PRINTING SYSTEM

Abstract

A process for producing a coated, printed substrate comprising (a) providing a printed substrate, wherein the substrate comprises a surface on which resides one or more areas of a layer of an ink, (b) bringing together a component A and a component B to form a urethane coating composition, wherein component A comprises a polyisocyanate prepolymer A1, wherein the polyisocyanate prepolymer A1 is a reaction product of a polyisocyanate monomer A1a and an isocyanate-polyreactive compound A1b, wherein component B comprises one or more polyol B1, wherein the urethane coating composition has isocyanate index greater than 0.9, (c) applying a layer of the urethane coating composition to the surface. Also provided is a coated printed substrate made by such a method.

Claims

1. A process for producing a coated, printed substrate comprising (a) providing a printed substrate, wherein the substrate comprises a surface on which resides one or more areas of a layer of an ink, wherein the ink comprises (i) one or more olefin copolymers, and (ii) one or more appearance additive selected from one or more pigments, one or more dyes, and mixtures thereof, and (iii) one or more conductivity additives, (b) bringing together a component A and a component B to form a urethane coating composition, wherein component A comprises a polyisocyanate prepolymer A1, wherein the polyisocyanate prepolymer A1 is a reaction product of a polyisocyanate monomer A1a and an isocyanate-polyreactive compound A1b, wherein component B comprises one or more polyol B1, wherein the urethane coating composition has isocyanate index greater than 0.9, and (c) applying a layer of the urethane coating composition to the surface.

2. The process of claim 1, wherein the polyol B1 comprises one or more polyurethane polyol B1PU, wherein polyol B1PU comprises a reaction product of a polyisocyanate monomer B1PUa and a polyol B1PUb.

3. The process of claim 1, wherein the olefin copolymer is selected from the group consisting of ethylene/acrylic copolymers, ethylene/ester copolymers, ethylene carbonyl copolymers, and mixtures thereof.

4. The process of claim 1, wherein component A comprises one or more fatty triglyceride.

5. The process of claim 1, wherein component A comprises one or more wax ester.

6. The process of claim 1, wherein component B additionally comprises one or more anti-block agents.

7. The process of claim 1, wherein component B additionally comprises one or more wetting agents.

8. The process of claim 1, wherein the substrate comprises polyethylene.

9. The process of claim 1, wherein the isocyanate-polyreactive compound A1b comprises one or more polyether polyol, one or more polyester polyol, or a mixture thereof.

10. The process of claim 1, wherein the urethane coating composition has isocyanate index of 0.9 to 1.6.

11. A coated printed substrate made by the process of claim 1.

Description

[0087] The following coating composition Examples of the present invention were used.

Component A of Example 1

[0088]

TABLE-US-00002 Ingredient Description Amount (wt. %) Ethyl acetate Solvent from UNIVAR, Inc. 24.049 Trimethylolpropane from Lanxess Corp, functionality = 3 11.480 monomeric toluene Mondur TD-80 Grade B from 43.612 diisocyanate (TDI) Covestro Wax Ester Synaceti 125 from Werner G. 1.191 Smith, Inc. Corn oil Fatty triglyceride, refined corn oil 1.191 from Cargill Inc. cyclohexane Cyclohexane from UNIVAR, Inc. 18.423 benzoyl chloride benzoyl chloride from Aldrich 0.055 Chemical Co.

[0089] To prepare Composition A of example 1, the wax ester and the trimethylolpropane were loaded to the reactor followed by ethyl acetate. The TDI was vacuum loaded to the reactor followed by the remainder of the ethyl acetate as a rinse. The batch was held at 70° C. for 3 hours. The batch was then cooled to 55° C. The viscosity of the batch was measured. If the viscosity was less than 380 mPa*s (380 cP), the viscosity of the batch was adjusted to 380 mPa*s (380 cP) by adding trimethylolpropane. If the viscosity was greater than 380 mPa*s (380 cP), or after the additional trimethylolpropane was added, the reactor was then cooled to 55° C. The corn oil was vacuum loaded to the reactor. The cyclohexane was then added to the reactor, and the contents were held at 45° C. and stirred 45 minutes until the contents became clear. The benzoyl chloride was then vacuum loaded to the reactor, and the contents were stirred for 15 minutes. Reactant Composition A was then packaged for use.

Component A of Example 2

[0090]

TABLE-US-00003 Ingredient Description Amount (wt. %) Ethyl acetate Solvent from UNIVAR, Inc. 24.049 Trimethylolpropane Trimethylolpropane from Lanxess 6.471 Corp, MW = 134; functionality = 3 Methylene diphenyl ISONATE 125M from Dow 48.62 diisocyanate Chemical Company Wax Ester Synaceti 125 from Werner G. Smith, 1.191 Inc. Corn oil Fatty triglyceride, refined corn oil 1.191 from Cargill Inc. cyclohexane Cyclohexane from UNIVAR, Inc. 18.423 benzoyl chloride benzoyl chloride from Aldrich 0.055 Chemical Co.

[0091] To prepare Composition A of example 2, the wax ester and the trimethylolpropane were loaded to the reactor followed by ethyl acetate. The MDI was vacuum loaded to the reactor followed by the remainder of the ethyl acetate as a rinse. The batch was held at 70° C. for 3 hours. The batch was then cooled to 55° C. The corn oil was vacuum loaded to the reactor. The cyclohexane was then added to the reactor, and the contents were held at 45° C. and stirred 45 minutes until the contents became clear. The benzoyl chloride was then vacuum loaded to the reactor, and the contents were stirred for 15 minutes. Reactant Composition A was then packaged for use.

Component B of Example 1

[0092]

TABLE-US-00004 Ingredient Description Amount (wt. %) ethyl acetate Solvent from UNIVAR, Inc. 26.5861 Triisopropylanolamine polyol from The Dow Chemical 20.2901 (TIPA) Company; MW = 191; functionality: 3 monomeric toluene Mondur TD-80 Grade B from 17.8299 diisocyanate (TDI) Covestro Voranol ™ 220-260 polyether diol (nominal molecular 13.8618 weight of 425), functionality = 2, OHN = 260 from The Dow Chemical Company Voranol ™ 220-110N Polyether polyol, MW = 1000; 21.4276 Functionality: 2; OHN = 110 from The Dow Chemical Company SAG-47 Anti foam from Momentive 0.0046 Performance Materials

[0093] To prepare Reactant Composition B of example 1, the TIPA was melted. The Voranol 220-260 was vacuum loaded into a reactor. The melted TIPA was vacuum loaded into the reactor, followed by the VORANOL 220-110N. The vacuum lines were rinsed with ethyl acetate and the contents of the reactor were stirred at 75 RPM. Ethyl acetate was vacuum loaded into the reactor. The contents of the reactor were cooled via a cooling jacket. After cooling, the TDI was loaded to the reactor, and the vacuum lines were rinsed with ethyl acetate. Because of the exothermic nature of the reaction, the contents of the reactor were cooled to a temperature of 75° C. The temperature in the reactor was held at 75° C. under agitation for 4 hours. The contents of the reactor were then cooled to 60° C., a mixture of the antifoam and the remaining ethyl acetate were vacuum loaded to the reactor. The contents were then stirred for 30 minutes. The reactor was then cooled to 50° C., and the Reactant Composition B was packaged for use.

Component B of Example 2

[0094]

TABLE-US-00005 Ingredient Description Amount (wt. %) ethyl acetate Solvent from UNIVAR, Inc. 34.196 Triisopropylanolamine Polyol from The Dow Chemical 17.644 (TIPA) Company; MW = 191; functionality: 3 Monomeric toluene Mondur TD-80 Grade B from Covestro 15.505 diisocyanate (TDI) Voranol ™ 220-260 polyether diol (nominal molecular weight 12.054 of 425), functionality = 2, OHN = 260 from The Dow Chemical Company Voranol ™ 220-110N Polyether polyol, MW = 1000; 18.633 Functionality: 2; OHN = 110 from The Dow Chemical Company SAG-47 Anti foam from Momentive Performance 0.004 Materials CAB-381-0.5 Cellulose acetate butyrate, anti block 1.121 agents from Eastman Chemical Company CAB-551-0.01 Cellulose acetate butyrate, anti block 0.280 agents from Eastman Chemical Company Modaflow wetting, leveling agent, acrylic polymer 0.561 from Allnex

[0095] To prepare Reactant Composition B of example 2, the TIPA was melted. The Voranol 220-260 was vacuum loaded into a reactor. The melted TIPA was vacuum loaded into the reactor, followed by the VORANOL 220-110N. The vacuum lines were rinsed with ethyl acetate and the contents of the reactor were stirred at 75 RPM. Ethyl acetate was vacuum loaded into the reactor. The contents of the reactor were cooled via a cooling jacket. After cooling, the TDI was loaded to the reactor, and the vacuum lines were rinsed with ethyl acetate. Because of the exothermic nature of the reaction, the contents of the reactor were cooled to a temperature of 75° C. The temperature in the reactor was held at 75° C. under agitation for 4 hours. The contents of the reactor were then cooled to 60° C., a mixture of the antifoam, cellulose acetate butyrate, modaflow, and the remaining ethyl acetate were vacuum loaded to the reactor. The contents were then stirred for 60 minutes at 60° C. The reactor was then cooled to 50° C., and the Reactant Composition B was packaged for use.

[0096] The following Comparative Examples were used.

TABLE-US-00006 Comparative Example Product Supplier Comment C3 1K OPV Flexo Siegwerk Single-component coating polyurethane C4 SQ 2K gloss Sun Chemical Two-component coating polyurethane C5 UV curing Sericol believed to be acrylic varnish 002

[0097] In the scratch resistance test, an area of the substrate was printed with a uniform block of a printing ink of a single color, and that printed area was tested. The result is the number of scratching cycles performed before the surface of the sample shows any visible damage. The test was stopped at 50 cycles, even though the best samples showed no damage at that time. The results were as follows:

TABLE-US-00007 Example Number of Scratch Cycles Before Damage 1 50 2 50 C3 30 C4 45 C5 20
The examples of the present invention showed better scratch resistance than all the comparative examples.

[0098] In the Chemical Resistance Test, three different chemical reagents were used: [0099] “Cl”=a liquid chlorine-containing disinfectant solution [0100] “Cl/det”=the same solution as in “Cl”, with detergent added [0101] “liq”=a commercial liquid all-purpose household cleaning solution
Three different standing times were used: 0.5 h (hour), 4 h, and 24 h.
The results were as follows:

TABLE-US-00008 Cl Cl Cl Cl/det Cl/det Cl/det liq liq liq Example 0.5 h 4 h 24 h 0.5 h 4 h 24 h 0.5 h 4 h 24 h 1 good good good good good good good good good 2 good good good good good good good good good C3 good bad bad good bad bad good bad bad C4 good bad bad good bad bad good bad bad C5 good fair bad good fair bad good fair bad
At 0.5 hours, all the examples showed good performance. At 4 hours and 24 hours, the examples of the present invention showed better chemical resistance than all the comparative examples.

[0102] The temperature resistance test was performed as described above. The results were as follows:

TABLE-US-00009 Example Temperature (° C.) 1 175 2 175 C3 125 C4 155 C5 135 uncoated printed film 75
The examples of the present invention showed better temperature resistance than all the comparative examples. The uncoated film showed damage at 75° C.; the comparative examples C3, C4, and C5 showed damage 125° C. to 155° C., while the invention examples did not show damage until 175° C.

[0103] In the gloss test, the result is the gloss observed at a 60 degree angle. The results were as follows:

TABLE-US-00010 Example Gloss (%) 1 77 2 82 C3 58 C4 72 C5 65 uncoated printed film 41

[0104] The examples of the present invention showed better gloss than all the comparative examples.