesion and blocking resistance. is there. The binder of the present invention is useful not only for the above-mentioned applications but also as a coating agent for flexographic printing inks, binders for paints, adhesives and paper.

Claims (5)

A printing ink binder comprising a polyurethane resin (U) obtained by reacting an active hydrogen component (A) with an organic polyisocyanate component (B), wherein the active hydrogen component (A) is represented by the general formula (1) A printing ink binder comprising the polylactone polyether polyol (a1), the polyester polyol (a2), and the polyether polyol (a3).

[Wherein, R ¹ is an alkylene group having 3 to 11 carbon atoms, a plurality of R ¹ may be the same or different, and R ² is an alkylene group having 2 to 12 carbon atoms, and there are a plurality of R ¹ R ² may be the same or different, a and c are each an integer of 0 or more, 5 ≦ a + c ≦ 16 is satisfied, and b is an integer of 5 to 250. ]   Ratio [(a1): {(a2) + (a3)}] of the weight of the polylactone polyether polyol (a1) and the total weight of the polyester polyol (a2) and the polyether polyol (a3) is 2: 8. The binder for printing ink according to claim 1, which is ˜8: 2.   The binder for printing ink according to claim 1 or 2, wherein the polyester polyol (a2) and / or the polyether polyol (a3) has a branched alkylene chain.   The binder for printing ink according to any one of claims 1 to 3, wherein the polyether polyol (a3) is polyoxypropylene glycol.   Printing ink formed by containing the binder for printing inks in any one of Claims 1-4.