Fluorescent visual composite material molding process release agent and preparation method thereof

Abstract

The invention discloses a fluorescent visual composite material molding process release agent and a preparation method thereof. Vegetable oil containing conjugated double bonds and dienophile benzoquinone containing a benzene ring are selected to be subjected to a Diels-Alder reaction, then an electron donating group is introduced to the introduced benzene ring in a chemical modification mode, and a substance obtained through the reaction and having a special structure is mixed with a resin related auxiliary agent according to a certain proportion. Therefore, the internal release agent with the fluorescence property is prepared; the release agent is very excellent in release performance, more importantly, the release agent can emit fluorescence under exciting light with a specific wavelength, the residual quantity of the release agent on a product can be visually detected through the fluorescence characteristic, the residual condition of the release agent on the product can be conveniently and visually judged, and the release agent is of great significance in quality control and product safety evaluation.

Description

Technical Field

[0001] The invention belongs to an internal mold release agent for molding materials such as epoxy resin, polyurethane, unsaturated polyester, etc., and particularly relates to a fluorescent visualized composite material molding process release agent and a preparation method thereof. Background Art

[0002] In the production process of composite products, internal release agents play a vital role. Traditional internal release agents mainly focus on improving demoulding effects, improving production efficiency, and reducing production costs. However, with the continuous development of industrial production and the improvement of product quality monitoring requirements, the performance requirements of release agents are becoming increasingly diversified. On the one hand, in a complex production environment, visual monitoring of the demoulding process has become a new demand point. On some automated production lines, or when the mold structure is more complex, traditional release agents cannot provide intuitive information to reflect whether the demoulding process is smooth and the distribution of the release agent in the mold. On the other hand, composite products are widely used in many fields, such as aerospace, electronics, and automobiles. These industries have extremely high requirements for product quality and traceability of the production process. Ordinary release agents cannot meet the requirements of these industries for material intelligence.

[0003] The introduction of fluorescence properties provides a new approach to solving these problems. Materials with fluorescence properties can emit fluorescence of a specific wavelength when irradiated with excitation light of a specific wavelength. By detecting the fluorescence signal, visual monitoring of the material's position, distribution and other information can be achieved. Combining fluorescence properties with internal release agents can enable the release agent to have traditional demolding functions, and can also intuitively reflect its distribution in the mold, demolding effect and other information through fluorescence signals during the production process, thereby achieving real-time monitoring of the demolding process, which is of great significance for improving product quality and optimizing production processes. At present, there are relatively few products on the market that specifically target epoxy resin internal release agents with fluorescence properties, and the existing preparation methods also have some defects such as unstable fluorescence properties and negative effects on demolding effects, which require further research and improvement.

[0004] Patent CN1316321A discloses a glass fiber reinforced plastic internal demoulding agent, which is synthesized from two raw materials, one is a phosphorylation reagent, including phosphorus pentoxide and phosphorus oxychloride, and the other is a straight-chain fatty alcohol. It has a low melting point, generally not exceeding 60°C, good compatibility with liquid resin, easy dispersion, and improves demoulding function and surface quality of products. However, in the process of industrial development, the change of resin curing system cannot achieve effective demoulding.

[0005] Patent CN 111349308 A discloses an internal mold release agent for epoxy resin LED packaging materials and a preparation method thereof. The mold release agent is prepared by addition reaction of the following raw materials in parts by weight: low hydrogen silicone oil, olefin compounds, and platinum catalyst. As an additive, it can be directly added to the curing agent of epoxy resin LED packaging materials and remain stable. However, the product has no detectable residue.

[0006] Therefore, if a release agent with excellent demoulding performance, visualization and high temperature resistance can be prepared, it will be of great significance in the field of release agents and have broad market prospects. Summary of the invention

[0007] In view of the above-mentioned deficiencies of the prior art, the problem solved by the present invention is to provide a composite material molding process release agent with excellent demolding performance, visualization, and high temperature resistance, and a preparation method thereof.

[0008] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0009] A fluorescent visualized composite material molding process release agent comprises the following components by weight: 25-200 parts by weight of fluorescent grease, 30-50 parts by weight of emulsifier, 5-10 parts by weight of salt former, 6-10 parts by weight of solvent, 6-10 parts by weight of compatibilizer, 6-10 parts by weight of film former and 2-5 parts by weight of dispersant.

[0010] Furthermore, the emulsifier is one or more of glyceryl monostearate, sucrose fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, sodium stearoyl lactylate, calcium stearoyl lactylate, phospholipids, propylene glycol fatty acid ester, soybean lecithin, sodium lauryl sulfate, polyoxyethylene fatty acid ester, polyglycerol fatty acid ester, alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, polyoxyethylene castor oil, polyoxypropylene glycerol ether, polyoxyethylene oleate, potassium stearate, and sodium dodecylbenzene sulfonate.

[0011] Furthermore, the salt-forming agent is one or more of sodium chloride, sodium sulfate, potassium nitrate, ammonium sulfate, ammonium chloride, barium chloride, ammonium carbonate, sodium phosphate, potassium phosphate, and sodium acetate.

[0012] Furthermore, the solvent is at least one of heptane, isoheptane, octane, isooctane, nonane, isononane, decane, isodecane, undecane, dodecane, tridecane, and tetradecane.

[0013] Furthermore, the compatibilizer is vinyltriethoxysilane.

[0014] Furthermore, the film-forming agent is one or more of polyvinyl alcohol, polyacrylamide, sodium carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, ethyl cellulose, polyethylene glycol, povidone, gelatin, gum arabic, starch, rosin, terpene resin, phenolic resin, epoxy resin, polyester resin, polyurethane resin, acrylic resin, and silicone resin.

[0015] Furthermore, the dispersant is polyethylene glycol fatty acid ester.

[0016] The invention discloses a preparation process of a fluorescent visualized composite material molding process release agent, and the steps are as follows: putting a conjugated double bond structure vegetable oil into a reaction container and heating it, then adding dienephilic benzoquinone, and adding p-toluenesulfonic acid as a catalyst; heating and stirring and refluxing at a uniform speed under nitrogen protection; the conjugated double bonds of the oil product and the dienephilic benzene ring monomer undergo a Diels-Alder addition reaction to form an addition product with a benzene ring; heating the above reaction product, and introducing an electron donating (withdrawing) group under the action of a PdCl2 catalyst; after the reaction is completed, cooling, filtering, extracting and purifying the reaction mixture; and then continuing to purify the product by column chromatography and distillation to obtain fluorescent oil; weighing the above prepared fluorescent oil product, polyoxyethylene sorbitan fatty acid ester and lauryl alcohol polyoxyethylene ether composite emulsifier, the above salt-forming agent ammonium chloride, the above solvent nonane, the above compatibilizer vinyl triethoxysilane, the above film-forming agent polyacrylamide, and the above dispersant polyethylene glycol fatty acid ester, and emulsifying to obtain a release agent.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1. Efficient demoulding: Fluorescent internal demoulding agent can significantly reduce the adhesion between composite products and molds, allowing products to be demoulded smoothly during pultrusion. This reduces the manpower and time required for demoulding and improves production efficiency. At the same time, good demoulding performance can reduce surface defects such as scratches and fuzz on products, and improve the appearance quality of products.

[0019] 2. Accurate detection of residues: With the help of fluorescence characteristics, the residue of internal release agent on the product can be easily detected. Through specific detection equipment, the distribution and residual amount of release agent can be quickly determined, providing accurate data for quality control in the production process. This helps to adjust process parameters in time to avoid affecting product performance due to excessive or insufficient release agent residue.

[0020] 3. Optimize the production process: Understand the residual situation of the release agent and optimize the pultrusion process. If there is too much residue, the amount of release agent can be adjusted; if there is too little residue, the amount of release agent can be increased or the pultrusion speed can be adjusted. This can improve the stability and consistency of production, reduce production costs, and improve the market competitiveness of products. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a graph of mechanical properties test data of pultruded board, where the abscissa is strain (%) and the ordinate is stress (MPa).

[0022] Figure 2 This is a test data graph of the fluorescence performance of the release agent, where the horizontal axis is the fluorescence intensity and the vertical axis is the wavelength. Figure 3 It is the thermal stability TGA graph of the release agent, where the abscissa is temperature (°C) and the ordinate is weight percentage (%). DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0024] The fluorescent oil preparation steps of the present invention are as follows: put the conjugated double bond structure vegetable oil into a reaction container and preheat it at 80°C for 30 minutes, then add dienephilic benzoquinone with a molar ratio of 1:1, and add an appropriate amount of p-toluenesulfonic acid as a catalyst; at 80°C, the speed is 300r / min, and the stirring reflux is uniform for 10 hours under nitrogen protection; the conjugated double bonds of the oil product and the dienephilic benzene ring monomer undergo Diels-Alder addition reaction to form an addition product with a benzene ring; the above reaction product is introduced into an electron-donating (withdrawing) group under the action of a PdCl2 catalyst at a temperature of 80°C; after the reaction is completed, the reaction mixture is cooled, filtered, extracted and purified; and the product is further purified by column chromatography and distillation to obtain the fluorescent oil. The conjugated double bond structure vegetable oil is tall oil.

[0025] Embodiment 1:

[0026] Weigh 200 parts of the fluorescent grease prepared above, 50 parts of a one-to-one compound emulsifier of polyoxyethylene sorbitan fatty acid ester and lauryl alcohol polyoxyethylene ether, 10 parts of the salt-forming agent ammonium chloride, 10 parts of the solvent nonane, 10 parts of the compatibilizer vinyl triethoxysilane, 10 parts of the film-forming agent polyacrylamide, and 5 parts of the dispersant polyethylene glycol fatty acid ester. In a reactor with an emulsification temperature of 80°C, a rotation speed of 2800r / min, a vacuum degree of 0.05MPa, and homogenization for 120min, a release agent 1 is obtained.

[0027] Embodiment 2:

[0028] Weigh 200 parts of the fluorescent grease prepared above, 40 parts of a 1:1 composite emulsifier of polyoxyethylene sorbitan fatty acid ester and lauryl alcohol polyoxyethylene ether, 8 parts of the salt-forming agent ammonium chloride, 8 parts of the solvent nonane, 8 parts of the compatibilizer vinyl triethoxysilane, 8 parts of the film-forming agent polyacrylamide, and 5 parts of the dispersant polyethylene glycol fatty acid ester. In a reactor with an emulsification temperature of 80°C, a rotation speed of 2800r / min, a vacuum degree of 0.05MPa, and homogenization for 120min, a release agent 2 is obtained.

[0029] Embodiment 3:

[0030] Weigh 200 parts of the fluorescent grease prepared above, 30 parts of a 1:1 composite emulsifier of polyoxyethylene sorbitan fatty acid ester and lauryl alcohol polyoxyethylene ether, 6 parts of the salt-forming agent ammonium chloride, 6 parts of the solvent nonane, 6 parts of the compatibilizer vinyl triethoxysilane, 6 parts of the film-forming agent polyacrylamide, and 5 parts of the dispersant polyethylene glycol fatty acid ester. In a reactor with an emulsification temperature of 80°C, a rotation speed of 2800r / min, a vacuum degree of 0.05MPa, and homogenization for 120min, a release agent 3 is obtained.

[0031] Embodiment 4:

[0032] Weigh 150 parts of the fluorescent grease prepared above, 50 parts of a one-to-one emulsifier of polyoxyethylene sorbitan fatty acid ester and lauryl alcohol polyoxyethylene ether, 10 parts of the salt-forming agent ammonium chloride, 10 parts of the solvent nonane, 10 parts of the compatibilizer vinyl triethoxysilane, 10 parts of the film-forming agent polyacrylamide, and 5 parts of the dispersant polyethylene glycol fatty acid ester. In a reactor with an emulsification temperature of 80°C, the speed is 2800r / min, the vacuum degree is 0.05MPa, and the homogenization is performed for 120min to obtain a release agent 4.

[0033] Embodiment 5:

[0034] Weigh 150 parts of the fluorescent grease prepared above, 40 parts of a 1:1 composite emulsifier of polyoxyethylene sorbitan fatty acid ester and lauryl alcohol polyoxyethylene ether, 8 parts of the salt-forming agent ammonium chloride, 8 parts of the solvent nonane, 8 parts of the compatibilizer vinyl triethoxysilane, 8 parts of the film-forming agent polyacrylamide, and 5 parts of the dispersant polyethylene glycol fatty acid ester. In a reactor with an emulsification temperature of 80°C, a rotation speed of 2800r / min, a vacuum degree of 0.05MPa, and homogenization for 120min, a release agent 5 is obtained.

[0035] Embodiment 6:

[0036] Weigh 150 parts of the fluorescent grease prepared above, 30 parts of a 1:1 composite emulsifier of polyoxyethylene sorbitan fatty acid ester and lauryl alcohol polyoxyethylene ether, 6 parts of the salt-forming agent ammonium chloride, 6 parts of the solvent nonane, 6 parts of the compatibilizer vinyl triethoxysilane, 6 parts of the film-forming agent polyacrylamide, and 5 parts of the dispersant polyethylene glycol fatty acid ester. In a reactor with an emulsification temperature of 80°C, a rotation speed of 2800r / min, a vacuum degree of 0.05MPa, and homogenization for 120min, a release agent 6 is obtained.

[0037] Performance test and comparative test

[0038] Test 1 Particle size detection of release agent

[0039] The mold release agents of Examples 1-6 were taken and their particle sizes were tested. According to the implementation standard ISO 22412: "Particle size analysis. Dynamic light scattering (DLS)", it is mainly applicable to the analysis of the particle size of particles in fluorescent grease by dynamic light scattering technology. The results show that the particle sizes of Examples 1-6 are all less than 5 μm.

[0040] Test 2: Refractive index test of release agent

[0041] The mold release agents of Examples 1-6 were taken and their particle sizes were tested. According to the implementation standard ASTM D1218: "Standard Test Method for Refractive Index and Refractive Dispersion of Hydrocarbon Liquids", the results showed that the refractive index of the mold release agent was 1.208 (± 0.02). The refractive index of the examples is shown in Table 1 below.

[0042] sample Refractive index nD20 Example 1 1.215 Example 2 1.208 Example 3 1.199 Example 4 1.210 Example 5 1.220 Example 6 1.214

[0043] Table 1

[0044] Test 3 Release agent fluorescence test

[0045] Take the release agents of Examples 1-6 and test the particle size of the release agents. According to the implementation standard EN ISO 22959:2009 "Determination of polycyclic aromatic hydrocarbons in animal and vegetable fats and oils by online donor-acceptor complex chromatography and by high performance liquid chromatography (HPLC) using fluorescence detection method": stipulates the method of determining polycyclic aromatic hydrocarbons in animal and vegetable fats and oils using fluorescence detection method. The test results are shown in the attached Figure 2 .

[0046] Test 4 Thermal stability test of release agent

[0047] The thermal stability of the release agents of Examples 1 to 6 was tested using a thermogravimetric analyzer.

[0048] Under the protection of N2 atmosphere, the release agent samples of Examples 1-6 were placed in a crucible of a heating furnace and heated at 10°C min -1 The temperature was raised from 35°C to 500°C at a rate of 1.5°C, and the mass loss of the test sample in the temperature range of 35-500°C was measured. The thermal stability test results of the release agent are shown in the attached Figure 3 , it can be seen that the thermal stability is good.

[0049] Test 5 Composite Pultrusion Test

[0050] Take the release agent of Example 6, add epoxy resin at an addition amount of 2%, and cut samples at pultrusion speeds of 0.2m / min, 0.4m / min, 0.6m / min, 0.8m / min, and 1.0m / min respectively to implement standard ASTM D3039. When testing the tensile strength, the test speed is 10mm / min, and the mechanical properties of the above materials are tested. The test results are attached. Figure 1 , it can be seen that the mechanical properties are still stable.

[0051] Test 6 Storage stability test of release agent

[0052] The release agents of Examples 1-6 were tested for storage stability. The release agent samples of Examples 1-6 were respectively placed in measuring cylinders (or centrifuge tubes) and left to stand at (30±2)°C. The release agents of Examples 1-6 were all stable within 12 months.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A fluorescent visualized release agent for composite material molding process, characterized in that: The invention comprises the following components by weight: 25-200 parts by weight of fluorescent oil, 30-50 parts by weight of emulsifier, 5-10 parts by weight of salt former, 6-10 parts by weight of solvent, 6-10 parts by weight of compatibilizer, 6-10 parts by weight of film former and 2-5 parts by weight of dispersant.

2. The fluorescent visualized composite material molding process release agent according to claim 1, characterized in that: The emulsifier is one or more of glyceryl monostearate, sucrose fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, sodium stearoyl lactylate, calcium stearoyl lactylate, phospholipids, propylene glycol fatty acid ester, soybean lecithin, sodium lauryl sulfate, polyoxyethylene fatty acid ester, polyglycerol fatty acid ester, alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, polyoxyethylene castor oil, polyoxypropylene glycerol ether, polyoxyethylene oleate, potassium stearate, and sodium dodecylbenzene sulfonate.

3. The fluorescent visualized composite material molding process release agent according to claim 1, characterized in that: The salt-forming agent is one or more of sodium chloride, sodium sulfate, potassium nitrate, ammonium sulfate, ammonium chloride, barium chloride, ammonium carbonate, sodium phosphate, potassium phosphate, and sodium acetate.

4. The fluorescent visualized composite material molding process release agent according to claim 1, characterized in that: The solvent is at least one of heptane, isoheptane, octane, isooctane, nonane, isononane, decane, isodecane, undecane, dodecane, tridecane and tetradecane.

5. The fluorescent visualized composite material molding process release agent according to claim 1, characterized in that: The compatibilizer is vinyltriethoxysilane.

6. The fluorescent visualized composite material molding process release agent according to claim 1, characterized in that: The film-forming agent is one or more of polyvinyl alcohol, polyacrylamide, sodium carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, ethyl cellulose, polyethylene glycol, povidone, gelatin, gum arabic, starch, rosin, terpene resin, phenolic resin, epoxy resin, polyester resin, polyurethane resin, acrylic resin, and silicone resin.

7. The fluorescent visualized composite material molding process release agent according to claim 1, characterized in that: The dispersant is polyethylene glycol fatty acid ester.

8. A process for preparing a release agent for composite material molding process with fluorescence visualization according to claim 1, characterized in that: The steps are as follows: putting a conjugated double bond structure vegetable oil into a reaction container and heating it, then adding dienephilic benzoquinone, and adding p-toluenesulfonic acid as a catalyst; heating and stirring and refluxing at a uniform speed under nitrogen protection; the conjugated double bonds of the oil product and the dienephilic benzene ring monomer undergo a Diels-Alder addition reaction to form an addition product with a benzene ring; heating the above reaction product, and introducing an electron donating (withdrawing) group under the action of a PdCl2 catalyst; after the reaction is completed, cooling, filtering, extracting and purifying the reaction mixture; then continuing to purify the product by column chromatography and distillation to obtain fluorescent oil; weighing the above prepared fluorescent oil product, polyoxyethylene sorbitan fatty acid ester and lauryl alcohol polyoxyethylene ether composite emulsifier, the above salt-forming agent ammonium chloride, the above solvent nonane, the above compatibilizer vinyl triethoxysilane, the above film-forming agent polyacrylamide, and the above dispersant polyethylene glycol fatty acid ester, emulsifying to obtain a release agent.

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