Bio-based waterborne polyurethane printing adhesive and preparation method thereof

Abstract

The invention belongs to the technical field of waterborne polyurethane dispersions, and particularly discloses a bio-based waterborne polyurethane printing adhesive and a preparation method thereof. The bio-based waterborne polyurethane printing adhesive is prepared from the following raw materials in parts by mass: # imgabs0. The bio-based waterborne polyurethane printing adhesive is prepared from bio-based polymer polyols, such as polytetrahydrofuran ether glycol and polypropylene glycol with 100% bio-based content, polycarbonate diol with 50-70% bio-based content, polyethylene glycol with 50-70% bio-based content, polyethylene glycol with 50-70% bio-based content and polyethylene glycol with 50-70% bio-based content, wherein the bio-based polymer polyols are similar to or completely identical to a petroleum-based structure; the characteristics of the traditional petroleum-based waterborne polyurethane printing adhesive are maintained; the prepared bio-based waterborne polyurethane printing adhesive has high bio-based content and is unique in the field of waterborne printing.

Description

Technical Field

[0001] The present invention belongs to the technical field of aqueous polyurethane dispersions, and particularly relates to a bio-based aqueous polyurethane printing binder and a preparation method thereof. Background Art

[0002] The three major raw materials of traditional polyurethanes, namely polymer polyols, isocyanates, and small molecule chain extenders, are mostly petroleum-based. Due to problems such as the non-renewability of petroleum resources and environmental pollution, the development of polyurethanes towards the bio-based direction has become a trend. In the printing industry, water-based technology has become increasingly mature and perfect. More and more brand manufacturers have begun to explore the fields of sustainability and recycling. More and more substrates (clothing, shoes) have started to use bio-based and degradable materials, which urgently requires the development of bio-based materials for printing materials. Aqueous polyurethane printing binders have excellent adhesion, which can firmly adhere dyes or pigments to fabrics, ensuring that the colors are not easily shed during washing and wearing; they still maintain the soft handfeel of the fabric after color fixation, without affecting the softness and comfort of the fabric; they have good wash fastness, and the printed patterns can still maintain bright colors and do not fade after multiple washes; they can maintain high color fastness under both dry and wet rubbing conditions, avoiding wear or fading of the printed patterns during use; they perform excellently in terms of transparency and do not affect the colors and effects of dyes or pigments, which is particularly important when used on light-colored or transparent materials; they have good light fastness, ensuring that the printed patterns are not easily faded under sunlight irradiation; they are made of environmentally friendly materials, are harmless to the human body, and comply with environmental protection regulations, reducing environmental pollution; they have good operability, are convenient to use in the printing process, are not easily blocked by equipment, and have stable performance during drying and curing.

[0003] Currently, most bio-based aqueous polyurethanes have many limitations. For example, when a small molecule chain extender is introduced alone, the bio-based content is low; when polylactic acid polyol is introduced alone, the performance is extremely poor.

[0004] Therefore, it is very necessary to develop a new bio-based aqueous polyurethane printing binder. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects existing in the prior art and provide a bio-based aqueous polyurethane printing binder and a preparation method thereof, introducing bio-based materials to prepare an aqueous polyurethane printing binder with a high bio-based content while maintaining the characteristics of traditional petroleum-based aqueous polyurethane printing binders.

[0006] To achieve the above purpose, one of the technical solutions of the present invention is: A bio-based aqueous polyurethane printing binder, the raw material composition of which includes, by mass parts:

[0007]

[0008]

[0009] In a preferred embodiment of the present invention, the bio-based polymer polyol mixture comprises at least two of bio-based polytetrahydrofuran ether glycol, bio-based polypropylene glycol, and bio-based polycarbonate diol; this is the key for this bio-based aqueous polyurethane printing binder to possess the characteristics of traditional petroleum-based aqueous polyurethane printing binders.

[0010] More preferably, the number-average molecular weight of the bio-based polytetrahydrofuran ether glycol is 1000 - 2000, the number-average molecular weight of the bio-based polypropylene glycol is 1000 - 2000, and the number-average molecular weight of the bio-based polycarbonate diol is 1000 - 3000.

[0011] More preferably, the bio-based content of the bio-based polytetrahydrofuran ether glycol and the bio-based polypropylene glycol is 100%, and the bio-based content of the bio-based polycarbonate diol is 50 - 70%; this ensures the characteristics of traditional petroleum-based aqueous polyurethane printing binders while endowing this bio-based aqueous polyurethane printing binder with a relatively high bio-based content.

[0012] In a preferred embodiment of the present invention, the bio-based diisocyanate mixture is a mixture of at least one of bio-based toluene diisocyanate, bio-based 1,5-pentane diisocyanate and at least one of non-bio-based isophorone diisocyanate, 1,6-hexane diisocyanate.

[0013] In a preferred embodiment of the present invention, the dicarboxylic acid hydrophilic monomer is one of dimethylolpropionic acid and dimethylolbutyric acid.

[0014] In a preferred embodiment of the present invention, the disulfonic acid hydrophilic monomer is sodium 2-aminoethanesulfonate.

[0015] In a preferred embodiment of the present invention, the bio-based small molecule chain extender is at least one of bio-based 1,3-propanediol, bio-based 1,4-butanediol, and bio-based 1,5-pentanediol.

[0016] In a preferred embodiment of the present invention, the crosslinking agent is at least one of trimethylolpropane and castor oil.

[0017] In a preferred embodiment of the present invention, the low-boiling solvent is a mixture of acetone and methyl acetate.

[0018] In a preferred embodiment of the present invention, the organometallic catalyst is one of an organobismuth catalyst and an organozinc catalyst, the neutralizing agent is at least one of triethylamine and ethanolamine, and the polyamine chain extender is at least one of ethylenediamine, 1,5-pentanediamine, isophoronediamine, diethylenetriamine, triethylenetetramine, and diethanolamine.

[0019] To achieve the above object, the second technical solution of the present invention is: a preparation method of a bio-based aqueous polyurethane printing adhesive, comprising the following steps:

[0020] (1) Put the bio-based polymer polyol mixture into a reaction device, control the temperature at 100 - 110 °C, stir and reduce pressure to dehydrate for 30 min - 1 h;

[0021] (2) Cool down to 80 - 90 °C, add the bio-based diisocyanate mixture, and then control the temperature at 80 - 90 °C, stir and react for 1 - 3 h;

[0022] (3) Cool down to 60 - 70 °C, add a bio-based small molecule chain extender, a crosslinking agent, a dicarboxyl hydrophilic monomer, a low-boiling solvent, and an organometallic catalyst to the reaction device, control the temperature at 60 - 70 °C, stir and react for 3 - 5 h;

[0023] (4) Cool down to 45 - 55 °C, add a disulfonic acid hydrophilic monomer to the reaction device, control the temperature at 45 - 55 °C, stir and react for 20 - 30 min to obtain a prepolymer;

[0024] (5) Transfer the obtained prepolymer to a dispersion device, add a neutralizing agent and deionized water for high-speed dispersion, add a polyamine chain extender for further reaction for 10 - 20 min to obtain a dispersion;

[0025] (6) Transfer the obtained dispersion to a decompression device, control the temperature at 40 - 60 °C, and remove the low-boiling solvent to obtain a completely environmentally friendly bio-based aqueous polyurethane printing adhesive.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The present invention uses a bio-based polymer polyol mixture, a bio-based diisocyanate mixture, a bio-based small molecule chain extender, a crosslinking agent, and a low-boiling solvent. By introducing dicarboxyl and disulfonic acid hydrophilic monomers, under the action of an organometallic catalyst, a prepolymer is obtained. After neutralization with a neutralizing agent, deionized water is added, and further chain extension reaction is carried out with a polyamine to prepare a self-emulsifying aqueous polyurethane dispersion; finally, the low-boiling solvent is removed by vacuum distillation to obtain a bio-based aqueous polyurethane printing adhesive with excellent performance;

[0028] 2. The present invention uses bio-based polymer polyols that are similar or identical in structure to petroleum-based ones, such as polytetrahydrofuran ether diol and polypropylene glycol with 100% bio-based content, and polycarbonate diol with 50-70% bio-based content, maintaining the characteristics of traditional petroleum-based waterborne polyurethane printing adhesives.

[0029] 3. The bio-based waterborne polyurethane printing adhesive prepared by the present invention has a high bio-based content and stands out in the field of waterborne printing. Detailed implementation manners

[0030] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be described in more detail below in combination with specific embodiments. However, the protection scope of the present invention is not limited to these embodiments.

[0031] The organic bismuth catalyst used in the following examples is 8108.

[0032] Example 1

[0033] A bio-based waterborne polyurethane printing adhesive, the raw material composition of which includes, by mass parts:

[0034]

[0035] Among them, the number-average molecular weights of the bio-based polytetrahydrofuran ether diol, bio-based polypropylene glycol, and bio-based polycarbonate diol are all 2000; the bio-based contents of the bio-based polytetrahydrofuran ether diol and bio-based polypropylene glycol are 100%, and the bio-based content of the bio-based polycarbonate diol is 57%.

[0036] The bio-based waterborne polyurethane printing adhesive is prepared by the following method, including the following steps:

[0037] (1) Put the bio-based polytetrahydrofuran ether diol, bio-based polypropylene glycol, and bio-based polycarbonate diol into a reaction device, stir and heat up to 100 °C, and remove the residual moisture through a decompression device for 30 min.

[0038] (2) Cool down to 90 °C, add bio-based 1,5-pentanediisocyanate and isophorone diisocyanate to the reaction device, and keep stirring and reacting at 90 °C for 2 h.

[0039] (3) Cool down to 70 °C, add a mixture of acetone and methyl acetate, dimethylolpropionic acid, trimethylolpropane, bio-based 1,4-butanediol, acetone, methyl acetate, and organic bismuth catalyst to the reaction device, and keep reacting at 70 °C for 3 h.

[0040] (4) Cool down to 50 °C, add sodium 2-aminoethanesulfonate to the reaction device, and keep reacting at 50 °C for 30 min to obtain a prepolymer.

[0041] (5) Transfer the obtained prepolymer into a dispersion device, add triethylamine and deionized water, disperse by high-speed stirring, and after 5 min, dropwise add isophorone diamine to carry out a chain extension reaction for 20 min to obtain a dispersion;

[0042] (6) Transfer the obtained dispersion into a decompression device, and carry out decompression to remove low-boiling solvents acetone and methyl acetate, control the temperature at 60 °C for 1 h; finally obtain a bio-based waterborne polyurethane printing binder with a solid content of about 50%.

[0043] Example 2

[0044] A bio-based waterborne polyurethane printing binder, the raw material composition of which includes by mass parts:

[0045]

[0046] Among them, the number average molecular weight of the bio-based polytetrahydrofuran ether diol is 2000, and the number average molecular weight of the bio-based polycarbonate diol is 3000; the bio-based content of the bio-based polytetrahydrofuran ether diol is 100%, and the bio-based content of the bio-based polycarbonate diol is 70%.

[0047] The bio-based waterborne polyurethane printing binder is prepared by the following method, including the following steps:

[0048] (1) Put the bio-based polytetrahydrofuran ether diol and the bio-based polycarbonate diol into a reaction device, stir and heat up to 100 °C, and remove the residual moisture through a decompression device for 30 min;

[0049] (2) Cool down to 90 °C, add bio-based 1,5-pentane diisocyanate and isophorone diisocyanate to the reaction device, and keep stirring and reacting at 90 °C for 2 min;

[0050] (3) Cool down to 70 °C, add a mixture of acetone and methyl acetate, dimethylolpropionic acid, trimethylolpropane, bio-based 1,3-propanediol, acetone, methyl acetate, and organic bismuth catalyst to the reaction device, and keep reacting at 70 °C for 3 h;

[0051] (4) Cool down to 50 °C, add sodium 2-aminoethanesulfonate to the reaction device, and keep reacting at 50 °C for 30 min to obtain a prepolymer;

[0052] (5) Transfer the obtained prepolymer into a dispersion device, add triethylamine and deionized water, disperse by high-speed stirring, and after 5 min, dropwise add ethylenediamine to carry out a chain extension reaction for 20 min to obtain a dispersion;

[0053] (6) The obtained dispersion is transferred into a decompression device to remove low boiling point solvents acetone and methyl acetate under reduced pressure, the temperature is controlled at 60° C., and the time is 1 hour; finally, a bio-based water-based polyurethane printing adhesive with a solid content of about 50% is obtained.

[0054] Example 3

[0055] A bio-based water-based polyurethane printing adhesive, the raw material composition of which includes, by weight:

[0056]

[0057] Among them, the number average molecular weight of bio-based polytetramethylene ether diol, bio-based polypropylene glycol, and bio-based polycarbonate diol are all 2000; the bio-based content of bio-based polytetramethylene ether diol and bio-based polypropylene glycol is 100%, and the bio-based content of bio-based polycarbonate diol is 57%.

[0058] The method comprises the following steps:

[0059] (1) adding bio-based polytetrahydrofuran ether diol, bio-based polypropylene glycol, and bio-based polycarbonate diol into a reaction device, stirring and heating to 100° C., and removing residual water through a decompression device for 30 minutes;

[0060] (2) Cooling to 90° C., adding bio-based 1,5-pentanediisocyanate and isophorone diisocyanate into the reaction device, and maintaining 90° C. with stirring for 2 h;

[0061] (3) cooling to 70° C., adding acetone methyl acetate mixture, dimethylolbutyric acid, castor oil, bio-based 1,5-pentanediol, acetone, methyl acetate, and an organic bismuth catalyst into the reaction device, and maintaining the temperature at 70° C. for 3 h;

[0062] (4) cooling to 50° C., adding sodium ethylenediaminoethanesulfonate to the reaction apparatus, and maintaining the temperature at 50° C. for reaction for 30 min to obtain a prepolymer;

[0063] (5) The obtained prepolymer is transferred into a dispersion device, ethanolamine and deionized water are added, and the mixture is dispersed by high-speed stirring. After 5 minutes, diethylenetriamine is added dropwise to carry out a chain extension reaction for 20 minutes to obtain a dispersion;

[0064] (6) The obtained dispersion is transferred into a decompression device to remove low boiling point solvents acetone and methyl acetate under reduced pressure, the temperature is controlled at 60° C., and the time is 1 hour; finally, a bio-based water-based polyurethane printing adhesive with a solid content of about 50% is obtained.

[0065] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A bio-based water-based polyurethane printing adhesive, characterized in that: The raw material composition includes the following by weight:

2. The bio-based waterborne polyurethane printing adhesive according to claim 1, characterized in that: The bio-based polymer polyol mixture includes at least two of bio-based polytetramethylene ether diol, bio-based polypropylene glycol and bio-based polycarbonate diol.

3. The bio-based waterborne polyurethane printing adhesive according to claim 1, characterized in that: The number average molecular weight of the bio-based polytetramethylene ether diol is 1000-2000, the number average molecular weight of the bio-based polypropylene glycol is 1000-2000, and the number average molecular weight of the bio-based polycarbonate diol is 1000-3000.

4. The bio-based waterborne polyurethane printing adhesive according to claim 1, characterized in that: The bio-based content of the bio-based polytetramethylene ether diol and the bio-based polypropylene glycol is 100%, and the bio-based content of the bio-based polycarbonate diol is 50-70%.

5. The bio-based waterborne polyurethane printing adhesive according to claim 1, characterized in that: The bio-based diisocyanate mixture is a mixture of at least one of bio-based toluene diisocyanate and bio-based 1,5-pentane diisocyanate and at least one of non-bio-based isophorone diisocyanate and 1,6-hexane diisocyanate.

6. The bio-based waterborne polyurethane printing adhesive according to claim 1, characterized in that: The dicarboxylic acid hydrophilic monomer is one of dimethylol propionic acid and dimethylol butyric acid, the disulfonic acid hydrophilic monomer is sodium ethylenediaminoethanesulfonate, and the bio-based small molecule chain extender is at least one of bio-based 1,3 propanediol, bio-based 1,4 butanediol, and bio-based 1,5 pentanediol.

7. The bio-based waterborne polyurethane printing adhesive according to claim 1, characterized in that: The cross-linking agent is at least one of trimethylolpropane and castor oil.

8. The bio-based waterborne polyurethane printing adhesive according to claim 1, characterized in that: The low boiling point solvent is a mixture of acetone and methyl acetate.

9. The bio-based waterborne polyurethane printing adhesive according to claim 1, characterized in that: The organic metal catalyst is one of an organic bismuth catalyst and an organic zinc catalyst, the neutralizer is at least one of triethylamine and ethanolamine, and the polyamine chain extender is at least one of ethylenediamine, 1,5-pentanediamine, isophoronediamine, diethylenetriamine, triethylenetetramine, and diethanolamine.

10. A method for preparing the bio-based waterborne polyurethane printing adhesive according to any one of claims 1 to 9, characterized in that: The steps include: (1) placing the bio-based polymer polyol mixture into a reaction device, controlling the temperature at 100-110° C., stirring and dehydrating under reduced pressure for 30 min-1 h; (2) cooling to 80-90° C., adding a mixture containing bio-based diisocyanate, and then controlling the temperature at 80-90° C., stirring and reacting for 1-3 hours; (3) Cooling to 60-70° C., adding a bio-based small molecule chain extender, a cross-linking agent, a dicarboxyl hydrophilic monomer, a low boiling point solvent, and an organic metal catalyst to the reaction device, controlling the temperature at 60-70° C., and stirring the reaction for 3-5 hours; (4) cooling to 45-55° C., adding disulfonic acid hydrophilic monomer to the reaction device, controlling the temperature at 45-55° C., stirring and reacting for 20-30 minutes to obtain a prepolymer; (5) moving the obtained prepolymer into a dispersion device, adding a neutralizing agent and deionized water for high-speed dispersion, adding a polyamine chain extender for further reaction for 10-20 minutes to obtain a dispersion; (6) The obtained dispersion is transferred into a decompression device, the temperature of which is controlled at 40-60° C., and the low-boiling point solvent is removed to obtain a completely environmentally friendly bio-based water-based polyurethane printing adhesive.

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