Composite emulsification system and PVB (polyvinyl butyral) resin preparation method adopting same

Abstract

The invention relates to a composite emulsification system and a PVB (Polyvinyl Butyral) resin preparation method adopting the system. A composite emulsification system of a fatty alcohol phosphate emulsifier and a polyether modified organic silicon emulsifier is adopted. The compound system takes organic components as main components, and the polyether modified organic silicon emulsifier does not have any inorganic component. The PVB liquid drop breaking energy barrier is greatly reduced through the ultra-low surface tension of siloxane, and ultra-fine breaking can be achieved; the phosphate group has weak acidity, so that the dosage of the catalyst is reduced. According to the compounding system, superfine crushing of PVB liquid drops is achieved, the PVB liquid drops can exist stably, gathering of the liquid drops is prevented, and low-particle-size PVB can be prepared. The PVB powder prepared by the emulsification system and process has remarkable advantages in the aspects of ash content, particle size and the like, and can meet the requirements of high-end electronics and optics fields.

Description

Technical Field

[0001] This invention belongs to the field of polyvinyl butyral resin preparation technology, specifically relating to a composite emulsion system and a method for synthesizing PVB resin using this system. Background Technology

[0002] Polyvinyl butyral (PVB) is a significant commercial application of polyvinyl acetal resin, holding a crucial position in both academic research and practical applications due to its excellent optical transparency, flexibility, thermal properties, and mechanical properties. Benefiting from the strong substrate adhesion resulting from the high vinyl alcohol content of PVB, it has traditionally been widely used as an interlayer in automotive and architectural laminated glass and as a photovoltaic encapsulation material. In recent years, its application scope has continued to expand, gradually finding applications in emerging fields such as smart windows, water treatment, flexible electronic devices, multifunctional films, anti-corrosion coatings, and composite materials. Simultaneously, the development of new synthesis methods has further broadened its application potential, covering multiple cutting-edge directions including wearable electronics and tissue engineering.

[0003] CN121343307A discloses a PVB composite film, its preparation method, and its application in heat insulation; EP1194289B1 discloses a colored PVB interlayer with improved haze characteristics; CN121091568A discloses the application of a PVB film in intelligent, dimmable, and heat-insulating automotive door glass; CN117069191A discloses the application of PVB as a binder in a high-efficiency solar adsorption filter evaporator.

[0004] Since its commercialization in 1944, the synthesis methods for PVB have been gradually improved. Based on the different raw materials used, they are mainly divided into a one-step method based on polyvinyl acetate (PVAc) and a two-step method based on polyvinyl alcohol (PVA). In the one-step method, acid simultaneously catalyzes the hydrolysis of PVAc and the acetalization of PVA. Introducing butyraldehyde (BA) can directly convert PVAc to PVB without separating and purifying PVA, reducing time and energy consumption. However, this results in the final product containing PVAc impurities. US2915504 discloses a one-step preparation method. The two-step method uses PVA as a raw material to directly prepare high-purity PVB through an acetalization reaction. This is currently the main choice for industrial PVB production. By adjusting the degree of alcoholysis and molecular weight of PVA, the molecular weight of the product and the content of vinyl acetate groups can be controlled. The degree of alcoholysis of PVA used for PVB synthesis typically exceeds 90%. In industrial production, the two-step aqueous synthesis method is widely used due to its low cost and simple purification process. A typical PVB aqueous production system consists of multiple corrosion-resistant reactors and filtration equipment. These reactors can sequentially realize key process steps such as PVA dissolution, low-temperature emulsification, and aging: After PVA is dissolved at high temperature, its aqueous solution is cooled to 5~10℃, and then butyraldehyde (BA) and a catalyst are added; in the emulsification stage, BA is dispersed in the reaction system in the form of small droplets, and PVB reacts gradually with the partially dissolved BA to form spherical PVB coils with low acetalization degree and precipitate from the reaction medium; subsequently, the semi-solid PVB undergoes an aging stage at 40~60℃, finally obtaining a PVB product with a high AD value. The final product can be easily separated by centrifugation or filtration.

[0005] The low-temperature emulsification stage in PVB synthesis still faces many limitations. Dispersion equipment and low-temperature conditions are crucial for ensuring uniform BA distribution during emulsification. If these requirements are not met, excessive PVB particle aggregation can easily occur, leading to low acetal degree (AD) and inadequate intermolecular cross-linking. Therefore, preparing PVB with uniform particle size distribution and high purity remains an important research goal. Regarding dispersion-related issues, there are currently two main approaches to address them:

[0006] Firstly, optimizing dispersion equipment involves using high-efficiency equipment such as high-speed stirrers and ultrasonic dispersers to enhance the dispersion of BA in PVA solutions, reduce agglomeration, and improve product uniformity. CN219988113U provides a multi-functional stirring device for PVB production raw materials, enabling thorough stirring of PVB and controlling the stirring temperature, which is beneficial for the mixing and reaction of raw materials. CN218689198U provides a heating and dissolving vessel device for PVB production raw materials, featuring a simple structure, high heating rate, good heat preservation, high stirring rate, uniform stirring, high production efficiency, and low energy consumption. CN209289593U provides a cooling device for PVB production with good cooling effect, improving PVB production efficiency.

[0007] Secondly, emulsifiers are used. Emulsifiers can effectively promote the dispersion of BA in PVA solution, prevent particle agglomeration, and can emulsify at 20°C or higher. In the existing technology, a variety of emulsifiers are used in the production of PVB resin, mainly including anionic emulsifiers {SDS (sodium dodecyl sulfate), SDBS (sodium dodecylbenzene sulfonate), SDP (sodium dodecyl phosphate)}, nonionic emulsifiers {Tween 80 / 60, OP-10 (polyoxyethylene octylphenol ether-10), Span 80}, and compound systems of the two. European Patent 0130872 discloses the use of sodium hexadecyl sulfosuccinate (DOS) as a single emulsifier; Chinese Patent CN96107793.X discloses the use of a mixture of sodium hexadecyl sulfosuccinate and other alkyl sulfosuccinates or octylphenyl polyoxyethylene ethers as an emulsion system; Chinese Patent CN1147524A discloses a mixed emulsion system of sodium hexadecyl sulfosuccinate and other alkyl sulfosuccinates or octylphenyl polyoxyethylene ethers; Chinese Patent CN120944026A discloses a surfactant of polyvinyl alcohol-acrylic acid or acrylate graft copolymer as an emulsifier for preparing PVB resin powder in a microreactor.

[0008] Currently available conventional emulsifiers and single emulsion systems can only meet the basic emulsification and dispersion requirements for industrial PVB resin production, and cannot adapt to the stringent application standards in high-end electronic components, optical films, and other fields. These emulsifiers have the following two main shortcomings in the PVB resin preparation process and subsequent PVB applications:

[0009] On the one hand, the extensive foaming during the acetalization reaction disrupts the uniform dispersion of the emulsion, resulting in a wide and large particle size distribution of PVB resin. The finished product particle size is not concentrated in the 30-60 mesh range (corresponding to a particle size of 500μm-250μm), with a significantly high proportion of large particles (>30 mesh). The hydroxyl groups inside the large resin particles cannot undergo sufficient condensation reaction with butyraldehyde, and the residual hydroxyl groups will significantly reduce the compatibility between the resin and the matching plasticizer. Later mixing is prone to stratification and precipitation, affecting the processing stability of the material. After the large resin particles are formed, defects such as local hard spots and light spots are very likely to appear, directly destroying the optical uniformity of the film material and failing to meet the stringent requirements of high-end optics and electronics for film surface flatness and optical consistency.

[0010] On the other hand, excessive emulsifier residue affects the performance of PVB resin. Conventional emulsifiers have a strong bond with the PVB resin matrix, making them difficult to completely remove during subsequent washing and centrifugal purification processes, resulting in persistently high levels of residual emulsifiers in the finished resin product. Residual emulsifiers significantly increase the ash content of the resin, and ash content is a core indicator affecting the optical performance of PVB: ash impurities scatter and block light transmission, directly reducing the light transmittance of the finished resin product. Simultaneously, it exacerbates film haze, causing problems such as a hazy appearance and uneven light transmission on the optical film surface, making it completely unsuitable for high-end optical devices, electronic packaging, glass interlayer adhesives, and other applications requiring high precision in light transmittance and low haze.

[0011] This invention employs a composite emulsification system of fatty alcohol phosphate esters and polyether-modified organosilicon. Fatty alcohol phosphate esters not only possess excellent acid resistance and compatibility with PVA, but their phosphate groups can also form hydrogen bonds with the hydroxyl groups of PVA molecules, stabilizing the butyraldehyde phase in the oil phase without interfering with the condensation reaction. Furthermore, they have low residual levels and inherently possess weak acidity (pK). a =2.5~3.5), which is highly compatible with the acidic catalytic system (pH=1~2) required for PVB condensation reaction. It can be used as an auxiliary acidic catalyst for PVB condensation reaction, and together with the main acidic catalyst in the system (such as hydrochloric acid and sulfuric acid), it promotes the aldol condensation reaction of PVA and butyraldehyde, accelerates the reaction rate, and improves the uniformity of acetalization. Organosilicon polyethers have both emulsification and high-efficiency defoaming functions. The siloxane backbone can quickly destroy the density of the foam film. Combined with the low foam generation characteristics of fatty alcohol phosphate esters, the compounded system has almost no stable foam, and no additional defoamer is needed. This avoids the secondary impurities introduced by the defoamer, while ensuring the uniform dispersion of butyraldehyde droplets, improving the PVB yield and reducing the ash content of PVB. Summary of the Invention

[0012] The present invention provides a composite emulsification system, which is composed of fatty alcohol phosphate emulsifiers and polyether modified organosilicon emulsifiers.

[0013] The fatty alcohol phosphate emulsifier has the structural formula (I); the polyether-modified organosilicon emulsifier has the structural formula (II).

[0014]

[0015] Among them, R 1 It is octyl, isooctyl, decyl, isodecyl, or dodecyl; R 2 It is hydrogen, octyl, isooctyl, decyl, isodecyl, or dodecyl; R 2 Except for being hydrogen, all are related to R 1 same.

[0016] The polyether-modified organosilicon emulsifier has the structural formula shown in (II):

[0017]

[0018] Where n is a natural number between 4 and 6.

[0019] The fatty alcohol phosphate emulsifiers mentioned are one or more selected from monooctyl phosphate, monoisooctyl phosphate, monoisodecyl phosphate, monodecyl phosphate, monododecyl phosphate, dioctyl phosphate, diisooctyl phosphate, diisodecyl phosphate, didecyl phosphate, and dodecyl phosphate diester.

[0020] The polyether-modified organosilicon emulsifier can be polyether-modified heptamethyltrisiloxane.

[0021] The weight ratio of the polyether-modified silicone emulsifier and the fatty alcohol phosphate emulsifier is 1:2 to 1:3, accounting for 2% to 3% of the weight of the PVA aqueous solution.

[0022] This invention provides a method for preparing PVB resin using the above-mentioned emulsification system, the specific steps of which are as follows:

[0023] S1. In a reactor, PVA is dissolved into an aqueous solution with a PVA weight concentration of 8% to 12%. After cooling to 20°C, a composite emulsion system is formed by adding a fatty alcohol phosphate emulsifier and a polyether-modified organosilicon emulsifier. Butyraldehyde (BA) and the catalyst are divided into two equal parts. The first part of butyraldehyde and the catalyst are slowly added dropwise to the reactor and dispersed and emulsified until uniform using a high-speed stirrer. The addition takes 0.5 to 2 hours.

[0024] S2. Under continuous stirring, the reactor is heated at a rate of 2℃ / min to 40-70℃. The second part of butyraldehyde and catalyst are added, the pH is adjusted to 1-2, and the reaction is maintained at the temperature for 1-5 hours. During this process, PVB resin gradually precipitates and hardens.

[0025] S3. Cool the reactor to 20–35°C, add NaOH solution to adjust the pH to neutral, stir for 15–30 min to terminate the reaction, filter or centrifuge to separate the PVB resin particles, wash the PVB particles three times with deionized water (3 times the weight of the PVB resin particles) to remove residues, until the pH of the washing water is neutral. After washing, vacuum dry at 50°C for 6–12 h to obtain PVB resin powder.

[0026] The S1 composite emulsification system is composed of fatty alcohol phosphate emulsifiers and polyether-modified heptamethyltrisiloxane;

[0027] In the S1 composite emulsification system, the weight ratio of fatty alcohol phosphate emulsifier and polyether-modified heptamethyltrisiloxane is 1:2 to 1:3, accounting for 2% to 3% of the weight of PVA aqueous solution.

[0028] In S1 and S2, butyraldehyde accounts for 40-60 wt% of PVA, and the catalyst accounts for 0.2%-0.5% of the total weight of the PVA aqueous solution.

[0029] In S1 and S2, the catalyst can be either hydrochloric acid or sulfuric acid.

[0030] The invention has the following beneficial effects

[0031] This invention relates to a composite emulsion system and a method for preparing PVB resin using this system. The system employs a composite emulsion system of fatty alcohol phosphate esters and polyether-modified organosilicon. The fatty alcohol phosphate ester groups themselves possess weak acidity (pK). a =2.5~3.5), which can be used as an auxiliary acidic catalyst to reduce the amount of catalyst used; organosilicon polyethers have both emulsifying and highly efficient defoaming functions; this compound system is mainly composed of organic components, resulting in extremely low ash content after combustion; this compound system can achieve ultra-fine breakage of PVB droplets and maintain their stability, preventing droplet aggregation, and can produce low-particle-size PVB. The PVB powder prepared by this emulsification system and process has significant advantages in terms of ash content and particle size, which can meet the needs of high-end electronics and optics fields. Detailed Implementation

[0032] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0033] Example 1

[0034] a. In a 25L enamel-lined reactor, 1kg of PVA (Sinopec Chongqing Chuanwei Chemical Co., Ltd., 1799, degree of polymerization 1700-1800, degree of alcoholysis 98-99) was dissolved into a PVA aqueous solution with a PVA weight concentration of 8%. After cooling to 20℃, 270g of mono-n-octyl phosphate (Hubei Xinmingtai Chemical Co., Ltd.) and 90g of polyether-modified heptamethyltrisiloxane (Shanghai Jieshikai Biotechnology Co., Ltd.) were added. Then, 200g of butyraldehyde (Changzhou Puhua Chemical Technology Co., Ltd.) and 15g of 37% hydrochloric acid were slowly added dropwise to the reactor. The mixture was dispersed evenly using a high-speed stirrer and added dropwise for 1 hour.

[0035] b. Under continuous stirring, the reactor is heated to 40°C at a rate of 2°C / min. 200g butyraldehyde and 15g hydrochloric acid are added, the pH is adjusted to 2, and the reaction is maintained at this temperature for 3 hours. During this process, PVB resin gradually precipitates and hardens.

[0036] c. Cool to 20℃, add NaOH solution (Sinopharm Chemical Reagent Co., Ltd.) to adjust pH to neutral, stir for 15 min to terminate the reaction, centrifuge to separate PVB resin particles, wash PVB particles three times with three times their weight of deionized water to remove residues, until the pH of the washing water is neutral. After washing, vacuum dry at 50℃ for 6 h to obtain PVB resin powder.

[0037] Example 2

[0038] a. In a 25L enamel-lined reactor, 1kg of PVA (Sinopec Chongqing Chuanwei Chemical Co., Ltd., 2099, degree of polymerization 2000-2100, degree of alcoholysis 98-99) was dissolved into a 10% PVA aqueous solution. After cooling to 20℃, 200g of monoisooctyl phosphate (Jiangsu Bosite Chemical Technology Co., Ltd.) and 100g of polyether-modified heptamethyltrisiloxane (Shanghai Jieshikai Biotechnology Co., Ltd.) were added. Then, 250g of butyraldehyde (Changzhou Puhua Chemical Technology Co., Ltd.) and 10g of 96% sulfuric acid were slowly added dropwise to the reactor. The mixture was dispersed evenly using a high-speed stirrer and added dropwise for 1 hour.

[0039] b. Under continuous stirring, the reactor is heated to 50°C at a rate of 2°C / min. 250g butyraldehyde and 10g sulfuric acid are added, the pH is adjusted to 2, and the reaction is maintained at the temperature for 4h. PVB resin gradually precipitates and hardens during this process.

[0040] c. Cool to 25℃, add NaOH solution (Sinopharm Chemical Reagent Co., Ltd.) to adjust pH to neutral, stir for 15 min to terminate the reaction, centrifuge to separate PVB resin particles, wash PVB particles 3 times with deionized water (3 times the weight of PVB resin particles) to remove residues, until the pH of the washing water is neutral. After washing, vacuum dry at 50℃ for 6 h to obtain PVB resin powder.

[0041] Example 3

[0042] a. In a 25L enamel-lined reactor, 1kg of PVA (Sinopec Chongqing Chuanwei Chemical Co., Ltd., 2499, degree of polymerization 2400-2500, degree of alcoholysis 98-99) was dissolved into a PVA aqueous solution with a PVA weight concentration of 12%. After cooling to 20℃, 180g of monoisodecyl phosphate (Dayang Chemical (Hangzhou) Co., Ltd.) and 70g of polyether-modified heptamethyltrisiloxane (Shanghai Jieshikai Biotechnology Co., Ltd.) were added. Then, 200g of butyraldehyde (Changzhou Puhua Chemical Technology Co., Ltd.) and 20g of 37% hydrochloric acid were slowly added dropwise to the reactor. The mixture was dispersed evenly using a high-speed stirrer and added dropwise for 1.5h.

[0043] b. Under continuous stirring, the reactor was heated to 60°C at a rate of 2°C / min. 300g butyraldehyde and 20g hydrochloric acid (Sinopharm Chemical Reagent Co., Ltd., 12mol / L) were added, the pH was adjusted to 2, and the reaction was kept at the temperature for 5h. PVB resin gradually precipitated and hardened during this process.

[0044] c. Cool to 30℃, add NaOH solution (Sinopharm Chemical Reagent Co., Ltd.) to adjust pH to neutral, stir for 15 min to terminate the reaction, centrifuge to separate PVB resin particles, wash PVB particles 3 times with deionized water (3 times the weight of PVB resin particles) to remove residues, until the pH of the washing water is neutral. After washing, vacuum dry at 50℃ for 8 h to obtain PVB resin powder.

[0045] Example 4

[0046] a. In a 25L enamel-lined reactor, 1kg of PVA (Sinopec Chongqing Chuanwei Chemical Co., Ltd., 1799, degree of polymerization 1700-1800, degree of alcoholysis 98-99) was dissolved into an 8% PVA aqueous solution. After cooling to 20℃, 180g of monodecyl phosphate (Jiangsu Aikon Biomedical R&D Co., Ltd.) and 70g of polyether-modified heptamethyltrisiloxane (Shanghai Jieshikai Biotechnology Co., Ltd.) were added. Then, 250g of butyraldehyde (Changzhou Puhua Chemical Technology Co., Ltd.) and 20g of 96% sulfuric acid were slowly added dropwise to the reactor. The mixture was dispersed evenly using a high-speed stirrer and added dropwise for 2 hours.

[0047] b. Under continuous stirring, the reactor was heated to 60°C at a rate of 2°C / min, 250g of butyraldehyde and 30g of hydrochloric acid were added, the pH was adjusted to 2, and the reaction was maintained at the temperature for 3 hours. During this process, PVB resin gradually precipitated and hardened.

[0048] c. Cool to 35℃, add NaOH solution (Sinopharm Chemical Reagent Co., Ltd.) to adjust pH to neutral, stir for 15 min to terminate the reaction, centrifuge to separate PVB resin particles, wash PVB particles three times with three times their weight of deionized water to remove residues, until the pH of the washing water is neutral. After washing, vacuum dry at 50℃ for 10 h to obtain PVB resin powder.

[0049] Example 5

[0050] a. In a 25L enamel-lined reactor, 1kg of PVA (Sinopec Chongqing Chuanwei Chemical Co., Ltd., 2099, degree of polymerization 2000-2100, degree of alcoholysis 98-99) was dissolved to form a 10% PVA aqueous solution. After cooling to 20℃, 140g of monododecyl phosphate (Shanghai Mairui Biochemical Technology Co., Ltd.) and 70g of polyether-modified heptamethyltrisiloxane (Shanghai Jieshikai Biotechnology Co., Ltd.) were added. Then, 225g of butyraldehyde (Changzhou Puhua Chemical Technology Co., Ltd.) and 25g of 37% hydrochloric acid were slowly added dropwise to the reactor. The mixture was dispersed evenly using a high-speed stirrer and added dropwise for 0.5h.

[0051] b. Under continuous stirring, the reactor was heated to 65°C at a rate of 2°C / min, 225g of butyraldehyde and 25g of hydrochloric acid were added, the pH was adjusted to 2, and the reaction was maintained at the temperature for 2 hours. During this process, PVB resin gradually precipitated and hardened.

[0052] c. Cool to 30℃, add NaOH solution (Sinopharm Chemical Reagent Co., Ltd.) to adjust pH to neutral, stir for 15 min to terminate the reaction, centrifuge to separate PVB resin particles, wash PVB particles 3 times with deionized water (3 times the weight of PVB resin particles) to remove residues, until the pH of the washing water is neutral. After washing, vacuum dry at 50℃ for 12 h to obtain PVB resin powder.

[0053] Example 6

[0054] a. In a 25L enamel-lined reactor, 1kg of PVA (Sinopec Chongqing Chuanwei Chemical Co., Ltd., 2499, degree of polymerization 2400-2500, degree of alcoholysis 98-99) was dissolved into a PVA aqueous solution with a PVA weight concentration of 11%. After cooling to 20℃, 150g of di-n-octyl phosphate (Shanghai Bangcheng Chemical Co., Ltd.) and 80g of polyether-modified heptamethyltrisiloxane (Shanghai Jieshikai Biotechnology Co., Ltd.) were added. Then, 265g of butyraldehyde (Changzhou Puhua Chemical Technology Co., Ltd.) and 15g of 96% sulfuric acid were slowly added dropwise to the reactor. The mixture was dispersed evenly using a high-speed stirrer and added dropwise for 1.5h.

[0055] b. Under continuous stirring, the reactor was heated to 70°C at a rate of 2°C / min, 265g of butyraldehyde and 15g of sulfuric acid were added, the pH was adjusted to 2, and the reaction was kept at the temperature for 1 hour. During this process, PVB resin gradually precipitated and hardened.

[0056] c. Cool to 30℃, add NaOH solution (Sinopharm Chemical Reagent Co., Ltd.) to adjust pH to neutral, stir for 15 min to terminate the reaction, centrifuge to separate PVB resin particles, wash PVB particles 3 times with deionized water (3 times the weight of PVB resin particles) to remove residues, until the pH of the washing water is neutral. After washing, vacuum dry at 50℃ for 6 h to obtain PVB resin powder.

[0057] Example 7

[0058] a. In a 25L enamel-lined reactor, 1kg of PVA (Sinopec Chongqing Chuanwei Chemical Co., Ltd., 1788, degree of polymerization 1700-1800, degree of alcoholysis 87-89) was dissolved into a PVA aqueous solution with a PVA weight concentration of 12%. After cooling to 20℃, 160g of diisooctyl phosphate (Sanmenxia Zhongda Chemical Co., Ltd.) and 80g of polyether-modified heptamethyltrisiloxane (Shanghai Jieshikai Biotechnology Co., Ltd.) were added. Then, 275g of butyraldehyde (Changzhou Puhua Chemical Technology Co., Ltd.) and 22.5g of 37% hydrochloric acid were slowly added dropwise to the reactor. The mixture was dispersed evenly using a high-speed stirrer and added dropwise for 1 hour.

[0059] b. Under continuous stirring, the reactor was heated to 45°C at a rate of 2°C / min, 275g of butyraldehyde and 22.5g of hydrochloric acid were added, the pH was adjusted to 2, and the reaction was maintained at this temperature for 1 hour. During this process, PVB resin gradually precipitated and hardened.

[0060] c. Cool to 25℃, add NaOH solution (Sinopharm Chemical Reagent Co., Ltd.) to adjust pH to neutral, stir for 15 min to terminate the reaction, centrifuge to separate PVB resin particles, wash PVB particles 3 times with deionized water (3 times the weight of PVB resin particles) to remove residues, until the pH of the washing water is neutral. After washing, vacuum dry at 50℃ for 6 h to obtain PVB resin powder.

[0061] Example 8

[0062] a. In a 25L enamel-lined reactor, 1kg of PVA (Sinopec Chongqing Chuanwei Chemical Co., Ltd., 2088, degree of polymerization 2000-2100, degree of alcoholysis 87-89) was dissolved into a 9% PVA aqueous solution. After cooling to 20℃, 200g of diisodecyl phosphate (Shanghai Mairui Biochemical Technology Co., Ltd.) and 100g of polyether-modified heptamethyltrisiloxane (Shanghai Jieshikai Biotechnology Co., Ltd.) were added. Then, 250g of butyraldehyde (Changzhou Puhua Chemical Technology Co., Ltd.) and 10g of 96% sulfuric acid were slowly added dropwise to the reactor. The mixture was dispersed evenly using a high-speed stirrer and added dropwise for 1.5h.

[0063] b. Under continuous stirring, the reactor was heated to 50°C at a rate of 2°C / min, 250g of butyraldehyde and 10g of sulfuric acid were added, the pH was adjusted to 2, and the reaction was maintained at the temperature for 4 hours. During this process, PVB resin gradually precipitated and hardened.

[0064] c. Cool to 35℃, add NaOH solution (Sinopharm Chemical Reagent Co., Ltd.) to adjust pH to neutral, stir for 15 min to terminate the reaction, centrifuge to separate PVB resin particles, wash PVB particles 3 times with deionized water (3 times the weight of PVB resin particles) to remove residues, until the pH of the washing water is neutral. After washing, vacuum dry at 50℃ for 8 h to obtain PVB resin powder.

[0065] Example 9

[0066] a. In a 25L enamel-lined reactor, 1kg of PVA (Sinopec Chongqing Chuanwei Chemical Co., Ltd., 2488, degree of polymerization 2400-2500, degree of alcoholysis 87-99) was dissolved into a PVA aqueous solution with a PVA weight concentration of 11%. After cooling to 20℃, 200g of di-n-decyl phosphate (Shanghai Mairui Biochemical Technology Co., Ltd.) and 100g of polyether-modified heptamethyltrisiloxane (Shanghai Jieshikai Biotechnology Co., Ltd.) were added. Then, 300g of butyraldehyde (Changzhou Puhua Chemical Technology Co., Ltd.) and 25g of 37% hydrochloric acid were slowly added dropwise to the reactor. The mixture was dispersed evenly using a high-speed stirrer and added dropwise for 1 hour.

[0067] b. Under continuous stirring, the reactor was heated to 55°C at a rate of 2°C / min, 300g of butyraldehyde and 25g of hydrochloric acid were added, the pH was adjusted to 2, and the reaction was maintained at this temperature for 5 hours. During this process, PVB resin gradually precipitated and hardened.

[0068] c. Cool to 30℃, add NaOH solution (Sinopharm Chemical Reagent Co., Ltd.) to adjust pH to neutral, stir for 15 min to terminate the reaction, centrifuge to separate PVB resin particles, wash PVB particles 3 times with deionized water (3 times the weight of PVB resin particles) to remove residues, until the pH of the washing water is neutral. After washing, vacuum dry at 50℃ for 8 h to obtain PVB resin powder.

[0069] Example 10

[0070] a. In a 25L enamel-lined reactor, 1kg of PVA (Sinopec Chongqing Chuanwei Chemical Co., Ltd., 1799, degree of polymerization 1700-1800, degree of alcoholysis 98-99) was dissolved to form a 10% PVA aqueous solution by weight. After cooling to 20℃, 300g of dodecyl phosphate diester (Shanghai Maclean Biochemical Technology Co., Ltd.) and 100g of polyether-modified heptamethyltrisiloxane (Shanghai Jieshikai Biotechnology Co., Ltd.) were added. Then, 200g of butyraldehyde (Changzhou Puhua Chemical Technology Co., Ltd.) and 20g of 96% sulfuric acid were slowly added dropwise to the reactor. The mixture was dispersed evenly using a high-speed stirrer and added dropwise for 1.5h.

[0071] b. Under continuous stirring, the reactor is heated to 70°C at a rate of 2°C / min. 200g of butyraldehyde and 20g of sulfuric acid are added, the pH is adjusted to 1, and the reaction is maintained at this temperature for 3 hours. During this process, PVB resin gradually precipitates and hardens.

[0072] c. Cool to 35℃, add NaOH solution (Sinopharm Chemical Reagent Co., Ltd.) to adjust pH to neutral, stir for 15 min to terminate the reaction, centrifuge to separate PVB resin particles, wash PVB particles 3 times with deionized water (3 times the weight of PVB resin particles) to remove residues, until the pH of the washing water is neutral. After washing, vacuum dry at 50℃ for 10 h to obtain PVB resin powder.

[0073] The operating procedures, drug manufacturers, and solution concentrations of Examples 11-20 are the same as those of Examples 1-10 above. Examples 11-15 are shown in Table 1, and Examples 16-20 are shown in Table 2.

[0074] Note: Emulsifier A* is a fatty alcohol phosphate ester emulsifier (monoctyl phosphate A). 1 Monoisooctyl phosphate A 2 Monoisodecyl phosphate A 3 Monodecyl phosphate A 4 Monododecyl phosphate A 5 di-n-octyl phosphate A 6 diisooctyl phosphate A 7 bis(diisodecyl) phosphate A 8 di-n-decyl phosphate A 9 and dodecyl phosphate diester A 10 Emulsifier B is polyether-modified heptamethyltrisiloxane.

[0075] Table 1: PVB Preparation Examples 11-15

[0076]

[0077] Table 2: PVB Preparation Examples 16-20

[0078]

[0079] Comparative Example 1

[0080] a. In a 25L enamel-lined reactor, 1kg of PVA (Sinopec Chongqing Chuanwei Chemical Co., Ltd., 1799, degree of polymerization 1700-1800, degree of alcoholysis 98-99) was dissolved into an 8% PVA aqueous solution by weight. After cooling to 20℃, 200g of butyraldehyde (Changzhou Puhua Chemical Technology Co., Ltd.) and 15g of 37% hydrochloric acid were slowly added dropwise to the reactor. The mixture was dispersed evenly using a high-speed stirrer and added dropwise for 1 hour.

[0081] b. Under continuous stirring, the reactor is heated to 40°C at a rate of 2°C / min. 200g butyraldehyde and 15g hydrochloric acid are added, the pH is adjusted to 2, and the reaction is maintained at this temperature for 3 hours. During this process, PVB resin gradually precipitates and hardens.

[0082] c. Cool to 20℃, add NaOH solution (Sinopharm Chemical Reagent Co., Ltd.) to adjust pH to neutral, stir for 15 min to terminate the reaction, centrifuge to separate PVB resin particles, wash PVB particles three times with three times their weight of deionized water to remove residues, until the pH of the washing water is neutral. After washing, vacuum dry at 50℃ for 6 h to obtain PVB resin powder.

[0083] Comparative Example 2

[0084] a. In a 25L enamel-lined reactor, 1kg of PVA (Sinopec Chongqing Chuanwei Chemical Co., Ltd., 1799, degree of polymerization 1700-1800, degree of alcoholysis 98-99) was dissolved into a 10% PVA aqueous solution. After cooling to 20℃, 200g of monoisooctyl phosphate (Jiangsu Bosite Chemical Technology Co., Ltd.) was added, followed by the slow addition of 250g of butyraldehyde (Changzhou Puhua Chemical Technology Co., Ltd.) and 10g of 96% sulfuric acid. The mixture was dispersed evenly using a high-speed stirrer and added dropwise for 1 hour.

[0085] b. Under continuous stirring, the reactor is heated to 50°C at a rate of 2°C / min. 250g butyraldehyde and 10g sulfuric acid are added, the pH is adjusted to 2, and the reaction is maintained at the temperature for 4h. PVB resin gradually precipitates and hardens during this process.

[0086] c. Cool to 25℃, add NaOH solution (Sinopharm Chemical Reagent Co., Ltd.) to adjust pH to neutral, stir for 15 min to terminate the reaction, centrifuge to separate PVB resin particles, wash PVB particles 3 times with deionized water (3 times the weight of PVB resin particles) to remove residues, until the pH of the washing water is neutral. After washing, vacuum dry at 50℃ for 6 h to obtain PVB resin powder.

[0087] Comparative Example 3

[0088] a. In a 25L enamel-lined reactor, 1kg of PVA (Sinopec Chongqing Chuanwei Chemical Co., Ltd., 1799, degree of polymerization 1700-1800, degree of alcoholysis 98-99) was dissolved into a PVA aqueous solution with a PVA weight concentration of 12%. After cooling to 20℃, 70g of polyether-modified heptamethyltrisiloxane (Shanghai Jieshikai Biotechnology Co., Ltd.) was added, followed by the slow addition of 200g of butyraldehyde (Changzhou Puhua Chemical Technology Co., Ltd.) and 20g of 37% hydrochloric acid. The mixture was dispersed evenly using a high-speed stirrer and added dropwise for 1.5h.

[0089] b. Under continuous stirring, the reactor is heated to 60°C at a rate of 2°C / min. 300g butyraldehyde and 20g hydrochloric acid are added, the pH is adjusted to 2, and the reaction is maintained at this temperature for 5 hours. During this process, PVB resin gradually precipitates and hardens.

[0090] c. Cool to 30℃, add NaOH solution (Sinopharm Chemical Reagent Co., Ltd.) to adjust pH to neutral, stir for 15 min to terminate the reaction, centrifuge to separate PVB resin particles, wash PVB particles 3 times with deionized water (3 times the weight of PVB resin particles) to remove residues, until the pH of the washing water is neutral. After washing, vacuum dry at 50℃ for 8 h to obtain PVB resin powder.

[0091] Comparative Example 4

[0092] a. In a 25L enamel-lined reactor, 1kg of PVA (Sinopec Chongqing Chuanwei Chemical Co., Ltd., 1799, degree of polymerization 1700-1800, degree of alcoholysis 98-99) was dissolved into an 8% PVA aqueous solution. After cooling to 20℃, 180g of sodium dodecyl sulfonate (Shanghai Aladdin Biochemical Technology Co., Ltd.) and 70g of OP-10 (Shandong Zhengxing New Materials Co., Ltd.) were added. Then, 250g of butyraldehyde (Changzhou Puhua Chemical Technology Co., Ltd.) and 20g of 96% sulfuric acid were slowly added dropwise to the reactor. The mixture was dispersed evenly using a high-speed stirrer and added dropwise for 2 hours.

[0093] b. Under continuous stirring, the reactor was heated to 60°C at a rate of 2°C / min, 250g of butyraldehyde and 20g of sulfuric acid were added, the pH was adjusted to 2, and the reaction was maintained at the temperature for 3h. During this process, PVB resin gradually precipitated and hardened.

[0094] c. Cool to 35℃, add NaOH solution (Sinopharm Chemical Reagent Co., Ltd.) to adjust pH to neutral, stir for 15 min to terminate the reaction, centrifuge to separate PVB resin particles, wash PVB particles three times with three times their weight of deionized water to remove residues, until the pH of the washing water is neutral. After washing, vacuum dry at 50℃ for 10 h to obtain PVB resin powder.

[0095] Comparative Example 5

[0096] a. In a 25L enamel-lined reactor, 1kg of PVA (Sinopec Chongqing Chuanwei Chemical Co., Ltd., 1799, degree of polymerization 1700-1800, degree of alcoholysis 98-99) was dissolved into a 10% PVA aqueous solution. After cooling to 20℃, 180g of sodium dodecyl sulfonate (Shanghai Aladdin Biochemical Technology Co., Ltd.) was added. Then, 225g of butyraldehyde (Changzhou Puhua Chemical Technology Co., Ltd.) and 25g of 37% hydrochloric acid were slowly added dropwise to the reactor. The mixture was dispersed evenly using a high-speed stirrer and added dropwise for 0.5h.

[0097] b. Under continuous stirring, the reactor was heated to 65°C at a rate of 2°C / min, 225g of butyraldehyde and 25g of hydrochloric acid were added, the pH was adjusted to 2, and the reaction was maintained at the temperature for 2 hours. During this process, PVB resin gradually precipitated and hardened.

[0098] c. Cool to 30℃, add NaOH solution (Sinopharm Chemical Reagent Co., Ltd.) to adjust pH to neutral, stir for 15 min to terminate the reaction, centrifuge to separate PVB resin particles, wash PVB particles 3 times with deionized water (3 times the weight of PVB resin particles) to remove residues, until the pH of the washing water is neutral. After washing, vacuum dry at 50℃ for 12 h to obtain PVB resin powder.

[0099] Comparative Example 6

[0100] a. In a 25L enamel-lined reactor, 1kg of PVA (Sinopec Chongqing Chuanwei Chemical Co., Ltd., 1799, degree of polymerization 1700-1800, degree of alcoholysis 98-99) was dissolved into a PVA aqueous solution with a PVA weight concentration of 11%. After cooling to 20℃, 80g of OP-10 (Shandong Zhengxing New Materials Co., Ltd.) was added, followed by the slow addition of 265g of butyraldehyde (Changzhou Puhua Chemical Technology Co., Ltd.) and 15g of 96% sulfuric acid. The mixture was dispersed evenly using a high-speed stirrer and added dropwise over 1.5 hours.

[0101] b. Under continuous stirring, the reactor was heated to 70°C at a rate of 2°C / min, 265g of butyraldehyde and 15g of sulfuric acid were added, the pH was adjusted to 2, and the reaction was kept at the temperature for 1 hour. During this process, PVB resin gradually precipitated and hardened.

[0102] c. Cool to 30℃, add NaOH solution (Sinopharm Chemical Reagent Co., Ltd.) to adjust pH to neutral, stir for 15 min to terminate the reaction, centrifuge to separate PVB resin particles, wash PVB particles 3 times with deionized water (3 times the weight of PVB resin particles) to remove residues, until the pH of the washing water is neutral. After washing, vacuum dry at 50℃ for 6 h to obtain PVB resin powder.

[0103] Performance testing

[0104] The PVB resins of Examples 1 to 20 and Comparative Examples 1 to 6 were tested for ash content and particle size using the following methods:

[0105] 1. PVB resin was ground into 80-100 mesh powder to obtain PVB sample powder, and ash content was tested. Following GB / T9345.1-2008, each group of samples was dried at 105±2℃ for 2 hours, and weighed in a constant-weight porcelain crucible (m0, m1); pre-carbonized at low temperature until no black smoke was observed, then ignited in a muffle furnace at 550±25℃ to constant weight, cooled, and weighed (m2); the ash mass fraction was calculated using the formula.

[0106] The ash content w (%) of PVB resin is calculated using the following formula:

[0107]

[0108] Note: m0 is the mass of the empty crucible after constant weight, in grams (g); m1 is the total mass of the constant weight crucible and the PVB sample, in grams (g); m2 is the total mass of the constant weight crucible and the ash after combustion, in grams (g).

[0109] 2. In accordance with the technical requirements and inspection of test sieves in GB / T 6003.1, PVB resin was sieved using 30, 60, and 90 mesh standard test sieves. The retention rate was defined as the percentage of the residual mass on each sieve relative to the total sample mass, which characterizes the particle size distribution.

[0110]

[0111] Note: R 30 R 60 R 90 Retention rates for 30-mesh, 60-mesh, and 90-mesh sieves, respectively; m 30 m 60 m 90 The corresponding values ​​are the residual mass on the sieve (g) and m0 is the total mass of the sample, 50 (g).

[0112] The test results are shown in Tables 3 and 4:

[0113] Table 3: Ash content test of PVB resin

[0114]

[0115] Table 4: PVB resin particle size test

[0116]

[0117] As shown in Table 3, and based on Examples 1 to 20 and Comparative Example 1, the increase in ash mass fraction w (%) of the compound emulsification system with and without emulsifier of the present invention is within a reasonable range (0.003–0.007%). As shown in Examples 1 to 20 and Comparative Examples 2 to 6, the ash mass fraction w (%) of the compound emulsification system of fatty alcohol phosphate and polyether-modified silicone is significantly lower than that of single polyether-modified silicone emulsifiers, single fatty alcohol phosphate ester emulsifiers, OP-10, SDS, and the combination of SDS and OP-10, especially with SDS alone, reaching 500%.

[0118] As shown in Table 4, based on Examples 1-4 and Comparative Examples 1-4, the particle size of PVB prepared using the compound emulsification system of the present invention reaches 90% within the range of 30-60 mesh. Compared with the compound emulsification system of the present invention, the particle size of PVB prepared by not adding emulsifiers, using a single polyether-modified silicone emulsifier, a single fatty alcohol phosphate emulsifier, or a compound of SDS and OP-10 is significantly reduced within the range of 30-60 mesh.

Claims

1. A method for preparing PVB resin, characterized in that, The emulsifier used in its preparation is a composite emulsion system of fatty alcohol phosphate esters and polyether-modified organosilicon.

2. The fatty alcohol phosphate emulsifier as described in claim 1, characterized in that, Its structural formula is shown in equation (I): Among them, R 1 It is octyl, isooctyl, decyl, isodecyl, or dodecyl; R 2 It is hydrogen, octyl, isooctyl, decyl, isodecyl, or dodecyl; when R 2 Except for being hydrogen, all are related to R 1 same.

3. The polyether-modified organosilicon emulsifier as described in claim 1, characterized in that, Its structural formula is shown in formula (II): Where n is a natural number between 4 and 6.

4. The fatty alcohol phosphate emulsifier as described in claims 1 and 2, characterized in that, The fatty alcohol phosphate emulsifier is one or more of the following: monooctyl phosphate, monoisooctyl phosphate, monoisodecyl phosphate, monodecyl phosphate, monododecyl phosphate, dioctyl phosphate, diisooctyl phosphate, diisodecyl phosphate, and didecyl phosphate dodecyl phosphate diester.

5. The polyether-modified organosilicon emulsifier as described in claims 1 and 3, characterized in that, The polyether-modified organosilicon emulsifier is polyether-modified heptamethyltrisiloxane.

6. The composite emulsification system as described in claim 1, characterized in that, The fatty alcohol phosphate ester and polyether modified organosilicon are composed in a weight ratio of 1:2 to 1:3, accounting for 2% to 3% of the weight of the PVA aqueous solution.

7. The method for preparing PVB resin as described in claim 1, characterized in that, It includes the following three steps: S1. In the reactor, PVA is dissolved into a PVA aqueous solution with a PVA weight concentration of 8% to 12%. After cooling to 20°C, the composite emulsion system is added. The butyraldehyde and catalyst are divided into two equal parts. The first part of butyraldehyde and catalyst is slowly added dropwise to the reactor. The mixture is dispersed and emulsified until uniform using a high-speed stirrer. The addition process takes 0.5 to 2 hours. S2. Under continuous stirring, the reactor is heated at a rate of 2℃ / min to 40-70℃. The second part of butyraldehyde and catalyst are added, the pH is adjusted to 1-2, and the reaction is maintained at the temperature for 1-5 hours. During this process, PVB resin gradually precipitates and hardens. S3. Cool the reactor to 20–35°C, add NaOH solution to adjust the pH to neutral, stir for 15–30 min to terminate the reaction, filter or centrifuge to separate the PVB resin particles, wash the PVB particles three times with deionized water (3 times the weight of the PVB resin particles) to remove residues, until the pH of the washing water is neutral. After washing, vacuum dry at 50°C for 6–12 h to obtain PVB resin powder.

8. Step S1 as described in claim 6, characterized in that, The S1 composite emulsion system is composed of fatty alcohol phosphate emulsifiers and polyether-modified heptamethyltrisiloxane.

9. Step S1 as described in claim 6, characterized in that, In the composite emulsification system, the weight ratio of fatty alcohol phosphate emulsifier and polyether-modified heptamethyltrisiloxane is 1:2 to 1:3, accounting for 2% to 3% of the weight of PVA aqueous solution.

10. In steps S1 and S2 of claim 6, the characteristic is that, Butyraldehyde accounts for 40-60 wt% of PVA; the catalyst can be either hydrochloric acid or sulfuric acid, accounting for 0.2%-0.5% of the total weight of the PVA aqueous solution.

Images