Preparation method of polyvinyl butyral resin
By adding a non-emulsifying defoamer to the PVB resin synthesis process and optimizing the process, the problems of low reaction efficiency and product quality caused by foam formation have been solved, achieving high yield and high quality PVB resin production, which is suitable for laminated glass production.
Patent Information
- Application Number
- CN202511799912.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-02
- Publication Date
- 2026-02-13
AI Technical Summary
In the current PVB resin synthesis process, foam generation affects reaction efficiency and product quality, leading to an increase in bulk waste and bubble defects that affect the quality of laminated glass.
Adding non-emulsifying defoamers to inorganic and organic acids inhibits foam formation and enhances the compatibility between resins and plasticizers. Optimizing formulations and process steps ensures a smooth reaction and reduces lumpy waste and bubble defects.
It significantly improves product yield and quality, with uniform resin particles and a smooth, defect-free film surface, meeting the requirements for high-quality laminated glass production.
Smart Images
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Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of high polymer material synthesis, and particularly relates to a preparation method of polyvinyl butyral resin. BACKGROUND
[0002] Polyvinyl butyral (PVB) is an important high polymer material synthesized by polyvinyl alcohol (PVA) and butyraldehyde through acetalization reaction under the catalysis of acid. The coexistence of hydroxyl and butyral groups in the molecular chain endows the material with unique adhesion, flexibility and transparency. Due to its high bonding strength and energy absorption characteristics, PVB is effectively applied to safety glass interlayer film to prevent glass from splashing when broken. With the development of PVB technology, it is also widely used in the fields of coating, ceramic printing and electronic packaging.
[0003] Since the existing PVB resin inevitably produces foam during the synthesis process by adding organic acid, the production of foam affects the reaction, hinders the judgment of the reaction degree, and the foam adheres to the kettle wall, which produces a large amount of blocky material. The incomplete reaction of a large amount of blocky material reduces the product yield. Thus, the reaction efficiency is reduced, and the generated foam wraps impurity particles, which reduces the performance of the resin and affects the quality of the film.
[0004] In the film preparation process, the wrapping effect of organic acid on gas can cause the formation of bubbles. When such bubble-containing film is used for the preparation of laminated glass, in the subsequent hot-pressing forming process, these micro-bubbles will break and merge under high temperature and pressure conditions, and finally form macro-scale bubble defects, thereby significantly affecting the product quality of the laminated glass. SUMMARY
[0005] In view of the problems in the background art, the application designs a preparation method of polyvinyl butyral resin. The method optimizes the formula, adds a non-emulsifying defoaming agent (i.e. the defoaming agent does not have emulsifier performance) in inorganic acid and organic acid, ensures the effect of organic acid, effectively inhibits the generation of foam during stirring, and inhibits the yellowing of the product, thereby significantly reducing the blocky waste, improving the good quality and yield of the product; the non-emulsifying defoaming agent (i.e. the defoaming agent does not have emulsifier performance) selected by the application not only has excellent defoaming performance, but also can enhance the compatibility of the plasticizer and the resin. The synthesized PVB resin particles are fine and uniform, and have no blocking and sticking phenomenon. In the subsequent extrusion casting process, the defoaming system can further inhibit the formation of bubbles, ensure that the surface of the finally formed film is smooth and defect-free, and meet the production requirements of high-quality laminated glass.
[0006] A preparation method of polyvinyl butyral resin, the specific steps are as follows:
[0007] I. Dissolution of polyvinyl alcohol
[0008] Polyvinyl alcohol is added to deionized water, heated to 90-100°C, and stirred for 1.5h to dissolve into a polyvinyl alcohol solution;
[0009] II. Filter the complex defoaming agent
[0010] The dissolved polyvinyl alcohol solution in step one is filtered through a filter device while hot, then the temperature of the polyvinyl alcohol solution is lowered to 30-40°C, and the inorganic acid solution, organic acid and defoaming agent are added to the polyvinyl alcohol solution while stirring to mix evenly;
[0011] III. Condensation reaction
[0012] The n-butyraldehyde solution is gradually added to the polyvinyl alcohol solution in step two, then the temperature is maintained at 30-40°C for 10-40min, gradually increased to 60-70°C, and maintained at this temperature for 20-120min;
[0013] IV. Post-treatment and drying
[0014] After the condensation reaction is completed, the reaction temperature is lowered to 30°C, and the solution is washed with deionized water for 3-5 times, then the pH value is adjusted to 11 with lye and maintained for 30min or more, and the solution is washed repeatedly with deionized water until the conductivity of the solution is reduced to 10us / cm, the product is centrifuged and dried to obtain polyvinyl butyral resin powder.
[0015] Preferably, the polyvinyl alcohol in step one is 50-150 parts, and the deionized water is 300-1500 parts, further preferably 900-1200 parts.
[0016] Preferably, the polyvinyl alcohol in step one is PVA1799, PVA1788, PVA1999, PVA2099, PVA2699, PVA1899, further preferably polyvinyl alcohol 1799.
[0017] Preferably, the filter device in step two is a general filter device, the specific structure of which is not described here, and the filter device is 80-200 mesh, further preferably 100-150 mesh.
[0018] Preferably, the inorganic acid solution in step two is 3-15 parts, the organic acid is 1-5 parts, and the defoaming agent is 4-20 parts, and the mass fraction of the inorganic acid solution is 30%.
[0019] Preferably, the organic acid in step two is acetic acid, aminosulfonic acid, linear alkylbenzenesulfonic acid, dodecyl sulfate (C 12 H25 one or more of a mixture of Methanesulfonic Acid, Ethanesulfonic acid, Dodecylbenzenesulfonic Acid.
[0020] Preferably, the defoaming agent in the second step is a non-emulsifying defoaming agent (defoaming agent without emulsifier performance), and the defoaming agent is one or more of Siltech 5800, GP-330, BD-3037-60 polyether silicone defoaming agent, SXP-107 silicone polyether composite high-temperature defoaming agent.
[0021] Preferably, the inorganic acid in the second step is one or more of a mixture of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid.
[0022] Preferably, the amount of n-butyraldehyde added in the third step is 20-100 parts, and further preferably 57-60 parts.
[0023] Preferably, the alkali solution in the fourth step is a mixture of one or more of sodium hydroxide, potassium hydroxide, sodium carbonate.
[0024] The beneficial effects of the present application: compared with the traditional organic acid system, the present application adds a non-emulsifying defoaming agent to the inorganic acid and the organic acid. On the one hand, the use of inorganic acid and organic acid can effectively inhibit product yellowing, improve reaction rate, improve product appearance stability, and reduce cost. On the other hand, the addition of a non-emulsifying defoaming agent not only has the advantages of less foam, excellent repeatability, low cost, and uniform product particle size, but also indirectly inhibits product yellowing due to its easy washing and low residual amount. In the preparation process of PVB resin, the n-butyraldehyde solution is gradually added to the PVA solution and subjected to heat preservation treatment, the condensation reaction proceeds smoothly, the phase change reaction is more easily controlled and the phenomenon is clear, the obtained resin product has uniform particle size, good quality, and significantly reduced block waste, and the yield is significantly improved. At the same time, the adhesion and optical properties of the resin are improved. By adding a non-emulsifying defoaming agent to the inorganic acid and the organic acid, the compatibility of the resin and the plasticizer can be enhanced without affecting the adhesion properties of the resin film, the solubility of the residual gas in the film during lamination can be improved, and the air bubble defects in the manufacturing of laminated glass can be inhibited from the source. The PVB resin prepared by the present application has excellent adhesion, transparent and pure color, and no impurity bubbles after being processed into a PVB film, and all detection indexes are qualified, which is suitable for various laminated glass production, and the PVB resin production process significantly improves the product yield and quality. DETAILED DESCRIPTION
[0025] The following will be described in detail the embodiments of the present application, the following embodiments are implemented under the technical solutions of the present application, the detailed implementation and specific operation process are given, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments, the protection scope of the present application is not limited to the following embodiments.
[0026] Example 1
[0027] 100 parts of polyvinyl alcohol were weighed and added to 1000 parts of deionized water, heated to 90-100℃, and stirred at the temperature for 1.5h to form a polyvinyl alcohol solution;
[0028] The dissolved polyvinyl alcohol solution was filtered with a 100-mesh general filter device while hot, and then the temperature was lowered to 30℃. 5 parts of 30% hydrochloric acid solution, 1 part of dodecyl sulfate and 10 parts of Siltech 5800 were added while stirring, and stirred uniformly. 60 parts of n-butyraldehyde were added dropwise while stirring, and after the addition was completed, the solution was kept at 30℃ for 30min. The stirring was maintained during the feeding process, and then the temperature was gradually increased at a rate of 20℃ / h to 65℃, and kept for 2h. After the condensation reaction was completed, the reaction temperature was lowered to 30℃, and the solution was washed with deionized water for 3-5 times. The pH value was adjusted to 11 with lye and kept for more than 30min, and then washed repeatedly with deionized water until the conductivity of the solution was reduced to 10us / cm. The product was separated by centrifugation and dried to obtain PVB resin powder.
[0029] Example 2
[0030] 100 parts of polyvinyl alcohol were weighed and added to 1000 parts of deionized water, heated to 90-100℃, and stirred at the temperature for 1.5h to form a polyvinyl alcohol solution;
[0031] The dissolved polyvinyl alcohol solution was filtered with a 100-mesh general filter device while hot, and then the temperature was lowered to 30℃. 5 parts of 30% hydrochloric acid solution, 1 part of dodecyl sulfate and 10 parts of Siltech 5800 were added while stirring, and stirred uniformly. 60 parts of n-butyraldehyde were added dropwise while stirring, and after the addition was completed, the solution was kept at 30℃ for 30min. The stirring was maintained during the feeding process, and then the temperature was gradually increased at a rate of 20℃ / h to 65℃, and kept for 2h. After the condensation reaction was completed, the reaction temperature was lowered to 30℃, and the solution was washed with deionized water for 3-5 times. The pH value was adjusted to 11 with lye and kept for more than 30min, and then washed repeatedly with deionized water until the conductivity of the solution was reduced to 10us / cm. The product was separated by centrifugation and dried to obtain PVB resin powder.
[0032] Example 3
[0033] Take 100 parts of polyvinyl alcohol and add to 1000 parts of deionized water, heat to 90-100℃, keep the temperature stirring for 1.5h, dissolved into polyvinyl alcohol solution;
[0034] The above dissolved polyvinyl alcohol solution is filtered with a 150 mesh general filter device while hot, then the temperature is lowered to 30℃, 5 parts of 30% mass fraction hydrochloric acid solution, 1 part of dodecyl sulfate and 10 parts of BD-3037-60 polyether organic silicon defoaming agent are added while stirring, stirred uniformly, 55 parts of n-butyraldehyde is added dropwise while stirring, after the dropwise addition is completed, 30min of preservation is carried out at 30℃, the feeding process is kept stirring all the time, then the temperature is gradually increased, the temperature is increased to 65℃ at a rate of 20℃ / h, and the temperature is kept for 2h; after the condensation reaction is completed, the reaction temperature is lowered to 30℃, and washed with deionized water for 3-5 times, then the pH value is adjusted to 11 with lye and kept for more than 30min, then washed with deionized water repeatedly until the solution conductivity is reduced to 10us / cm, the product is centrifuged and dried to obtain PVB resin powder.
[0035] Example 4
[0036] Take 100 parts of polyvinyl alcohol and add to 1000 parts of deionized water, heat to 90-100℃, keep the temperature stirring for 1.5h, dissolved into polyvinyl alcohol solution;
[0037] The above dissolved polyvinyl alcohol solution is filtered with a 150 mesh general filter device while hot, then the temperature is lowered to 30℃, 5 parts of 30% mass fraction hydrochloric acid solution, 1 part of dodecyl sulfate and 10 parts of BD-3037-60 polyether organic silicon defoaming agent are added while stirring, stirred uniformly, 55 parts of n-butyraldehyde is added dropwise while stirring, after the dropwise addition is completed, 30min of preservation is carried out at 30℃, the feeding process is kept stirring all the time, then the temperature is gradually increased, the temperature is increased to 65℃ at a rate of 20℃ / h, and the temperature is kept for 2h; after the condensation reaction is completed, the reaction temperature is lowered to 30℃, and washed with deionized water for 3-5 times, then the pH value is adjusted to 11 with lye and kept for more than 30min, then washed with deionized water repeatedly until the solution conductivity is reduced to 10us / cm, the product is centrifuged and dried to obtain PVB resin powder.
[0038] Comparative Example 1
[0039] Take 100 parts of polyvinyl alcohol and add to 1000 parts of deionized water, heat to 90-100℃, keep the temperature stirring for 1.5h, dissolved into polyvinyl alcohol solution;
[0040] The dissolved polyvinyl alcohol aqueous solution is filtered with a general filter device of 100 mesh while hot, and then the temperature is lowered to 30°C, 5 parts of 30% hydrochloric acid solution and 1 part of dodecyl sulfate are added while stirring, stirred uniformly, 58 parts of n-butyraldehyde is added dropwise while stirring, and after the dropwise addition is completed, it is kept at 30°C for 30 min. The temperature is gradually increased to ensure a temperature increasing rate of 20°C / h to 65°C, and kept for 2 h. After the condensation reaction is completed, the reaction temperature is lowered to 30°C, and washed with deionized water for 3-5 times, the pH value is adjusted to 11 with lye and kept for more than 30 min, and then washed with deionized water repeatedly until the solution conductivity is reduced to 10 us / cm. The product is centrifuged and dried to obtain PVB resin powder.
[0041] Comparative Example 2
[0042] 100 parts of polyvinyl alcohol is weighed and added to 1000 parts of deionized water, heated to 90-100°C, and stirred for 1.5 h to dissolve into a polyvinyl alcohol solution;
[0043] The dissolved polyvinyl alcohol aqueous solution is filtered with a general filter device of 150 mesh while hot, and then the temperature is lowered to 30°C, 5 parts of 30% hydrochloric acid solution and 1 part of methyl sulfonic acid are added while stirring, stirred uniformly, 60 parts of n-butyraldehyde is added dropwise while stirring, and after the dropwise addition is completed, it is kept at 30°C for 30 min. The temperature is gradually increased to ensure a temperature increasing rate of 20°C / h to 65°C, and kept for 2 h. After the condensation reaction is completed, the reaction temperature is lowered to 30°C, and washed with deionized water for 3-5 times, the pH value is adjusted to 11 with lye and kept for more than 30 min, and then washed with deionized water repeatedly until the solution conductivity is reduced to 10 us / cm. The product is centrifuged and dried to obtain PVB resin powder.
[0044] Comparative Example 3
[0045] 100 parts of polyvinyl alcohol is weighed and added to 1000 parts of deionized water, heated to 90-100°C, and stirred for 1.5 h to dissolve into a polyvinyl alcohol solution;
[0046] The dissolved polyvinyl alcohol aqueous solution is filtered with a general filter device of 90 mesh while hot, and then the temperature is lowered to 30°C, 5 parts of 30% hydrochloric acid solution by mass fraction and 1 part of linear alkyl benzene sulfonic acid are added while stirring, 60 parts of n-butyraldehyde are added dropwise while stirring, and after the dropwise addition is completed, the solution is kept at 30°C for 30 min. The temperature is gradually increased to 65°C at a rate of 20°C / h while stirring is maintained during the feeding process. After the condensation reaction is completed, the reaction temperature is lowered to 30°C, and the solution is washed with deionized water for 3-5 times. The pH value is adjusted to 11 with lye and kept for more than 30 min. The solution is washed repeatedly with deionized water until the conductivity of the solution is reduced to 10 us / cm. The product is separated by centrifugation and dried to obtain PVB resin powder.
[0047] Comparative Example 4
[0048] 100 parts of polyvinyl alcohol are weighed and added to 1000 parts of deionized water. The temperature is raised to 90-100°C, and the temperature is kept while stirring for 1.5 h to dissolve the polyvinyl alcohol into a solution.
[0049] The dissolved polyvinyl alcohol aqueous solution is filtered with a general filter device of 120 mesh while hot, and then the temperature is lowered to 30°C, 6 parts of dodecyl sulfate and 10 parts of Siltech 5800 are added while stirring, and the solution is stirred uniformly. 60 parts of n-butyraldehyde are added dropwise while stirring, and after the dropwise addition is completed, the solution is kept at 30°C for 30 min. The temperature is gradually increased to 65°C at a rate of 20°C / h while stirring is maintained during the feeding process. After the condensation reaction is completed, the reaction temperature is lowered to 30°C, and the solution is washed with deionized water for 3-5 times. The pH value is adjusted to 11 with lye and kept for more than 30 min. The solution is washed repeatedly with deionized water until the conductivity of the solution is reduced to 10 us / cm. The product is separated by centrifugation and dried to obtain PVB resin powder.
[0050] The PVB resin powders obtained in Examples 1-4 and Comparative Examples 1-4 are subjected to performance evaluation, and the evaluation method is as follows:
[0051] Hydroxyl value test method
[0052] Accurately weigh 1 g of polyvinyl butyral, to 0.1 mg, into a 250 ml ground conical flask; accurately add 10 ml of pyridine acetic anhydride mixture (9 ml of pyridine + 1 ml of acetic anhydride); put a condenser on the conical flask, heat to 95°C and reflux for 3 h until the sample is completely dissolved, cool to room temperature, add 25 ml of 1,2-dichloroethane from the top of the condenser, remove the condenser, cover with a plug and shake gently, wash the plug and the wall of the flask with 5 ml of distilled water, shake gently, and stand for 1 h; use a pipette to remove the distilled water and wash along the wall of the conical flask, add about 2 ml of phenothalin indicator; titrate with 0.5 mol / L sodium hydroxide standard solution until red, which is the end point; at the same time, do a blank experiment.
[0053] Hydroxyl content calculation formula:
[0054]
[0055] In the formula: X - hydroxyl content, %; Vb - the amount of sodium hydroxide solution used in the blank test, mL; Vs - the amount of sodium hydroxide solution used in the sample test, mL; C - the molar concentration of sodium hydroxide solution, mol / L; M - the mass of the sample, g; H - the volatile matter content of the sample, %. The difference between the two values of the parallel test results is not more than 0.3%.
[0056] PVB resin light transmittance and haze test method
[0057] After the resin is pressed into a 1 ± 0.03 mm sheet, the sheet is placed on a light transmittance-haze meter for light transmittance testing, and the reading is taken.
[0058] PVB resin bulk density test method
[0059] The tare weight of the measuring cylinder is weighed with a balance and recorded as W. A piece of paper is folded in half to collect PVB resin and slowly fill the measuring cylinder to 100 mL. A glass rod is used to scrape the upper edge flat, weigh it, and record it as T. Repeat the measurement twice and take the average value.
[0060]
[0061] In the formula: X - bulk density, g / mL; W - the weight of the measuring cylinder, g; T - the weight of the measuring cylinder plus PVB resin, g.
[0062] PVB resin yield test method
[0063] The formula is calculated as follows: (total weight of PVB resin after drying with water content <1% wt) / (PVA feed amount + 0.75 x total butyraldehyde feed amount) x 100%.
[0064] Yellowing index test method
[0065] After the polyvinyl butyral prepared by high-temperature baking at 180℃ is baked for 2h, the PVB sample is melted and pressed into a sheet, and the yellowing index is tested by a yellow index instrument.
[0066] Table 1: Test results of PVB resin prepared in examples and comparative examples
[0067]
[0068] As shown in Table 1, the polyvinyl butyral prepared by adding only organic acid and defoaming agent without adding inorganic acid, or adding only organic acid and inorganic acid without adding defoaming agent has the problems of high hydroxyl value (up to 21.6%), low light transmittance (as low as 78.3%), high haze value (up to 0.83%), low bulk density (as low as 18.1g / 100mL), low yield (as low as 82.5%) and high yellowing index (up to 20.2); in the present application, the non-emulsified defoaming agent is added in the inorganic acid and organic acid, which can effectively inhibit the generation of foam during stirring while ensuring the effect of organic acid, so that the polyvinyl butyral has good hydroxyl value (as low as 18.2%), improved light transmittance (up to 92.8%), low haze value (as low as 0.26%), good bulk density of the obtained resin (up to 21.92g / 100mL), high yield (up to 99.8%) and good high-temperature yellowing resistance (low yellowing index of 1.0); in the preparation of PVB resin, the n-butyraldehyde solution is gradually added to the PVA solution and subjected to heat preservation treatment, the condensation reaction proceeds smoothly, the phase change reaction is more easily controlled and the phenomenon is clear and identifiable, the obtained resin product has uniform particle size and good quality, the blocky waste is significantly reduced, and the yield is significantly improved; the resin prepared in the present application has uniform particle size, and after being used to prepare PVB film, the prepared PVB film has good adhesion, transparent and pure color, and no impurity bubbles.
Claims
1. A method for preparing polyvinyl butyral resin, characterized in that: The specific steps are as follows: I. Polyvinyl alcohol dissolution Add polyvinyl alcohol to deionized water, heat to 90-100℃, maintain the temperature and stir for 1.5 hours to dissolve into a polyvinyl alcohol solution. II. Filter-blended defoamer The polyvinyl alcohol solution dissolved in step one is filtered while hot through a filter device. Then, the temperature of the polyvinyl alcohol solution is lowered to 30℃-40℃. While stirring, the inorganic acid solution, organic acid and defoamer are added to the polyvinyl alcohol solution and stirred until uniform. III. Condensation Reaction The n-butyraldehyde solution was gradually added dropwise to the polyvinyl alcohol solution in step two, and then kept at 30℃-40℃ for 10-40 min. The temperature was then gradually increased to 60-70℃ and kept at this temperature for 20-120 min. IV. Post-treatment drying After the condensation reaction is completed, the reaction temperature is lowered to 30℃, and the product is washed with deionized water 3-5 times. The pH value is then adjusted to 11 with alkaline solution and maintained for more than 30 minutes. The washing with deionized water is repeated until the conductivity of the solution drops to 10 μS / cm. The product is then separated by centrifugation and dried to obtain polyvinyl butyral resin powder.
2. The method for preparing polyvinyl butyral resin as described in claim 1, characterized in that: In step one, the amount of polyvinyl alcohol is 50-150 parts and the amount of deionized water is 300-1500 parts.
3. The method for preparing polyvinyl butyral resin as described in claim 1, characterized in that: In step one, the polyvinyl alcohol is PVA1799, PVA1788, PVA1999, PVA2099, PVA2699, or PVA1899.
4. The method for preparing polyvinyl butyral resin as described in claim 1, characterized in that: The filtration device in step two is a general-purpose filtration device with a mesh size of 80-200.
5. The method for preparing polyvinyl butyral resin as described in claim 1, characterized in that: In step two, the inorganic acid solution comprises 3-15 parts, the organic acid 1-5 parts, and the defoamer 4-20 parts, with the inorganic acid solution having a mass fraction of 30%.
6. The method for preparing polyvinyl butyral resin as described in claim 1, characterized in that: The organic acid in step two is one or a mixture of several of the following: acetic acid, aminosulfonic acid, linear alkylbenzene sulfonic acid, dodecyl sulfuric acid, methanesulfonic acid, ethylsulfonic acid, and dodecylbenzene sulfonic acid.
7. The method for preparing polyvinyl butyral resin as described in claim 1, characterized in that: In step two, the defoamer is a non-emulsifying defoamer, which is one or more of Siltech5800, GP-330, BD-3037-60 polyether silicone defoamer, and SXP-107 silicone polyether composite high-temperature defoamer.
8. The method for preparing polyvinyl butyral resin as described in claim 1, characterized in that: In step two, the inorganic acid is one or a mixture of several of the following: hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid.
9. The method for preparing polyvinyl butyral resin as described in claim 1, characterized in that: In step three, the amount of n-butyraldehyde added is 20-100 parts.
10. The method for preparing polyvinyl butyral resin as described in claim 1, characterized in that: The alkaline solution in step four is one or a mixture of sodium hydroxide, potassium hydroxide, and sodium carbonate.