Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D11/00—Inks
  • C09D11/02—Printing inks
  • C09D11/03—Printing inks characterised by features other than the chemical nature of the binder
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L83/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
  • C08L83/04—Polysiloxanes
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D11/00—Inks
  • C09D11/02—Printing inks
  • C09D11/10—Printing inks based on artificial resins
  • C09D11/101—Inks specially adapted for printing processes involving curing by wave energy or particle radiation, e.g. with UV-curing following the printing

Definitions

• This invention relates to printing inks, particularly to additives for printing inks that provide a low energy surface and articles using printing inks with additives.
• Repositionable note pads, tapes and linerless labels typically consist of sheets of stock (paper, films, etc.) coated with pressure sensitive adhesive ("PSA") (and optionally a primer) on one side of the sheet and a release coating (also referred to as "low adhesion backsize” or “LAB”) on the other side.
• PSA pressure sensitive adhesive
• LAB low adhesion backsize
• the release coating is in contact with the adhesive.
• the release coating is used to lower the force required to remove the adhesive from the adjacent sheet in order to facilitate dispensing and minimize stock deformation or curl.
• the release coating is used to ensure easy unwind during processing and dispensing.
• Lithographic, flexographic, or gravure printing processes are often used to prepare printed repositionable notes, tapes and linerless labels. Often, the printing process is separate from and subsequent to the process that applies the adhesive and release coating. In such situations, a roll of stock that has been pre-coated with adhesive and a release material is routed through a printing press, ink is printed on top of the release coating, and the printed material is immediately either rolled back up or cut into a stack of discrete sheets. Printing of ink over the release coating renders the release coating ineffective.
• organopolysiloxanes that contain mercapto groups to lithographic inks in order to improve the properties of printed PSA products such as repositionable notes, tapes and linerless labels. It would be advantageous to have ink that would not form undesirable adhesive-ink interactions, and, preferably, would act as a release material. Such ink would eliminate the aforementioned problems of poor release and high "ink transfer" and allow for the manufacture of improved (better release, less ink transfer) printed repositionable notes, tapes and linerless labels.
• releasable lithographic inks that provide release characteristics to printed inks comprising (a) UV-curable or air-curable printing inks and (b) a release additive.
• the preferred additives to the UV- curable or air-curable inks are mercaptopolydiorganosiloxane copolymers.
• Inks containing additives such as mercaptopolydiorganosiloxane copolymers can be advantageously used in products that have pressure sensitive adhesives (PSAs) in contact with the printed inks in order to reduce undesirable PSA/ink interactions.
• PSAs pressure sensitive adhesives
• Undesirable PSA/ink interactions that are avoided by this invention include "ink transfer" from the printed image to the adhesive which results in damage to the printed image and adhesive contamination, and high release forces during unwind or sheet removal which can cause damage to the backing or render the product unusable.
• Another class of additives that provide good properties for UV-curable inks are acrylate terminated silicones ("silicone macromers").
• Silicone "Plus” HG-10 Siloxane which is commercially available from 3M Company , St. Paul, MN.
• Silicone "Puls” HG-10 is a methacrylate terminated poly(dimethylsilicone) polymer having a number average molecular weight of 10,000.
• adhesive coated articles comprising (a) a backing substrate having a front and back surface, (b) a layer of pressure sensitive adhesive on at least one portion of the back surface of the backing substrate, and (c) indicia on the front surface of the backing substrate, wherein the indicia is printed using lithographic inks having release characteristics.
• a pad assembly comprising a multiplicity of flexible sheets each having similarly sized body portion that have pressure sensitive adhesive on the back surface and indicia printed on the front surface, wherein the indicia is printed with lithographic inks having release characteristics, such that when a sheet is removed from the pad assembly, the sheet is easily removable and the lithographic ink is not transferred from the front of the sheet of a first sheet to the back of the sheet of second sheet overlaying the first sheet.
• the multiplicity of sheets have pressure sensitive adhesive coated onto the back surface of the sheets and the sheets are disposed in a stack with the corresponding peripheral edges of the body portions of the sheets aligned and the pressure sensitive adhesive of each sheet adhering that sheet to the adjacent sheet in the stack.
• Such products include printed repositionable note pads (such as 3M Post-it® Notes), linerless labels, printed pressure sensitive tapes, adhesive coupons, and the like.
• lithographic inks having release characteristics provides a construction that eliminates the need of providing a release coating on sheets having indicia printed on the front of them.
• a method of using lithographic inks having release characteristics are providing comprising the steps of:
• ink additives have been discovered that eliminate the aforementioned problems of poor release and high "ink transfer".
• the additives can be blended with commercially available UV or air-curable lithographic inks and the resultant inks printed on standard lithographic printing presses.
• the mercapto group of the additive enters into the curing processes of both air-curable and UV-curable lithographic inks and becomes covalently bound to the cured ink.
• the bound additive will not transfer to and contaminate pressure sensitive adhesives that may come in contact with the ink.
• Preferred additives are mercaptopolydiorganosiloxane copolymers that are described by the following general formula
• Ri, R 2 and R 3 are monovalent moieties that can independently be the same or different and are selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, hydroxyl, hydrogen, fiuoroalkyl, divalent linking groups and are most preferably alkyl moieties;
• R 4 , R 5 , and Re are monovalent moieties that can independently be the same or different and are selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, hydroxyl, hydrogen, fiuoroalkyl, and are most preferably alkyl moieties;
• z can range from 1 to about 16, preferably from 1 to 5 and is most preferably 3.
• x and y are integers of at least one and the sum of x + y is an integer of 10 or greater.
• the molecular weight of the additive can range from about 1000 to about 200,000.
• the preferable range is from about 5000 to about 50,000.
• the additive has a viscosity which is desirable for blending into inks.
• the molecular weight can also affect additive effectiveness. Optimal molecular weights will be dependent on additive and ink type.
• any cyclic material that may be present is removed prior to use by such methods as evaporation under vacuum at elevated temperatures (for example, 150°C, 200 mm Hg).
• Additional most preferred additives of varying values of R, x, y and z are available from Huls America Inc. (Piscataway, NJ).
• the additive is added to the ink in amounts ranging from 0.1 to 15% by weight of the ink and most preferably between 1 and 5%.
• the optimum additive amount will be dependent on the strength of the pressure sensitive adhesive and desired release value in the printed product. Addition of too much additive can cause wetting problems on the print rollers and blankets and adversely affect the printing process.
• the upper limit of additive ranges between about 5 and 15% depending on the printing press type, roller and blanket materials, and ink formulation.
• the mercapto content (weight percent SH moieties based on weight of additive) in the additive can range from about 0.1 to about 20 weight percent. Most preferable mercapto contents range from 0.35 to about 4 weight %. Additive effectiveness appears to decrease at very high levels of SH. For example, poly(mercaptopropylmethylsiloxane) (26 wt% SH) is not a very effective additive.
• acrylate terminated silicones (“silicone macromers”).
• Silicone "Plus” HG-10 Siloxane which is commercially available from 3M Company , St. Paul, MN.
• Silicone "Puls” HG-10 is a mefhacrylate terminated poly(dimethylsilicone) polymer having a number average molecular weight of 10,000.
• Preferable lithographic inks are curable by UV irradiation although lithographic inks that are curable by air-oxidation may also be used. Typical lithographic inks that are commercially available from common ink suppliers can be used.
• Suitable UV-curable lithographic inks include UV 1/D process inks from Kohl and Madden Corporation (Minneapolis, MN), and UVALUX process inks from Zeller Interchem Corporation (2205 Tomlynn Street, Richmond, VA 23230).
• Standard lithographic printing presses can be used. Such presses for air-curable inks include: Didde's (Emporia, Kansas) Webcom and Apollo presses and printing presses available from Stevens International (Fort Worth, Texas). Laboratory presses include the Little Joe Proving Press (Little Joe Color Swatcher, Somerville, NJ). UV Presses include those available from Sanden (Cambridge, Ontario) and Mueller Martini (New York).
• Additives were added to the base ink and mixed with a wood applicator until uniform. The amount of additive is reported as weight % based on the mass of base ink used.
• Printing was carried out using a Little Joe Lithographic Proving Press (Little Joe Color Swatcher, Somerville, NJ) according to the following procedure. Brayers and print blankets designed specifically for either air-curable or UV-curable inks were used.
• Print #2 was discarded. Prints 3-6 were retained and evaluated.
• each printed sample was immediately attached to a piece of cardboard and passed through an ultraviolet curing unit (Fusion UV Curing Systems, Rockville, MD, F300 ultraviolet lamp system, MC-6R conveyor) at a speed of approximately 15 feet (4.57 meters) per minute.
• an ultraviolet curing unit Fusion UV Curing Systems, Rockville, MD, F300 ultraviolet lamp system, MC-6R conveyor
• the proving press was thoroughly cleaned prior to the printing of another sample. Samples were tested after equilibration in a controlled temperature and humidity room for at least 24 hours.
• This test is similar to TAPPI test method UM-504.
• a 25 mm wide strip of 3M 810 MagicTM Tape was applied to a substrate.
• a 2 kg roller was rolled over the tape on the substrate (two passes) in order to adhere the tape to the substrate.
• One end of the tape was attached to a tensile tester. The tape was peeled from the surface at a 90 degree angle at
• Re-Adhesion is a qualitative measure of the amount of adhesive contamination that occurs when 3M 810 MagicTM Tape is peeled from a substrate.
• the tape that was used in the Peel Adhesion test is applied to the non-adhesive side of unprinted Post- it® Note paper (yellow Ashdown paper). Peel Adhesion was measured and the tape strip was retained for evaluation of ink transfer. The test was carried out on prints 3-6. The average of these tests is reported. The "re-adhesion value" was compared to the Peel
• Sheet removal force is the force required to remove the top sheet from a pad of repositionable notes such as Post-it® Notes. This test was carried out by cutting a one inch (2.54 cm) wide strip across the top sheet of the note pad such that the strip was perpendicular to the adhesive stripe. The adhesive-free end of the strip was attached to a tensile tester. The strip was peeled from the surface at a 90 degree angle at 12" (30.48 cm)/min. The force in g/1" (2.54 cm) was recorded. The test was repeated and the average of the trials was reported.
• Comparative examples C1-C3 showed the detrimental effect of printing a typical air-curable lithographic ink onto a paper coated with a release coating.
• Re-adhesion values were significantly lower (117 and 105 g/1.25" (3.175 cm)) than 140 g/1.25" (3.175 cm), which indicates that contamination of the adhesive with ink was significant. Ink transfer was high (2.5) for both C2 and C3.
• Comparative Examples C4-C12 Comparative examples C4-C6 (Table 1) showed that use of typical ink additives such as polyethylene and polytetrafluoroethylene (such as Teflon®) waxes did not improve release and cause adhesive contamination as indicated by the high peel adhesion and low re-adhesion values. Comparative examples C7-C12 showed that stearic acid, fluorine containing monomers, a methacrylate terminated silicone "silicone macromer", and polyethylene glycol monomethacrylate also provided poor results. JM410-9, 410-8, and 413-3 are typical waxes that are used in lithographic inks.
• JM410-9 is commercially available as "Super Poly 4" from Lawter International, pleasant, WI.
• JM410-8 is commercially available as "CC5510-D” and JM413-3 is commercially available as "PROTECH 200" both materials are available from Carrol Scientific, Countryside, LL.
• CW-750 is polyethylene glycol monomethacrylate 10 moles, EO obtained from Polysciences, Inc., Warrington, PA (Cat. #16713).
• Comparative examples C13 and C14 showed that using mercaptan-free polydimethylsiloxanes that did not have mercaptan functionality did not provide improved properties.
• polydimethylsiloxane trimethylsiloxy terminated, CAS No. [63148-62-9]
• CAS No. [63148-62-9] trimethylsiloxy terminated
• Examples 9 and 10 showed that poor print quality was obtained if 3.75% or 5% of X-22-980 was used. This indicated that print quality could be affected on certain printing presses if relatively high levels of X-22-980 were used. It should be noted, however, that Didde Webcom lithographic printing presses were found to successfully print ink containing 5% X-22-980 and that an upper limit for X-22-980 level was dependent on press type.
• Ink did not wet out the inking plate or printing plate very well. Inks were obtained from Kohl & Madden Printing Ink Corp (Minneapolis, MN). Red ink was labeled PMS-185-ABD (OFF-ABD-STD-RED).
• Black Ink was labeled MSP-42200-D-STG-S (OFF-SOY-ABDT-BLACK).
• Comparative examples C100-C101 were carried out in a similar fashion as examples C1-C3.
• the high peel adhesion value in CIO 1 illustrated the detrimental PSA ink interactions that resulted when printing a typical UV-curable lithographic ink onto a paper coated with a release coating.
• low ink transfer and low adhesive contamination were observed when using UV-curable inks and proper curing conditions.
• Comparative Examples C103-C109 Comparative examples C107-C109 (Table 2) showed that typical ink additives, such as polyethylene and polytetrofluoroethylene (such as Telfon®) waxes did not improve release. Comparative examples C103-C106 showed that fluorine-containing monomers and polyethylene glycol monomethacrylate were also ineffective at reducing PSA/ink interactions. JM410-9, 410-8, and 413-3 are typical waxes that are used in lithographic inks.
• JM410-9 is commercially available as "Super Poly 4" from Lawter International, pleasant, WI. JM410-8 is commercially available as "CC5510-D” from Carrol Scientific, Countryside, IL. JM413-3 is commercially available as "PROTECH 200" from Carrol Scientific. Countryside, LL. FluoradTM FX- 13 , FluoradTM FX- 189 and FluoradTM FX- 14 were obtained from 3M Company (Industrial Chemical Products Division, St. Paul, MN).
• CW-750 is polyethylene glycol monomethacrylate 10 moles, EO obtained from Polysciences, Inc., Warrington, PA (Cat. #16713).
• Comparative Examples C110 and Clll Comparative examples C 110 and Cl l l show that the use of mercaptan-free polydimethylsiloxanes that do not have the mercaptan functionality do not provide improved properties.
• polydimethylsiloxane trimethylsiloxy terminated, CAS No. [63148-62-9]
• peel adhesion values for Examples 100-108 show that X-22-980 reduces PSA / ink interactions. Peel adhesion decreases as X-22-980 levels are increased from 1 to 6 wt%. The high re-adhesion values indicate that adhesive contamination is low. Examples 109 and 110 show that poor print quality is obtained if 7.5% or 10% X-
• Examples 109-116 (Table 2) illustrate the positive affects of additives with various amounts of mercapto content and variations in polymer structure. Except for PS 927 and
• PS405 the additives are dimethylsiloxy / 3-mercaptopropylmethylsiloxy copolymers of varying comonomer ratios and molecular weights.
• PS927 is the homopolymer based on a 3-mercaptopropylmethylsiloxy repeat unit.
• PS405 is described as "polydimethylsiloxane, mercaptopropyl t-structure with branch points" by Huls America.
• the additives are described in detail in Table 3.
• Example 117 illustrated that methacrylate-terminated poly(dimethylsiloxane) of a number average molecular weight of 10,000 (Silicone PLUS HG-10, commercially available from 3M) was an effective additive.
• Inks used in these examples were obtained from Zeller Interchem Corporation. Black ink was labeled UVALUX US4826LD; yellow ink was labeled UVALUX US4825LD. Ink additive "X-22-980" was added to the inks at 1, 3 and 5 weight percent based on the weight of the ink. Black ink was cured with 4 lights whereas the yellow ink was cured with one UV light.
• Examples C200-C203 and 201-202 demonstrate that the additives described in this invention can be used to make printed tapes that have good release characteristics.
• Printing was carried out on the non-adhesive side of several strips of 1" (2.54 cm) wide ScotchTM MagicTM Tape (810 tape, commercially available from 3M company, St. Paul, MN) in a similar manner as C 1 and C 100.
• the several strips of ScotchTM MagicTM Tape were laminated next to each other onto bond paper prior to printing in order to create a large area for printing.
• Results in Table 5 show that addition of 2.5% of X-22-980 results in low ink transfer and low peel adhesion for both UV and air-curable inks.
• UV-curable ink UVALUX US423185 LD UN RED obtained from Zeller and
• Air-curable ink PMS-185-ABD (OFF-ABD-STD-RED) obtained from Kohl and Madden Corp.
• Examples C210-C213 and 211-212 demonstrate that the additives described in this invention can be used to make printed labels that have good release characteristics.
• UV-curable ink UVALUX US423185 LD UN RED obtained from Zeller and Gmelin.
• Air-curable ink PMS- 185-ABD (OFF-ABD-STD-RED) obtained from Kohl and Madden Corp.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Wood Science & Technology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Inks, Pencil-Leads, Or Crayons (AREA)
• Adhesive Tapes (AREA)
• Adhesives Or Adhesive Processes (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=22340570

Family Applications (1)

Country Status (6)

Families Citing this family (10)

Family Cites Families (8)

• 1999
  • 1999-03-11 AU AU29984/99A patent/AU749524B2/en not_active Ceased
  • 1999-03-11 WO PCT/US1999/005309 patent/WO2000002966A1/en not_active Ceased
  • 1999-03-11 KR KR1020017000202A patent/KR20010053416A/ko not_active Withdrawn
  • 1999-03-11 EP EP99911311A patent/EP1102819A1/en not_active Withdrawn
  • 1999-03-11 JP JP2000559192A patent/JP2002520440A/ja active Pending
  • 1999-03-11 CA CA002336856A patent/CA2336856A1/en not_active Abandoned

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events