Aqueous polyhydroxyl-modified amino resins, methods of making and using the same

Abstract

The application belongs to the technical field of sizing liquid preparation, and particularly discloses a water-based polyhydroxy modified amino resin, a preparation method and application thereof. The water-based polyhydroxy modified amino resin is prepared by condensation of urea and a binary aldehyde, and then adding a polyhydroxy compound. The water-based polyhydroxy modified amino resin prepared by condensation of urea and a binary aldehyde under weak acid condition and then adding a polyhydroxy compound has a solid content of 6-15%, and then the water-based polyhydroxy modified amino resin is mixed with butyroptus latex and deionized water to prepare a sizing liquid, and the sizing liquid has a solid content of 15-20%. The sizing liquid does not contain formaldehyde and resorcinol, which are harmful to human body, and the production process is simple, the production capacity is high, and the sizing liquid is beneficial to industrialized production and has a good application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of dipping solution preparation, and specifically discloses a water-based polyhydroxy modified amino resin and a preparation method and application thereof. Background Art

[0002] As a crucial component of automobiles, tires are of undeniable importance and safety. Tires are primarily composed of rubber and fiber, but the adhesion between the two is unsatisfactory. To address this, a resorcinol-formaldehyde-butylpyrrolidone latex (RFL) dipping system was developed. RFL significantly enhances the interaction between rubber and fiber through chemical reactions and hydrogen bonding, enhancing tire stability under high loads and high speeds. However, because the dipping solution contains hazardous substances such as resorcinol and formaldehyde, formaldehyde is released during production and application, posing a health hazard.

[0003] In order to replace the resorcinol used in the preparation of RFL, Meng XZ et al. used low-toxic meta-cresol to react with formaldehyde to prepare a simple, low-toxic meta-cresol-formaldehyde-butylpyrrolidone latex (CFL) impregnation system. When the C / F molar ratio was 1 / 2, the temperature was 80°C, the pH was 8, the reaction time was 2h, and the mass ratio of CF resin / butylpyrrolidone latex was 23 / 100, the peel force and H extraction force of the PET fiber / rubber composite material after CFL impregnation reached 7.3N / piece and 56.8N, respectively. However, formaldehyde will inevitably be released during the preparation process and use, which will cause harm to human body and environment.

[0004] The use of environmentally friendly phenolic compounds, such as tea polyphenols, to replace resorcinol has also become a focus of attention. Huang W et al. developed a novel, environmentally friendly nylon 66 fiber impregnation system using tea polyphenols. Tea polyphenol (TP) was first coated on the PA66 fiber surface through hydrogen bonding, followed by a second coating with a mixture of glycerol triglycidyl ether (GTE), 2-ethyl-4-methylimidazole (MZ), and butylpyrrolidone latex (VP). Results showed that when the MZ / GTE ratio in the impregnation system was 0.2:1, the H extraction force of the impregnated nylon 66 fiber / rubber composite reached 193.1±7.8N. However, a drawback of this impregnation system is that it requires a two-step impregnation coating process, making it more complex than the RFL impregnation system. Furthermore, the cost of 1ml of tea polyphenol was 304 yuan, making it unsuitable for industrial production. Furthermore, the composition of the tea polyphenols varied significantly between batches during the two coatings, making it difficult to maintain product stability.

[0005] Some researchers have replaced RF with amino resins. For example, Shi ZH et al. synthesized a new, resorcinol-formaldehyde-free, environmentally friendly polyester fiber impregnation adhesive. First, water-soluble glycerol triglycidyl ether (GLTE) and triethylenetetramine (TETA) were mixed at 60°C for 40 minutes in a weight ratio of 5:2. This mixture was then mixed with latex and stirred for 2 hours to prepare a glycerol triglycidyl ether-triethylenetetramine-butylpyridine latex (GTL) impregnation solution, replacing the resorcinol-formaldehyde-latex (RFL) impregnation system. Results showed that the peel strength of the PET-GTL / rubber composite was 16.5 N / mm, which fell short of the peel strength of the PET-RFL / rubber composite.

[0006] In fact, the above improved methods cannot meet the needs of industrialization, and the preparation process is complicated. Summary of the Invention

[0007] The purpose of the present invention is to overcome the problems pointed out in the background technology, such as the high toxicity of the raw materials used in the preparation of the RFL dipping system for industrial use, the short storage period of the existing environmentally friendly dipping system, the complex process flow, and the inability to meet practical applications. The present invention provides a preparation method and application method of an aqueous polyhydroxy-modified amino resin for preparing an environmentally friendly dipping solution with a simple process, environmentally friendly raw materials, and non-toxicity.

[0008] To achieve the above object, the preparation method of the water-based polyhydroxy modified amino resin of the present invention comprises the following steps:

[0009] (1) Dissolve urea in deionized water; add an aqueous solution of a dialdehyde compound dropwise, adjust the pH to 5-6, and react until the aldehyde group is fully reacted;

[0010] Wherein, the dialdehyde compound is glyoxal, glutaraldehyde or a mixture thereof.

[0011] The reaction temperature is 55 to 85°C, preferably 65 to 75°C.

[0012] The reaction time is 2 to 8 hours, preferably 3 to 5 hours.

[0013] The molar ratio of the dialdehyde compound to urea is 0.5 to 1.2:1, preferably 0.8 to 1.0:1.

[0014] (2) Add a polyhydroxy compound dropwise to the product of step (1), control the viscosity of the reaction solution to 0.80-3.00 mPa·s, and adjust the pH to 7-8.

[0015] The polyhydroxy compound added dropwise is one of pentaerythritol, polyvinyl alcohol, and triethanolamine, or a mixture of several of them.

[0016] The molar ratio of the added polyhydroxy compound to urea is 0.02-0.2:1, and the molar ratio decreases as the number of hydroxyl groups in the polyhydroxy compound increases. The molar amount of polyvinyl alcohol is the molar number converted from the molecular weight of the monomer vinyl alcohol.

[0017] The molar ratio of the polyol added dropwise to urea is preferably 0.05 to 0.15:1.

[0018] The solid content of the water-based polyhydroxy modified amino resin prepared by the above method is 6 to 15%, preferably 6 to 10%.

[0019] The water-based polyhydroxy-modified amino resin prepared by the above method is used to prepare a dipping solution. First, the dipping solution is prepared according to the following weight percentages: 31-37% of 40±5% butylpyrrolidone latex, 36-40% of 6-15% of water-based polyhydroxy-modified amino resin, and 23-30% of deionized water; and then ammonia water is used to adjust the pH to 9-11.

[0020] The preparation method of the dipping solution is as follows:

[0021] (1) Take 40±5% butylpyrrolidone latex and add water-based polyhydroxy modified amino resin dropwise; then add deionized water to adjust the ratio.

[0022] (2) Adjust the pH to 9-11 with ammonia water;

[0023] (3) Curing at room temperature for 15 to 20 hours.

[0024] Wherein, the pH in step (2) is preferably 9.5 to 10.5;

[0025] The aging time in step (3) is preferably 16 to 18 hours.

[0026] Beneficial Effects: The water-based polyhydroxy-modified amino resin used in the dipping system prepared by the present invention is prepared from urea, dialdehyde, and polyhydroxy compounds. The raw materials do not contain formaldehyde or m-diphenol, reducing harm to the human body and the environment. The resin viscosity and solids content are consistent with those of RF resin, facilitating the preparation of the dipping system. The preparation process of the water-based polyhydroxy-modified amino resin is simple, cost-effective, and controllable. Furthermore, the prepared water-based polyhydroxy-modified amino resin has a high number of active groups, which facilitates bonding with fibers and rubber. DETAILED DESCRIPTION

[0027] The present application is illustrated below with reference to specific embodiments. However, the embodiments are provided for illustrative purposes only and are not intended to be the entire technical solution of the present invention, nor are they intended to limit the overall technical solution of the present invention. Any modifications or substitutions with the same or similar technical features fall within the scope of protection of the present invention.

[0028] Preparation Example of Waterborne Polyhydroxy Modified Amino Resin:

[0029] Example 1

[0030] 4.03 g (0.067 mol) of urea and 88.10 mL of deionized water were added to a 250 mL four-necked flask equipped with a stirrer, a thermometer, and a constant pressure dropping funnel. Heating and stirring were turned on, the urea gradually dissolved, the solution became clear, and the reaction temperature was controlled at about 75° C. 5.86 g (0.04 mol) of a 40% aqueous solution of glyoxal was added dropwise over a period of 0.5 h. The pH was adjusted to 6 with a 3 mol / L sodium hydroxide solution, the temperature was controlled at 75° C. for 5 h, 0.96 g (0.0074 mol) of polyvinyl alcohol was added, the mixture was kept warm for 0.5 h, and then cooled to room temperature. The viscosity of the reaction solution was measured to be 1.68 mPa·s. Ammonia water was then added to adjust the pH of the solution to 7. The resulting water-based polyhydroxy-modified amino resin had a solid content of 6.50%.

[0031] Example 2

[0032] 4.05 g (0.067 mol) of urea and 107.41 mL of deionized water were added to a 250 mL four-necked flask equipped with a stirrer, a thermometer, and a constant pressure dropping funnel. Heating and stirring were turned on, the urea gradually dissolved, the solution became clear, and the reaction temperature was controlled at about 75° C.; 9.66 g (0.067 mol) of a 40% aqueous solution of glyoxal was added dropwise over a period of 0.5 h; the pH was adjusted to 6 with a 3 mol / L sodium hydroxide solution, the temperature was controlled at 75° C. for 5 h, 0.87 g (0.0067 mol) of polyvinyl alcohol was added, the mixture was kept warm for 0.5 h, and then cooled to room temperature. The viscosity of the reaction solution was measured to be 1.94 mPa·s. Ammonia water was then added to adjust the pH of the solution to 7. The resulting water-based polyhydroxy-modified amino resin had a solid content of 6.53%.

[0033] Example 3

[0034] 4.02 g (0.067 mol) of urea and 107.89 mL of deionized water were added sequentially to a 250 mL four-necked flask equipped with a stirrer, a thermometer, and a constant pressure dropping funnel; heating and stirring were turned on, the urea gradually dissolved, the solution became clear, and the reaction temperature was controlled at about 55° C.; 9.69 g (0.067 mol) of a 40% aqueous solution of glyoxal was added dropwise over a period of 0.5 h; the pH was adjusted to 6 with a 3 mol / L sodium hydroxide solution, the temperature was controlled at 55° C. for 5 h, 1.33 g (0.0087 mol) of polyvinyl alcohol was added, the mixture was kept warm for 0.5 h, and then cooled to room temperature. The viscosity of the reaction solution was measured to be 1.35 mPa·s, and then ammonia was added to adjust the pH of the solution to 7. The resulting water-based polyhydroxy-modified amino resin had a solid content of 6.49%.

[0035] Example 4

[0036] 4.03 g (0.067 mol) of urea and 107.40 mL of deionized water were added sequentially to a 250 mL four-necked flask equipped with a stirrer, a thermometer, and a constant pressure dropping funnel; heating and stirring were turned on, the urea gradually dissolved, the solution became clear, and the reaction temperature was controlled at about 75° C.; 9.68 g (0.067 mol) of a 40% aqueous solution of glyoxal was added dropwise over a period of 0.5 h; the pH was adjusted to 6 with a 3 mol / L sodium hydroxide solution, the temperature was controlled at 75° C. and the reaction was continued for 7 h. 0.46 g (0.0034 mol) of pentaerythritol was added and the mixture was kept warm for a further 0.5 h. The reaction was then cooled to room temperature, and the viscosity of the reaction solution was measured to be 2.32 mPa·s. Ammonia water was then added to adjust the pH of the solution to 7. The resulting water-based polyhydroxy-modified amino resin had a solid content of 6.52%.

[0037] Example 5

[0038] 4.05 g (0.067 mol) of urea and 100.12 mL of deionized water were added sequentially to a 250 mL four-necked flask equipped with a stirrer, a thermometer, and a constant pressure dropping funnel; heating and stirring were turned on, the urea gradually dissolved, the solution became clear, and the reaction temperature was controlled at about 85° C.; 11.75 g (0.081 mol) of a 40% aqueous solution of glyoxal was added dropwise over a period of 0.5 h; the pH was adjusted to 6 with a 3 mol / L sodium hydroxide solution, the temperature was controlled at 85° C. for 2 h, 0.70 g (0.0047 mol) of triethanolamine was added, and the mixture was kept warm for 0.5 h. The mixture was then cooled to room temperature, and the viscosity of the reaction solution was measured to be 1.81 mPa·s. Ammonia water was then added to adjust the pH of the solution to 7. The resulting water-based polyhydroxy-modified amino resin had a solid content of 7.52%.

[0039] Example 6

[0040] 4.01 g (0.067 mol) of urea and 67.39 mL of deionized water were added to a 250 mL four-necked flask equipped with a stirrer, a thermometer, and a constant pressure dropping funnel. Heating and stirring were turned on, the urea gradually dissolved, the solution became clear, and the reaction temperature was controlled at about 75° C.; 9.67 g (0.067 mol) of a 40% aqueous solution of glyoxal was added dropwise over a period of 0.5 h; the pH was adjusted to 6 with a 3 mol / L sodium hydroxide solution, the temperature was controlled at 75° C. for 5 h, 0.78 g (0.0060 mol) of polyvinyl alcohol was added, the mixture was kept warm for 0.5 h, and then cooled to room temperature. The viscosity of the reaction solution was measured to be 2.17 mPa·s. Ammonia water was then added to adjust the pH of the solution to 7. The resulting water-based polyhydroxy-modified amino resin had a solid content of 9.72%.

[0041] Example 7

[0042] 8.04 g (0.134 mol) of urea and 80.50 mL of deionized water were added sequentially to a 250 mL four-necked flask equipped with a stirrer, a thermometer, and a constant pressure dropping funnel; heating and stirring were turned on, the urea gradually dissolved, the solution became clear, and the reaction temperature was controlled at about 75° C.; 19.41 g (0.134 mol) of a 40% aqueous solution of glyoxal was added dropwise over a period of 0.5 h; the pH was adjusted to 6 with a 3 mol / L sodium hydroxide solution, the temperature was controlled at 75° C. for 5 h, 0.52 g (0.0040 mol) of polyvinyl alcohol was added, the mixture was kept warm for 0.5 h, and then cooled to room temperature. The viscosity of the reaction solution was measured to be 2.59 mPa·s, and then ammonia was added to adjust the pH of the solution to 7. The resulting water-based polyhydroxy-modified amino resin had a solid content of 14.62%.

[0043] Example 8

[0044] To a 250mL four-necked flask equipped with a stirrer, thermometer, and constant-pressure dropping funnel, 4.05g (0.067mol) of urea and 135.62mL of deionized water were added sequentially. Heating and stirring were initiated, and the urea gradually dissolved, resulting in a clear solution. The reaction temperature was maintained at approximately 65°C. 10.81g (0.054mol) of a 50% aqueous glutaraldehyde solution was added dropwise over a period of 0.5h. The pH was adjusted to 6 with 3mol / L sodium hydroxide solution, and the reaction was maintained at 65°C for 4h. 0.70g (0.0047mol) of triethanolamine was added, and the mixture was kept warm for another 0.5h. The reaction mixture was then cooled to room temperature, and the viscosity of the reaction solution was measured to be 1.89mPa·s. Ammonia was then added to adjust the pH to 7. The resulting water-based polyhydroxy-modified amino resin had a solids content of 6.28%.

[0045] Example 9

[0046] To a 250mL four-necked flask equipped with a stirrer, thermometer, and constant-pressure dropping funnel, 4.02g (0.067mol) of urea and 142.69mL of deionized water were added sequentially. Heating and stirring were initiated, and the urea gradually dissolved, resulting in a clear solution. The reaction temperature was maintained at approximately 55°C. 16.10g (0.080mol) of a 50% aqueous glutaraldehyde solution was added dropwise over a period of 0.5h. The pH was adjusted to 6 with 3mol / L sodium hydroxide solution, and the reaction was maintained at 55°C for 5h. 0.46g (0.0034mol) of pentaerythritol was added, and the reaction was continued at 55°C for another 0.5h. The reaction mixture was cooled to room temperature, and the viscosity was measured to be 1.75mPa·s. Ammonia was then added to adjust the pH to 7. The resulting water-based polyhydroxy-modified amino resin had a solids content of 7.41%.

[0047] Comparative Example 1

[0048] To a 250mL four-necked flask equipped with a stirrer, thermometer, and constant-pressure dropping funnel, 7.38g (0.067mol) of resorcinol and 158.45mL of deionized water were added sequentially. The solution was stirred under heating until it became clear, and the pH was adjusted to 9 with 3mol / L sodium hydroxide solution. The reaction temperature was gradually raised to 25°C, and 10.88g (0.134mol) of a 37% aqueous formaldehyde solution was added dropwise over 0.5h. The reaction was then maintained at 25°C for 6h. The resulting resorcinol-formaldehyde (RF) resin had a solids content of 6.45% and a viscosity of 1.42mPa·s.

[0049] The results of modified amino resins and RF with different solid contents are shown in Table 1.

[0050] Table 1

[0051]

[0052] Example of preparing environmentally friendly dipping solution:

[0053] Example 10

[0054] Weigh 24.70g, 24.72g, 24.69g, 24.73g, 24.70g, 24.68g, 24.71g, 24.69g, 24.72g, and 24.68g of 40% butylpyrrolidone latex into 10 100mL beakers respectively and mark them as dipping solutions 1 to 10. 17.71g, 17.69g, 17.75g, 17.72g, 17.70g, 17.70g, 17.71g, 17.70g, 17.69g, and 17.71g of deionized water were added to dipping solutions 1 to 10, respectively. 26.60g, 26.63g, 26.62g, 26.60g, 26.62g, 26.61g, 26.61g, 26.60g, 26.62g, and 26.60g of the water-based polyhydroxy-modified amino resin prepared in Examples 1 to 9 and the RF resin prepared in the comparative example were weighed and added dropwise to dipping solutions 1 to 10. The pH was adjusted to 10 with aqueous ammonia. The mixture was aged at room temperature for 16 hours. The prepared dipping solutions were observed, and the results are shown in Table 2.

[0055] Table 2

[0056]

[0057] H extraction force test example:

[0058] Example 11

[0059] Dipping and Drying: Use the above dipping solutions 1-10 in a continuous process to impregnate the nylon fiber, followed by drying. The dipping solution temperature is controlled at 25±5°C, and the fiber remains in the dipping solution for 0.5 seconds. The fiber is then dried in an oven at 130±5°C for 1 minute, followed by curing at 135±5°C for 50 minutes. The impregnated fiber is then stored away from light for future use.

[0060] According to the standard GB / T2942-2009 method, the above-mentioned impregnated fibers were sequentially prepared into test specimens. A 10 mm × 10 mm × 10 mm rubber strip was used. The vulcanization temperature was 135 ± 5°C, the vulcanization pressure was 3 MPa, and the vulcanization time was 50 minutes. After cooling to room temperature, eight test specimens were prepared for each fiber.

[0061] A universal electronic tensile testing machine was used to test the H-extraction force of composite materials in accordance with GB / T2942-2009. The cord segments were kept vertical during the test, and the tensile test was performed at a speed of 100 ± 10 mm / min. The maximum tensile force during the process of pulling the cord out of the rubber was recorded. The average value of eight samples was taken for each test.

[0062] The test results are shown in Table 3 below:

[0063] Table 3

[0064]

[0065] The H withdrawal force test requires no less than 120N during industrial production. The results demonstrate that the H withdrawal force achieved by the dipping solution of the present invention meets industrial requirements, demonstrating excellent adhesion between nylon fiber and rubber, reaching the level of adhesion achieved with traditional RFL dipping solutions, and making it a viable alternative to RFL dipping solutions. The raw materials used in the preparation of the water-based polyhydroxy-modified amino resin of the present invention are formaldehyde- and resorcinol-free, demonstrating promising application prospects.

Claims

1. An application of a water-based polyhydroxy modified amino resin, characterized in that: The water-based polyhydroxy modified amino resin is used to prepare an environmentally friendly dipping solution; The composition of the environmentally friendly dipping solution is as follows: 31-37% of butylpyrrolidone latex with a content of 40±5%, 36-40% of water-based polyhydroxy-modified amino resin with a solid content of 6-15%, and 23-30% of deionized water. The preparation method of waterborne polyhydroxy modified amino resin is as follows: (1) Dissolve urea in deionized water, then add an aqueous solution of a dialdehyde compound and adjust the pH to 5-6 to allow the aldehyde group to fully react; (2) Adding a polyhydroxy compound to the product of step (1), controlling the viscosity of the reaction solution to 0.80-3.00 mPa·s; adjusting the pH to 7-8, and obtaining a waterborne polyhydroxy-modified amino resin.

2. The use of the water-based polyhydroxy modified amino resin according to claim 1, characterized in that: The preparation method of the environmentally friendly dipping solution comprises the following steps: (1) Take 40±5% butylpyrrolidone latex, add water-based polyhydroxy modified amino resin dropwise, and then add deionized water to adjust the ratio; (2) Adjust the pH to 9-11 with ammonia water and mature at room temperature for 15-20 hours.

3. The use of the water-based polyhydroxy-modified amino resin according to claim 1, characterized in that: In step (1), the dialdehyde compound is glyoxal, glutaraldehyde or a mixture thereof.

4. The use of the water-based polyhydroxy modified amino resin according to claim 1, characterized in that: In step (1), the molar ratio of the dialdehyde compound to urea is 0.5-1.2:

1.

5. The use of the water-based polyhydroxy modified amino resin according to claim 1, characterized in that: In step (1), the reaction temperature is 55-85°C, and the reaction time is 2-8 hours.

6. The use of the water-based polyhydroxy modified amino resin according to claim 1, characterized in that: In step (2), the polyhydroxy compound added is one or a mixture of pentaerythritol, polyvinyl alcohol, and triethanolamine.

7. The use of the water-based polyhydroxy-modified amino resin according to claim 1, characterized in that: In step (2), the molar ratio of the added polyhydroxy compound to urea is 0.02-0.2:1.

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