Polyurethane modified casein water-based decorative paper ink and preparation method thereof

Abstract

The invention relates to polyurethane modified casein water-based decorative paper ink and a preparation method thereof. The ink comprises the following components: pigment, water-based polyurethane / casein resin, modified silicone acrylic resin, an amino curing agent, a dispersing agent, a wetting agent, a defoaming agent, a cosolvent and the balance of water, the waterborne polyurethane / casein resin comprises a mica modified polyurethane dispersion, a cross-linking agent, a casein solution and water, wherein the mica modified polyurethane dispersion comprises the following components: organic modified mica, polyol, polyamine, a carboxyl hydrophilic monomer, polyisocyanate, a pH regulator, an end-capping reagent and water; the casein liquid comprises the following components: casein, an alkaline solubilizing substance and the balance of water. Compared with the prior art, the water-based paint has good adhesion to paper, is easy to permeate and does not decolorize during impregnation, a formed film is resistant to high temperature and good in leveling property, a good decorative effect is achieved, and the problem that a casein formed film is hard and brittle is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of decorative paper inks and relates to polyurethane-modified casein water-based decorative paper ink and a preparation method thereof. Background Art

[0002] Decorative paper is an essential raw material for many building materials. It mainly provides decorative patterns and covers the bottom glue to prevent penetration. Generally, after the decorative base paper is printed with ink, the printed matter is impregnated with melamine resin or polyester resin solution, and then pressed on the substrate by hot pressing to form a decorative board. Therefore, the ink not only needs to have good adhesion and penetration with the paper, but also requires good heat resistance.

[0003] Casein is a natural polymer, commonly used in leather finishing agents, adhesives and inks, etc., with the advantages of fast drying, strong adhesion and high temperature resistance. Casein has a large number of polar groups such as carboxyl, amino, hydroxyl, thiol, etc., which has a good effect on pigment dispersion, loose film formation, good air permeability, and easy melamine penetration, which meets the needs of decorative paper processing. However, due to the large number of polar groups, the casein film is hard and brittle, with poor elongation and water resistance, and the ink decolorization problem is prone to occur during the impregnation of melamine. On the other hand, due to the fast speed of decorative paper printing equipment, the solid content of the ink on the machine is low, the amount of general connecting material resin is small, and the adhesion is difficult to meet the requirements, so casein needs to be thickened and thickened. Modification. Waterborne polyurethane is a good adhesive material. The use of polyurethane to modify casein can play a thickening role, and the flexibility of polyurethane can be used to improve the film-forming performance of casein. However, the heat resistance of polyurethane is poor, and it will affect the looseness of the film, which is not conducive to the impregnation of melamine.

[0004] Patent CN109233431A discloses a water-based decorative paper ink, which is composed of the following substances in weight percentage: 10-40% pigment, 22-37% water-based polyurethane / casein resin, 0.5-3% modified silicone-acrylic resin, 0.1-0.6% amino curing agent, 1-3% dispersant, 0-0.5% wetting agent, 0.1-0.3% defoamer, 3-6% cosolvent, and the balance is deionized water. However, the patent uses organic modified attapulgite to modify the polyurethane dispersion in the water-based polyurethane / casein resin, and the leveling property of the ink is poor, and the decorative performance needs to be improved. Summary of the invention

[0005] The purpose of the present invention is to provide a polyurethane modified casein water-based decorative paper ink and a preparation method thereof in order to overcome at least one defect of the above-mentioned prior art. The present invention has good adhesion to paper, is easy to penetrate and does not discolor when impregnated, has high temperature resistance in film formation, has good leveling properties, plays a good decorative role, and improves the problem of hard and brittle casein film formation.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] One of the technical solutions of the present invention is to provide a polyurethane modified casein water-based decorative paper ink, which includes the following components in weight percentage:

[0008] Pigment 10-40%, waterborne polyurethane / casein resin 22-37%, modified silicone-acrylic resin 0.5-3%, amino curing agent 0.1-0.6%, dispersant 1-3%, wetting agent 0.1-0.5%, defoamer 0.1-0.3%, cosolvent 3-6%, and the rest is water;

[0009] The waterborne polyurethane / casein resin comprises a mica-modified polyurethane dispersion, a crosslinking agent, a casein solution and water, wherein the mica-modified polyurethane dispersion comprises the following components in parts by weight:

[0010] 1-5 parts of organic modified mica, 20-60 parts of polyol, 2-6 parts of polyamine, 5-7 parts of carboxyl hydrophilic monomer, 14-30 parts of polyisocyanate, 1-4 parts of pH regulator, 7-17 parts of end-capping agent and 100-500 parts of water;

[0011] The casein solution comprises the following components in percentage by weight:

[0012] Casein 10-20%, alkaline solubilizer 3-8%, the rest is water;

[0013] The mass ratio of the components except water in the mica-modified polyurethane dispersion to the cross-linking agent and casein is (4-10):(0.5-2):(6-15), and the weight parts of the mica-modified polyurethane dispersion, the cross-linking agent, the casein liquid and water in the waterborne polyurethane / casein resin total 100 parts.

[0014] As a preferred technical solution, the pigment is selected from one or more of titanium dioxide and color pigments.

[0015] As a preferred technical solution, when the pigment is titanium dioxide and color pigment, the mass ratio of the titanium dioxide to the color pigment is (4-5):(2-3).

[0016] Furthermore, the modified silicone-acrylic resin is selected from one or more of epoxy-modified silicone-acrylic resin, polyester-modified silicone-acrylic resin, and polyurethane-modified silicone-acrylic resin.

[0017] The amino curing agent is selected from one or more of tetramethylol glycoluril resin and methyl etherified glycoluril resin.

[0018] The heat deformation temperature of ordinary polypropylene (PP) decorative paper is generally 110°C, and the actual use temperature is only about 100°C. The curing temperature of water-based decorative paper ink is generally 100°C or below. The cross-linking curing temperature of commonly used etherified melamine resin curing agents is mostly higher than 130°C, or the curing temperature is reduced by catalysis under acidic conditions, while the tetramethylol glycoluril resin or methyl etherified glycoluril resin used in the present invention can be cured at 95°C. The cured product has good corrosion resistance and baking performance, which meets the processing and use requirements of water-based decorative paper ink.

[0019] Furthermore, the dispersant is selected from one or more of polyethylene wax and polyethylene glycol.

[0020] The wetting agent is acetylene glycol,

[0021] The defoamer is polyether polydimethylsiloxane.

[0022] The co-solvent is selected from one or more of ethylene glycol, ethylene glycol butyl ether, diethylene glycol, and dipropylene glycol.

[0023] Furthermore, the organic modified mica is selected from one or more of organosilicon modified mica and long carbon chain quaternary ammonium salt modified mica.

[0024] Mica is a rock-forming mineral with hexagonal flaky crystals, and is one of the main rock-forming minerals. Mica crystals have a layered structure inside, and due to its unique lamellar structure, the prepared ink has good leveling properties; at the same time, mica has good heat resistance, and the thermal properties of polyurethane can be improved by grafting polyurethane with mica; due to the unique optical properties of mica, the ink prepared by adding mica can play a good decorative role.

[0025] The surface polarity of mica is large, the compatibility is poor, it is easy to agglomerate, the dispersion is uneven, and it is not easy to be grafted and copolymerized with organic matter. Therefore, the surface of mica needs to be modified. There are a small amount of exposed active hydroxyl groups on the surface of mica. The mica can be modified with silicone or long carbon chain quaternary ammonium salt to introduce new groups, so that the mica can be grafted and copolymerized with organic matter.

[0026] Furthermore, the polyamine is 1,3-propylene glycol bis(4-aminobenzoate).

[0027] Polyamines are added during the preparation of polyurethane. The amino groups of the polyamines react with polyisocyanates to introduce urea groups. The introduction of urea groups can destroy the hydrogen bonds in the casein molecules to improve the problem of hard and brittle film formation and difficulty in dispersion of casein.

[0028] Further, the polyol is selected from one or more of polyethylene adipate, polybutylene adipate, polyhexane adipate, polycarbonate diol, polycaprolactone diol, polypropylene ether diol, polytetrahydrofuran diol, hydroxy-terminated polybutadiene diol, and polyaspartic acid diol.

[0029] The carboxyl hydrophilic monomer is selected from one or more of 2,2-dimethylol propionic acid and 2,2-dimethylol butyric acid.

[0030] The polyisocyanate is selected from one or more of isophorone diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, and diphenylmethane diisocyanate.

[0031] The pH regulator is selected from one or more of triethylamine, ammonia water, sodium hydroxide and potassium hydroxide.

[0032] The end-capping agent is polyethyleneimine, and the molecular weight of the end-capping agent is 300-1000.

[0033] Polyethyleneimine is a water-soluble multi-branched polymer with amino end groups, good heat resistance and hydrophilicity, positive in aqueous solution, and can cross-link with aldehyde hydroxyl groups in paper cellulose. The present invention uses polyethyleneimine to end-cap mica-modified polyurethane, and uses ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride to graft casein. Through the high hydrophilicity of polyethyleneimine, the casein adsorbed with pigment is stably dispersed in the aqueous solution, thereby improving the storage stability of the ink; and polyethyleneimine is cross-linked with the aldehyde hydroxyl groups on the paper to improve the adhesion of the ink to the paper, preventing the ink layer from decolorizing when it is impregnated with melamine resin liquid. In addition, the branched structure of polyethyleneimine allows the polymerized resin to form a three-dimensional network structure, which is conducive to the penetration of the resin liquid, thereby reducing the influence of the introduction of polyurethane on the film permeability.

[0034] If the molecular weight of polyethyleneimine is too large, its distribution uniformity in the polyurethane / casein resin molecular chain will be reduced, affecting the uniformity of glue penetration.

[0035] Furthermore, the cross-linking agent is ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDAC).

[0036] Furthermore, the alkaline solubilizer is selected from one or more of borax, urea, triethylamine, ethanolamine, triethanolamine, and sodium silicate.

[0037] One of the technical solutions of the present invention is to provide a method for preparing the polyurethane modified casein water-based decorative paper ink, the method comprising the following steps:

[0038] S1, adding organic modified mica, polyol, polyamine and carboxyl hydrophilic monomer, and mixing until uniformly dispersed;

[0039] S2, adding polyisocyanate, reacting until the residual -NCO value is basically stable;

[0040] S3, after adding a pH adjuster for neutralization, adding a capping agent and water, reacting to obtain a mica-modified polyurethane dispersion;

[0041] S4, add alkaline solubilizer and water, mix evenly, add casein, mix until casein is completely dissolved, obtain casein liquid;

[0042] S5, add mica modified polyurethane dispersion and crosslinking agent, mix until uniformly dispersed, add the mixture to casein solution and water, react, and obtain waterborne polyurethane / casein resin;

[0043] S6, adding pigment, water-based polyurethane / casein resin, modified silicone-acrylic resin, amino curing agent, dispersant, wetting agent, defoaming agent, cosolvent and water, mixing until uniformly dispersed, grinding, and obtaining polyurethane-modified casein water-based decorative paper ink.

[0044] Furthermore, in step S1, the mixing temperature is 70 to 90°C, the speed is 200 to 400 r / min, and the time is 20 to 40 min;

[0045] In step S2, the reaction temperature is 70-90°C, the speed is 200-400 r / min, and the time is 30-60 min;

[0046] In step S3, the reaction temperature is -10 to 10°C, the speed is 800 to 1500 r / min, and the reaction time is 1 to 2 h;

[0047] The mixing temperature in step S4 is 20-40°C, the speed is 200-400 r / min, and the time is 20-40 min.

[0048] The dissolution temperature is 60-80°C, the speed is 200-400 r / min, and the time is 20-40 min;

[0049] The mixing temperature in step S5 is 20-40°C, the speed is 200-400 r / min, and the time is 20-40 min.

[0050] The reaction temperature is 20-40°C, the speed is 200-400 r / min, and the time is 30-60 min;

[0051] The mixing temperature in step S6 is 20-40°C, the speed is 800-1500 r / min, and the time is 20-40 min.

[0052] The grinding fineness is ≤20μm.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] (1) The waterborne polyurethane of the present invention is modified by grafting mica, which improves the heat resistance and the leveling property of the ink, making it easy to process and use, and at the same time enables the ink to play a good decorative role;

[0055] (2) The present invention adds polyamines during the preparation of polyurethane, and the amino groups of the polyamines react with polyisocyanates to introduce urea groups, so as to improve the problem that casein film is hard and brittle and difficult to disperse;

[0056] (3) The water-based resin of the present invention is prepared by capping mica-modified polyurethane with polyethyleneimine, and then cross-linking the amino group of polyethyleneimine with the carboxyl group of casein using ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride as a cross-linking agent; polyethyleneimine can react with the aldehyde hydroxyl group in the cellulose of the paper and cross-link, thereby increasing the adhesion of the ink to the paper and preventing the ink layer from being discolored when impregnated with melamine resin liquid; the polyethyleneimine-capped mica-modified polyurethane is grafted with casein, and the casein adsorbed with the pigment is stably dispersed in the aqueous solution due to the high hydrophilicity of polyethyleneimine, thereby improving the storage stability of the ink; the branched structure of polyethyleneimine enables the polymerized resin to form a three-dimensional network structure, thereby improving the film-forming permeability;

[0057] (4) The present invention adopts mica-modified waterborne polyurethane / casein resin and modified silicone-acrylic resin to prepare ink. The waterborne polyurethane / casein resin can form a three-dimensional network structure due to the unique branching structure of polyethyleneimine. When the ink is formed into a film, the modified silicone-acrylic resin is cross-linked and cured under the action of an amino curing agent to form an interpenetrating network structure, thereby achieving dual curing and further improving the water resistance, heat resistance and adhesion of the ink film.

[0058] (5) The water-based decorative paper ink prepared by the present invention has good storage stability, good adhesion to paper, no discoloration when immersed in water and easy penetration, and high temperature resistance in film formation, thus meeting the requirements for post-processing of decorative paper. DETAILED DESCRIPTION

[0059] The present invention is described in detail below in conjunction with specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and a specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0060] Unless otherwise specified, the equipment used in the following examples are all conventional equipment in the art; the reagents used are all commercially available products or prepared by conventional methods in the art unless otherwise specified. Anything not described in detail in the following examples can be achieved by conventional experimental means in the art.

[0061] In this embodiment, the organic modified mica includes organosilicon modified mica or long carbon chain quaternary ammonium salt modified mica, and the long carbon chain quaternary ammonium salt is selected from hexadecyl trimethyl ammonium bromide. The specific steps are as follows:

[0062] M1, silicone modified mica,

[0063] 10 g of mica was added to a 20 g, 5 wt% KH550 silane coupling agent alcohol-water solution (the mass ratio of ethanol to water was 9:1), the pH was adjusted to 2.5 with oxalic acid, and stirred at room temperature at 25°C for 24 h;

[0064] Wash with deionized water, vacuum dry, crush, sieve and set aside;

[0065] M2, hexadecyltrimethylammonium bromide modified mica,

[0066] 10 g of mica was added to 40 g of 5 wt% hexadecyltrimethylammonium bromide aqueous solution, stirred slightly, and ultrasonicated at 20 kHz for 15 min;

[0067] Wash with deionized water, vacuum dry, crush, sieve and set aside.

[0068] Example:

[0069] A method for preparing polyurethane-modified casein water-based decorative paper ink, the specific steps are as follows:

[0070] S1. Add organic modified mica, polyol, polyamine and carboxyl hydrophilic monomer into a reaction kettle, and stir and mix at 80°C and 300r / min for 30 min until the mixture is evenly dispersed;

[0071] S2, add polyisocyanate, stir and react at 80°C and 300 r / min for 45 min until the residual -NCO value is basically stable;

[0072] S3, cooling, replacing with an ice water bath, adding a pH adjuster for neutralization, adding a capping agent and deionized water, stirring and reacting at 0°C and 1200 r / min for 1.5 h to obtain a mica-modified polyurethane dispersion;

[0073] S4, in another reactor, add alkaline solubilizer and deionized water, stir and mix uniformly at room temperature 25°C and 300 r / min for 30 min, add casein, stir and mix at 70°C and 300 r / min for 30 min until the casein is completely dissolved, to obtain casein solution;

[0074] S5, in another reactor, the mica-modified polyurethane and the cross-linking agent were stirred and mixed at room temperature of 25°C and 300 r / min for 30 min until they were uniformly dispersed, and the mixture was slowly added to the casein solution and deionized water in another reactor, and stirred and reacted at room temperature of 25°C and 300 r / min for 45 min to obtain a waterborne polyurethane / casein resin;

[0075] S6. Add pigment, water-based polyurethane / casein resin, modified silicone-acrylic resin, amino curing agent, dispersant, wetting agent, defoaming agent, co-solvent and deionized water into another reaction kettle, stir and mix at room temperature (25°C) and 1200 r / min for 30 min until uniformly dispersed, and grind with a sand mill to a fineness of 10 μm to obtain polyurethane-modified casein water-based decorative paper ink.

[0076] The following describes seven embodiments according to different components and proportions.

[0077] Embodiment 1:

[0078] A polyurethane-modified casein water-based decorative paper ink comprises the following components in parts by weight:

[0079] 30 parts (37%) of titanium dioxide, 25 parts (31%) of waterborne polyurethane / casein resin, 0.5 parts (0.62%) of polyester modified silicone-acrylic resin, 0.4 parts (0.49%) of tetramethylol glycoluril resin, 2 parts (2.5%) of polyethylene glycol, 0.2 parts (0.25%) of acetylene glycol, 0.1 parts (0.12%) of methyl ether polydimethylsiloxane, 1.5 parts (1.8%) of ethylene glycol butyl ether, 1.5 parts (1.8%) of diethylene glycol and 20 parts of deionized water;

[0080] The waterborne polyurethane / casein resin comprises the following components in parts by weight:

[0081] 20 parts of mica modified polyurethane dispersion, 1 part of ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDAC), 62 parts of casein solution and 17 parts of deionized water;

[0082] The mica-modified polyurethane dispersion comprises the following components in parts by weight:

[0083] 2 parts of organosilicon-modified mica, 55 parts of polytetramethylene glycol, 3 parts of 1,3-propylene glycol bis(4-aminobenzoate), 5 parts of 2,2-dimethylol propionic acid, 18 parts of isophorone diisocyanate, 3.8 parts of triethylamine, 27 parts of 50% polyethyleneimine aqueous solution (Mw=600), and 137 parts of deionized water;

[0084] Casein liquid comprises the following components in parts by weight:

[0085] Casein 16 parts (16%), borax 3.2 parts (3.2%), urea 3.2 parts (3.2%), ethanolamine 0.3 parts (0.30%) and deionized water 77 parts;

[0086] The mass ratio of components other than water to the cross-linking agent and casein in the mica-modified polyurethane dispersion is 9.1:1:9.9.

[0087] Embodiment 2:

[0088] A polyurethane-modified casein water-based decorative paper ink comprises the following components in parts by weight:

[0089] 20 parts of titanium dioxide (28%), 25 parts of waterborne polyurethane / casein resin (35%), 0.5 parts of polyester modified silicone-acrylic resin (0.70%), 0.4 parts of tetramethylol glycoluril resin (0.56%), 2 parts of polyethylene glycol (2.8%), 0.2 parts of acetylene glycol (0.28%), 0.1 parts of methyl ether polydimethylsiloxane (0.14%), 0.5 parts of ethylene glycol butyl ether (0.70%), 3 parts of diethylene glycol (4.2%) and 20 parts of deionized water;

[0090] The waterborne polyurethane / casein resin comprises the following components in parts by weight:

[0091] 30 parts of mica modified polyurethane dispersion, 1 part of EDAC, 62 parts of casein solution and 7 parts of deionized water;

[0092] The mica-modified polyurethane dispersion comprises the following components in parts by weight:

[0093] 3 parts of organosilicon-modified mica, 25 parts of polyaspartic acid glycol ester, 3 parts of 1,3-propylene glycol bis(4-aminobenzoate), 6 parts of 2,2-dihydroxymethylbutyric acid, 20 parts of hexamethylene diisocyanate, 3.8 parts of triethylamine, 30 parts of 50% polyethyleneimine aqueous solution (Mw=600), and 380 parts of deionized water;

[0094] Casein liquid comprises the following components in parts by weight:

[0095] 12 parts of casein (12%), 1.5 parts of borax (1.5%), 1 part of urea (1.0%), 0.5 parts of triethylamine (0.50%), 0.3 parts of ethanolamine (0.30%) and 84.5 parts of deionized water;

[0096] The mass ratio of components other than water to cross-linking agent and casein in the mica-modified polyurethane dispersion is 5.8:1:7.5.

[0097] Embodiment 3:

[0098] A polyurethane-modified casein water-based decorative paper ink comprises the following components in parts by weight:

[0099] 20 parts (28%) of titanium dioxide, 25 parts (35%) of waterborne polyurethane / casein resin, 0.5 parts (0.70%) of polyester modified silicone-acrylic resin, 0.4 parts (0.56%) of tetramethylol glycoluril resin, 2 parts (2.8%) of polyethylene glycol, 0.2 parts (0.28%) of acetylene glycol, 0.1 parts (0.14%) of methyl ether polydimethylsiloxane, 1.5 parts (2.1%) of ethylene glycol butyl ether, 1.5 parts (2.1%) of diethylene glycol and 20 parts of deionized water;

[0100] The waterborne polyurethane / casein resin comprises the following components in parts by weight:

[0101] 20 parts of mica modified polyurethane dispersion, 1 part of EDAC, 62 parts of casein solution and 17 parts of deionized water;

[0102] The mica-modified polyurethane dispersion comprises the following components in parts by weight:

[0103] 3 parts of organosilicon-modified mica, 25 parts of polyethylene adipate, 3 parts of 1,3-propylene glycol bis(4-aminobenzoate), 6 parts of 2,2-dimethylolpropionic acid, 30 parts of diphenylmethane diisocyanate, 3.8 parts of triethylamine, 27 parts of 50% polyethyleneimine aqueous solution (Mw=600), and 380 parts of deionized water;

[0104] Casein liquid comprises the following components in parts by weight:

[0105] Casein 20 parts (19%), borax 3.2 parts (3.1%), urea 3.2 parts (3.1%), ethanolamine 0.3 parts (0.29%) and deionized water 77 parts;

[0106] The mass ratio of components other than water to cross-linking agent and casein in the mica-modified polyurethane dispersion is 4.1:1:12.0.

[0107] Embodiment 4:

[0108] A polyurethane-modified casein water-based decorative paper ink comprises the following components in parts by weight:

[0109] 20 parts (24%) of titanium dioxide, 10 parts (12%) of red pigment, 25 parts (31%) of waterborne polyurethane / casein resin, 0.5 parts (0.61%) of polyester modified silicone-acrylic resin, 0.4 parts (0.49%) of tetramethylol glycoluril resin, 2 parts (2.4%) of polyethylene glycol, 0.2 parts (0.24%) of acetylene glycol, 0.1 parts (0.12%) of methyl ether polydimethylsiloxane, 0.5 parts (0.61%) of ethylene glycol butyl ether, 3 parts (3.7%) of diethylene glycol and 20 parts of deionized water;

[0110] The waterborne polyurethane / casein resin comprises the following components in parts by weight:

[0111] 20 parts of mica modified polyurethane dispersion, 1 part of EDAC, 62 parts of casein solution and 17 parts of deionized water;

[0112] The mica-modified polyurethane dispersion comprises the following components in parts by weight:

[0113] 3 parts of organosilicon-modified mica, 50 parts of hydroxy-terminated polybutadiene diol, 3 parts of 1,3-propylene glycol bis(4-aminobenzoate), 6 parts of 2,2-dihydroxymethylbutyric acid, 20 parts of hexamethylene diisocyanate, 3.8 parts of triethylamine, 27 parts of 50% polyethyleneimine aqueous solution (Mw=600), and 280 parts of deionized water;

[0114] Casein liquid comprises the following components in parts by weight:

[0115] 12 parts of casein (12%), 1.5 parts of borax (1.5%), 1 part of urea (1.0%), 0.5 parts of triethylamine (0.50%), 0.3 parts of ethanolamine (0.30%) and 84.5 parts of deionized water;

[0116] The mass ratio of components other than water to cross-linking agent and casein in the mica-modified polyurethane dispersion is 5.7:1:7.5.

[0117] Embodiment 5:

[0118] A polyurethane-modified casein water-based decorative paper ink comprises the following components in parts by weight:

[0119] 20 parts (25%) of titanium dioxide, 10 parts (12%) of red pigment, 25 parts (31%) of waterborne polyurethane / casein resin, 0.5 parts (0.61%) of polyester modified silicone-acrylic resin, 0.2 parts (0.25%) of methyl etherified glycoluril resin, 2 parts (2.5%) of polyethylene glycol, 0.2 parts (0.25%) of acetylene glycol, 0.1 parts (0.12%) of methyl ether polydimethylsiloxane, 0.5 parts (0.61%) of ethylene glycol butyl ether, 3 parts (3.7%) of diethylene glycol and 20 parts of deionized water;

[0120] The waterborne polyurethane / casein resin comprises the following components in parts by weight:

[0121] 20 parts of mica modified polyurethane dispersion, 1 part of EDAC, 62 parts of casein solution and 17 parts of deionized water;

[0122] The mica-modified polyurethane dispersion comprises the following components in parts by weight:

[0123] 3 parts of mica modified by long carbon chain quaternary ammonium salt, 50 parts of polypropylene ether diol, 3 parts of 1,3-propylene glycol bis(4-aminobenzoate), 7 parts of 2,2-dihydroxymethylpropionic acid, 25 parts of hexamethylene diisocyanate, 3.8 parts of triethylamine, 27 parts of 50% polyethyleneimine aqueous solution (Mw=600), and 300 parts of deionized water;

[0124] Casein liquid comprises the following components in parts by weight:

[0125] Casein 20 parts (19%), borax 3.2 parts (3.1%), urea 3.2 parts (3.1%), ethanolamine 0.3 parts (0.29%) and deionized water 77 parts;

[0126] The mass ratio of components other than water to cross-linking agent and casein in the mica-modified polyurethane dispersion is 5.7:1:12.0.

[0127] Embodiment 6:

[0128] A polyurethane-modified casein water-based decorative paper ink comprises the following components in parts by weight:

[0129] 20 parts (25%) of titanium dioxide, 10 parts (12%) of red pigment, 25 parts (31%) of waterborne polyurethane / casein resin, 0.5 parts (0.61%) of polyester modified silicone-acrylic resin, 0.2 parts (0.25%) of methyl etherified glycoluril resin, 2 parts (2.5%) of polyethylene glycol, 0.2 parts (0.25%) of acetylene glycol, 0.1 parts (0.12%) of methyl ether polydimethylsiloxane, 0.5 parts (0.61%) of ethylene glycol butyl ether, 3 parts (3.7%) of diethylene glycol and 20 parts of deionized water;

[0130] The waterborne polyurethane / casein resin comprises the following components in parts by weight:

[0131] 30 parts of mica modified polyurethane dispersion, 1 part of EDAC, 62 parts of casein solution and 7 parts of deionized water;

[0132] The mica-modified polyurethane dispersion comprises the following components in parts by weight:

[0133] 3 parts of mica modified by long carbon chain quaternary ammonium salt, 55 parts of polybutylene adipate, 3 parts of 1,3-propylene glycol bis(4-aminobenzoate), 7 parts of 2,2-dihydroxymethylbutyric acid, 25 parts of hexamethylene diisocyanate, 3.8 parts of triethylamine, 27 parts of 50% polyethyleneimine aqueous solution (Mw=600), and 280 parts of deionized water;

[0134] Casein liquid comprises the following components in parts by weight:

[0135] 12 parts of casein (12%), 1.5 parts of borax (1.5%), 1 part of urea (1.0%), 0.5 parts of triethylamine (0.50%), 0.3 parts of ethanolamine (0.30%) and 84.5 parts of deionized water;

[0136] The mass ratio of components other than water to cross-linking agent and casein in the mica-modified polyurethane dispersion is 9.2:1:7.5.

[0137] Embodiment 7:

[0138] A polyurethane-modified casein water-based decorative paper ink comprises the following components in parts by weight:

[0139] 20 parts (25%) of titanium dioxide, 10 parts (12%) of red pigment, 25 parts (31%) of waterborne polyurethane / casein resin, 0.5 parts (0.61%) of polyester modified silicone-acrylic resin, 0.2 parts (0.25%) of methyl etherified glycoluril resin, 2 parts (2.5%) of polyethylene glycol, 0.2 parts (0.25%) of acetylene glycol, 0.1 parts (0.12%) of methyl ether polydimethylsiloxane, 0.5 parts (0.61%) of ethylene glycol butyl ether, 3 parts (3.7%) of diethylene glycol and 20 parts of deionized water;

[0140] The waterborne polyurethane / casein resin comprises the following components in parts by weight:

[0141] 30 parts of mica modified polyurethane dispersion, 1 part of EDAC, 62 parts of casein solution and 7 parts of deionized water;

[0142] The mica-modified polyurethane dispersion comprises the following components in parts by weight:

[0143] 3 parts of mica modified by long carbon chain quaternary ammonium salt, 55 parts of poly(hexanediol adipate), 3 parts of 1,3-propylene glycol bis(4-aminobenzoate), 6 parts of 2,2-dimethylolpropionic acid, 25 parts of toluene diisocyanate, 3.8 parts of triethylamine, 27 parts of 50% polyethyleneimine aqueous solution (Mw=600), and 280 parts of deionized water;

[0144] Casein liquid comprises the following components in parts by weight:

[0145] Casein 20 parts (19%), borax 3.2 parts (3.1%), urea 3.2 parts (3.1%), ethanolamine 0.3 parts (0.29%) and deionized water 77 parts;

[0146] The mass ratio of components other than water to cross-linking agent and casein in the mica-modified polyurethane dispersion is 9.1:1:12.0.

[0147] Comparative Examples 1 to 7:

[0148] A polyurethane-modified casein water-based decorative paper ink is substantially the same as Examples 1 to 7, except that 1,3-propylene glycol bis(4-aminobenzoate) is not added to the mica-modified polyurethane dispersion.

[0149] Comparative Examples 8 to 14:

[0150] A polyurethane-modified casein water-based decorative paper ink is substantially the same as Examples 1 to 7, except that the modified mica in the mica-modified polyurethane dispersion is replaced by modified attapulgite.

[0151] The performance test of the above polyurethane modified casein water-based decorative paper ink is carried out in the following specific steps:

[0152] Viscosity test: According to GB / T 13217.4, the viscosity of water-based decorative paper ink is tested using a 4# cup;

[0153] Centrifugal stability: take 10 mL of water-based decorative paper ink and add it to a 10 mL centrifuge tube. Centrifuge at 3000 r / min for 0.5 h to observe whether the water-based decorative paper ink has stratification or precipitation.

[0154] Printing sample preparation: Use a No. 120 wire rod to scrape the water-based decorative paper ink onto the base paper of the decorative paper, and bake it in an oven at 100°C for 30 s to obtain the printing sample for testing;

[0155] For the heat resistance test, the printed sample was divided into two parts according to the scraping direction of the water-based decorative paper ink. One part was baked in an oven at a set temperature for 60 seconds, and the other part was used as a control sample. The color change of the ink film was observed according to GB / T 13217.1-2009. The test temperature started from 160℃ and increased by 10℃. The highest temperature at which the ink film color did not change was used as the evaluation standard for heat resistance.

[0156] For the permeability test, a drop of distilled water is dropped from a height of 15 mm onto the flat printed sample, and the diffusion shape and range of the water mark within 120 seconds are observed and recorded. The average value of the longitudinal and transverse diffusion radial lengths is used to represent the permeability of the printed sample, which is used to characterize the permeability of melamine during post-processing and glue penetration.

[0157] Adhesion test: drop a drop of distilled water from a height of 15 mm on the flat printed sample. After 120 seconds, wipe the water mark with filter paper and observe the color fading to characterize the difficulty of fading when impregnated with melamine.

[0158] Gloss test: Use a gloss tester to test the gloss with an incident angle of 60°.

[0159] Compared with comparative examples 1 to 7, the viscosity of examples 1 to 7 is reduced by 5 to 8%, the heat resistance is increased by 10 to 12%, and the glossiness is increased by 5 to 10%;

[0160] Compared with comparative examples 8 to 14, in terms of centrifugal stability, the embodiments 1 to 7 have no stratification or precipitation, while comparative examples 8, 9 and 10 have trace precipitation, and the permeability is increased by 10 to 15%. In terms of adhesion, the embodiments basically do not fade, while comparative examples 9, 11, 12 and 13 fade slightly.

[0161] After testing, the water-based decorative paper ink prepared in this embodiment has good storage stability, high heat resistance, good water resistance, excellent adsorption of the ink to paper, good permeability, which is conducive to the impregnation of melamine. The prepared paper has high color fastness, is easy to process and use, has unique optical effects, and has outstanding decorative effect.

[0162] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A polyurethane modified casein water-based decorative paper ink, characterized in that, The ink comprises the following components in weight percentage: Pigment 10-40%, waterborne polyurethane / casein resin 22-37%, modified silicone-acrylic resin 0.5-3%, amino curing agent 0.1-0.6%, dispersant 1-3%, wetting agent 0.1-0.5%, defoamer 0.1-0.3%, cosolvent 3-6%, and the rest is water; The waterborne polyurethane / casein resin comprises a mica-modified polyurethane dispersion, a crosslinking agent, a casein solution and water, wherein the mica-modified polyurethane dispersion comprises the following components in parts by weight: 1-5 parts of organic modified mica, 20-60 parts of polyol, 2-6 parts of polyamine, 5-7 parts of carboxyl hydrophilic monomer, 14-30 parts of polyisocyanate, 1-4 parts of pH regulator, 7-17 parts of end-capping agent and 100-500 parts of water; The casein solution comprises the following components in percentage by weight: Casein 10-20%, alkaline solubilizer 3-8%, the rest is water; The mass ratio of the components except water in the mica-modified polyurethane dispersion to the crosslinking agent and casein is (4-10):(0.5-2):(6-15).

2. A polyurethane modified casein water-based decorative paper ink according to claim 1, characterized in that, The modified silicone-acrylic resin is selected from one or more of epoxy-modified silicone-acrylic resin, polyester-modified silicone-acrylic resin, and polyurethane-modified silicone-acrylic resin. The amino curing agent is selected from one or more of tetramethylol glycoluril resin and methyl etherified glycoluril resin.

3. A polyurethane modified casein water-based decorative paper ink according to claim 1, characterized in that, The dispersant is selected from one or more of polyethylene wax and polyethylene glycol. The wetting agent is acetylene glycol, The defoamer is polyether polydimethylsiloxane. The co-solvent is selected from one or more of ethylene glycol, ethylene glycol butyl ether, diethylene glycol, and dipropylene glycol.

4. A polyurethane modified casein water-based decorative paper ink according to claim 1, characterized in that, The organic modified mica is selected from one or more of organosilicon modified mica and long carbon chain quaternary ammonium salt modified mica.

5. A polyurethane modified casein water-based decorative paper ink according to claim 1, characterized in that, The polyamine is 1,3-propylene glycol bis(4-aminobenzoate).

6. A polyurethane modified casein water-based decorative paper ink according to claim 1, characterized in that, The polyol is selected from one or more of polyethylene adipate, polybutylene adipate, polyhexane adipate, polycarbonate diol, polycaprolactone diol, polypropylene ether diol, polytetrahydrofuran diol, hydroxy-terminated polybutadiene diol, and polyaspartic acid diol. The carboxyl hydrophilic monomer is selected from one or more of 2,2-dimethylol propionic acid and 2,2-dimethylol butyric acid. The polyisocyanate is selected from one or more of isophorone diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, and diphenylmethane diisocyanate. The pH regulator is selected from one or more of triethylamine, ammonia water, sodium hydroxide and potassium hydroxide. The end-capping agent is polyethyleneimine, and the molecular weight of the end-capping agent is 300-1000.

7. A polyurethane modified casein water-based decorative paper ink according to claim 1, characterized in that: The cross-linking agent is ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride.

8. A polyurethane modified casein water-based decorative paper ink according to claim 1, characterized in that: The alkaline solubilizer is selected from one or more of borax, urea, triethylamine, ethanolamine, triethanolamine, and sodium silicate.

9. A method for preparing a polyurethane-modified casein water-based decorative paper ink as claimed in any one of claims 1 to 8, characterized in that: The method comprises the following steps: S1, adding organic modified mica, polyol, polyamine and carboxyl hydrophilic monomer, and mixing; S2, adding polyisocyanate, reacting; S3, after adding a pH adjuster for neutralization, adding a capping agent and water, reacting to obtain a mica-modified polyurethane dispersion; S4, add alkaline solubilizer and water, mix, add casein, mix and dissolve, obtain casein liquid; S5, add mica modified polyurethane dispersion and crosslinking agent, mix, add the mixture to casein solution and water, react, obtain waterborne polyurethane / casein resin; S6, adding pigment, water-based polyurethane / casein resin, modified silicone-acrylic resin, amino curing agent, dispersant, wetting agent, defoaming agent, co-solvent and water, mixing and grinding to obtain polyurethane-modified casein water-based decorative paper ink.

10. The method for preparing a polyurethane modified casein water-based decorative paper ink according to claim 9, characterized in that: In step S1, the mixing temperature is 70-90°C, the speed is 200-400 r / min, and the time is 20-40 min; In step S2, the reaction temperature is 70-90°C, the speed is 200-400 r / min, and the time is 30-60 min; In step S3, the reaction temperature is -10 to 10°C, the speed is 800 to 1500 r / min, and the time is 1 to 2 h; The mixing temperature in step S4 is 20-40°C, the speed is 200-400 r / min, and the time is 20-40 min. The dissolving temperature is 60-80°C, the speed is 200-400r / min, and the time is 20-40min; The mixing temperature in step S5 is 20-40°C, the speed is 200-400 r / min, and the time is 20-40 min. The reaction temperature is 20-40°C, the speed is 200-400r / min, and the time is 30-60min; The mixing temperature in step S6 is 20-40°C, the speed is 800-1500 r / min, and the time is 20-40 min. The grinding fineness is ≤20μm.