Release agent for plastic product processing

Abstract

The invention discloses a release agent for plastic product processing, and relates to the technical field of plastic product processing. The release agent for plastic product processing at least comprises the following raw materials: 15-20 parts by mass of methyl phenyl hydrogen-containing silicone oil; 15-25 parts by mass of long-chain alkyl polyether-amino modified silicone oil; 1-3 parts by mass of a surfactant; 0.1-1 part by mass of a stabilizer; and 50-70 parts by mass of deionized water. According to the prepared release agent for plastic product processing, through compounding of the methyl phenyl hydrogen-containing silicone oil and the long-chain alkyl polyether-amino modified silicone oil, use of an emulsifier is reduced, and the good release effect and heat resistance of the release agent are effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of plastic product processing, and in particular to a mold release agent for plastic product processing. Background Art

[0002] From the end of the last century to now, the world's rubber and plastic industries have continued to grow at a high speed. Among them, my country has become a major producer and consumer of rubber, metal parts and components, and plastics in the world. In 2010, the production capacity of plastic products has reached 58.3 million tons, and it is still growing at a rate of more than 10% per year. The annual production and consumption of rubber has exceeded 5 million tons, ranking first in the world. Due to the rapid development and growth of these industries, the application direction of release agents is becoming more and more extensive, and the amount is also growing rapidly. Especially in recent years, with the rapid progress of calendering, injection molding, molding, extrusion and other processes, the development of release agents in variety types and demand and output has also greatly improved. In the rubber, plastics and other industries, release agents have become an indispensable type of processing aids.

[0003] Release agent is a kind of auxiliary agent that can solidify on the surface of the mold, effectively isolate the mold and the product, prevent the product from sticking to the mold and make it easy to peel off. Release agent is required to have certain thermal stability, no corrosion to the mold, chemical inertness, no reaction with the components in the resin, no residual decomposition products, no effect on the color and post-processing of the product, good cleaning performance, good molding and demoulding performance, and no pollution to the environment. At present, the existing release agents mainly include fluorine-based release agents, polyether release agents, silicone-based release agents, etc. Fluorine-based release agents have good isolation performance and little pollution to the mold, but they are high in cost and poor in heat resistance; polyether release agents have good chemical resistance, but poor heat resistance; silicone-based release agents have excellent demoulding effect and heat resistance, and are particularly suitable for demoulding of high-temperature molded products. Therefore, it is an urgent problem to develop a release agent for plastic product processing that does not affect the color and post-processing of the product, has good heat resistance, and does not pollute the environment. Summary of the invention

[0004] The purpose of the present invention is to provide a release agent for plastic product processing to solve the following technical problems: Existing emulsion release agents for plastic product processing have problems such as easy oil bleed during production and application, poor demoulding effect and poor heat resistance.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A mold release agent for processing plastic products, comprising at least the following raw materials in parts by weight: Methylphenyl hydrogen silicone oil 15-20; Long chain alkyl polyether-amino modified silicone oil 15-25; Surfactant 1-3; Stabilizer 0.1-1; Deionized water 50-70.

[0006] As a further embodiment of the present invention: the preparation method of the methylphenyl hydrogen-containing silicone oil comprises at least the following steps: Add diphenyldimethoxysilane monomer, 60wt% sulfuric acid as a catalyst and toluene into a three-necked flask, and perform hydrolysis reaction at 50-100°C for 4-6h under stirring to obtain diphenyldihydroxysilane; Methyl hydrogenated silicone oil and 98 wt % concentrated sulfuric acid are sequentially added to the diphenyldihydroxysilane under stirring, reacted at 50-100° C. for 10-15 hours, and washed with distilled water until neutral to obtain the methylphenyl hydrogenated silicone oil.

[0007] As a further embodiment of the present invention, the mass ratio of the diphenyldimethoxysilane monomer to the toluene is 1:3-4, and the mass ratio of the diphenyldihydroxysilane to the methyl hydrogen silicone oil is 1-3:1.

[0008] As a further embodiment of the present invention: the preparation method of the long-chain alkyl polyether-amino-modified silicone oil comprises the following steps: In a 250 mL three-necked flask equipped with a thermometer, a stirrer and a reflux condenser, hydrogenated silicone oil, allyl epoxy polyether, 1-hexadecene and isopropanol were added in sequence, the temperature was slowly raised to 65-80°C in a constant temperature oil bath, chloroplatinic acid catalyst was added, the temperature was continued to be raised to 90-100°C, and after reacting for 2-3 hours, a long-chain alkyl polyether modified intermediate was obtained; The long-chain alkyl polyether modified intermediate is cooled to 40-50°C, and N-(2-hydroxyethyl)piperazine is added dropwise for 1-2 hours. After the addition is completed, the reaction is continued at a constant temperature for 2-3 hours. After the solution becomes transparent, the low-boiling point substances are removed by reduced pressure distillation to obtain the long-chain alkyl polyether-amino modified silicone oil.

[0009] As a further embodiment of the present invention, the mass ratio of the hydrogen-containing silicone oil, the allyl epoxy polyether and the 1-hexadecene is 18-20:1:2-3, and the molar ratio of the allyl epoxy polyether and the N-(2-hydroxyethyl) piperazine is 1:1.

[0010] As a further embodiment of the present invention: the stabilizer is a mixture of one or more of polyethylene glycol, sodium carboxymethyl cellulose, calcium chloride or ammonium chloride in any proportion.

[0011] As a further embodiment of the present invention: the surfactant is a mixture of one or more of lauric acid polyoxyethylene ether, polyvinyl alcohol, oleic acid polyoxyethylene ether, lauryl alcohol polyoxyethylene ether, hexadecanol polyoxyethylene ether or stearyl alcohol polyoxyethylene ether in any proportion.

[0012] Beneficial effects of the present invention: The present application forms a composite release agent by stirring a long-chain alkyl polyether-amino-modified silicone oil and a surfactant at high speed to form an emulsified mixture, and then adding methylphenyl hydrogenated silicone oil to mix and stir, thereby forming a composite release agent, which can stably exert a release effect at almost all processing temperatures of plastic resins, etc., and the allowable use temperature exceeds almost all plastic processing temperatures. Even if the actual working temperature is too high and the organosilicon polymer decomposes, no toxic substances will be generated. In addition, the long-chain alkyl polyether-amino-modified silicone oil and methylphenyl hydrogenated silicone oil in the present application have good emulsification effect and good compatibility. After emulsification, a low-cost, green and environmentally friendly release agent can be obtained. After the emulsion is made, the release agent can be simply brushed or sprayed on the mold surface to carry out the next step of plastic product molding and processing, and the product demolding is simple.

[0013] In this application, methylphenyl hydrogenated silicone oil is prepared as the main release agent. The prepared release agent has low surface tension and low surface energy. It can be spread as a thin oil film on the mold surface, and can cope with various molds with complex configurations. The amount of release agent residue in the mold is small, which improves the demoulding effect, does not react with the molding material, ensures that the surface of the product is clean, and does not have chemical reactions such as thermal decomposition and carbonization that affect the effect of the release agent. It can be demoulded multiple times after coating once, which can improve the production efficiency of the molded product. The introduction of phenyl in the release agent of methylphenyl hydrogenated silicone oil improves the thermal stability of the release agent, and the synthesis method of methylphenyl hydrogenated silicone oil as a hydrogen source in this application is more conducive to synthesizing methylphenyl hydrogenated silicone oil with a larger molecular weight, and the thermal stability of the prepared methylphenyl hydrogenated silicone oil is better.

[0014] The present application adds long-chain alkyl polyether-amino modified silicone oil to the release agent, and the long-chain alkyl modified silicone oil is used to not only enhance the hydrophobicity of silicone oil, so that it has better lubricity, but also improve the compatibility of silicone oil with organic matter. Polyether-modified silicone oil has both polyether hydrophilicity and polysiloxane hydrophobicity, shows good surface activity, and enhances the stability of the emulsion. Long-chain alkyl polyether-amino modified silicone oil and surfactant can produce synergistic effects, reduce surface tension more, facilitate emulsification, and reduce the use of emulsifiers. Due to the addition of long-chain alkyl, its lubricity is increased, and a film that can resist adhesion is formed on the surface of the mold. When used as a release agent, the finished product that is taken out does not need to clean the surface to print, color, and bond, which reduces the residual amount of the release agent in the mold, and can be directly printed without cleaning. Color, green and environmentally friendly, and also simplifies the work procedure. Since the long-chain alkyl polyether-amino modified silicone oil structure also has hydroxyl and amino, adding an appropriate amount of acid, allowing amino salts to improve the emulsification efficiency of silicone oil and enhance the stability of the emulsion. DETAILED DESCRIPTION

[0015] The following will be described clearly and completely in conjunction with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] Example 1 The preparation method of methylphenyl hydrogen-containing silicone oil comprises the following steps: Add 8 ml of diphenyldimethoxysilane monomer, 35 ml of 60 wt% sulfuric acid as a catalyst and 25 ml of toluene into a three-necked flask, and perform hydrolysis reaction at 65°C (bath temperature) for 5 h under stirring to obtain diphenyldihydroxysilane; The diphenyldihydroxysilane obtained above was added into a three-necked flask, and 10 ml of methyl hydrogenated silicone oil and 5 ml of 98 wt % concentrated sulfuric acid were added in sequence under stirring. The mixture was reacted at 65° C. (bath temperature) for 12 h, and washed with distilled water until neutral. The solvent and small molecular compounds were removed by rotary evaporation to obtain methylphenyl hydrogenated silicone oil.

[0017] The preparation method of long-chain alkyl polyether-amino modified silicone oil comprises the following steps: In a 250 mL three-necked flask equipped with a thermometer, a stirrer and a reflux condenser, 20 g of hydrogenated silicone oil, 1 g of allyl epoxy polyether, 3 g of 1-hexadecene and isopropanol were added in sequence, the temperature was slowly raised to 70°C in a constant temperature oil bath, chloroplatinic acid catalyst was added, the temperature was continued to rise to 90°C, and after reacting for 3 h, a long-chain alkyl polyether modified intermediate was obtained; The long-chain alkyl polyether modified intermediate is cooled to 50° C., and N-(2-hydroxyethyl)piperazine is added dropwise for 1 hour. After the addition is completed, the reaction is continued at a constant temperature for 3 hours. After the solution becomes transparent, low-boiling point substances are removed by reduced pressure distillation to obtain a long-chain alkyl polyether-amino modified silicone oil.

[0018] The preparation method of the release agent for plastic product processing comprises the following steps: 20 parts by weight of chain alkyl polyether-amino modified silicone oil and 1.5 parts by weight of surfactant hexadecanol polyoxyethylene ether were poured into a reaction kettle, and then 58 parts by weight of deionized water were added, and the temperature in the reaction kettle was adjusted to 80° C., and then mixed and stirred at a stirring speed of 400 rpm for 30 minutes to obtain an emulsified mixture; Pour 20 parts by weight of methylphenyl hydrogenated silicone oil into the reaction kettle containing the emulsified mixture, adjust the temperature to 80° C., stir at a stirring speed of 1800 rpm for 2 hours, and obtain a composite mixture after the stirring is completed; Add 0.5 parts by mass of stabilizer polyethylene glycol to the reaction kettle containing the composite mixture, and then stir at a speed of 240 rpm for 40 minutes, and then use a regulator to adjust the pH value to 6-7 to obtain a finished release agent for plastic product processing.

[0019] Embodiment 2 The preparation method of methylphenyl hydrogen-containing silicone oil comprises at least the following steps: Add 10 ml of diphenyldimethoxysilane monomer, 35 ml of 60 wt% sulfuric acid as a catalyst and 25 ml of toluene into a three-necked flask, and perform hydrolysis reaction at 85°C (bath temperature) for 6 hours under stirring to obtain diphenyldihydroxysilane; The diphenyldihydroxysilane obtained above was added into a three-necked flask, and 10 ml of methyl hydrogenated silicone oil and 5 ml of 98 wt % concentrated sulfuric acid were added in sequence under stirring. The mixture was reacted at 85° C. (bath temperature) for 12 h, and washed with distilled water until neutral. The solvent and small molecular compounds were removed by rotary evaporation to obtain methylphenyl hydrogenated silicone oil.

[0020] The long-chain alkyl polyether-amino-modified silicone oil component and preparation method are the same as those in Example 1.

[0021] In the preparation step of the release agent for plastic product processing, an equal amount of methylphenyl hydrogenated silicone oil is replaced with the methylphenyl hydrogenated silicone oil prepared in this embodiment, and other components and preparation methods are the same as those in Example 1.

[0022] Example 3 The preparation method of long-chain alkyl polyether-amino modified silicone oil comprises the following steps: In a 250 mL three-necked flask equipped with a thermometer, a stirrer and a reflux condenser, 20 g of hydrogenated silicone oil, 1 g of allyl epoxy polyether, 3 g of 1-hexadecene and isopropanol were added in sequence, the temperature was slowly raised to 80°C in a constant temperature oil bath, chloroplatinic acid catalyst was added, the temperature was continued to rise to 100°C, and after reacting for 2 h, a long-chain alkyl polyether modified intermediate was obtained; The long-chain alkyl polyether modified intermediate is cooled to 60°C, and N-(2-hydroxyethyl)piperazine is added dropwise for 1 hour. After the addition is completed, the reaction is continued at a constant temperature for 3 hours. After the solution becomes transparent, low-boiling point substances are removed by reduced pressure distillation to obtain a long-chain alkyl polyether-amino modified silicone oil.

[0023] The components and preparation method of the methylphenyl hydrogen silicone oil are the same as those in Example 1.

[0024] In the preparation step of the release agent for plastic product processing, the long-chain alkyl polyether-amino-modified silicone oil is replaced by an equal amount of the long-chain alkyl polyether-amino-modified silicone oil prepared in this embodiment, and the other components and preparation method are the same as those in Example 1.

[0025] Example 4 The preparation method of a release agent for plastic product processing comprises the following steps: 15 parts by mass of the alkyl polyether-amino-modified silicone oil obtained in Example 1 and 1.5 parts by mass of the surfactant hexadecanol polyoxyethylene ether were poured into a reaction kettle, and then 63 parts by mass of deionized water were added, and the temperature in the reaction kettle was adjusted to 80° C., and then mixed and stirred at a stirring speed of 400 rpm for 20 minutes to obtain an emulsified mixture; Pour 20 parts by weight of the methylphenyl hydrogenated silicone oil obtained in Example 1 into the reaction kettle where the emulsified mixture is located, adjust the temperature to 80° C., stir at a stirring speed of 1800 rpm for 2.5 hours, and obtain a composite mixture after the stirring is completed; Add 0.5 parts by mass of stabilizer polyethylene glycol to the reaction kettle containing the composite mixture, and then stir at a speed of 240 rpm for 40 minutes, and then use a regulator to adjust the pH value to 6-7 to obtain a finished release agent for plastic product processing.

[0026] Comparative Example 1 The preparation step of preparing methylphenyl hydrogen-containing silicone oil was omitted.

[0027] The long-chain alkyl polyether-amino-modified silicone oil component and preparation method are the same as those in Example 1.

[0028] In the preparation steps of the release agent for plastic product processing, methylphenyl hydrogenated silicone oil is replaced with dimethyl silicone oil in equal amounts, and other components and preparation methods are the same as those in Example 1.

[0029] Comparative Example 2 The step of preparing the long-chain alkyl polyether-amino-modified silicone oil was omitted.

[0030] The components and preparation method of the methylphenyl hydrogen silicone oil are the same as those in Example 1.

[0031] In the preparation step of the release agent for plastic product processing, the long-chain alkyl polyether-amino-modified silicone oil is replaced with an equal amount of the traditional emulsifier fatty alcohol polyoxyethylene ether, and the other components and preparation method are the same as those in Example 1.

[0032] Performance Testing Oil floating condition: observe whether there are oil spots, oil threads and other oily substances on the surface of the release agent emulsions obtained in Examples 1-4 and Comparative Examples 1-2. If there are oily substances, it is judged that there is oil floating, otherwise it is judged that there is no oil floating; the test results are shown in the table below.

[0033] Storage stability: The release agent emulsions obtained in Examples 1-4 and Comparative Examples 1-2 were stored at room temperature for 6 months to observe whether stratification and oil bleaching occurred; the test results are shown in the table below.

[0034] High temperature demoulding performance: The high temperature adhesion performance of the release agents obtained in Examples 1-4 and Comparative Examples 1-2 was measured. A 50×50×8 (unit: mm) SS-41 test piece was used as the research object. The adhesion performance of the release agent to the test piece at 300°C was measured by a pneumatic spray coating method for 5s. The test results are shown in the table below.

[0035]

[0036] As can be seen from the above table, the mold release agent for plastic product processing prepared in the present application has good storage stability, high temperature adhesion and thermal stability. Comparative Example 1 uses traditional dimethyl silicone oil as the main mold release agent, which does not have high temperature resistance and thermal stability. When the temperature exceeds 200°C, the adhesion of the mold release agent significantly deteriorates, and compared with the long-chain alkyl polyether-amino-modified silicone oil prepared by the present invention, it does not produce a better emulsification effect. Comparative Example 2 does not use long-chain alkyl polyether-amino-modified silicone oil. Although the obtained mold release agent also has a certain thermal stability, the methylphenyl hydrogenated silicone oil is not completely compatible with the traditional emulsifier, and the optimal emulsification effect cannot be achieved, thereby affecting the adhesion performance of the mold release agent at high temperature.

[0037] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A release agent for plastic product processing, characterized in that: At least the following raw materials by weight: Methylphenyl hydrogen silicone oil 15-20; Long chain alkyl polyether-amino modified silicone oil 15-25; Surfactant 1-3; Stabilizer 0.1-1; Deionized water 50-70.

2. A release agent for plastic product processing according to claim 1, characterized in that: The preparation method of the methylphenyl hydrogen-containing silicone oil at least comprises the following steps: Add diphenyldimethoxysilane monomer, 60wt% sulfuric acid as a catalyst and toluene into a three-necked flask, and perform hydrolysis reaction at 50-100°C for 4-6h under stirring to obtain diphenyldihydroxysilane; Methyl hydrogenated silicone oil and 98 wt % concentrated sulfuric acid are sequentially added to the diphenyldihydroxysilane under stirring, reacted at 50-100° C. for 10-15 hours, and washed with distilled water until neutral to obtain the methylphenyl hydrogenated silicone oil.

3. A release agent for plastic product processing according to claim 2, characterized in that: The mass ratio of the diphenyldimethoxysilane monomer to the toluene is 1:3-4, and the mass ratio of the diphenyldihydroxysilane to the methyl hydrogen silicone oil is 1-3:

1.

4. A release agent for plastic product processing according to claim 1, characterized in that: The preparation method of the long-chain alkyl polyether-amino modified silicone oil comprises the following steps: In a 250 mL three-necked flask equipped with a thermometer, a stirrer and a reflux condenser, hydrogenated silicone oil, allyl epoxy polyether, 1-hexadecene and isopropanol were added in sequence, the temperature was slowly raised to 65-80°C in a constant temperature oil bath, chloroplatinic acid catalyst was added, the temperature was continued to be raised to 90-100°C, and after reacting for 2-3 hours, a long-chain alkyl polyether modified intermediate was obtained; The long-chain alkyl polyether modified intermediate is cooled to 40-50°C, and N-(2-hydroxyethyl)piperazine is added dropwise for 1-2 hours. After the addition is completed, the reaction is continued at a constant temperature for 2-3 hours. After the solution becomes transparent, the low-boiling point substances are removed by reduced pressure distillation to obtain the long-chain alkyl polyether-amino modified silicone oil.

5. A release agent for plastic product processing according to claim 4, characterized in that: The mass ratio of the hydrogen-containing silicone oil, the allyl epoxy polyether and the 1-hexadecene is 18-20:1:2-3, and the molar ratio of the allyl epoxy polyether and the N-(2-hydroxyethyl)piperazine is 1:

1.

6. A release agent for plastic product processing according to claim 1, characterized in that: The stabilizer is a mixture of one or more of polyethylene glycol, sodium carboxymethyl cellulose, calcium chloride or ammonium chloride in any proportion.

7. A release agent for plastic product processing according to claim 1, characterized in that: The surfactant is a mixture of one or more of isomeric tridecanol polyoxyethylene ether, lauric acid polyoxyethylene ether, polyvinyl alcohol, oleic acid polyoxyethylene ether, lauryl alcohol polyoxyethylene ether, hexadecanol polyoxyethylene ether or stearyl alcohol polyoxyethylene ether in any proportion.

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