Water-based polyhydroxy phenolic resin for preparing environment-friendly sizing liquid and preparation method thereof

Abstract

The application belongs to the technical field of sizing liquid preparation, and particularly discloses a water-based polyhydroxy phenolic resin for preparing environment-friendly sizing liquid and a preparation method thereof. The water-based polyhydroxy phenolic resin is prepared by condensation of m-hydroxybenzoic acid and binary aldehyde under weak acid condition, and has a solid content of 5-13%. The phenolic resin is prepared into sizing liquid by being mixed with butyroptine latex and deionized water, and has a solid content of 15-20%. The sizing liquid does not contain harmful substances such as formaldehyde and m-dihydroxybenzene to human body, and has the advantages of simple production process, high production capacity, favorable industrialized production and good application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of sizing liquid preparation, and particularly discloses a water-based polyhydroxy phenolic resin for preparing an environmentally-friendly sizing liquid and a preparation method thereof. BACKGROUND

[0002] Automobile is an important means of transportation in today's society, which brings convenience to life. With the rapid development of the automobile industry, the demand for tires, as an important component of automobiles, is also increasing, and higher requirements are put forward for the safety performance thereof.

[0003] From the surface, the tire is shaped by rubber, but in fact, the tire rubber is wrapped with fibers to improve the strength of the tire; and the adhesion between the fibers and the rubber relates to the safety of the tire in use. The polarity difference between the fibers and the rubber greatly reduces the adhesion. In order to solve this problem, in 1938, DuPont Company developed resorcinol-formaldehyde-latex (RFL), and because of its excellent curing speed, it can form a solid adhesion layer in a short time, meeting the high requirements of modern industry on tires.

[0004] Since DuPont Company developed the RFL sizing system in 1938, this method has been widely used in the field of fiber modification due to its simplicity and effectiveness. However, with the improvement of human health and safety awareness, the toxicity of formaldehyde and resorcinol used in the preparation of RFL sizing liquid has attracted widespread attention. For the above reasons, it is imperative to develop a new environmentally-friendly sizing system to replace the traditional RFL system, so as to avoid the use of formaldehyde and resorcinol sizing system.

[0005] Formaldehyde is the first to be considered for replacement. In order to replace the formaldehyde used in the preparation of RFL, Wang J C et al. prepared a sizing system HRH from hydrated silicon dioxide-resorcinol-hexamethylol melamine hexamethoxymethyl ether and latex, and investigated its adhesion performance to polyethylene terephthalate (PET) soft wire and nitrile rubber (NBR), and compared it with the RFL sizing system. The results show that the H pull-out force of the PET soft wire treated with HRH and nitrile rubber reaches 40 N, which is 40% higher than the H pull-out force (29 N) of the PET soft wire treated with resorcinol-formaldehyde-latex (RFL). However, the hexamethylol melamine hexamethoxymethyl ether used in this method is synthesized from formaldehyde as raw material, which indirectly uses formaldehyde, and complicates the preparation process. Formaldehyde will inevitably be released during the preparation and use of HRH, and the reactivity of HRH itself is relatively low. The fibers impregnated with HRH are prone to aging, which affects the durability thereof.

[0006] The use of natural, environmentally friendly phenolic compounds, such as plant polyphenols, to replace resorcinol has also become a focus of attention. Zhang Bo et al. developed a green and environmentally friendly plant polyphenol / polyamine dipping system for aramid cord, the PTA dipping solution. Plant polyphenols and polyamines were first added to deionized water, adjusted to a pH of 9-11 with sodium hydroxide solution, and stirred at room temperature for 60 minutes. VP latex was then added and stirred to homogenize the solution, resulting in the PTA dipping solution. Results showed that the initial and heat-aged H extraction forces of the aramid cord impregnated with the PTA dipping solution were slightly higher, at 174 N, compared to those of aramid cord impregnated with the RFL dipping solution. This approach reached the H extraction force level (168 N) achieved with aramid cord impregnated with conventional RFL dipping solution and rubber matrix. Although plant polyphenols are relatively less toxic, they are extracted from plants, resulting in limited yields, batch-to-batch variations in structural composition, and unstable composition. Furthermore, the structure of the plant polyphenols mentioned is unclear, as is how they react with polyamines and what they produce, making them of limited practical application value.

[0007] Therefore, the above improved methods cannot actually meet the needs of industrialization, and the preparation process is complicated.

[0008] Nacide NC et al. developed an environmentally friendly polymer resin impregnation solution composed of acrylic resin, epoxy resin, polyisocyanate, and rubber latex to study the adhesion properties of various fibers in this system. Although the research reports indicate good bonding properties, the interaction mechanism between this mixed resin and the fibers and rubber, and between the mixed resins themselves, is complex, the effects are unpredictable, and improvement and optimization methods are difficult to determine. In fact, after a period of time, the bonding effect of the fibers treated with this mixed resin significantly decreased, possibly due to hydrolysis and cleavage of the ester bonds formed between the acrylic ester and epoxy resin and the fibers. Summary of the Invention

[0009] The present invention aims to overcome the difficulties noted in the background art, such as the high toxicity of raw materials used in the preparation of industrially used RFL dipping systems, the poor stability of existing environmentally friendly dipping systems, and the complex process flow that cannot meet the needs of practical applications. The present invention provides a method for preparing an environmentally friendly dipping solution using a simple process and environmentally friendly, non-toxic raw materials, and its application.

[0010] To achieve the above object, the preparation method of the water-based polyhydroxy phenolic resin of the present invention comprises the following steps:

[0011] (1) Dissolve phloroglucinol in deionized water and adjust the pH to 5-6;

[0012] (2) Adding an aqueous solution of a dialdehyde compound to the solution of step (1) dropwise, reacting until the aldehyde group reaction is complete, and controlling the viscosity of the reaction solution to be 1.50-4.00 mPa·s, so that the hydroxyl group can be controlled to undergo almost no dehydration reaction.

[0013] In steps (1) and (2), the molar ratio of the dialdehyde compound to phloroglucinol is 1.1-1.9:1. Preferably, it is 1.2-1.6:1.

[0014] The dialdehyde compound is glyoxal, glutaraldehyde, or a mixture thereof; the reaction temperature is 35-70°C, preferably 50-60°C; and the reaction time is 1-7h, preferably 2-4h.

[0015] (3) Adjust the pH to 7-8.

[0016] The aqueous polyhydroxy phenolic resin prepared by the above method has a solid content of 5-13%. Preferably, it is 6-10%.

[0017] The aqueous polyhydroxy phenolic resin is used to prepare a sizing liquid, and the sizing liquid has the following composition by weight percentage: butyroin latex with a solid content of 40±5% 33-38%, the aqueous polyhydroxy phenolic resin with a solid content of 5-13% 34-41%, and deionized water 21-33%.

[0018] The preparation method of the sizing liquid is as follows:

[0019] (1) Take butyroin latex with a solid content of 40±5%, and drop the aqueous polyhydroxy phenolic resin with a solid content of 5-13%; then add deionized water to adjust the ratio.

[0020] (2) Adjust the pH to 9.5-10.5 with ammonia water; and mature at room temperature for 15-20h. Preferably, the pH is adjusted to 9.5-10, and the maturation time is 16-18h.

[0021] Beneficial effects: The aqueous polyhydroxy phenolic resin used in the sizing system prepared by the present application is prepared from phloroglucinol and dialdehyde, which overcomes the toxicity of raw materials, formaldehyde and m-diphenol, used in RFL; the resin viscosity and solid content are consistent with those of RF resin, which is conducive to the preparation of the sizing system. The preparation process of the aqueous polyhydroxy phenolic resin is controllable, the product structure is controllable, and the repeatability is high; and the prepared aqueous polyhydroxy phenolic resin has many active groups, which is conducive to the linkage with fibers and rubber. DETAILED DESCRIPTION

[0022] The present application is exemplarily described below in combination with specific examples, but the examples are given only as examples, and are not regarded as the whole technical solution of the present application, and are not limited to the general technical solution of the present application. Any technical features with the same or similar technical features, simple changes or replacements, are within the protection scope of the present application.

[0023] Preparation test example of the aqueous polyhydroxy phenolic resin:

[0024] Example 1

[0025] Into a 250 mL four-necked flask, equipped with stirring, thermometer and constant pressure dropping funnel, 3.02 g (0.024 mol) of phloroglucinol, 78.61 mL of deionized water were added successively, and stirred under heating until the solution became clear. The pH was adjusted to 6 with 11% sodium hydroxide solution by mass concentration, and the reaction temperature was gradually increased to 65°C, and 5.28 g (0.026 mol) of glutaraldehyde aqueous solution with 50% by mass concentration was added dropwise for 0.5 h, and the reaction was controlled for 1 h. After cooling to room temperature, the pH of the solution was adjusted to 7 with ammonia water. The solid content of the obtained aqueous polyhydroxy phenolic resin was 6.72%, and the viscosity was 1.85 mPa-s.

[0026] Example 2

[0027] Into a 250 mL four-necked flask, equipped with stirring, thermometer and constant pressure dropping funnel, 3.02 g (0.024 mol) of phloroglucinol, 78.61 mL of deionized water were added successively, and stirred under heating until the solution became clear. The pH was adjusted to 6 with 11% sodium hydroxide solution by mass concentration, and the reaction temperature was gradually increased to 65°C, and 5.28 g (0.026 mol) of glutaraldehyde aqueous solution with 50% by mass concentration was added dropwise for 0.5 h, and the reaction was controlled for 1 h. After cooling to room temperature, the pH of the solution was adjusted to 7 with ammonia water. The solid content of the obtained aqueous polyhydroxy phenolic resin was 6.72%, and the viscosity was 1.85 mPa-s.

[0028] Example 3

[0029] Into a 250 mL four-necked flask, equipped with stirring, thermometer and constant pressure dropping funnel, 3.02 g (0.024 mol) of phloroglucinol, 78.61 mL of deionized water were added successively, and stirred under heating until the solution became clear. The pH was adjusted to 6 with 11% sodium hydroxide solution by mass concentration, and the reaction temperature was gradually increased to 65°C, and 5.28 g (0.026 mol) of glutaraldehyde aqueous solution with 50% by mass concentration was added dropwise for 0.5 h, and the reaction was controlled for 1 h. After cooling to room temperature, the pH of the solution was adjusted to 7 with ammonia water. The solid content of the obtained aqueous polyhydroxy phenolic resin was 6.72%, and the viscosity was 1.85 mPa-s.

[0030] Example 4

[0031] Into a 250 mL four-necked flask, equipped with a mechanical stirrer, thermometer and a dropping funnel, 3.02 g (0.024 mol) of phloroglucinol, 68.35 mL of deionized water were added successively, the solution was stirred to become clear under heating, the pH was adjusted to 6 with a sodium hydroxide solution with a mass concentration of 11%, the reaction temperature was gradually increased to 65°C, a glyoxal aqueous solution with a mass concentration of 40% 4.91 g (0.034 mol) was added dropwise, the dropping was completed in 0.5 h, the temperature was controlled for 3 h, after cooling to room temperature, the pH of the solution was adjusted to 7 by adding ammonia water, the solid content of the obtained aqueous polyhydroxyl phenolic resin was 7.12%, and the viscosity was measured to be 3.08 mPa·s.

[0032] Example 5

[0033] Into a 250 mL four-necked flask, equipped with a mechanical stirrer, thermometer and a dropping funnel, 3.02 g (0.024 mol) of phloroglucinol, 68.35 mL of deionized water were added successively, the solution was stirred to become clear under heating, the pH was adjusted to 6 with a sodium hydroxide solution with a mass concentration of 11%, the reaction temperature was gradually increased to 65°C, a glyoxal aqueous solution with a mass concentration of 40% 4.91 g (0.034 mol) was added dropwise, the dropping was completed in 0.5 h, the temperature was controlled for 3 h, after cooling to room temperature, the pH of the solution was adjusted to 7 by adding ammonia water, the solid content of the obtained aqueous polyhydroxyl phenolic resin was 7.12%, and the viscosity was measured to be 3.08 mPa·s.

[0034] Example 6

[0035] Into a 250 mL four-necked flask, equipped with a mechanical stirrer, thermometer and a dropping funnel, 3.02 g (0.024 mol) of phloroglucinol, 68.35 mL of deionized water were added successively, the solution was stirred to become clear under heating, the pH was adjusted to 6 with a sodium hydroxide solution with a mass concentration of 11%, the reaction temperature was gradually increased to 65°C, a glyoxal aqueous solution with a mass concentration of 40% 4.91 g (0.034 mol) was added dropwise, the dropping was completed in 0.5 h, the temperature was controlled for 3 h, after cooling to room temperature, the pH of the solution was adjusted to 7 by adding ammonia water, the solid content of the obtained aqueous polyhydroxyl phenolic resin was 7.12%, and the viscosity was measured to be 3.08 mPa·s.

[0036] Example 7

[0037] Into a 250 mL four-necked flask, equipped with a mechanical stirrer, thermometer and a constant pressure dropping funnel, 3.03 g (0.024 mol) of phloroglucinol, 78.38 mL of deionized water were added successively, the solution was stirred to become clear under heating, the pH was adjusted to 6 with a 11% sodium hydroxide solution, the reaction temperature was gradually increased to 55°C, 4.89 g (0.034 mol) of a 40% aqueous glyoxal solution was added dropwise, the dropping was completed in 0.5 h, the temperature was controlled for 4 h, after cooling to room temperature, the pH of the solution was adjusted to 7 with ammonia water, the solid content of the obtained aqueous polyhydroxyl phenolic resin was 6.26%, the viscosity was 1.90 mPa-s.

[0038] Example 8

[0039] Into a 250 mL four-necked flask, equipped with a mechanical stirrer, thermometer and a constant pressure dropping funnel, 6.03 g (0.048 mol) of phloroglucinol, 95.12 mL of deionized water were added successively, the solution was stirred to become clear under heating, the pH was adjusted to 6 with a 11% sodium hydroxide solution, the reaction temperature was gradually increased to 55°C, 11.45 g (0.057 mol) of a 50% aqueous glutaraldehyde solution was added dropwise, the dropping was completed in 0.5 h, the temperature was controlled for 2 h, after cooling to room temperature, the pH of the solution was adjusted to 7 with ammonia water, the solid content of the obtained aqueous polyhydroxyl phenolic resin was 10.54%, the viscosity was 2.72 mPa-s.

[0040] Example 9

[0041] Into a 250 mL four-necked flask, equipped with a mechanical stirrer, thermometer and a constant pressure dropping funnel, 6.02 g (0.048 mol) of phloroglucinol, 73.50 mL of deionized water were added successively, the solution was stirred to become clear under heating, the pH was adjusted to 6 with a 11% sodium hydroxide solution, the reaction temperature was gradually increased to 55°C, 11.47 g (0.057 mol) of a 50% aqueous glutaraldehyde solution was added dropwise, the dropping was completed in 0.5 h, the temperature was controlled for 2 h, after cooling to room temperature, the pH of the solution was adjusted to 7 with ammonia water, the solid content of the obtained aqueous polyhydroxyl phenolic resin was 12.95%, the viscosity was 3.24 mPa-s.

[0042] Comparative Example 1

[0043] In a 250 mL four-necked flask equipped with stirring, thermometer and constant pressure dropping funnel, 6.04 g (0.048 mol) of resorcinol, 166.50 mL of deionized water were added successively, stirred under heating until the solution became clear, the pH was adjusted to 6 with 11% sodium hydroxide solution, the reaction temperature was gradually increased to 55°C, 5.53 g (0.057 mol) of furfural was added dropwise, the dropping was completed in 0.5 h, the temperature was controlled for 2 h, after cooling to room temperature, the pH of the solution was adjusted to 7 with ammonia water, the solid content of the obtained aqueous polyhydroxyl phenolic resin was 6.5%, the solution had stratification phenomenon, and the solution viscosity could not be accurately measured.

[0044] Comparative Example 2

[0045] In a 250 mL four-necked flask equipped with stirring, thermometer and constant pressure dropping funnel, 5.52 g (0.050 mol) of resorcinol, 118.50 mL of deionized water were added successively, stirred under heating until the solution became clear, the pH was adjusted to 9 with 11% sodium hydroxide solution, the reaction temperature was gradually increased to 25°C, 8.13 g (0.100 mol) of 37% formaldehyde aqueous solution was added dropwise, the dropping was completed in 0.5 h, the temperature was controlled for 6 h, the solid content of the obtained resorcinol-formaldehyde (RF) resin was 6.49%, and the viscosity was measured to be 1.58 mPa·s.

[0046] Table 1

[0047]

[0048] Table 2

[0049]

[0050] Preparation example of environmentally friendly sizing solution:

[0051] Example 11

[0052] Take 24.69g, 24.69g, 24.68g, 24.67g, 24.71g, 24.67g, 24.70g, 24.72g, 24.72g, 24.71g, 24.75g of butyl latex with solid content of 40% into 11 100mL beakers, labeled as dipping solution 1-11. Add 17.72g, 17.72g, 17.74g, 17.69g, 17.73g, 17.70g, 17.74g, 17.71g, 25.21g, 30.30g, 16.71g of deionized water into the dipping solution 1-11, respectively, and then add 26.61g, 26.62g, 26.61g, 26.64g, 26.65g, 26.64g, 26.66g, 26.63g, 13.33g, 13.40g, 26.64g of waterborne polyhydric phenolic resin prepared in Examples 1-9 and Comparative Examples 1-2 into the dipping solution 1-11, respectively; adjust the pH to 10 with ammonia water. Curing at room temperature for 16 hours. Observe the prepared dipping solution, and the results are shown in Table 3.

[0053] Table 3

[0054]

[0055] The prepared dipping solution, No. 10 dipping solution is demulsified, and the rest are not.

[0056] H extraction force test example:

[0057] Example 12

[0058] Dipping and drying: No. 10 dipping solution cannot be used for dipping because of the stratification phenomenon, and no dipping test is performed. The above-mentioned dipping solutions 1-9 and 11 are used in turn to dip the nylon fibers by the continuous method, and then dried. The dipping solution temperature is controlled at 25±3℃, the fibers stay in the dipping solution for 0.5 seconds, and then dried in an oven, the drying temperature is 130±3℃, and the drying time is 1 min; 136±2℃, and the curing time is 50 min. The dipped fibers are stored in the dark for subsequent use.

[0059] According to the method of standard GB / T2942-2009, the above-mentioned dipped fibers are prepared in turn. The rubber strips with a size of 10mm×10mm×10mm are used, the vulcanization temperature is 136±2℃, the vulcanization pressure is 3MPa, the vulcanization time is 50 min, and the cooling temperature is room temperature. 8 samples are prepared for each fiber.

[0060] The H pull-out force of the composite material is tested by using a universal electronic tensile testing machine according to GB / T 2942-2009. During the test, the cord segment is ensured to be vertical, the tensile test is carried out at a speed of 100±10 mm / min, the maximum tensile force in the process of pulling out the cord from the rubber is recorded, and 8 samples in each group are taken for average.

[0061] The test results are shown in Table 4 below.

[0062] Table 4

[0063]

[0064] The H pull-out force test requires not less than 120 N during the industrial production process. The results show that the H pull-out force reaches the industrial requirement by using the dipping solution of the application, indicating that the nylon fiber and the rubber have good adhesion effect, reaching the adhesion level of the traditional RFL, and the dipping solution can replace the RFL dipping solution. The raw material of the water-based polyhydroxy phenolic resin used in the application does not contain formaldehyde and resorcinol, and has a good application prospect.

Claims

1. A method for preparing an aqueous polyhydroxyphenolic resin for preparing an environmentally friendly dipping solution, characterized in that: The preparation method of the water-based polyhydroxy phenolic resin comprises the following steps: (1) Dissolve phloroglucinol in deionized water and adjust the pH to 5-6; (2) adding an aqueous solution of a dialdehyde compound to the solution of step (1) to allow the aldehyde groups to react fully, and controlling the viscosity of the reaction solution to be 1.50-4.00 mPa·s so that the hydroxyl groups do not undergo dehydration reaction; The molar ratio of the dialdehyde compound to phloroglucinol is 1.1-1.9:1; the dialdehyde compound is glyoxal, glutaraldehyde or a mixture thereof; (3) Adjust the pH to 7-8; The solid content of the water-based polyhydroxy phenolic resin is 5-13%.

2. The method for preparing an aqueous polyhydroxyphenolic resin for preparing an environmentally friendly dipping solution according to claim 1, wherein: In step (2), the reaction temperature is 35-70°C and the reaction time is 1-7 h.

3. An aqueous polyhydroxyphenolic resin for preparing an environmentally friendly dipping solution prepared according to the method of claim 1, characterized in that: The solid content of the water-based polyhydroxy phenolic resin is 5-13%.

4. An application of a water-based polyhydroxyphenol-formaldehyde resin prepared by the method according to claim 1, characterized in that: The water-based polyhydroxyphenolic resin is used for preparing an environmentally friendly dipping solution.

5. The use of the water-based polyhydroxyphenolic resin according to claim 4, characterized in that: The composition of the dipping solution by weight percentage is: 33-38% of butylpyrrolidone latex with a solid content of 40±5%, 34-41% of water-based polyhydroxy phenolic resin with a solid content of 5-13%, and 21-33% of deionized water.

6. The use of the water-based polyhydroxyphenol-formaldehyde resin according to claim 4, characterized in that: The preparation method of the dipping solution comprises the following steps: (1) Add water-based polyhydroxyphenolic resin with a solid content of 5-13% to a 40±5% solid content butylpyrrolidone latex, and then add deionized water; (2) Adjust the pH to 9.5-10.5 with ammonia water; mature at room temperature for 15-20 hours.

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