JP6014348B2 - Polyurethane printing ink composition - Google Patents

Description

  The present invention relates to a polyurethane-based printing ink composition.

  Conventionally, the decorativeness of a printing medium has been improved by printing on the printing medium by a general-purpose printing method such as gravure printing or flexographic printing. Examples of the printing ink used when printing on the printing medium include polyurethane-based printing ink.

  In Patent Document 1, in a printing ink binder containing a polyurethane resin obtained by reacting a polymer polyol and a polyisocyanate, the polymer polyol is a polyester polyol composed of glycol and dibasic acid. A printing ink composition containing a printing ink binder containing 50% by weight or more and the glycol being 80% by weight or more of neopentyl glycol with respect to the total amount of the glycol is disclosed.

  On the other hand, printed materials include various materials such as ionomers, ethylene-vinyl acetate copolymers, synthetic resins such as polyvinyl chloride and tetrafluoroethylene-ethylene copolymers, metals such as aluminum and stainless steel, and carbon fibers. Although formed, the printing ink composition has a problem that it cannot be printed favorably on a printing medium formed from the materials exemplified above.

JP 2012-12596 A

  The present invention provides a polyurethane-based printing ink composition that can be favorably printed on a printing medium formed from various materials.

  The polyurethane printing ink composition of the present invention is chlorinated with respect to 100 parts by weight of the polyurethane resin solid content in a polyurethane printing ink having a polyurethane resin obtained by reacting a polymer polyol and polyisocyanate as a binder. 5 to 20 parts by weight of a modifying main agent containing 60 to 80% by weight of polyolefin and 20 to 40% by weight of maleic anhydride-methyl methacrylate copolymer, and 0.5 to 5.5% by weight of tris (isocyanatophenyl) thiophosphate Part.

  As the polyurethane printing ink, a polyurethane resin obtained by reacting a polymer polyol and polyisocyanate may be used as a binder, a general-purpose polyurethane printing ink is used, and a two-component curable polyurethane printing ink is preferable. A two-component curable polyurethane printing ink consists of a main component containing a polymer polyol component and a curing agent containing a polyisocyanate. In use, the main component and the curing agent are mixed and heated as necessary. It is used after being reacted and cured. When mixing the main component containing the polymer polyol component and the curing agent containing the polyisocyanate, the total number of isocyanate groups in the polyisocyanate is adjusted to be the same as or greater than the total number of hydroxyl groups in the polymer polyol. It is preferable to do.

  Examples of the polymer polyol constituting the main component of the two-component curable polyurethane printing ink include polyether polyol, polyester polyol, polycarbonate polyol, and acrylic polyol.

  Examples of the polyether polyol include polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, and the like, such as 1,2-ethanediol, 1,2-propanediol, 1,4-butanediol, and the like. Can be obtained by condensation polymerization or ring-opening polymerization of cyclic ethers such as ethylene oxide, propylene oxide, and tetrahydrofuran.

  Examples of the polyester polyol include polyester polyols obtained by condensation polymerization of dibasic acids such as adipic acid, sebacic acid, and terephthalic acid and low molecular weight polyols, polycaprolactone glycol, and the like.

  Examples of the polycarbonate polyol include polycarbonate polyols obtained by condensation polymerization of dialkyl carbonates such as dimethyl carbonate and diethyl carbonate, phosgene, chloroformate, diallyl carbonate, alkylene carbonate and the like and low molecular weight polyols.

  The acrylic polyol is a polymer in which a hydroxyl group is introduced into an acrylic copolymer. In general, hydroxyalkyl (meth) such as (meth) acrylate serving as a hard segment, (meth) acrylic acid serving as a soft segment, 2-hydroxyethyl (meth) acrylate for introducing a hydroxyl group, and 2-hydroxypropyl (meth) acrylate It is a copolymer obtained by various combinations of acrylates and the like. In addition, (meth) acrylate means an acrylate or a methacrylate.

  The polyether polyol, polyester polyol and polycarbonate polyol may be polyurethane-modified. That is, a polyester polyurethane having hydroxyl groups (-OH groups) at both ends, obtained by reacting diisocyanate and polyester polyol so that the total number of hydroxyl groups of the polyester polyol is larger than the total number of isocyanate groups of the diisocyanate. It has hydroxyl groups (-OH groups) at both ends, obtained by reacting polyol, diisocyanate and polyether polyol so that the total number of hydroxyl groups of the polyether polyol is greater than the total number of isocyanate groups of the diisocyanate. Polyether polyurethane polyol, obtained by reacting diisocyanate and polycarbonate polyol so that the total number of hydroxyl groups of polycarbonate polyol is greater than the total number of isocyanate groups of diisocyanate. It may be a polycarbonate polyurethane polyol having a hydroxyl group (-OH group) in the end.

  Examples of the diisocyanate include toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, polymeric MDI, tolylene diisocyanate, p-phenylene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated MDI, and the like.

  Moreover, it does not specifically limit as polyisocyanate which comprises the hardening | curing agent of a two-component curing type polyurethane type printing ink, For example, toluene diisocyanate, 4,4'- diphenylmethane diisocyanate, polymeric MDI, tolylene diisocyanate, p- And diisocyanates such as phenylene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and hydrogenated MDI. In addition, polyisocyanate may be used independently or 2 or more types may be used together.

  The polyurethane printing ink contains a solvent. Such solvents include aromatic organic solvents such as toluene and xylene, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, ethyl acetate, n-propyl acetate, isopropyl acetate, isobutyl acetate, propylene glycol monoethyl ether acetate, propylene Examples include ester solvents such as glycol monomethyl ether acetate, and alcohol solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol, propylene glycol monoethyl ether, and propylene glycol monomethyl ether. In addition, a solvent may be used independently or 2 or more types may be used together.

  The polyurethane printing ink contains a colorant in order to obtain a desired color. The colorant is not particularly limited as long as it is a general-purpose printing ink, and examples thereof include organic pigments such as carbon black, inorganic pigments, and dyes.

  The polyurethane resin of the polyurethane printing ink may be subjected to a chain extension reaction with a low molecular weight polyol, a low molecular weight polyamine, or the like, if necessary. Examples of the low molecular weight polyol include 1,4-butanediol, trimethylolpropane, and bishydroxyethoxybenzene. Examples of the low molecular weight polyamine include methylene bis-2-chloroaniline.

  The polyurethane-based printing ink composition of the present invention comprises, in a polyurethane-based printing ink, a modifying main agent containing 60 to 80% by weight of chlorinated polyolefin and 20 to 40% by weight of maleic anhydride-methyl methacrylate copolymer, And isocyanatophenyl) thiophosphate.

  The polyolefin used as the base of the chlorinated polyolefin is a polymer obtained by singly or copolymerizing an olefin having 2 to 10 carbon atoms such as ethylene, propylene, butylene and hexene, the above olefin, and a copolymer with the olefin. Examples thereof include copolymers with possible monomers, and polypropylene is preferred. The polyolefin may be modified by graft polymerization of a monomer copolymerizable with the olefin to the polyolefin.

  Here, as the monomer copolymerizable with the olefin, for example, unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, acid anhydride such as maleic anhydride, methyl acrylate, Examples thereof include acrylic acid esters such as ethyl acrylate, methacrylic acid esters such as methyl methacrylate and ethyl methacrylate, styrene, acrylonitrile, and methacrylonitrile. Acid anhydrides are preferable, and maleic anhydride is more preferable.

  The polyolefin is chlorinated by, for example, blowing chlorine gas into an organic solvent solution obtained by dissolving polyolefin in an organic solvent or an organic solvent dispersion obtained by dispersing polyolefin in an organic solvent.

  The chlorine content of the chlorinated polyolefin is preferably 20 to 40% by weight, and more preferably 25 to 40% by weight. This is because when the chlorine content of the chlorinated polyolefin is low, the adhesiveness of the polyurethane printing ink composition to the printing medium may be reduced and the printing property may be lowered. When the chlorine content is high, the polyurethane printing ink composition may be reduced. This is because gelation may occur. In addition, the chlorine content rate of chlorinated polyolefin means what was measured based on the determination method (oxygen flask combustion method) of the chlorine in JISK7229 chlorine containing resin.

  When the content of the chlorinated polyolefin in the modifying main agent is small, the adhesiveness of the polyurethane printing ink composition to the printing material is lowered and the printing property is lowered. When the content is large, the polyurethane printing ink composition is gelled. Or the hardness and abrasion resistance of the coating film obtained by using the polyurethane-based printing ink composition are reduced, so that it is limited to 60 to 80% by weight, preferably 62 to 78% by weight, and 65 to 78% by weight. Is more preferable.

  If the content of the maleic anhydride-methyl methacrylate copolymer in the modifying main agent is small, the polyurethane-based printing ink composition gels, and if it is large, the polyurethane-based printing ink composition has an adhesive property to the printing medium. Since it decreases and printability falls, it is limited to 20-40 weight%, 22-38 weight% is preferable and 28-35 weight% is more preferable.

  If the amount of the modifying main agent added to the polyurethane-based printing ink is small, the adhesiveness of the polyurethane-based printing ink composition to the printing material is lowered, and the printability is lowered. Since the hardness and abrasion resistance of the coating film obtained by using the resin are reduced, the polyurethane resin solid content in the polyurethane-based printing ink is 100 parts by weight of the polyurethane resin that becomes a binder obtained by reacting the polymer polyol and the polyisocyanate. It is limited to 5 to 20 parts by weight, preferably 7 to 20 parts by weight, and more preferably 7.5 to 13 parts by weight.

  Further, in the polyurethane-based printing ink composition of the present invention, tris (isocyanatophenyl) thiophosphate represented by the following formula 1 is also added to the polyurethane-based printing ink.

  If the content of tris (isocyanatophenyl) thiophosphate added to the polyurethane-based printing ink is small, the adhesiveness of the polyurethane-based printing ink composition to the substrate to be printed is lowered, and the printability is lowered. Since the hardness and abrasion resistance of the coating film obtained using the polyurethane-based printing ink composition are reduced, the polyurethane resin solid serving as a binder obtained by reacting the polymer polyol and the polyisocyanate in the polyurethane-based printing ink It is limited to 0.5 to 5.5 parts by weight with respect to 100 parts by weight per minute, preferably 1 to 4.5 parts by weight, and more preferably 2 to 4 parts by weight.

  The polyurethane printing ink composition of the present invention may contain additives such as an antistatic agent, an antioxidant, and an ultraviolet absorber as long as the physical properties are not impaired.

  Next, the manufacturing method of a polyurethane type printing ink composition is demonstrated. A polyurethane-based printing ink composition can be produced by adding and mixing a modifying main agent and tris (isocyanatophenyl) thiophosphate in a general-purpose manner to a general-purpose polyurethane-based printing ink.

  For example, a polyurethane-based printing ink is produced by adding a polyurethane-based printing ink curing agent to the main component of the polyurethane-based printing ink. Next, the modifying main agent and tris (isocyanatophenyl) thiophosphate are separately added to the polyurethane-based printing ink, and stirred and mixed uniformly to produce a polyurethane-based printing ink composition. The order of adding the modifying main agent and tris (isocyanatophenyl) thiophosphate to the polyurethane printing ink is not limited.

  Also, a polyurethane printing ink is prepared by adding a curing agent for polyurethane printing ink to the main component of polyurethane printing ink. On the other hand, the modified main agent and tris (isocyanatophenyl) thiophosphate may be mixed and then added to the polyurethane printing ink and stirred and mixed uniformly to produce a polyurethane printing ink composition.

  Next, the usage point of a polyurethane type printing ink composition is demonstrated. Examples of a method for forming a printing layer on a printing material using a polyurethane-based printing ink composition include, for example, a desired printing material using a polyurethane-based printing ink composition by a general-purpose printing method such as screen printing or gravure printing. It is possible to form a coating layer on the surface of the substrate by curing the polyurethane-based printing ink by heating the coating layer as necessary to form a coating layer. Although the heating temperature of an application layer is suitably adjusted according to the kind of polyurethane type printing ink, 25-120 degreeC is preferable. Although the heating time of an application layer is suitably adjusted according to the kind of polyurethane type printing ink, 20 to 40 minutes are preferable.

  As a printing material, it was possible to print well on printing materials having various shapes formed of various materials such as organic compounds such as synthetic resins, inorganic compounds such as carbon fibers, or metals, and obtained. The printed layer adheres well to the printing medium, has excellent wear resistance and hardness, and maintains a good adhesion state on the printing medium over a long period of time.

  In particular, the substrate to be printed is formed from an ionomer, an ethylene-vinyl acetate copolymer, a synthetic resin such as polyvinyl chloride or tetrafluoroethylene-ethylene copolymer, a metal such as aluminum or stainless steel, or a carbon fiber. In this case, when printing on the surface of these printed materials, surface modification treatment such as surface treatment such as corona discharge treatment or plasma irradiation treatment or primer layer is usually performed on the surface of the printing material. It is necessary to apply.

  However, according to the polyurethane-based printing ink composition of the present invention, even if the printed material is difficult to form a printing layer as described above, the surface of the printed material is not subjected to any surface modification treatment. A printed layer having excellent wear resistance and hardness can be formed on the surface of the printing medium with a strong adhesive force.

  Therefore, according to the polyurethane-based printing ink composition of the present invention, a desired printing layer can be easily formed on the surface of various printed materials without requiring a step such as surface modification treatment on the surface of the printed material. be able to.

  According to the polyurethane-based printing ink composition of the present invention, since it has the above-described configuration, it is general-purpose without subjecting the printing body formed of various materials to surface modification treatment. It is possible to easily print with this printing method.

  And the printing layer formed in the to-be-printed layer has the outstanding abrasion resistance and hardness, and can maintain a beautiful state reliably over a long period of time.

  Hereinafter, embodiments of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Examples 1-6, Comparative Examples 1-4)
Curing agent for polyurethane-based printing ink containing solvent in 100 parts by weight of main component A of polyurethane-based printing ink containing carbon black as solvent and colorant (polyester polyurethane polyol, trade name “SG740 710 black” manufactured by Seiko Advance Co., Ltd.) (Polyisocyanate, trade name “SG740 curing agent” manufactured by Seiko Advance Co., Ltd.) 10 parts by weight were added to prepare a polyurethane-based printing ink using a polyurethane resin obtained by reacting a polyester polyurethane polyol and polyisocyanate as a binder. . The hydroxyl group of the polyester polyurethane polyol disappeared due to the reaction with the isocyanate group of the polyisocyanate.

  For polyurethane-based printing ink, a predetermined amount of modifying main agent A (trade name “Mu-10” manufactured by Front Laboratory Co., Ltd.) shown in Table 1 with respect to 100 parts by weight of solid content of polyurethane resin in polyurethane-based printing ink. Added and mixed uniformly. The modifying main agent A contained 66% by weight of chlorinated polypropylene having a chlorine content of 30% by weight and 34% by weight of maleic anhydride-methyl methacrylate copolymer.

  Next, a predetermined amount of tris (isocyanatophenyl) thiophosphate (front) shown in Table 1 with respect to 100 parts by weight of the polyurethane resin solid content in the polyurethane-based printing ink is added to the polyurethane-based printing ink to which the modifying main agent is added. R & D Co., Ltd., trade name “m-3b”) and an organic solvent diluent (trade name “T-926”, Seiko Advance Co., Ltd.) 6 parts by weight are added and mixed uniformly to make a polyurethane printing ink. A composition was obtained.

(Example 7)
Instead of the main component A of polyurethane-based printing ink, the main component B of polyurethane-based printing ink containing carbon black and barium sulfate as a solvent and colorant (acrylic polyol: 35% by weight, trade name “MS8” manufactured by Seiko Advance) A polyurethane-based printing ink composition was obtained in the same manner as in Example 2 except that it was used. In addition, the hydroxyl group of the acrylic polyol disappeared by the reaction with the isocyanate group of the polyisocyanate.

( Comparative Examples 9 and 10 )
In place of the modifying main agent A, the modifying main agent B (trade name “MF-8” manufactured by Front Laboratory) is used instead of the modifying main agent A for the polyurethane printing ink to 100 parts by weight of the polyurethane resin solid content in the polyurethane printing ink. A polyurethane-based printing ink composition was obtained in the same manner as in Example 1 except that a predetermined amount shown in Table 1 was added. The modifying main agent B contained 80% by weight of chlorinated polypropylene having a chlorine content of 36% by weight and 20% by weight of maleic anhydride-methyl methacrylate copolymer.

(Comparative Example 5)
Addition of 40 parts by weight of epoxy printing ink curing agent (Seiko Advance Co., Ltd., trade name “1000 curing agent”) to 100 parts by weight of Epoxy printing ink base A (Seiko Advance, trade name “1000 710 Black”) Thus, an epoxy printing ink was produced.

  An epoxy printing ink composition was obtained in the same manner as in Example 3 except that the above epoxy printing ink was used instead of the polyurethane printing ink. The contents of the modifying main agent and tris (isocyanatophenyl) thiophosphate shown in Table 1 are amounts relative to 100 parts by weight of the epoxy resin solid content in the epoxy printing ink.

(Comparative Example 6)
An acrylic printing ink composition was obtained in the same manner as in Example 3 except that an acrylic printing ink (trade name “2500” manufactured by Seiko Advance Co., Ltd.) was used instead of the polyurethane printing ink. The contents of the modifying main agent and tris (isocyanatophenyl) thiophosphate shown in Table 1 are amounts relative to 100 parts by weight of the acrylic resin solid content in the acrylic printing ink.

(Comparative Example 7)
An acrylic printing ink composition was obtained in the same manner as in Example 3 except that polyester printing ink (trade name “GAP Shin” manufactured by Seiko Advance Co., Ltd.) was used instead of polyurethane printing ink. The contents of the modifying main agent and tris (isocyanatophenyl) thiophosphate shown in Table 1 are amounts relative to 100 parts by weight of the polyester resin solid content in the polyester printing ink.

(Comparative Example 8)
A polyolefin-based printing ink composition was obtained in the same manner as in Example 3, except that a polyolefin-based printing ink (trade name “0P22” manufactured by Seiko Advance Co., Ltd.) was used instead of the polyurethane-based printing ink. The contents of the modifying main agent and tris (isocyanatophenyl) thiophosphate shown in Table 1 are amounts relative to 100 parts by weight of the polyolefin resin solid content in the polyolefin printing ink.

  About the obtained polyurethane-based printing ink composition, epoxy-based printing ink composition, acrylic-based printing ink composition and polyolefin-based printing ink composition (hereinafter sometimes collectively referred to as “ink composition”) The scratch hardness and wear resistance were measured in the following manner, and the results are shown in Table 1.

(Adhesiveness)
The adhesion of the printing ink composition was measured according to JIS K5600-5-6 (adhesion (cross-cut method)). Specifically, the ink composition was applied to the surface of the high-luminance aluminum plate (surface roughness Ra: 0.01 μm) by screen printing and dried to form a coating layer having a thickness of 20 μm on the surface of the high-luminance aluminum plate. . In the case of an acrylic printing ink composition and a polyolefin printing ink composition, the coating layer was a printing layer.

  In the case of a polyurethane printing ink composition, the coating layer was heated and cured at 80 ° C. for 30 minutes to form a printing layer. In the case of an epoxy printing ink composition, the coating layer was heated and cured at 80 ° C. for 40 minutes to form a printing layer having a thickness of 20 μm.

  Eleven cut lines A reaching the high-luminance aluminum plate from the surface and parallel to each other were formed on the printed layer at intervals of 1.0 mm. Furthermore, 11 cut lines B that reach the high-luminance aluminum plate from the surface of the print layer and are orthogonal to the cut lines A and parallel to each other are formed at intervals of 1.0 mm, and the print layers are formed by the cut lines A, B Were divided into 100 planar square sections.

  Next, a pressure-sensitive adhesive tape (product name “No. 405” manufactured by Nichiban Co., Ltd.) is attached to the entire surface of the partition part, and the pressure-sensitive adhesive tape is abruptly set at an angle of 60 ° with respect to the surface of the printing layer. It peeled from the surface of the printing layer. The number of compartments adhered to the adhesive tape was measured, and the percentage of the total number of compartments (100) was calculated and evaluated based on the following criteria. In addition, about the polyurethane type printing ink composition of the comparative example 1, since the polyurethane type printing ink composition did not fully solidify, it was not able to measure.

It was 0 ... 0%.
1 ... more than 0% and less than 5%.
2 ... 5% or more and less than 15%.
3 ... 15% or more and less than 35%.
4 ... 35% or more and less than 65%.
5 ... 65% or more.

(Scratch hardness)
A printed layer was formed on the surface of the high-luminance aluminum plate in the same manner as the evaluation of adhesion. The pencil hardness of the printed layer was measured according to JIS K5600-5-4 (scratch hardness (pencil method)). The pencil hardness is as follows.
2B <B <HB <F <H <2H <3H (harder as it goes to the right)

  In addition, about the polyurethane type printing ink composition of the comparative example 1, since the polyurethane type printing ink composition did not fully solidify, it was not able to measure.

(Abrasion resistance)
A printed layer was formed on the surface of the high-luminance aluminum plate in the same manner as the evaluation of adhesion. The abrasion resistance of the printed layer was measured in accordance with JIS K5600-5-9 (Abrasion resistance (wear wheel method)). Specifically, a cylindrical sand eraser with a diameter of 10 mm is prepared, the sand eraser is pressed so as to be perpendicular to the surface of the printing layer, and the sand eraser is pressed against the surface of the printing layer with a pressure of 50 kPa. However, the sand eraser is reciprocated on a virtual straight line of 30 mm on the printing layer, and when the total length of the completely peeled printing layer portion becomes 10 mm, the reciprocation of the sand eraser is stopped, The number of reciprocations was used as an evaluation standard for wear resistance. The number of reciprocations was determined only when one complete reciprocation was made.

  In addition, about the polyurethane type printing ink composition of the comparative example 1, since the polyurethane type printing ink composition did not fully solidify, it was not able to measure.

Claims (1)

A polyurethane-based printing ink having a polyurethane resin obtained by reacting a polymer polyol and a polyisocyanate as a binder, 62 to 78 % by weight of chlorinated polyolefin and maleic anhydride with respect to 100 parts by weight of the solid content of the polyurethane resin. A polyurethane comprising 5 to 20 parts by weight of a modifying main agent containing 22 to 38 % by weight of a methyl methacrylate copolymer and 0.5 to 5.5 parts by weight of tris (isocyanatophenyl) thiophosphate. Printing ink composition.