PRETREATMENT FORMULATION AND A CORRESPONDING INK SET

Abstract

A pretreatment formulation is disclosed which includes at least one ink fixation agent and at least one vinyl acetate/ethylene copolymer (VAE) and/or a VAE derivative.

Claims

1.-64. (canceled)

65. A pretreatment formulation comprising at least one ink fixation agent and at least one vinyl acetate/ethylene copolymer (VAE) and/or a VAE derivative, the formulation being free of a pigment or a dye, wherein VAE is a copolymerization product of vinyl acetate and ethylene, having vinyl acetate content between 60 and 95%, and ethylene content between 5 and 40% (w/w) and wherein the VAE derivative is a modified VAE wherein a further monomer is introduced along the VAE chain; or at least a portion or all of the vinyl acetate monomers and/or at least a portion or all of the ethylene monomers are chemically functionalized; or at least a portion or all of the vinyl acetate monomers are chemically functionalized, and none of the ethylene monomers are chemically functionalized; or none of the vinyl acetate monomers are chemically functionalized, and a plurality or all of the ethylene monomers are chemically functionalized; or wherein the backbone of a VAE polymer is chemically functionalized.

66. The formulation according to claim 65, configured and adapted for use with an ink formulation free of a combination of a fixation agent and at least one vinyl acetate/ethylene copolymer (VAE) or a VAE derivative; or for use with an ink formulation that is free of at least one vinyl acetate/ethylene copolymer (VAE) or a VAE derivative.

67. The formulation according to claim 65, wherein the VAE derivative is a copolymer of vinyl acetate, ethylene and an N-methylol-based compound.

68. The formulation according to claim 67, wherein the VAE derivative is a self-crosslinkable polymer having one or more crosslinkable functionalities.

69. The formulation according to claim 68, wherein the one or more crosslinkable functionalities are selected to inter-molecularly self-crosslink.

70. The formulation according to claim 68, wherein the one or more crosslinkable functionalities are selected from alcohols, amines, vinyl groups, carboxyl groups, and silanols.

71. The formulation according to claim 65, wherein the VAE derivative is a copolymerization product of vinyl acetate (VA) monomers, ethylene (E) monomers with N-methylol-functionalized ethylene monomers.

72. The formulation according to claim 71, wherein the N-methylol-functionalized ethylene monomer is derived from N-methylol-acrylamide (NMA), N-methylol methacrylamide, N-methylol maleimide, N-methylol maleinamic acid, N-methylol maleinamic acid esters, or N-methylol amide of vinyl aromatic acids.

73. The formulation according to claim 72, wherein the N-methylol-functionalized ethylene monomer is an N-methylol-acrylamide (NMA).

74. The formulation according to claim 65, wherein the VAE derivative is a copolymerization product of ethylene (E) monomers, vinyl acetate (VA) monomers, with N-methylol-functionalized vinyl acetate monomers.

75. The formulation according to claim 74, wherein the N-methylol-functionalized vinyl acetate monomer is derived from N-methylol-acrylamide (NMA), N-methylol methacrylamide, N-methylol maleimide, N-methylol maleinamic acid, N-methylol maleinamic acid esters, or N-methylol amide of vinyl aromatic acids.

76. The formulation according to claim 65, wherein the ink fixation agent is at least one cationic material.

77. A method of forming an ink pattern on a surface, the method comprising coating a surface region of a substrate (or forming a coat or a film) with a pretreatment formulation according to claim 65 and patterning an ink formulation on at least one region of the surface region of the substrate coated with the pretreatment formulation, wherein the at least one region coated with the pretreatment formulation is a dry or a wet region.

78. A method of forming an ink pattern on a dry or wet recipient surface present on a textile substrate, the method comprising obtaining a textile substrate having a part of its surface region or the complete surface region coated with a pretreatment formulation according to claim 65, and forming a pattern of an ink formulation on at least a portion of the surface region coated with the pretreatment formulation, wherein optionally prior to the forming of the ink pattern the coated region is dried to obtain a dry recipient surface.

79. The method according to claim 78, wherein the pretreatment formulation comprises at least one metal salt optionally selected from calcium acetate, CaCl.sub.2, CaF.sub.2, CaBr.sub.2, or CaI.sub.2, wherein the amount of the salt does not exceed 20 wt % or is between 0.1 and 20 wt %; VAE and/or a VAE derivative in an amount ranging between 0.1 and 20 wt %; and an aqueous carrier.

80. The method according to claim 78, wherein the pretreatment formulation is patterned by digital printing, direct to garment (DTG), roll-to-roll, transfer printing processes, flexo, roto gravure, direct to film (DTF), offset, screen printing, brushing or spraying.

81. A dried or cured pattern or coat or film formed on a substrate, the film being formed of a formulation according to claim 65.

82. The film according to claim 81, formed on substrate selected from absorptive or non-absorptive materials, natural or synthetic materials, paper materials, polymeric materials.

83. A fabric coated with a dry or wet film of a pretreatment formulation according to claim 65, the formulation comprising VAE and/or a VAE derivative, and at least one ink fixation agent, wherein: when the film is a wet film, the film further comprises water; and when the film is a dry film, the film is (substantially) free of water.

84. A fabric coated with a dry film of a pretreatment formulation comprising VAE and/or a VAE derivative, and at least one ink fixation agent, wherein said dry film is overlayed with an ink film or an ink pattern.

Description

DETAILED DESCRIPTION OF EMBODIMENTS

Exemplary Formulations According to Embodiments of the Present Invention:

[0247] Various VAE-based pretreatment formulations have been prepared and utilized on a variety of surfaces, such as fabrics. Formulations comprising VAE and/or a VAE derivative, as defined and selected herein, have demonstrated efficient formation of robust solid films and coats that could be used as effective recipient layers of ink-based formulations.

[0248] In the data below, data relating to exemplary formulations is provided. Generally, VAE derivatives tested include derivatives regraded herein as copolymers of VA and E, wherein either one or both of VA and E is derivatized or functionalized with an N-methylol derived from N-methylol-acrylamide (NMA), N-methylol methacrylamide, N-methylol maleimide, N-methylol maleinamic acid, N-methylol maleinamic acid eater, or N-methylol amide of vinyl aromatic acids (or additionally with VA monomers and/or E monomers, which are not functionalized).

[0249] In some cases, the VAE derivative is a copolymer of VA with E functionalized with N-methylol derived from NMA (or additionally with ethylene monomers (E) which are not functionalized).

[0250] Table 1 demonstrates use of a copolymer of VA and/or and E with E- or VA-functionalized with N-methylol derived from NMA according to the invention, when implemented in several non-limiting pretreatment formulations. Each of these formulations may be used to form a precoat or a recipient coat on a fabric or a polymeric substrate to enable subsequent printing or patterning by an ink formulation. The carrier for all formulations was water. Additives were added or were excluded, depending on the particular intended use.

TABLE-US-00001 TABLE 1 Exemplary formulations according to some embodiments of the invention Wt % of copolymer of VA, E and Wt % of Wt % of E-functionalized metal salt cationic polymer with N-methylol such as poly(diallyldimethyl Additives No. derived from NMA* CaCl.sub.2 ammonium chloride) (Wt %) 1 3.6 0.5 2 3.6 0.5 Tego Foamex 852 (0.4) 3 3.6 2 4 3.9 0.6 5 3.9 0.6 RUCOFIN X- GWA NEW (5) 6 3.9 0.6 AIRASE 5355 (0.3), 7 0.55 1 8 0.55 1 (Nuosept 95 supplied by Troy Corporation (Arxada)(0.3) 9 0.55 1 Nuosept 95 supplied by Troy Corporation (Arxada)(0.3), Borchers AF 1171 (0.3) 10 0.55 1 Borchi Burst DFS 600 (0.2) 11 5 0.3 RUCOFIN SIQ NEW (5) 12 5 1 AIRASE 4500 (0.5) 13 4.5 1.5 14 4.5 1.5 O,O-Di-t-butyl phenylphosphonate (0.4) 15 5 2 16 5 2 RUCOFIN GWE (5) 17 0.55 2.4 18 1.2 0.1 19 1.1 2 20 2.4 1.1 21 6.8 1.4 22 8.6 10.1 23 10.9 4.2 24 10.9 10 25 10.9 1 26 8.5 0.1 27 8.5 2.1 28 8.5 0.5 29 3.3 5.5 1.2 Borchi Burst DFS 600 (0.2) 30 3.3 5.5 1.2 RUCOFIN SIQ NEW (5) 31 3.3 5.5 1.2 AIRASE 4500 (0.5) 32 3.3 5.5 1.2 *the copolymer of VA, E and E-functionalized with N-methylol derived from NMA may be synthetically made or commercially obtained from a variety of sources such as Celanese under Vinamul and Mowilith series, and Wacker Chemie AG under the VINNAPAS series.

[0251] The above formulations, when applied on a substrate such as a fabric, demonstrated excellent hand feel and exhibited no ink bleeding or ink smearing when printed on.

Application of a Pretreatment Formulation:

[0252] A T-shirt, cotton or polyester, was treated with a pretreatment formulation via use of an automatic pretreatment machine (Schulze PRETREATmaker IV). Subsequent to the application of the formulation onto the shirt, thermal energy was applied via hot air dryer or a heat press to cause drying or curing of the coating.

[0253] Following the formation of a dry pretreatment coat on the T-shirt, an inkjet DTG (direct to garment) printer was used to print an image onto the pretreated T-shirt. Thermal energy was again applied to accomplish drying or curing of the ink pattern by utilizing a hot air dryer or a heat press.

[0254] This process was repeated, mutatis mutandis, on a variety of other textiles, polymeric substrates and other substrate materials as disclosed herein.

[0255] The ink formulation used for patterning on top of the pretreatment coat was an aqueous pigmented ink having the composition provided in Table 2.

TABLE-US-00002 TABLE 2 Exemplary ink formulation used in testing durability of a pretreatment formulation of the invention Ingredient Amount Humectants 7%-50% w/w DI Water 4%-40% w/w Wetting agents 0.1%-12% w/w Polyurethane resin 16%-40% w/w dispersion C/M/Y/K/W Pigment 0.5%-20% w/w dispersion

[0256] Other ink formulations may be used in place of that in Table 2.

Stability and Mechanical Properties of the Dried and or Cured Image Printed on the Pretreated Fabric Substrate:

[0257] To test the durability of the pattern formed on the pretreatment coating, the T-shirt was washed in a washing machine numerous times beginning on the day following printing. A wash-fastness test was conducted to evaluate water and detergent resistance, the ability to withstand different pH and temperature conditions, as well as rub resistance.

[0258] Further, a color fade wash-resistance test was conducted with a standard household laundry machine (LAVAMAT LVW9140T). Twenty wash cycles (1000 rpm, at 30 C. using day-to-day 60 minutes wash mode) were carried throughout the test, every 5 sequential cycles the entire full load was dried on a drying stand. This process was repeated 4 times.

[0259] Table 3 depicts wash-fastness results onto different type of T-shirt substrates with having applied the various pretreatment formulations of Table 1. The data herein reflects the outcome of separate multiple tests, all involving different formulations, yet same or substantially same surface application, drying or curing processes of the substrate prior and post printing (e.g., via a heat press-Stahls Hotronix Air Fusion Heat Press), while using the conditions listed in Table 3, followed by a color fade wash-resistance test. Note that the conditions used in the Table may be varied based on the substate use, the test conditions and the type of mechanical durability that is investigated.

TABLE-US-00003 TABLE 3 Test conditions Pre-treatment Post-printing drying/curing drying/curing Grade after (temp./duration, (temp./duration, 20 laundry Substrate pressure) pressure) cycles White cotton 140 C./30 sec, 170 C./60 sec, 4.5 (B&C 50 psi 50 psi organic) White 140 C./30 sec, 170 C./60 sec, 4.5 Polyester 50 psi 50 psi (Sense) Black cotton 140 C./60 sec, 170 C./60 sec, 4.5 (B&C 50 psi 50 psi organic) Black 140 C./50 sec, 110 C./3 min, 4 Polyester 50 psi 50 psi (Augusta) Black 140 C./50 sec, 110 C./2 min, 4.5 Polyester 50 psi 50 psi (Sportek)

Results and Discussion

[0260] Generally, wash-fastness is measured via sequential or non-sequential set number of laundry cycles. The resistance of a material to change in any of its colors characteristics is evaluated while stimulating rubbing-fastness, withstanding changes in pH and temperature parameters and exposing to water and detergent. The grades range between 1 and 5, while the lowest rank is 1 and the highest 5. Manufacturers target a minimum of grade 3, but usually aim for a grade equal to or above 4.

[0261] As noted herein, pretreating of a substrate with formulations of the invention resulted in high wash-fastness ranking scores, ranging between 4 and 4.5. This stands to show that the pretreatment allows an enhanced resistance to external forces, reflecting on the bonding of the substrate-pretreatment-ink formulations as well as on the robust physical and chemical properties of the pretreatment film/coat applied onto the substrate and resulted from the self-crosslinking of the VAE derivative used.