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CN-121973368-A - HP-RTM external release agent and preparation method thereof

CN121973368ACN 121973368 ACN121973368 ACN 121973368ACN-121973368-A

Abstract

An HP-RTM external release agent comprises a bottom reinforcing phase and a middle layer functional phase, wherein the thickness of the bottom reinforcing phase is 0.2-5 mu m, the total thickness of the middle layer functional phase is 1-20 mu m, the bottom reinforcing phase comprises 5-15% of vinyl silicone resin, 2-6% of hydrogen-containing silicone resin, 70-88% of hydrocarbon solvents, 0.2-1.5% of nano silicon dioxide, 0.3-1.5% of fluorinated leveling agent, 5-60 ppm of platinum-series catalyst, the middle layer functional phase comprises 10-40% of hydroxyl silicone oil, 3-15% of silane crosslinking agent, 8-20% of modified silicone oil, 3-10% of nonionic emulsifying agent, 20-60% of deionized water, 0.5-5% of nano silicon dioxide and 0.01-0.5% of organotin catalyst. The release agent system can improve the film scouring resistance, the self-repairing performance, the scratch repairing rate of more than 80 percent, the film stability and the service life of more than 3 times.

Inventors

  • ZENG QINGYA
  • XU QITONG
  • Guan Chuangqi
  • JIAO XIN
  • ZHANG TAIXIAN

Assignees

  • 青岛国恩复合材料有限公司

Dates

Publication Date
20260505
Application Date
20251226

Claims (10)

  1. 1. An HP-RTM external release agent comprises a bottom reinforcing phase and a middle layer functional phase, wherein the thickness of the bottom reinforcing phase is 0.2-5 mu m, the total thickness of the middle layer functional phase is 1-20 mu m, the bottom reinforcing phase comprises 5-15% of vinyl silicone resin, 2-6% of hydrogen-containing silicone resin, 70-88% of hydrocarbon solvents, 0.2-1.5% of nano silicon dioxide, 0.3-1.5% of fluorinated leveling agent, 5-60 ppm of platinum-series catalyst, the middle layer functional phase comprises 10-40% of hydroxyl silicone oil, 3-15% of silane crosslinking agent, 8-20% of modified silicone oil, 3-10% of nonionic emulsifying agent, 20-60% of deionized water, 0.5-5% of nano silicon dioxide and 0.01-0.5% of organotin catalyst.
  2. 2. The external release agent according to claim 1, wherein the bottom release agent comprises 8-12% of vinyl silicone resin, 3-5% of hydrogen-containing silicone resin, 75-85% of hydrocarbon solvent, 0.5-1% of nano silicon dioxide, 0.5-1% of fluorinated leveling agent and 10-50 ppm of platinum-series catalyst.
  3. 3. The external release agent according to claim 1, wherein the middle surface layer release agent comprises 20-30% of hydroxyl silicone oil, 5-10% of silane crosslinking agent, 10-18% of modified silicone oil, 4-8% of nonionic emulsifier, 30-50% of deionized water, 1-3% of nano silicon dioxide and 0.1-0.3% of organotin catalyst.
  4. 4. The external mold release agent according to claim 1, wherein the vinyl silicone resin is one or more of terminal vinyl silicone resin, side group vinyl silicone resin and MQ vinyl silicone resin, the hydrogen-containing silicone resin is one or more of branched chain hydrogen-containing silicone resin and MQ hydrogen-containing silicone resin, the alkane solvent is one or more of alkane, alkene, cycloalkane and arene with carbon chain of 3-12, preferably one or more of isohexane, cyclohexane, isopropyl alcohol and isobutane, the silane crosslinking agent is one or more of methyltriethylsilane and tetramethylsilane, the modified silicone oil is one or more of alkyl silicone oil, vinyl silicone oil and amino silicone oil, the hydroxyl silicone oil is one of hydroxyl-terminated polydimethylsiloxane and side chain hydroxyl silicone oil, the average particle size of the platinum nano silicon dioxide is 10-100nm, the platinum catalyst is one or more of platinum/alumina, platinum/silica, platinum chloric acid and platinum black, the platinum catalyst is calculated by the content of platinum is one or more of dibutyl tin acetate and dibutyl tin acetate.
  5. 5. The method for producing an external mold release agent according to any one of claims 1 to 4, comprising the steps of: (1) Preparing a bottom layer release agent, namely adding an isoparaffin solvent into a reaction kettle, controlling the temperature to be 25+/-5 ℃, stirring and uniformly mixing, slowly adding vinyl resin, continuously stirring until the vinyl resin and the vinyl resin are completely dissolved, heating hydrogen-based silicon resin and a fluorinated flatting agent, heating to 40-50 ℃, continuously stirring at a high speed, adding nano silicon dioxide and a platinum catalyst, cooling to normal temperature, and filtering to obtain the bottom layer release agent; (2) The preparation process of the middle surface layer release agent comprises the steps of premixing a silicone oil phase, mixing hydroxyl silicone oil, modified silicone oil, a silane cross-linking agent and an emulsifier, heating to 60-70 ℃, adding deionized water for uniform dispersion, controlling the particle size of emulsion to 80-150nm, adding nano silicon dioxide, cooling to below 40 ℃, adding an organotin catalyst, adjusting the pH value of the emulsion to 5.5-6.5, and filtering to obtain the middle surface layer release agent.
  6. 6. The method according to claim 5, wherein the stirring in the steps (1) and (2) is carried out under stirring conditions at a stirring speed of 100-500rmp, and the high-speed stirring in the step (1) is carried out at a stirring speed of 1000-3000rmp, preferably the stirring is carried out under ultrasonic conditions.
  7. 7. The method according to claim 5, wherein the deionized water is added in the step (2) in a plurality of times, preferably in 4 to 8 times at intervals of 3 to 10 minutes, and the deionized water is added in a high-pressure homogenizer at a working pressure of 80 to 120MPa and is circularly treated for 3 to 5 times.
  8. 8. A method of using the HP-RTM external mold release agent according to any one of claims 1-4, comprising the steps of: (a) Cleaning the surface of a die, and heating the die to 80-110 ℃; (b) Adding the bottom layer release agent into a low pressure high flow (HVLP) spray gun, and spraying for two times for 3-5 min; (c) Adding the middle surface layer release agent into a spray gun, spraying for 1 time on the basis of the bottom layer release agent, thermal insulation after finishing spraying and (5) producing the product for 2-3 min.
  9. 9. The method of claim 8, wherein the HP-RTM external mold release agent is used by spraying the bottom layer mold release agent every 40-50 mold and spraying the middle surface layer mold release agent every 10-15 mold according to the mold release condition.
  10. 10. The method according to claim 8, wherein the cleaning treatment in the step (a) uses an organic solvent and/or a cleaning agent, the organic solvent comprises one of ketones, ethers and alcohols, preferably acetone and ethanol, the caliber of the spray gun in the step (b) is 1.2-2mm, the pressure is 0.2-0.5MPa, the distance is 25-35cm, the moving path of the spray gun in the step (c) is s-shaped, and each path coincides with the previous spraying path by 1/3-1/2.

Description

HP-RTM external release agent and preparation method thereof Technical Field The invention relates to the technical field of composite material molding, in particular to an external release agent suitable for a high-pressure resin transfer molding (HP-RTM) process and a preparation method thereof. Background The HP-RTM technology rapidly injects resin into a closed mold through high pressure (120-180 bar), realizes high-efficiency molding by combining high-temperature curing (80-120 ℃), and has the advantages of short molding period, high dimensional accuracy, high glass fiber content and low porosity. The method is successfully applied to the industrial production of key components such as automobile bumpers, roof reinforcing plates, upper covers of new energy battery boxes and the like. However, the high temperature and high pressure conditions of the HP-RTM process place stringent demands on the mold release system, firstly, the high pressure permeation protection demands are that when the resin is injected into the cavity at a pressure of 120-180bar, the mold release needs to have sufficient strength and elastic modulus to resist fluid shear force, otherwise, the resin can permeate into the mold release layer to cause adhesion or dry spots on the surface of the product, secondly, the mold release needs to complete uniform film construction in a short period to ensure full coverage of the surface of the mold due to rapid production beats, and furthermore, the mold release needs to have continuous film stability, reduce the rate of scale increase as much as possible, and reduce the mold cleaning frequency as the number of repair sprays increases. With the increase of the light weight requirement of automobiles and the wide application of HP-RTM technology in related fields, the continuous technical improvement of release agent products is carried out, but the existing release agent is difficult to meet the following requirements that complex structural parts or thin-wall large parts are difficult to realize complete release due to large release force or product deformation is caused by large release stress, the local release is difficult due to local damage of a film layer caused by release stress or external force, the surface of the film layer is rough due to the fact that the release agent is easy to remain, the release agent is poor in color difference and uneven in film formation in a mode of spraying the release agent, the follow-up technology is influenced, the problems of the release agent is serious in color difference, the damage of the film layer and the accumulation of release agent scale are serious due to the increase of the spraying times, and the release agent scale is required to be cleaned after continuous operation of 60-100 moulds, so that the production efficiency is greatly influenced. CN113527767a discloses a preparation method of a magnetic internal release agent, which comprises the following steps of 1) preparing magnetic material particles, preferably ferrite magnetic material, 2) adding the magnetic material particles into a mixed solution of distilled water and ethanol, fully dispersing by ultrasonic, dropwise adding a compound with amino and alkoxy under the protection of nitrogen, fully stirring until the reaction is finished, washing and freeze-drying to obtain the amino modified magnetic material, 3) adding the amino modified magnetic material into absolute ethanol, fully dispersing by ultrasonic, adding an activating agent, fully stirring, dropwise adding hydroxyl end-capped polysiloxane release agent grafts under stirring, stirring until the reaction is finished, washing and freeze-drying to obtain the magnetic internal release agent. The release agent has excellent continuous release performance, and can greatly improve the production efficiency of the composite material. CN107599250a discloses a release agent for an organosilicon automobile cushion, which comprises, by weight, 5% of simethicone, 5% of silicone resin, 0.05% of wetting agent BYK306, 0.02% of adhesion promoter BYK4509, 0.05% of odor masking agent, 50% of dichloromethane, 39.88% of 120 # solvent oil, and 0.01% of wetting agent, 0.1% of adhesion promoter, 0.05% of odor masking agent, 50% of dichloromethane, 39.88% of 120 # solvent oil. Disclosure of Invention The invention forms an external release agent system suitable for the epoxy resin HP-RTM technology through the matched use of the two release agents. The system comprises a bottom layer strengthening phase and a middle layer functional phase, wherein the bottom layer and the middle layer cooperate to reduce the deformation of products caused by demolding force and demolding stress and reduce the accumulation of a demolding agent and the demolding frequency. The bottom reinforcing phase ensures the strength of the film layer, the middle functional phase reduces the demolding force and simultaneously endows the system with molecular-level self-repairing