A semi-permanent release agent based on POSS-based organosilicon emulsifier and preparation method thereof

Abstract

The present invention relates to the field of release agents and specifically discloses a semi-permanent release agent based on a POSS-based organosilicon emulsifier and a preparation method thereof. The semi-permanent release agent based on a POSS-based organosilicon emulsifier comprises the following components: 19.8-20.2 parts of a curing agent; 10 parts of a hydroxy silicone oil; 0.89-0.91 parts of a POSS-based organosilicon emulsifier; 88-92 parts of water; and the POSS-based organosilicon emulsifier is prepared by a synthetic reaction of silsesquioxane and methoxypolyethylene glycol methacrylate groups under chloroplatinic acid catalysis. The present invention has the advantages of reducing demoulding force and reducing the post-processing problems caused by the transfer of low-molecular emulsifiers to products.

Description

Technical Field

[0001] The invention relates to the field of release agents, in particular to a semi-permanent release agent based on a POSS-based organosilicon emulsifier and a preparation method thereof. Background Art

[0002] A release agent is a functional substance placed between the mold and the finished product. It can easily separate the product from the mold surface and is a consumable auxiliary agent that helps the product to be removed from the mold.

[0003] In recent years, due to increasingly stringent environmental protection requirements, water-based semi-permanent release agents have been increasingly researched and developed. This type of release agent has the dual characteristics of environmental protection and long-lasting demoulding, and therefore has broad application prospects. However, water-based release agents require the addition of emulsifiers to convert the active ingredients of the release agent into stable small particles. The emulsifiers used in existing release agents usually use anionic surfactants or non-ionic surfactants. The amount of these surfactants added is usually about 7-20% of the emulsified silicone material. Therefore, a large amount of emulsifier will remain after the system dries, causing the demoulding interface to have a larger demoulding force. What's more serious is that a large amount of emulsifier will also be transferred to the product, causing problems in post-processing of the product (painting, bonding, etc.). These problems may make water-based release agents simply unusable in many application scenarios. Summary of the Invention

[0004] In order to solve the problems currently plaguing the industry, it is necessary to further reduce the demoulding force and reduce the post-processing problems caused by the transfer of low-molecular emulsifiers to the products. The present application provides a semi-permanent demoulding agent based on a POSS-based silicone emulsifier and a preparation method thereof.

[0005] In the first aspect, the present application provides a semi-permanent release agent based on a POSS-based silicone emulsifier, which adopts the following technical solution:

[0006] A semi-permanent release agent based on a POSS-based organosilicon emulsifier comprises the following components in parts by mass:

[0007] 19.8-20.2 parts of curing agent;

[0008] 10 parts of hydroxy silicone oil;

[0009] 0.89-0.91 parts of POSS-based silicone emulsifier;

[0010] 88-92 parts water;

[0011] The POSS-based organosilicon emulsifier is prepared by a synthetic reaction between silsesquioxane and methoxy polyethylene glycol methacrylate under the catalysis of chloroplatinic acid.

[0012] By adopting the above technical solution, the POSS-based silicone emulsifier has good emulsion stability, and does not require anionic or cationic emulsifiers, avoiding changes in emulsion stability caused by changes in charge or pH value. In addition, the required amount of POSS-based silicone emulsifier is relatively small, so it can reduce the post-processing problems of the product caused by the large amount of emulsifier transferred to the product, such as the product not being able to adhere to the adhesive or the surface paint adhesion being poor and shrinkage holes. In addition, the POSS-based silicone emulsifier has the effect of strengthening the hardness and increasing the toughness of the final coating, making the release coating stronger and more wear-resistant, thereby increasing the number of release agent demolding times.

[0013] Preferably, the curing agent has the following general formula:

[0014]

[0015] Wherein R is an alkyl group with 1 to 4 carbon chains or an alkoxy group with 1 to 4 carbon chains, and T, P, and Q are alkoxy groups with 1 to 4 carbon chains or propylamino groups.

[0016] By adopting the above technical solution, in order to obtain a coating with a certain strength, the curing agent in the system needs to have 3-4 functionalities. By specifically selecting the curing agent, the strength of the release agent can be further improved, thereby achieving a better effect of increasing the number of demoulding times.

[0017] Preferably, the curing agent is a compound of tetraethoxysilane and methyltrimethoxysilane.

[0018] Preferably, the preparation method of the POSS-based organosilicon emulsifier comprises the following steps:

[0019] Step 1), mixing silsesquioxane and a toluene solution, and then adding chloroplatinic acid to obtain a premix;

[0020] Step 2), adding methoxy polyethylene glycol methacrylate to the premix, reacting at 50-80° C. for 8-14 hours to obtain a reactant;

[0021] Step 3), removing the catalyst and toluene solvent from the reactants to obtain a POSS-based organosilicon emulsifier.

[0022] By adopting the above technical solution, a POSS-based silicone emulsifier is prepared, which has a better performance-improving effect on the release agent after being added to the release agent. Moreover, a small amount of emulsifier can meet the needs, reducing or eliminating the adverse effects of the emulsifier on post-processing.

[0023] Preferably, in step 3), activated carbon is added to the reactants, stirred for 30-35 minutes, and the activated carbon is filtered off to remove the catalyst.

[0024] By adopting the above technical solution, the influence of the catalyst on subsequent reactions is reduced, the quality of the emulsifier is improved, and the performance of the release agent is better improved.

[0025] Preferably, in step 3), the toluene solution is removed by rotary evaporation.

[0026] By adopting the above technical solution, the solvent residue can be better reduced, the quality of the emulsifier can be further improved, and the contamination of the release agent to the product can be reduced.

[0027] Preferably, the structural formula of the silsesquioxane is as follows:

[0028]

[0029] Wherein, R is a C4-C18 alkyl chain.

[0030] Preferably, the structural formula of the methoxy polyethylene glycol methacrylate group is as follows:

[0031]

[0032] Wherein, n=4-15.

[0033] In a second aspect, the present application provides a method for preparing a semi-permanent release agent based on a POSS-based silicone emulsifier, using the following technical solution:

[0034] A method for preparing the above-mentioned semi-permanent release agent based on a POSS-based organosilicon emulsifier is characterized in that it comprises the following steps:

[0035] Step 01), mixing a curing agent and hydroxy silicone oil to obtain an oil phase liquid;

[0036] Step 02), the oil phase liquid is added to a mixed solution of POSS-based organosilicon emulsifier and water, and emulsified using a homogenizer to obtain a semi-permanent release agent based on the POSS-based organosilicon emulsifier.

[0037] Preferably, the kinematic viscosity of the hydroxy silicone oil is between 10-1000 cst.

[0038] By adopting the above technical solution, a homogenizer is used to form a stable emulsion of fine particles of the release agent, thereby forming a better quality release coating, more demoulding times, and the product has no defects on the surface. The emulsion has good stability and a long storage time, and therefore has higher economic value.

[0039] In summary, this application has the following beneficial effects:

[0040] 1. The present application adopts a POSS-based organosilicon emulsifier, which has good emulsion stability and does not require anionic or cationic emulsifiers, thus avoiding changes in emulsion stability caused by changes in charge or pH value, greatly reducing the requirement for dilution water, and the required amount of POSS-based organosilicon emulsifier is relatively small, so it can greatly reduce the post-processing problems of the product such as product adhesion problems or poor surface paint adhesion and shrinkage cavities caused by the large amount of emulsifier transferred to the product. In addition, the POSS-based organosilicon emulsifier has the effect of strengthening the hardness and increasing the toughness in the final coating, making the release coating stronger and more wear-resistant, thereby increasing the number of release agent demoulding times.

[0041] 2. In this application, it is preferred to use an alkyl chain of C4-C18 in the silsesquioxane, so that the emulsification stability of the emulsifier is higher and the emulsifier transferability is small, and the effect of improving the strength of the release agent is better, with a higher number of demolding times.

[0042] 3. In this application, it is preferred to use methoxy polyethylene glycol methacrylate with n=4-15, so as to further enhance the emulsifying effect of the emulsifier and reduce the amount of emulsifier used, so that the stability of the release agent after emulsification is higher, the release agent strength is higher, the demolding effect is better, and the demolding times of the release agent are further increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is the nuclear magnetic spectrum of the POSS-based organosilicon emulsifier of Example 1;

[0044] Figure 2 This is a particle size distribution diagram of the semi-permanent release agent based on the POSS-based silicone emulsifier of Example 1. DETAILED DESCRIPTION

[0045] The present application is further described in detail below with reference to the accompanying drawings and embodiments.

[0046] Example 1

[0047] A semi-permanent release agent based on a POSS-based silicone emulsifier comprises the following components:

[0048] Curing agent, hydroxy silicone oil, POSS-based silicone emulsifier, water.

[0049] Wherein, the curing agent is a compound of tetraethoxysilane and methyltrimethoxysilane.

[0050] Wherein, the preparation method of POSS-based organosilicon emulsifier is as follows:

[0051] Step 1) 30 g of silsesquioxane (Hybrid Plastics, USA) and 30 ml of toluene were placed in a three-necked flask, followed by the addition of 0.03 g of chloroplatinic acid, and nitrogen was introduced to maintain the flask free of water and oxygen to obtain a premix;

[0052] Step 2) 60 g of methoxy polyethylene glycol methacrylate was evacuated to 10 kPa at 80 ° C., maintained for 10 min to remove moisture, and then added dropwise to the premix at a dropping rate of 3 g / min. After the addition was complete, the temperature was kept at 50 ° C. and the reaction was carried out for 8 hours to obtain the reactant;

[0053] Step 3), the reactant was naturally cooled to room temperature, 2g of dry activated carbon was added, magnetic stirring was carried out for 30min, the rotation speed was 1000r / min, chloroplatinic acid in the reactant was adsorbed, the activated carbon was filtered to remove the chloroplatinic acid, and the filtrate was then placed in a rotary evaporator for rotary evaporation and concentrated at a constant temperature of 45°C, 10KPa, and rotary evaporation for 10min to remove the toluene solvent, and finally an oily transparent product was obtained, which was a POSS-based organosilicon emulsifier with a yield of 80.50%.

[0054] Among them, the structural formula of silsesquioxane is as follows:

[0055]

[0056] R=C8H 17 .

[0057] Among them, the structural formula of methoxy polyethylene glycol methacrylate group is as follows:

[0058]

[0059] n=10.

[0060] The structural formula of POSS-based silicone emulsifier is as follows:

[0061]

[0062] R=C8H 17 .

[0063] n=10.

[0064] The reaction equation for the preparation method of POSS-based silicone emulsifier is as follows:

[0065]

[0066] R=C8H 17 .

[0067] n=10.

[0068] The NMR spectrum of the POSS-based silicone emulsifier used in this example is shown in Figure 1 .

[0069] The preparation method of the semi-permanent release agent based on POSS-based silicone emulsifier is as follows:

[0070] Step 01) 100g of tetraethoxysilane, 100g of methyltrimethoxysilane, and 100g of hydroxy silicone oil with a viscosity of 1000cst are put into a beaker, the speed is 600r / min, and stirring is carried out for 30s to obtain an oil phase liquid.

[0071] Step 02), 9gPOSS base organosilicon emulsifier and 900g water are dropped in there-necked flask, rotating speed 1200r / min, stirs 30s, makes aqueous phase liquid, then the 300g oil phase liquid that step 01) is made drops in aqueous phase liquid, homogenizing emulsification, emulsification shear rate is 30m / s, emulsification time 10min, makes aqueous emulsion, is the semi-permanent type releasing agent based on POSS base organosilicon emulsifier.Record the semi-permanent type releasing agent particle diameter D50=156nm based on POSS base organosilicon emulsifier by laser particle size analyzer.

[0072] The particle size distribution of the semi-permanent release agent based on POSS-based silicone emulsifier in this embodiment is shown in Figure 2 .

[0073] The hydroxy silicone oil is commercially available and has a CAS number of 70131-67-8.

[0074] Tetraethoxysilane is commercially available and has a CAS number of 78-10-4.

[0075] Methyltrimethoxysilane is commercially available with a CAS number of 1185-55-3.

[0076] Example 2

[0077] A semi-permanent release agent based on a POSS-based organosilicon emulsifier, compared with Example 1, differs only in that:

[0078] In the preparation method of POSS-based silicone emulsifier:

[0079] In step 2), methoxy polyethylene glycol methacrylate is added dropwise to the premix, and the mixture is reacted at 80° C. for 14 h to obtain a reactant.

[0080] In step 3), 10 g of dry activated carbon was added and magnetic stirring was performed for 35 min.

[0081] Example 3

[0082] A semi-permanent release agent based on a POSS-based organosilicon emulsifier, compared with Example 1, differs only in that:

[0083] The structural formula of silsesquioxane is:

[0084] R=C8H 19 .

[0085] The structural formula of methoxy polyethylene glycol methacrylate group:

[0086] n=10.

[0087] Example 4

[0088] A semi-permanent release agent based on a POSS-based organosilicon emulsifier, compared with Example 1, differs only in that:

[0089] The structural formula of silsesquioxane is:

[0090] R=C 16 H 37 .

[0091] The structural formula of methoxy polyethylene glycol methacrylate group:

[0092] n=15.

[0093] Example 5

[0094] A semi-permanent release agent based on a POSS-based organosilicon emulsifier, compared with Example 1, differs only in that:

[0095] The preparation method of the semi-permanent release agent based on POSS-based silicone emulsifier is as follows:

[0096] Step 01) 99g of tetraethoxysilane, 99g of methyltrimethoxysilane, and 100g of 1000cst viscosity hydroxy silicone oil are put into a beaker, the speed is 600r / min, and stirring is carried out for 30s to obtain an oil phase liquid.

[0097] Step 02), 8.9gPOSS base organosilicon emulsifier and 880g water are dropped in there-necked flask, rotating speed 1200r / min, stir 30s, make aqueous phase liquid, then the 298g oil phase liquid that step 01) is made is dropped in aqueous phase liquid, homogenizing emulsification, emulsification shear rate is 30m / s, emulsification time 10min, makes aqueous emulsion, is the semi-permanent type releasing agent based on POSS base organosilicon emulsifier.Emulsion particle diameter D50=170nm is recorded by laser particle size analyzer.

[0098] Example 6

[0099] A semi-permanent release agent based on a POSS-based organosilicon emulsifier, compared with Example 1, differs only in that:

[0100] The preparation method of the semi-permanent release agent based on POSS-based silicone emulsifier is as follows:

[0101] Step 01) 101 g of tetraethoxysilane, 101 g of methyltrimethoxysilane, and 100 g of 1000 cSt viscosity hydroxy silicone oil were put into a beaker, and the speed was 600 r / min and stirred for 30 s to obtain an oil phase liquid.

[0102] Step 02), 9.1gPOSS base organosilicon emulsifier and 920g water are dropped into there-necked flask, rotating speed 1200r / min, stir 30s, make aqueous phase liquid, then the 302g oil phase liquid that step 01) is made is dropped into aqueous phase liquid, homogenizing emulsification, emulsification shear rate is 30m / s, emulsification time 10min, makes aqueous emulsion, is the semi-permanent type releasing agent based on POSS base organosilicon emulsifier.Emulsion particle diameter D50=143nm is recorded by laser particle size analyzer.

[0103] Comparative Example 1

[0104] A release agent comprising the following components:

[0105] Curing agent, hydroxy silicone oil, emulsifier, water.

[0106] Wherein, the curing agent is a compound of tetraethoxysilane and methyltrimethoxysilane.

[0107] Among them, the emulsifier is sodium lauryl sulfate.

[0108] The preparation method of the release agent is as follows:

[0109] Step 01) 100g of tetraethoxysilane, 100g of methyltrimethoxysilane, and 100g of hydroxy silicone oil with a viscosity of 1000cst are put into a beaker, the speed is 600r / min, and stirring is carried out for 30s to obtain an oil phase liquid.

[0110] In step 02), 24 g of emulsifier and 900 g of water were put into a three-necked flask, the speed was 1200 r / min, and the stirring was performed for 30 seconds to obtain an aqueous phase liquid. Then, 300 g of the oil phase liquid obtained in step 01) was added to the aqueous phase liquid, homogenized and emulsified, the emulsification shear speed was 30 m / s, and the emulsification time was 10 minutes to obtain an aqueous emulsion, which was the release agent.

[0111] Comparative Example 2

[0112] A release agent, compared with Comparative Example 1, the only difference is:

[0113] In step 02), the amount of emulsifier used is 45g.

[0114] Comparative Example 3

[0115] A release agent, compared with Comparative Example 2, the only difference is:

[0116] The emulsifier is dodecylphenol polyoxyethylene ether.

[0117] Comparative Example 4

[0118] A release agent, compared with Comparative Example 2, the only difference is:

[0119] The emulsifier is triethanolamine.

[0120] Comparative Example 5

[0121] A semi-permanent release agent based on a POSS-based organosilicon emulsifier, compared with Example 1, differs only in that:

[0122] The structural formula of silsesquioxane is:

[0123] R=C3H7.

[0124] The structural formula of methoxy polyethylene glycol methacrylate group:

[0125] n=10.

[0126] Comparative Example 6

[0127] A semi-permanent release agent based on a POSS-based organosilicon emulsifier, compared with Example 1, differs only in that:

[0128] The structural formula of silsesquioxane is:

[0129] R=C 18 H 39 .

[0130] The structural formula of methoxy polyethylene glycol methacrylate group:

[0131] n=17.

[0132] Test Method

[0133] Experiment 1

[0134] Centrifugal stability test of release agent emulsion:

[0135] 10 ml of the release agent of each embodiment and comparative example was taken and placed in a centrifuge at 3000 rpm for 30 min to observe whether precipitation occurred.

[0136] Experiment 2

[0137] Transfer test of release agent:

[0138] The release agent of each embodiment and comparative example was sprayed on the surface of the stainless steel plate at a spraying amount of 10 g / m 2, heat curing at 110℃ for 5 minutes to form a release coating, then compact the tape on the surface of the release coating, peel off the tape and fold it in half and bond it together, then measure the tape peeling force (180° peeling angle) by a tensile testing machine, and judge the transferability of the release agent by the peeling force. The peeling force is the average of 5 times. The lower the peeling force, the more serious the transfer, and the higher the peeling force, the less the transfer.

[0139] The tape used in the experiment was 3M tape, which was directly folded in half and bonded before the coating was adhered. The tested peel force was 8N.

[0140] Experiment 3

[0141] Determination of demoulding times for semi-permanent release agents based on POSS-based silicone emulsifiers:

[0142] Bisphenol A epoxy resin was injected into the mold. After curing, the lower mold was fixed on a tensile testing machine, and the upper mold was pulled to detect the demolding force when the mold was opened. When the demolding force was ≥200N, it was considered that the demolding effect was poor and the release agent needed to be added. The number of demolding times with a demolding force <200N was recorded to obtain the number of demolding times of the release agent in each embodiment and comparative example.

[0143] Bisphenol A type epoxy resin includes 10 parts of curing agent and 100 parts of epoxy resin.

[0144] The curing agent was purchased from Huntsman Corporation and its brand name is ARADUR 3426-1H CL.

[0145] The epoxy resin was purchased from Huntsman Corporation and its brand name was ARALDITE LY 3573E CL.

[0146] When preparing bisphenol A epoxy resin, the curing agent and epoxy resin were stirred at a rotation speed of 600 r / min for 1 minute to mix evenly, then injected into a mold and cured at 110° C. for 7 minutes to obtain a sample to be tested.

[0147] The mold includes an upper mold and a lower mold. The upper mold and the lower mold have the same shape. The mold cavity of the upper mold is a circular blind hole with a diameter of 10 cm and a depth of 1 cm. The obtained product is cylindrical with a diameter of 10 cm and a height of 2 cm.

[0148] Test 4

[0149] The emulsion was placed in a sealed bottle 10 cm high at room temperature, and the state of the emulsion was observed after a period of time.

[0150] The specific experimental data of Experiments 1-4 are shown in Table 1.

[0151] Table 1

[0152]

[0153] According to the data comparison of Example 1 and Comparative Examples 1-4 in Table 1, the release agent of Example 1 adopts a POSS-based silicone emulsifier, and the emulsifier dosage is greatly reduced while the emulsification stability is high, which has less effect on the peeling force of the adhesive tape, proving that the emulsifier migrates less, reduces the pollution to the product, significantly improves the number of peeling times, is durable, has higher economic value, eliminates the need for frequent spraying of the release agent during the production process, and reduces the complexity of the operation.

[0154] Comparing the data in Table 1 for Example 1 and Comparative Examples 5-6 reveals that when the chain length of R in the silsesquioxane structure is too long or too short, and when n in the methoxy polyethylene glycol methacrylate structure is too large or too small, the number of demolding attempts decreases. The specific selection of R and n in Example 1 results in the highest number of demolding attempts. Meanwhile, inappropriate R and n values ​​can deteriorate the stability of the emulsion.

[0155] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A semi-permanent release agent based on a POSS-based organosilicon emulsifier, characterized in that: The composition includes the following parts by weight: 19.8-20.2 parts of curing agent; 10 parts of hydroxy silicone oil; 0.89-0.91 parts of POSS-based silicone emulsifier; 88-92 parts water; The preparation method of the POSS-based organosilicon emulsifier comprises the following steps: Step 1), mixing silsesquioxane and a toluene solution, and then adding chloroplatinic acid to obtain a premix; Step 2), adding methoxy polyethylene glycol methacrylate to the premix, reacting at 50-80° C. for 8-14 hours to obtain a reactant; Step 3), removing the catalyst and toluene solvent in the reactant to obtain a POSS-based organosilicon emulsifier; The structural formula of the silsesquioxane is as follows: Wherein, R is a C4-C18 alkyl chain; The structural formula of the methoxy polyethylene glycol methacrylate group is as follows: Wherein, n=4-15.

2. a kind of semi-permanent type release agent based on POSS base organosilicon emulsifier according to claim 1, is characterized in that: The general formula of the curing agent is: Wherein R is an alkyl group with 1 to 4 carbon chains or an alkoxy group with 1 to 4 carbon chains, T, P, and Q are alkoxy groups with 1 to 4 carbon chains, and the functionality of the alkoxy group in the curing agent is not less than 3.

3. a kind of semi-permanent type releasing agent based on POSS base organosilicon emulsifier according to claim 1, is characterized in that: In the step 3), activated carbon is added to the reactants, stirred for 30-35 minutes, and the activated carbon is filtered off to remove the catalyst.

4. a kind of semi-permanent type releasing agent based on POSS base organosilicon emulsifier according to claim 1, is characterized in that: In the step 3), the toluene solution is removed by rotary evaporation.

5. a preparation method of a semi-permanent release agent based on the arbitrary described POSS-based organosilicon emulsifier according to claim 1-4, characterized in that: The following steps are involved: Step 01), mixing a curing agent and hydroxy silicone oil to obtain an oil phase liquid; Step 02), the oil phase liquid is added to a mixed solution of POSS-based organosilicon emulsifier and water, and emulsified using a homogenizer to obtain a semi-permanent release agent based on the POSS-based organosilicon emulsifier.

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