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CN-121991444-A - Polyvinyl acetal resin and preparation method and application thereof

CN121991444ACN 121991444 ACN121991444 ACN 121991444ACN-121991444-A

Abstract

The invention provides a polyvinyl acetal resin, a preparation method and application thereof, wherein the raw materials for preparing the polyvinyl acetal resin comprise, by weight, 100 parts of polyvinyl alcohol, 30-45 parts of aldehyde compounds, 0.5-5 parts of cross-linking agents and 1-10 parts of catalysts, and the viscosity of the polyvinyl acetal resin is 100-150 mPa.s. According to the invention, the degraded polyvinyl alcohol reacts with the aldehyde compound and the cross-linking agent, so that a three-dimensional network structure is constructed, short-chain molecules are integrated into a continuous three-dimensional cross-linked network, and the cohesive strength, toughness and mechanical properties of the low-viscosity polyvinyl acetal resin are obviously improved.

Inventors

  • ZHU XIONGBING
  • GU XIAO
  • ZHU FUHAI
  • WANG MENGDAN

Assignees

  • 亿光年高分子材料(江苏)有限公司

Dates

Publication Date
20260508
Application Date
20251121

Claims (10)

  1. 1. The polyvinyl acetal resin is characterized by comprising the following raw materials in parts by weight: Polyvinyl alcohol 100 parts 30-45 Parts of aldehyde compound 0.5-5 Parts of cross-linking agent 1-10 Parts of a catalyst; the viscosity of the polyvinyl acetal resin is 100-150 mPa s.
  2. 2. The polyvinyl acetal resin according to claim 1, wherein the aldehyde compound comprises any one or a combination of at least two of formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, caproaldehyde, heptanal, glutaraldehyde, benzaldehyde, or octaldehyde; Preferably, the crosslinking agent comprises any one or a combination of at least two of phenolic resin, epoxy resin, amino resin or formaldehyde hydrate; preferably, the catalyst comprises an acidic catalyst; Preferably, the acidic catalyst comprises any one or a combination of at least two of hydrochloric acid, dilute sulfuric acid, phosphoric acid, hydrobromic acid, hydroiodic acid, chloroacetic acid, sulfamic acid, benzenesulfonic acid, o-toluenesulfonic acid, m-toluenesulfonic acid, ethylbenzenesulfonic acid or m-phenylenedisulfonic acid.
  3. 3. The polyvinyl acetal resin according to claim 1 or 2, wherein the raw materials for preparing the polyvinyl acetal resin further comprise a surfactant and an antioxidant; preferably, the surfactant comprises any one or a combination of at least two of sodium dodecyl sulfate, sodium laureth sulfate, potassium perfluorooctyl sulfonate, cocamidopropyl betaine, dodecyldimethyl amine oxide, sodium monolauryl phosphate, potassium isooctyl phosphate, sodium dodecylbenzene sulfonate or sodium xylene sulfonate; Preferably, the surfactant is used in an amount of 0.5 to 0.8 parts; Preferably, the antioxidant comprises any one or a combination of at least two of pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], N-stearyl beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, 4 '-thiobis (6-tert-butyl-3-methylphenol), 1, 2-bis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl ] hydrazine, N' - (hexane-1, 6-diyl) bis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionamide ] or tris (2, 4-di-tert-butylphenyl) phosphite; preferably, the antioxidant is used in an amount of 0.1 to 1 part.
  4. 4. A method for producing the polyvinyl acetal resin according to any one of claims 1 to 3, wherein the method comprises the steps of: and reacting polyvinyl alcohol, aldehyde compounds and a cross-linking agent under the action of a catalyst, and curing to obtain the polyvinyl acetal resin.
  5. 5. The method according to claim 4, further comprising dissolving polyvinyl alcohol in water to obtain a polyvinyl alcohol solution; Preferably, the mass fraction of the polyvinyl alcohol solution is 10-18%; Preferably, the temperature of dissolution is 80-100 ℃; Preferably, the dissolution time is 2-4 h.
  6. 6. The method according to claim 4 or 5, wherein the method further comprises degrading the polyvinyl alcohol solution with a degradation agent and an accelerator; preferably, the degradation agent comprises any one or a combination of at least two of sodium hypochlorite, hydrogen peroxide, dilute nitric acid, chlorine dioxide or peracetic acid; Preferably, the degradation agent is used in an amount of 0.1 to 1 part; preferably, the promoter comprises any one or a combination of at least two of copper sulfate, copper chloride or ferrous sulfate; preferably, the accelerator is used in an amount of 0.01 to 0.1 part; preferably, the degree of polymerization of the degraded polyvinyl alcohol is 300-500; Preferably, the degradation is performed in the presence of an alkaline substance; Preferably, the alkaline substance comprises sodium hydroxide and/or potassium hydroxide.
  7. 7. The process according to any one of claims 4 to 6, wherein the temperature of the reaction is 40 to 70 ℃; Preferably, the reaction time is 3-6 h; preferably, the curing temperature is 30-40 ℃; preferably, the curing time is 2-3 h; preferably, the preparation method comprises adding an aldehyde compound, a catalyst and a cross-linking agent into the degraded polyvinyl alcohol solution; preferably, the preparation method further comprises the step of adding a surfactant and an antioxidant into the degraded polyvinyl alcohol solution; Preferably, the temperature at the time of adding the surfactant is controlled to be 30-35 ℃; Preferably, the temperature at which the aldehyde compound, the catalyst, the crosslinking agent and the antioxidant are added is each independently controlled at 5-15 ℃.
  8. 8. The method of any one of claims 4-7, wherein the post-maturation treatment further comprises post-treatment; Preferably, the post-treatment comprises washing and drying; Preferably, the washing comprises washing with an alkaline solution and washing with water; Preferably, the alkaline solution comprises any one or a combination of at least two of sodium hydroxide solution, potassium hydroxide solution, sodium carbonate solution or potassium carbonate solution; Preferably, the alkaline solution has a pH of 9-10; preferably, the number of washes is 4-5.
  9. 9. The preparation method according to any one of claims 4 to 8, characterized in that it comprises in particular the following steps: (1) Dissolving polyvinyl alcohol in water at 80-100 ℃ and stirring for 2-4 h to obtain a polyvinyl alcohol solution; (2) Adding sodium hydroxide into the polyvinyl alcohol solution in the step (1), regulating the pH value of the solution to 8-10, and then adding a degradation agent and an accelerator to degrade the polyvinyl alcohol solution; (3) Controlling the temperature to be 30-35 ℃, adding a surfactant into the polyvinyl alcohol solution degraded in the step (2), further reducing the temperature to 5-15 ℃, adding an aldehyde compound, a cross-linking agent, a catalyst and an antioxidant, reacting at 40-70 ℃ for 3-6 h, and curing at 30-40 ℃ for 2-3 h; (4) Adding alkaline solution for washing to enable the pH value to be 9-10, then washing the product with water for 4-5 times, and drying to obtain the polyvinyl acetal resin.
  10. 10. Use of the polyvinyl acetal resin according to any of claims 1-3 in inks, coatings, adhesives or electronic materials.

Description

Polyvinyl acetal resin and preparation method and application thereof Technical Field The invention belongs to the technical field of polyvinyl acetal resin, and particularly relates to a polyvinyl acetal resin, a preparation method and application thereof. Background The polyvinyl acetal resin is an important thermoplastic polymer material prepared by acetalation reaction of polyvinyl alcohol and aldehyde compounds under acid catalysis. The molecular main chain is a carbon-carbon skeleton, and the side chain simultaneously comprises a hydrophobic acetal group, a hydrophilic hydroxyl group and a small amount of unhydrolyzed acetoxy group. The unique multi-functional group coexisting structure endows the resin with higher transparency, good solubility, excellent moldability, good weather resistance, cold resistance, adhesive property and certain impact resistance. The polyvinyl acetal resin is classified into a low viscosity resin and a high viscosity resin according to the intrinsic viscosity. Among them, the low viscosity polyvinyl acetal resin is widely used in the fields of ink, paint, adhesive, ceramic printing, electronic material, etc. because of its good fluidity, solubility and adhesion. The low viscosity properties of the polyvinyl acetal resin are fundamentally derived from its relatively low molecular weight and relatively short molecular chains, which structural feature, while leading to good processability, also leads to inherent performance defects of weak entanglement of the molecular chains and insufficient physical crosslinking points, which result in relatively low cohesive strength of the film formed by itself, and failure of the stress to be efficiently dispersed and conducted through the tough molecular chain network when subjected to high-strength shear forces, peeling forces or sustained loads. This results in a rapid concentration of stresses at certain weak points inside the glue line, the final failure mode of which often does not occur at the interface of the adhesive and the adherend, but rather inside the glue line, the so-called "cohesive failure", making it unsuitable for bonding situations where structural loads need to be borne. Although the polyvinyl acetal resin has sufficient adhesive force to an adherend, it exhibits significant drawbacks for applications requiring bearing a certain structural load, dynamic load or long-term reliability due to insufficient strength itself. Therefore, the strength, the toughness and the overall mechanical properties of the low-viscosity polyvinyl acetal resin are effectively improved on the premise of not reducing other properties of the polyvinyl acetal resin, and the technical problem to be solved in the field is urgent. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a polyvinyl acetal resin, a preparation method and application thereof, according to the invention, the polyvinyl alcohol after degradation reacts with the aldehyde compound and the cross-linking agent, so that the prepared polyvinyl acetal resin has lower viscosity and excellent toughness and cohesive strength. To achieve the purpose, the invention adopts the following technical scheme: the invention provides a polyvinyl acetal resin, which is prepared from the following raw materials in parts by weight: Polyvinyl alcohol 100 parts 30-45 Parts of aldehyde compound 0.5-5 Parts of cross-linking agent 1-10 Parts of catalyst The viscosity of the polyvinyl acetal resin is 100-150 mPa s Aiming at the problem that the cohesive strength and toughness of the low-viscosity polyvinyl acetal resin are poor due to short molecular chains and insufficient physical winding, the invention introduces the cross-linking agent to chemically cross-link the hydroxyl and the cross-linking agent, thereby constructing a three-dimensional network structure, integrating short-chain molecules into a continuous three-dimensional cross-linked network, obviously improving the cohesive strength, toughness and mechanical property of the polyvinyl acetal resin, effectively transferring and dispersing local stress to the whole cross-linked system under the action of external force, avoiding damage caused by stress concentration and widening the application field of the low-viscosity polyvinyl acetal resin. The amount of the aldehyde compound may be 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts, 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, 45 parts or the like. The crosslinking agent may be used in an amount of 0.5 parts, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, or the like. The catalyst may be used in an amount of 1 part, 2 parts, 4 parts, 6 parts, 8 parts, 10 parts, etc. The viscosity of the polyvinyl acetal resin may be 100 mPa ·s, 105 mPa ·s, 110 mPa ·s, 115 mPa ·s, 120 mPa ·s, 125 mPa ·s, 130 mPa ·s, 135 mPa ·s, 140 mPa ·s, 145 mPa ·s, 150 mPa ·s, or the like. The following is a preferred technical