Preparation method and application of UV-curable bio-based water-based resin

Abstract

The invention relates to the technical field of light-cured resin, in particular to a preparation method and application of UV-curable bio-based water-based resin. The waterborne polyurethane adhesive is prepared from the following components in percentage by weight: 10 to 35 percent of bio-based polyol, 0 to 25 percent of non-bio-based polyol, 5 to 25 percent of diisocyanate, 0.005 to 0.1 percent of a catalyst, 0.5 to 6 percent of a sulfonate hydrophilic chain extender, 0.2 to 5 percent of hydroxyl acrylate, 0.2 to 1 percent of a neutralizing agent, 0.5 to 3 percent of a hydroxyl diamine chain extender and the balance of deionized water. UV curing is achieved through a specific formula, the problems that existing waterborne polyurethane resin for digital ink-jet needs to be synthesized through a solvent method, and a large amount of solvent needs to be added in the synthesis process are solved, and meanwhile the requirement for ink-jet printing is met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of light-cured resin, in particular, relates to a preparation method and application of a UV-curable bio-based water-based resin. BACKGROUND

[0002] The extreme requirement of printing fluency in the digital inkjet industry leads to the current resin-based inkjet ink which seriously depends on petroleum-based resin and a large amount of petroleum-based high-boiling-point solvent to reduce the viscosity, enhance the moisturizing to maintain the printing performance. Not only does it aggravate the consumption of non-renewable resources, but also has defects such as environmental unsustainability, performance bottleneck and high energy consumption process. Although bio-based resin is regarded as a replacement, it still cannot balance high bio-based content, low viscosity, high solid content, excellent printing performance and rapid curing. The conventional water-based resin has too strong hydrophobicity after drying due to the large molecular weight, which forces the need to add a large amount of solvent to maintain the printing performance; and it does not have UV curing ability, which cannot fundamentally solve the problems of bleeding and ink flow caused by slow ink drying.

[0003] Chinese patent application CN108794723A discloses a bio-based matte waterborne polyurethane dispersion and a preparation method thereof. The matte waterborne polyurethane dispersion with high stability, excellent mechanical properties and easy degradation is prepared by the reaction of bio-based polyol and isocyanate and the cooperation of chain extender, solves the brittleness and environmental pollution problems of existing materials, and realizes efficient matte characteristics and environmental performance. However, the application does not have UV curing ability, and does not explore the problems of ink bleeding and ink flow. SUMMARY

[0004] The present application provides a UV-curable bio-based water-based resin in the first aspect, the components include: bio-based polyol 10-35%, non-bio-based polyol 0-25%, diisocyanate 5-25%, catalyst 0.005-0.1%, sulfonate hydrophilic chain extender 0.5-6%, hydroxy acrylate 0.2-5%, neutralizing agent 0.2-1%, hydroxyl diamine chain extender 0.5-3%, and deionized water makes up the balance.

[0005] Optionally, the components include: bio-based polyol 10-35%, non-bio-based polyol 0-22%, diisocyanate 10-25%, catalyst 0.01-0.05%, sulfonic acid hydrophilic chain extender 1-6%, hydroxy acrylate 0.2-5%, neutralizing agent 0.2-1%, and hydroxyl diamine chain extender 0.5-3% by weight percentage.

[0006] Optionally, the components include, by weight percentage: bio-based polyol 25-35%, diisocyanate 20-25%, catalyst 0.01-0.05%, sulfonate hydrophilic chain extender 4-6%, hydroxy acrylate 0.5-5%, neutralizing agent 0.2-1%, hydroxy diamine chain extender 1-2%, and deionized water to make up the balance.

[0007] The present application balances the solid content, hydrophilicity and viscosity of the water-based resin by adding specific bio-based polyols and sulfonate hydrophilic chain extenders, avoiding the use of petroleum-based resins and petroleum-based high-boiling solvents. Bio-based polyols contain long-chain fatty acids and flexible segments, which can enhance the toughness of the resin, but excessive use will cause the viscosity to increase dramatically due to high molecular weight or hydrophobicity. The acid groups in the sulfonate hydrophilic chain extender and the hydroxyl groups in the hydroxy diamine chain extender provide strong hydrophilicity, allowing the resin to self-emulsify in water to form stable nanoparticles. At the same time, the electrostatic repulsion of the ionic groups inhibits the aggregation of molecular chains, offsetting the viscosity-increasing effect of bio-based polyols, and the combination of the two can maintain low viscosity at high solid content without the need to add petroleum-based solvents. At the same time, the sulfonate also ensures the hydrophilicity of the bio-based resin, avoiding dispersion instability due to hydrophobicity, and a large number of hydrophilic hydroxyl groups can also bring excellent moisturizing performance, avoiding the need to add high-boiling solvents for moisturizing.

[0008] Optionally, the addition amount of the hydroxy acrylate in the water-based resin component is 0.5-1.5wt%.

[0009] The weight ratio of the sulfonate hydrophilic chain extender and the hydroxy diamine chain extender is (2-6):1.

[0010] Optionally, the weight ratio of the sulfonate hydrophilic chain extender and the hydroxy diamine chain extender is (3-5):1.

[0011] Optionally, the bio-based polyol includes at least one of bio-based polycarbonate diol, bio-based polyether diol, and bio-based polyester diol.

[0012] Optionally, the bio-based polyol has a hydroxyl value of 50-250mgKOH / g and an average number average molecular weight of 500-3000.

[0013] Optionally, the bio-based polyol has an average number average molecular weight of 500-2000.

[0014] The non-bio-based polyol includes at least one of polycarbonate diol, polyether diol, and polyester diol.

[0015] Optionally, the catalyst includes at least one of bismuth octoate, bismuth octanate, and zinc octoate.

[0016] Optionally, the sulfonate hydrophilic chain extender includes at least one of sulfonate diol, sulfonate diamine, triethylamine salt of dihydroxypropyl sulfonate.

[0017] Optionally, the hydroxy acrylate includes at least one of glycerol 1,3-diglycerol diacrylate (2-acrylic acid-(2-hydroxy-1,3-propylene) di[oxy(2-hydroxy-3,1-propylene)] ester), 2-hydroxy-3-phenoxypropyl acrylate.

[0018] Optionally, the hydroxy diamine chain extender includes at least one of N-(2-hydroxyethyl)ethylenediamine, 2N,N-bis(2-hydroxyethyl)ethylenediamine.

[0019] Optionally, the diisocyanate includes at least one of toluene diisocyanate (TDI), 4,4'-diphenyl methane diisocyanate (MDI), isophorone diisocyanate (IPDI), 1,6-hexane diisocyanate (HDI), dicyclohexyl methane diisocyanate (HMDI).

[0020] Optionally, the neutralizing agent includes triethylamine.

[0021] The second aspect of the present application provides a preparation method of a UV-curable bio-based waterborne resin, including the following steps:

[0022] Step 1: Dehydrate the bio-based polyol;

[0023] Step 2: Add diisocyanate and catalyst dropwise to the dehydrated bio-based polyol for reaction, then add sulfonate hydrophilic chain extender and hydroxy acrylate, and react at 50-85℃ for 2-3h to obtain an isocyanate-terminated prepolymer;

[0024] Step 3: Add a neutralizing agent to the isocyanate-terminated prepolymer for neutralization reaction, then add deionized water for emulsification, and then add a hydroxy diamine chain extender for chain extension reaction, and finally filter to obtain a UV-curable bio-based waterborne resin.

[0025] Optionally, the dehydration temperature is 60-120℃.

[0026] Optionally, the dehydration temperature is 80-120℃.

[0027] Optionally, the reaction temperature in step 2 is 60-120℃, and the reaction time is 2-6h.

[0028] Optionally, the neutralization reaction time is 5-60min.

[0029] The third aspect of the present application provides an application of a UV-curable bio-based waterborne resin, which is applied to the preparation of digital inkjet printing ink.

[0030] The content of the UV-curable bio-based water-based resin in the digital inkjet printing ink is 10-95wt%.

[0031] Optionally, the content of the UV-curable bio-based water-based resin in the digital inkjet printing ink is 19-90wt%.

[0032] Advantages

[0033] 1. The present application balances the solid content, hydrophilicity and viscosity of the water-based resin by adding specific bio-based polyols, hydroxyl-containing diamine chain extenders and sulfonate hydrophilic chain extenders, avoiding the use of petroleum-based resins and petroleum-based high-boiling solvents.

[0034] 2. The present application provides a water-based resin with UV curing properties by adding hydroxy acrylate and limiting the addition amount of hydroxy acrylate in the water-based resin component to 0.2-5.0wt%, improving the drying performance of the ink through instant curing by UV, thereby solving the bleeding and ink flow performance of the ink, and also improving the toughness and chemical resistance of the prepared water-based resin.

[0035] 3. By limiting the weight ratio of the sulfonate hydrophilic chain extender and the hydroxyl diamine chain extender to (2-6):1, the viscosity (ISO 2555) of the prepared water-based resin can be controlled to ≤200mPa.s, the number average molecular weight is controlled to ≤1000, and the D50 particle size is controlled to ≤50nm.

[0036] 4. The water-based resin prepared by the present application has excellent elongation at break (>500%), which can meet the demand of various printing media such as film materials, paper, textiles and leather for high flexibility of ink.

[0037] 5. The water-based resin prepared by the present application has a bio-based content (ASTM D6866) ≥20%, which solves the technical problem of printing smoothness. DETAILED DESCRIPTION

[0038] Examples 1-6

[0039] A UV-curable bio-based water-based resin, the components are shown in Table 1, wherein the addition amount of the blank in Table 1 is 0.

[0040] Table 1

[0041]

[0042]

[0043] Wherein, the grade of castor oil-based polyol is: D-1000, hydroxyl value 122 mgKOH / g, average number average molecular weight 1000; Bio-based polycarbonate diol grade: HBE500, hydroxyl value 224 ± 20 mgKOH / g, average number average molecular weight 500; Bio-based polyether polyol grade: BioPTMG650, hydroxyl value 160-187 mgKOH / g, average number average molecular weight 650; Cashew oil-based polyol grade: NX 9212, hydroxyl value 55 mgKOH / g, average number average molecular weight 2000; Bio-based polyester polyol grade: Cargill Priplast TM 1838, hydroxyl value 56 mgKOH / g, average number average molecular weight 2000;

[0044] A method for preparing a UV-curable bio-based waterborne resin, comprising the following steps:

[0045] S1, dehydrating (105°C) the bio-based polyol;

[0046] S2, adding diisocyanate and catalyst dropwise to the dehydrated bio-based polyol for reaction (80°C for 3h), then adding sulfonate hydrophilic chain extender and hydroxy acrylate for reaction (60°C for 3h) to obtain an isocyanate-terminated prepolymer;

[0047] S3, cooling the prepolymer to 40°C, adding a neutralizing agent to the isocyanate-terminated prepolymer for neutralization reaction (0.5h), then adding deionized water for emulsification, and dropwise adding a hydroxy diamine chain extender for chain extension reaction, and then filtering to obtain the UV-curable bio-based waterborne resin.

[0048] Example 10

[0049] The specific implementation is the same as that of Example 5, except that the castor oil-based polyol grade used in Example 10 is SY752 (hydroxyl value 115-125 mgKOH / g).

[0050] Example 11

[0051] The specific implementation is the same as that of Example 1, except that the addition amount of the bio-based polycarbonate diol in Example 11 is 25wt%, and the addition amount of diisocyanate is 16wt%.

[0052] Comparative Example 1

[0053] The specific implementation is the same as that of Example 2, except that the bio-based polyol is replaced by polycarbonate diol (grade: 963) in Comparative Example 1, and the addition amount of diisocyanate is 18wt%.

[0054] Comparative Example 2

[0055] The specific implementation is the same as that of Example 4; except that no castor oil-based polyol is added in Comparative Example 2, no hydroxy acrylate is added, the addition amount of the bio-based polycarbonate diol is 12wt%, the addition amount of the diisocyanate is 12wt%, the addition amount of the sulfonate hydrophilic chain extender is 3.6wt%, and the addition amount of the hydroxyl diamine chain extender is 1wt%.

[0056] Comparative Example 3

[0057] The specific implementation is the same as that of Example 1; except that the addition amount of the bio-based polycarbonate diol is 15wt% in Comparative Example 3, the addition amount of the diisocyanate is 22wt%, the addition amount of the sulfonate hydrophilic chain extender is 3wt%, the addition amount of the hydroxy acrylate is 6wt%, and the addition amount of the hydroxyl diamine chain extender is 0.5wt%.

[0058] Comparative Example 4

[0059] The specific implementation is the same as that of Example 4; except that 0.5wt% of 1,4-butanediol is further included in Comparative Example 4, the addition amount of the castor oil-based polyol is 10.5wt%, the addition amount of the bio-based polyester diol is 8.0wt%, the addition amount of the diisocyanate is 15.0wt%, the addition amount of the sulfonate hydrophilic chain extender is 4.0wt%, the addition amount of the hydroxy acrylate is 3.0wt%, and the addition amount of the hydroxyl diamine chain extender is 0.2wt%.

[0060] Performance test method

[0061] The water-based resins prepared in the examples and comparative examples are subjected to performance tests, and the test data are listed in Table 2.

[0062] Among them, the printability test: using the I3200 nozzle of Epson to print on the uniform medium in bidirectional continuous printing, the printing area is 30m 2 and then observe whether the defects such as wire breaking, nozzle blocking, ink flowing, and ink bleeding occur.

[0063] Performance test data

[0064] Table 2

[0065]

[0066]

[0067] As shown in Table 2, the formulation in the preferred range of the present application solves the problem that the current waterborne polyurethane resin for digital inkjet needs to be synthesized by solvent method, and a large amount of solvent needs to be added in the synthesis process. Meanwhile, the formulation of the present application achieves the effects of high solid content and low viscosity, has a relatively high bio-based content, the D50 particle size can be controlled to be ≤50 nm, can be UV cured, and the toughness can be up to more than 500%, meeting the requirements of inkjet printing.

Claims

1. A UV-curable bio-based water-based resin, characterized in that: Calculated by weight, the components include: 10-35% of bio-based polyol, 0-25% of non-bio-based polyol, 5-25% of diisocyanate, 0.005-0.1% of catalyst, 0.5-6% of sulfonate hydrophilic chain extender, 0.2-5% of hydroxy acrylate, 0.2-1% of neutralizer, 0.5-3% of hydroxy diamine chain extender, and deionized water makes up the balance.

2. The UV-curable bio-based water-based resin according to claim 1, characterized in that Calculated by weight percentage, the components include: 10-35% bio-based polyol, 0-22% non-bio-based polyol, 10-25% diisocyanate, 0.01-0.05% catalyst, 1-6% sulfonic acid hydrophilic chain extender, 0.2-5% hydroxy acrylate, 0.2-1% neutralizer, and 0.5-3% hydroxy diamine chain extender.

3. The UV-curable bio-based water-based resin according to claim 2, characterized in that The amount of the hydroxy acrylate added to the water-based resin component is 0.5-1.5 wt %.

4. The UV-curable bio-based waterborne resin according to claim 1 or 3, characterized in that The weight ratio of the sulfonate hydrophilic chain extender to the hydroxydiamine chain extender is (2-6):

1.

5. The UV-curable bio-based water-based resin according to claim 4, characterized in that The weight ratio of the sulfonate hydrophilic chain extender to the hydroxydiamine chain extender is (3-5):

1.

6. The UV-curable bio-based waterborne resin according to claim 1, characterized in that The bio-based polyol includes at least one of bio-based polycarbonate diol, bio-based polyether diol, and bio-based polyester diol.

7. The UV-curable bio-based waterborne resin according to claim 6, characterized in that The bio-based polyol has a hydroxyl value of 50-250 mgKOH / g and an average number average molecular weight of 500-3000.

8. A method for preparing a UV-curable bio-based waterborne resin according to any one of claims 1 to 7, characterized in that: The following steps are involved: The bio-based polyol is dehydrated; a diisocyanate and a catalyst are added dropwise to the dehydrated bio-based polyol for reaction, and then a sulfonate hydrophilic chain extender and a hydroxy acrylate are added to obtain an isocyanate-terminated prepolymer; a neutralizer is added to the isocyanate-terminated prepolymer for neutralization reaction, deionized water is added after the reaction for emulsification, and then a hydroxy diamine chain extender is added dropwise for chain extension reaction, and after filtration, a UV-curable bio-based water-based resin is obtained.

9. A use of the UV-curable bio-based waterborne resin according to any one of claims 1 to 7, characterized in that: Used in the preparation of digital inkjet printing ink.

10. The use of the UV-curable bio-based water-based resin according to claim 9, characterized in that: The content of the UV-curable bio-based water-based resin in the digital inkjet printing ink is 10-95 wt %.

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