CN115286727A - Preparation method of low-residue polyvinyl butyral - Google Patents

Abstract

The invention provides a preparation method of low-residue polyvinyl butyral, which comprises the following steps: fatty alcohol-polyoxyethylene ether (emulsifier A) and sodium fatty alcohol-polyoxyethylene ether sulfonate (emulsifier B) or sulfo fatty alcohol-polyoxyethylene ether sodium succinate (emulsifier C) are used, and the neutralization alkali concentration is low, and the alkali neutralization and washing temperature is high. The PVB resin powder prepared by the method provided by the invention has the total sodium ion residual quantity of less than 50ppm, the emulsifier residual quantity of less than 0.1%, and has the advantages of low agglomeration rate, high light transmittance, strong moisture resistance and good thermal stability.

Description

A kind of preparation method of low residual polyvinyl butyral

technical field

The invention belongs to the technical field of polyvinyl butyral, and in particular relates to a preparation method of low-residue polyvinyl butyral.

Background technique

Polyvinyl butyral resin (PVB) is a high-performance polymer material with a wide range of uses. It has excellent optical properties and has high adhesion to various substrates such as glass, ceramics, metals, and cellulose. It can be processed and applied in many convenient ways such as solution and melting.

PVB resin powder is usually prepared by the process of reacting polyvinyl alcohol aqueous solution with butyraldehyde. The preparation process mainly includes acid-catalyzed condensation reaction, neutralization, washing and drying. Generally, the reaction between polyvinyl alcohol aqueous solution and butyraldehyde is carried out with the participation of acid catalyst and emulsifier, and the reaction temperature is 5-15°C. The acid catalyst usually uses cheap hydrochloric acid, neutralization mostly uses cheap sodium hydroxide, and there are many choices of emulsifiers, which have a significant impact on the overall performance of the final PVB. However, the existing PVB synthesis process easily causes more impurities (such as emulsifiers, chloride ions, sodium ions, etc.) to remain in the PVB resin, resulting in a decrease in the light transmittance, moisture resistance and thermal stability of the PVB resin film. In addition, in order to improve the synthesis efficiency and butyraldehyde conversion rate of PVB resin powder, the final stage of the condensation reaction is usually carried out at 60-70°C for 1-3 hours. During this process, the resin powder is prone to yellowing.

Contents of the invention

In view of this, the purpose of the embodiments of the present invention is to provide a method for preparing polyvinyl butyral with low residues. The polyvinyl butyral prepared by the method provided by the present invention has low residual amounts of sodium ions and emulsifiers.

The invention provides a preparation method of low-residue polyvinyl butyral, comprising:

Reacting polyvinyl alcohol hydrochloric acid mixed solution, fatty alcohol polyoxyethylene ether, n-butyraldehyde and emulsifier to obtain low-residue polyvinyl butyral;

The emulsifier is selected from fatty alcohol polyoxyethylene ether sodium sulfonate or sulfo fatty alcohol polyoxyethylene ether succinic acid monoester disodium salt.

Preferably, the preparation method of described polyvinyl alcohol hydrochloric acid mixed solution comprises:

Polyvinyl alcohol and water are first mixed to obtain an aqueous solution of polyvinyl alcohol;

The polyvinyl alcohol solution and hydrochloric acid are mixed for the second time to obtain a polyvinyl alcohol hydrochloric acid mixed solution.

Preferably, the temperature of the first mixing is 80-98°C; the method of the first mixing is stirring and dissolving;

The mass concentration of the polyvinyl alcohol aqueous solution is 8-12%.

Preferably, the hydrochloric acid is used in an amount such that the pH of the mixing system is 1.0-2.5; the second mixing is carried out under stirring, and the stirring time is 5-10 minutes.

Preferably, the mass of the fatty alcohol polyoxyethylene ether is 0.05% to 0.5% of the mass of polyvinyl alcohol in the polyvinyl alcohol hydrochloric acid mixed solution;

The quality of the n-butyraldehyde is 50% to 70% of the polyvinyl alcohol quality in the polyvinyl alcohol hydrochloric acid mixed solution;

The quality of the emulsifier is 0.2% to 1.0% of the mass of polyvinyl alcohol in the polyvinyl alcohol hydrochloric acid mixed solution;

The n-butyraldehyde contains antioxidant, and the quality of the antioxidant is 0.5-1.5% of the n-butyraldehyde mass.

Preferably, the temperature of the reaction is 60-70° C., and the heating rate of the reaction is 0.5-2° C./min.

Preferably, after the reaction is completed, it also includes:

The obtained reaction product is washed, filtered, and dried to obtain a low-residue polyvinyl butyral resin;

The reagent for the washing is sodium hydroxide aqueous solution, the temperature of the washing is 50-70°C, and the pH of the product is greater than 9.0 during the washing.

Preferably, the preparation method of the low-residue polyvinyl butyral specifically comprises the following steps:

a. Add polyvinyl alcohol and deionized water into the reaction kettle, heat up to 80°C-98°C, stir and dissolve into 8-12% polyvinyl alcohol aqueous solution, filter, then cool down to 5-15°C, put in hydrochloric acid catalyst, Adjust the pH value to 1.0-2.5, and stir for 5-10 minutes to obtain a polyvinyl alcohol/hydrochloric acid mixed solution;

b. According to 0.05-0.5% of the mass of polyvinyl alcohol, put in emulsifier A whose chemical composition is fatty alcohol polyoxyethylene ether, and stir for 5-10 minutes;

c. According to 50-70% of the polyvinyl alcohol mass, slowly add n-butyraldehyde containing 0.5-1.5% antioxidant to the solution in step b;

d. After the addition of n-butyraldehyde, continue to react for 10-15 minutes, and according to 0.2-1.0% of the mass of polyvinyl alcohol, the input chemical composition is fatty alcohol polyoxyethylene ether sodium sulfonate emulsifier B or the chemical composition is sulfonate Emulsifier C of fatty alcohol polyoxyethylene ether succinic acid monoester disodium salt, continue to stir and react for 30-180min;

e. Raise the reaction temperature to 60-70°C at a heating rate of 0.5-2°C/min, and continue the reaction at this temperature for 30-120 minutes to obtain polyvinyl butyral resin powder;

f. Then add sodium hydroxide aqueous solution, wash at 50-70°C for several times until the pH of the reaction solution is greater than 9.0, filter and dry to obtain low-residue polyvinyl butyral resin.

Preferably, the number of fatty alcohol carbon atoms in the fatty alcohol polyoxyethylene ether is 8-18, and the polymerization degree of polyoxyethylene is 3-20.

Preferably, the mass concentration of the aqueous sodium hydroxide solution is 50-300 ppm.

PVB emulsification and condensation technology is still the industry's first choice, and the choice of emulsifier is very important. Method provided by the invention has used fatty alcohol polyoxyethylene ether (emulsifier A) and fatty alcohol polyoxyethylene ether sodium sulfonate (emulsifier B) or sulfo fatty alcohol polyoxyethylene ether sodium succinate (emulsifier C) , also used lower neutralizing alkali concentration, higher alkali neutralization and washing temperature; the total sodium ion residual amount in the PVB resin powder prepared by the method provided by the invention is lower than 50ppm, and the emulsifier residual amount is lower than 0.1% . The low-residue polyvinyl butyral resin prepared by the invention is particularly suitable for the fields of 3D printing, ceramic adhesives, high-transparency automobile windshields, building safety glasses, and the like.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The invention provides a preparation method of low-residue polyvinyl butyral, comprising:

Reacting polyvinyl alcohol hydrochloric acid mixed solution, fatty alcohol polyoxyethylene ether, n-butyraldehyde and emulsifier to obtain low-residue polyvinyl butyral;

The emulsifier is selected from fatty alcohol polyoxyethylene ether sodium sulfonate or sulfo fatty alcohol polyoxyethylene ether succinic acid monoester disodium salt.

In the present invention, the preparation method of described polyvinyl alcohol hydrochloric acid mixed solution preferably comprises:

Polyvinyl alcohol and water are first mixed to obtain an aqueous solution of polyvinyl alcohol;

The polyvinyl alcohol aqueous solution and hydrochloric acid are mixed for the second time to obtain a polyvinyl alcohol hydrochloric acid mixed solution.

In the present invention, the degree of polymerization of the polyvinyl alcohol is preferably 1500-2000, more preferably 1600-1800, most preferably 1700; the water is preferably deionized water; the first mixing temperature is preferably 80 ~98°C, more preferably 85~95°C, more preferably 88~92°C, most preferably 90°C; the mass concentration of the polyvinyl alcohol aqueous solution is preferably 8~12%, more preferably 9~11%, Most preferably 10%.

In the present invention, the concentration of the hydrochloric acid is preferably 32-35%, more preferably 33-34%.

In the present invention, after obtaining the polyvinyl alcohol aqueous solution, it is preferred to also include:

The polyvinyl alcohol aqueous solution was filtered and then mixed with hydrochloric acid for a second time.

In the present invention, the temperature of the second mixing is preferably 5-15°C, more preferably 8-12°C, most preferably 10°C; the added amount of hydrochloric acid is preferably such that the pH of the mixing system is 1.0-2.5 , more preferably 1.5 to 2.0, most preferably 1.6 to 1.8; the second mixing is preferably carried out under stirring conditions, and the stirring time is preferably 5 to 10 minutes, more preferably 6 to 9 minutes, most preferably 7 minutes ~8min.

In the present invention, the main function of the fatty alcohol polyoxyethylene ether (emulsifier A) is to control the agglomeration of PVB resin powder. Usually, when nonionic surfactants and anionic surfactants are used together, the two will synergistically The effect makes the system have lower surface energy, which is beneficial to control the agglomeration of resin powder. Emulsifier A also helps to inhibit the yellowing reaction of PVB resin powder during high temperature condensation, and emulsifier A is conducive to conducting protons from resin powder to water, thereby reducing the acid-catalyzed dehydration side reaction of PVB resin powder.

In the present invention, the number of carbon atoms of the fatty alcohol in the fatty alcohol polyoxyethylene ether is preferably 10 to 22, more preferably 14 to 18, and most preferably 15 to 16; a higher number of carbon atoms usually causes subsequent It is difficult to wash with water, and the emulsification efficiency is lower with a lower number of carbon atoms.

In the present invention, the degree of polymerization of polyoxyethylene in the fatty alcohol polyoxyethylene ether is preferably 3-20, more preferably 5-15, more preferably 5-10, most preferably 6-8; when polyoxyethylene When the degree of polymerization of polyoxyethylene is high, the compatibility between the emulsifier and PVB is insufficient, and the efficiency in controlling the agglomeration of PVB resin powder is reduced; when the degree of polymerization of polyoxyethylene is low, the cloud point of the emulsifier decreases, and it is compatible with PVB The increase in capacity will easily lead to agglomeration of PVB resin powder in the final condensation stage and neutralization stage, and the difficulty of thorough cleaning and removal will increase.

In the present invention, the mass of the fatty alcohol polyoxyethylene ether is preferably 0.05-0.5% of the mass of polyvinyl alcohol in the polyvinyl alcohol hydrochloric acid mixed solution, more preferably 0.1-0.4%, most preferably 0.2-0.3%.

In the present invention, the mass of the n-butyraldehyde is preferably 50-70% of the mass of polyvinyl alcohol in the polyvinyl alcohol hydrochloric acid mixed solution, more preferably 55-65%, and most preferably 60%.

In the present invention, the n-butyraldehyde preferably contains an antioxidant, and the quality of the antioxidant is preferably 0.5-1.5% of the n-butyraldehyde mass, more preferably 0.8-1.2%, most preferably 1%; The antioxidant is preferably Antioxidant 1010.

In the present invention, the emulsifier is selected from fatty alcohol polyoxyethylene ether sodium sulfonate (emulsifier B) or sulfo fatty alcohol polyoxyethylene ether succinic acid monoester disodium salt (emulsifier C).

In the present invention, the number of carbon atoms of the fatty alcohol in the sodium fatty alcohol polyoxyethylene ether sulfonate is preferably 8 to 18, more preferably 10 to 14, and most preferably 12 to 13; higher carbon atoms are usually It will cause difficulty in subsequent washing, and the emulsification efficiency is lower with a lower number of carbon atoms.

In the present invention, the degree of polymerization of polyoxyethylene in the sodium fatty alcohol polyoxyethylene ether sulfonate is preferably 3-20, more preferably 5-15, more preferably 5-10, most preferably 6-8; When the degree of polymerization of polyoxyethylene is high, the efficiency of the emulsifier in controlling the agglomeration of PVB resin powder decreases; when the degree of polymerization of polyoxyethylene is low, the difficulty of thorough washing and removal increases.

In the present invention, the number of carbon atoms of the fatty alcohol in the disodium salt of polyoxyethylene ether succinate monoester of sulfo fatty alcohol is preferably 8-18, more preferably 10-14, most preferably 12-13; A high number of carbon atoms usually makes subsequent washing difficult, and a lower number of carbon atoms has lower emulsification efficiency.

In the present invention, the degree of polymerization of polyoxyethylene in the fatty alcohol in the sulfo fatty alcohol polyoxyethylene ether succinic acid monoester disodium salt is preferably 3-20, more preferably 10-15, more preferably 5-20 10, most preferably 6-8; when the degree of polymerization of polyoxyethylene is high, the efficiency of the emulsifier in controlling the agglomeration of PVB resin powder is reduced; when the degree of polymerization of polyoxyethylene is low, it is difficult to thoroughly wash and remove Increase.

In the present invention, the mass of the emulsifier is preferably 0.2-1.0%, more preferably 0.4-0.8%, and most preferably 0.6% of the mass of polyvinyl alcohol in the polyvinyl alcohol hydrochloric acid mixed solution.

In the present invention, the emulsifier (emulsifier B or emulsifier C) is preferably added within 1 to 10 minutes, more preferably within 3 to 6 minutes, most preferably 4 Add within ~5 minutes; if emulsifier B or emulsifier C is added immediately after the phase transition of the PVB condensation reaction, it is usually difficult to judge, and it is easy to cause the emulsifier to be wrapped inside the primary particles of the resin powder, adding water to remove the emulsifier process Difficulty; if the emulsifier is added after the phase transition of the PVB condensation reaction for a long time, it will easily lead to an increase in the amount of PVB resin powder agglomeration and affect the product yield.

In the present invention, the reaction temperature is preferably 60-70°C, more preferably 62-68°C, most preferably 64-66°C.

In the present invention, after the reaction is finished, preferably also include:

The obtained reaction product is washed, filtered and dried to obtain a low-residue polyvinyl butyral resin.

In the present invention, the reagent for the washing is preferably an aqueous sodium hydroxide solution, and the mass concentration of the aqueous sodium hydroxide solution is preferably 50-300 ppm, more preferably 100-250 ppm, most preferably 150-200 ppm; Sodium hydroxide solution, although the neutralization efficiency increases, tends to lead to a greater residual amount of sodium ions; a lower concentration of sodium hydroxide solution, although the residual amount of sodium ions is lower, tends to increase the number of washings.

In the present invention, the washing temperature is preferably 45-70°C, more preferably 50-65°C, and most preferably 55-60°C; higher washing temperatures tend to increase energy consumption, and lower washing temperatures tend to This makes it difficult to completely neutralize residual hydrochloric acid.

In the present invention, the washing is preferably repeated washing until the pH of the product is >9.0.

In the present invention, the preparation method of the low-residue polyvinyl butyral preferably includes:

Add fatty alcohol polyoxyethylene ether to polyvinyl alcohol hydrochloric acid mixed solution and stir;

Add n-butyraldehyde to the resulting mixture to react, then add emulsifier to continue the reaction;

Heat up and continue to stir and react to obtain polyvinyl butyral resin powder;

Adding the polyvinyl butyral resin powder to an aqueous sodium hydroxide solution to wash, filter and dry to obtain a low-residue polyvinyl butyral resin.

In the present invention, the stirring time is preferably 5 to 10 minutes, more preferably 6 to 9 minutes, and most preferably 7 to 8 minutes; the addition of n-butyraldehyde is preferably slow dropwise addition; the time for adding n-butyraldehyde to react Preferably 10-15min, more preferably 11-14min, most preferably 12-13min; the time for continuing the reaction is preferably 30-180min, more preferably 50-150min, more preferably 80-120min, most preferably 100min; The speed is preferably 0.5 to 2°C, more preferably 1 to 1.5°C; the temperature for heating is preferably 60 to 70°C, more preferably 62 to 68°C, most preferably 64 to 66°C; Preferably it is 30-120 min, more preferably 50-100 min, most preferably 60-80 min.

In the present invention, the preparation method of the low-residue polyvinyl butyral more preferably comprises:

a. Preparation of polyvinyl alcohol solution: Add polyvinyl alcohol with a degree of polymerization of 1700 and deionized water into the reactor, heat up to 80°C to 98°C, stir and dissolve into an 8% to 12% polyvinyl alcohol aqueous solution, filter, and then Cool down to 5-15°C, put in hydrochloric acid catalyst, adjust the pH value to 1.0-2.5, and stir for 5-10 minutes to prepare polyvinyl alcohol/hydrochloric acid mixed solution;

b. According to 0.05-0.5% of the mass of polyvinyl alcohol, put in emulsifier A whose chemical composition is fatty alcohol polyoxyethylene ether, and stir for 5-10 minutes;

c, according to 50～70% of polyvinyl alcohol quality, slowly add n-butyraldehyde in step b solution;

d. After adding n-butyraldehyde, continue to react for 10-15 minutes, and according to the mass ratio of polyvinyl alcohol of 0.2-1.0%, the input chemical composition is emulsifier B of fatty alcohol polyoxyethylene ether sodium sulfonate or the chemical composition is Emulsifier C of sulfo fatty alcohol polyoxyethylene ether succinic acid monoester disodium salt, continue to stir and react for 30-180 minutes;

e. Raise the reaction temperature to 60-70°C at a heating rate of 0.5-2°C/min, and continue the reaction at this temperature for 30-120 minutes to obtain polyvinyl butyral resin powder;

f. Then add sodium hydroxide aqueous solution, wash at 45-70°C several times until the pH of the reaction solution is greater than 9.0, filter and dry to obtain a low-residue polyvinyl butyral resin.

The method provided by the invention has high synthesis efficiency, no resin powder agglomeration, low residual rate of sodium ions and emulsifiers, the light transmittance of the PVB film prepared by it is greater than 90% (1mm thickness), high moisture resistance, and good thermal stability The advantages.

The invention provides a method for preparing low-residue polyvinyl butyral (PVB) resin powder. Those skilled in the art can learn from the content of this article and appropriately improve the process parameters to realize it. In particular, it should be pointed out that all similar substitutions and modifications are obvious to those skilled in the art, and they all belong to the protection scope of the present invention. The method and application of the present invention have been described through preferred embodiments, and relevant personnel can obviously make changes or appropriate changes and combinations to the method and application herein without departing from the content, spirit and scope of the present invention to realize and apply the present invention Invent technology.

The polyvinyl alcohol used in the following examples of the present invention has a degree of polymerization of 1700 and a degree of alcoholysis ≥ 99%. It is a 17-99 product produced by Anhui Wanwei Company.

Example 1

Add 1000g of polyvinyl alcohol and 9L of deionized water into the reaction kettle, raise the temperature to 80°C~98°C, stir and dissolve it into a 10% aqueous solution of polyvinyl alcohol and filter it, then cool it down to 5~15°C, and put in 170g of polyvinyl alcohol with a concentration of 32~ 35% hydrochloric acid (catalyst), the pH value at this time is 1.2, and stirred for 10 minutes to prepare a polyvinyl alcohol/hydrochloric acid mixed solution. According to 0.25% of the mass of polyvinyl alcohol, the chemical composition is decyl alcohol polyoxyethylene ether-6 (E-06, produced by Jiangsu Haian Petrochemical Company) emulsifier A, and stirred for 10 minutes. According to 61% of the mass of polyvinyl alcohol, slowly add n-butyraldehyde containing 0.8% antioxidant 1010 to the reactor dropwise, and drop it within 5 minutes; after adding n-butyraldehyde, continue to react for about 8 minutes, and condensation occurs Phase change reaction, then continue to react for 5min, according to 0.25% of polyvinyl alcohol quality, the chemical composition of input is decyl alcohol polyoxyethylene ether-6 sodium sulfonate (reference literature " fatty alcohol/alkylphenol polyoxyethylene ether sulfonic acid Synthetic process of salt, fine petrochemical industry, 2009, 26 (05), 8-11 "method synthesis) emulsifier B, continue to stir and react for 60min. The reaction temperature was increased to 68° C. at a heating rate of 1° C./min, and the reaction was continued at this temperature for 80 minutes to end the reaction. Remove most of the water by filtration, then add 4L sodium hydroxide aqueous solution with a concentration of 200ppm, wash it several times at 60°C until the pH of the filtrate is > 9.0, collect PVB resin powder by filtration, and dry to obtain low-residue polyethylene Alcohol butyral resin.

Example 2

Prepare low-residue polyvinyl butyral resin according to the method of Example 1, and the difference from Example 1 is that DNS-628 (sulfodecanol polyoxyethylene ether-6 disodium succinate monoester, Guangzhou double bond Chemical production, ie emulsifier C) replaces emulsifier B in Example 1.

Example 3

Prepare low-residue polyvinyl butyral resin according to the method of Example 1, and the difference with Example 1 is that the emulsifier A in Example 1 is changed to Laureth-8 (AEO-8, Guangzhou Li'anhui Chemical Co., Ltd.), emulsifier B was changed to sodium lauryl polyoxyethylene ether-8 sulfonate (reference "Synthesis process of fatty alcohol/alkylphenol polyoxyethylene ether sulfonate, fine petrochemical industry, 2009 , 26(05), 8-11" method synthesis).

Example 4

Prepare low-residue polyvinyl butyral resin according to the method of Example 1. The difference from Example 1 is that the emulsifier A is changed to Lauryl Polyoxyethylene Ether-8, and Sulfur Lauryl Polyoxyethylene Ether-8 is used. 8 disodium succinate monoester (reference "Synthesis and performance research of disodium salt of fatty alcohol polyoxyethylene (7) ether sulfosuccinate monoester", Daily Chemical Industry, 2002, 32 (1), 12-14 "The method is synthesized) (emulsifier C) substitutes the emulsifier B among the embodiment 1.

Example 5

Prepare low-residue polyvinyl butyral resin according to the method of Example 1, and the difference with Example 1 is that emulsifier A is changed to stearyl polyoxyethylene ether-8 (O-8, Shanghai Kaibite Chemical Industry Co., Ltd. production), emulsifier B is changed to stearyl polyoxyethylene ether-8 sodium sulfonate (references "synthetic process of fatty alcohol/alkylphenol polyoxyethylene ether sulfonate, fine petrochemical industry, 2009,26(05 ), 8-11 "method synthesis).

Example 6

According to the method of Example 1 to prepare low-residue polyvinyl butyral resin, the difference from Example 1 is that the emulsifier A is changed to stearyl polyoxyethylene ether-8, and sulfostearyl alcohol polyoxyethylene is used. Ether-8 succinic acid monoester disodium (references "Synthesis and performance research of fatty alcohol polyoxyethylene (7) ether sulfosuccinic acid monoester disodium salt, Daily Chemical Industry, 2002, 32 (1), 12 -14 "method synthesis) (emulsifier C) replaces emulsifier B in Example 1.

Example 7

A low-residue polyvinyl butyral resin was prepared according to the method of Example 1, the difference from Example 1 was that the concentration of the aqueous sodium hydroxide solution was changed to 100 ppm.

Example 8

A low-residue polyvinyl butyral resin was prepared according to the method of Example 1, the difference from Example 1 was that the concentration of the aqueous sodium hydroxide solution was changed to 50 ppm.

Comparative example 1

The low-residue polyvinyl butyral resin was prepared according to the method of Example 1. The difference from Example 1 was that emulsifier A was not used, and the amount of emulsifier B was 0.5% of the polyvinyl alcohol mass.

Comparative example 2

The low-residue polyvinyl butyral resin was prepared according to the method of Example 1. The difference from Example 1 was that emulsifier B was not used, and the amount of emulsifier A was 0.5% of the polyvinyl alcohol mass.

Comparative example 3

The low-residue polyvinyl butyral resin was prepared according to the method of Example 1. The difference from Example 1 was that the emulsifier A was replaced with disodium sulfocetyl monosuccinate (RACE MS68, Shanghai Ruishi Biological Co., Ltd. Technology Co., Ltd.), the dosage is 0.5% of the polyvinyl alcohol quality, and no emulsifier B is added.

Comparative example 4

The low-residue polyvinyl butyral resin was prepared according to the method of Example 1. The difference from Example 1 was that the emulsifier B was replaced with disodium sulfocetyl monosuccinate (RACE MS68, Shanghai Ruishi Biological Co., Ltd. Technology Co., Ltd.).

Comparative Example 5

A low-residue polyvinyl butyral resin was prepared according to the method of Example 1, the difference from Example 1 was that the concentration of the aqueous sodium hydroxide solution was changed to 400 ppm.

Comparative Example 6

A low-residue polyvinyl butyral resin was prepared according to the method of Example 1, the difference from Example 1 was that the concentration of the aqueous sodium hydroxide solution was changed to 1000 ppm.

performance testing

Condensation reaction agglomeration degree analysis: completely collect the PVB resin powder synthesized in the experiment, and use a 20-mesh standard sieve to sieve, and calculate the agglomeration degree based on the weight ratio of the unsieved part. The larger the weight ratio of this part, the more serious the condensation reaction agglomeration.

Determination of sodium ion content: Take about 0.5g of resin powder, put it in a clean quartz dry pot, calcinate at 550°C for 6h, cool to room temperature, dissolve with a small amount of dilute nitric acid, and dilute to 5mL with ultrapure water; under the same conditions Using the same amount of dilute nitric acid aqueous solution as a blank, the sodium ion content was determined by ICP-MS.

Sulfonate emulsifier residue analysis: measure sulfur content by X-ray fluorescence spectrometer, and calculate emulsifier residue according to molecular structure.

Analysis of non-ionic emulsifier residue: take 0.5g resin powder, dissolve it in 10mL of spectrally pure n-propanol, and precipitate with 15mL distilled water, centrifuge, collect the liquid phase, and test the emulsifier residue by liquid chromatography.

Thermal stability evaluation: Take 0.2g of the resin powder obtained in the experiment, spread it on a glass slide, heat it on a hot stage at 180°C for 30 minutes, and observe the color change of the resin powder. The yellower the color, the worse the thermal stability.

Measurement of light transmittance: Take 25g of resin powder and mix it with 10.0g of 3GO (triethylene glycol diisocaprylate) plasticizer evenly, then use an open mill for 5min at 150°C, and then put it on a flat vulcanizer A film with a thickness of 1.0 mm is pressed by medium pressure; the light transmittance at 550 nm is tested with a UV-Vis spectrophotometer.

Determination of moisture resistance performance: Take the above film and soak it in pure water at a constant temperature of 23°C. After 24 hours, use a UV-visible spectrophotometer to test the absorbance at 550nm. The lower the absorbance, the higher the moisture resistance.

According to the method described above, the low-residue polyvinyl butyral resin prepared by the embodiments of the present invention and comparative examples is tested for performance, and the test results are as follows:

As can be seen from the above table, emulsifier A of the present invention helps to improve the thermal stability of PVB resin powder (comparative example 1 and comparative example 1), and emulsifier B and C then help to reduce the agglomeration of PVB resin powder (Comparative Example 1 and Comparative Example 2), and the two are easier to be cleaned and removed than the sodium alkyl sulfosuccinate emulsifier (Comparative Example 1, ratio 3 and Comparative Example 4). In addition, comparing Example 1, Example 7, Example 8, Comparative Example 5 and Comparative Example 6, it can be found that the concentration of sodium hydroxide neutralizing solution has a significant impact on the residual sodium ion and light transmittance and moisture resistance. The concentration of sodium oxide neutralizing solution helps to reduce sodium ion residues and increase light transmittance.

The method provided by the invention has high synthesis efficiency, no resin powder agglomeration, low residual rate of sodium ions and emulsifiers, the light transmittance of the PVB film prepared by it is greater than 90% (1mm thickness), high moisture resistance, and good thermal stability The advantages.

While the invention has been described and illustrated with reference to particular embodiments of the invention, these descriptions and illustrations do not limit the invention. It will be clearly understood by those skilled in the art that various changes may be made to make a particular situation, material, composition of matter, substance , method or process suitable for the object, spirit and scope of the present application. All such modifications are intended to come within the scope of the claims appended hereto. Although methods disclosed herein have been described with reference to particular operations performed in a particular order, it should be understood that such operations may be combined, subdivided, or reordered to form equivalent methods without departing from the teachings of the invention. Thus, unless otherwise indicated herein, the order and grouping of operations is not a limitation of the present application.

Claims (10)

1. A preparation method of low-residue polyvinyl butyral, comprising: Reacting polyvinyl alcohol hydrochloric acid mixed solution, fatty alcohol polyoxyethylene ether, n-butyraldehyde and emulsifier to obtain low-residue polyvinyl butyral; The emulsifier is selected from fatty alcohol polyoxyethylene ether sodium sulfonate or sulfo fatty alcohol polyoxyethylene ether succinic acid monoester disodium salt. 2. method according to claim 1, is characterized in that, the preparation method of described polyvinyl alcohol hydrochloric acid mixed solution comprises: Polyvinyl alcohol and water are first mixed to obtain an aqueous solution of polyvinyl alcohol; The polyvinyl alcohol solution and hydrochloric acid are mixed for the second time to obtain a polyvinyl alcohol hydrochloric acid mixed solution. 3. The method according to claim 2, characterized in that, the temperature of the first mixing is 80-98°C; the method of the first mixing is stirring and dissolving; The mass concentration of the polyvinyl alcohol aqueous solution is 8-12%. 4. method according to claim 2 is characterized in that, the consumption of described hydrochloric acid makes the pH value of mixing system be 1.0～2.5; Described second mixing is carried out under the condition of stirring, and the time of described stirring is 5. ~10min. 5. The method according to claim 1, wherein the quality of the fatty alcohol polyoxyethylene ether is 0.05% to 0.5% of the polyvinyl alcohol quality in the polyvinyl alcohol hydrochloric acid mixed solution; The quality of the n-butyraldehyde is 50% to 70% of the polyvinyl alcohol quality in the polyvinyl alcohol hydrochloric acid mixed solution; The quality of the emulsifier is 0.2% to 1.0% of the mass of polyvinyl alcohol in the polyvinyl alcohol hydrochloric acid mixed solution; The n-butyraldehyde contains antioxidant, and the quality of the antioxidant is 0.5-1.5% of the n-butyraldehyde mass. 6. The method according to claim 1, characterized in that the temperature of the reaction is 60-70°C, and the heating rate of the reaction is 0.5-2°C/min. 7. method according to claim 1, is characterized in that, also comprises after described reaction is finished: The obtained reaction product is washed, filtered, and dried to obtain a low-residue polyvinyl butyral resin; The reagent for the washing is sodium hydroxide aqueous solution, the temperature of the washing is 50-70°C, and the pH of the product is greater than 9.0 during the washing. 8. The method according to claim 1, characterized in that, the preparation method of said low-residue polyvinyl butyral specifically comprises the following steps: a. Add polyvinyl alcohol and deionized water into the reaction kettle, heat up to 80°C-98°C, stir and dissolve into 8-12% polyvinyl alcohol aqueous solution, filter, then cool down to 5-15°C, put in hydrochloric acid catalyst, Adjust the pH value to 1.0-2.5, and stir for 5-10 minutes to obtain a polyvinyl alcohol/hydrochloric acid mixed solution; b. According to 0.05-0.5% of the mass of polyvinyl alcohol, put in emulsifier A whose chemical composition is fatty alcohol polyoxyethylene ether, and stir for 5-10 minutes; c. According to 50-70% of the polyvinyl alcohol mass, slowly add n-butyraldehyde containing 0.5-1.5% antioxidant to the solution in step b; d. After the addition of n-butyraldehyde is completed, continue the reaction for 10-15 minutes, and according to 0.2-1.0% of the mass of polyvinyl alcohol, the input chemical composition is fatty alcohol polyoxyethylene ether sodium sulfonate emulsifier B or the chemical composition is sulfonate Emulsifier C of fatty alcohol polyoxyethylene ether succinic acid monoester disodium salt, continue stirring and reacting for 30-180min; e. Raise the reaction temperature to 60-70°C at a heating rate of 0.5-2°C/min, and continue the reaction at this temperature for 30-120 minutes to obtain polyvinyl butyral resin powder; f. Then add sodium hydroxide aqueous solution, wash at 50-70°C for several times until the pH of the reaction solution is greater than 9.0, filter and dry to obtain low-residue polyvinyl butyral resin. 9. The method according to claim 1, characterized in that the number of fatty alcohol carbon atoms in the fatty alcohol polyoxyethylene ether is 8-18, and the polymerization degree of polyoxyethylene is 3-20. 10. The method according to claim 7, characterized in that the mass concentration of the aqueous sodium hydroxide solution is 50-300 ppm.