Writable organic silicon emulsion release agent and preparation method thereof

Abstract

The invention discloses a writable organic silicon emulsion release agent which is prepared from 20 to 40 parts of vinyl silicone oil, 1 to 20 parts of modified vinyl silicone oil, 0.5 to 8 parts of hydrogen-containing silicone oil, 0.5 to 3 parts of an emulsifier, 0.1 to 10 parts of water-soluble resin and 40 to 100 parts of deionized water. According to the writable organic silicon emulsion release agent provided by the invention, on one hand, moderate release force can be obtained, on the other hand, the writing effect of an oil pen can be achieved on a release layer, and the requirements of writing, printing and separation of materials are accurately balanced. A benzene ring structure and a carbamate fragment are introduced into a molecular system. A rigid plane structure of a benzene ring can enhance a pi-pi accumulation effect between molecules, a polar group in a carbamate fragment and an active site on the surface of a base material generate multiple interactions such as a hydrogen bond and Van der Waals force, and the adhesive force and the compatibility of the release agent and the base material are remarkably improved; the ink can generate moderate adsorption and infiltration effects with pigments, resin and other components in oil pen ink, and an excellent oil pen writing effect is achieved.

Description

Technical Field

[0001] The present invention relates to a writable silicone emulsion release agent and a preparation method thereof. Background Art

[0002] In the fields of tapes, labels, etc., silicone release agents are widely used. Classified by product form, silicone release agents are mainly solventless, solvent-based, and emulsion-based. For example, CN 109504281 A describes an aqueous emulsion release agent prepared by using traditional vinyl silicone oil combined with hydrogen-containing silicone oil and an emulsifier. Although this type of release agent has a fast curing speed, good anchoring property, and light release force, the paper coated with this type of release agent is difficult to write on.

[0003] Non-silicon and non-fluorine release agents perform excellently in printing and writable properties, mainly including polyolefin resins, paraffin wax, and its derivatives. For example, in CN 114014959 A, a release agent with adjustable release force and adjustable melting point is prepared by modifying polyvinyl alcohol with octadecyl isocyanate. The advantage of this type of release agent is that it has a relatively large peeling force and is suitable for industrial scenarios with high requirements for release strength, but this conflicts with easily peelable application scenarios. And the long-chain alkyl-modified acrylate release agent, with its unique molecular structure design, exhibits extremely excellent adhesion performance and can achieve firm bonding with a variety of materials, and is widely used in fields such as packaging and label printing. CN111206456A prepared an environmentally friendly non-silicon release agent through an aqueous formulation and the synthesis of 3-hydroxy polyacrylate octadecylcarbamate, but the process is too complex and relies on aprotic solvents, with high costs and being unfriendly to the environment. If the non-silicon and non-fluorine release agents are innovatively combined with silicone release agents through advanced processes such as emulsification, an environmentally friendly silicone emulsion release agent product with medium and low release force and writable properties can be developed. Summary of the Invention

[0004] One of the purposes of the present invention is to provide a writable silicone emulsion release agent and a preparation method thereof. On the one hand, a moderate release force can be obtained. On the other hand, the writing effect of an oil-based pen can be achieved on the release layer, precisely balancing the requirements of material writing, printing, and separation.

[0005] One of the purposes of the present invention is achieved through the following technical solutions: A writable silicone emulsion release agent is prepared from 20 - 40 parts of vinyl silicone oil, 1 - 20 parts of modified vinyl silicone oil, 0.5 - 8 parts of hydrogen-containing silicone oil, 0.5 - 3 parts of emulsifier, 0.1 - 10 parts of water-soluble resin, and 40 - 100 parts of deionized water.

[0006] The modified vinyl silicone oil is a compound having the structure of formula (I):

[0007] Among them, (x + y) = 10 - 500 and is an integer.

[0008] The modified vinyl silicone oil is a compound having the structure of formula (II):

[0009] Among them, (q + p) = 10 - 500 and is an integer; Among them, R1 is one of methyl and phenylmethylene; R2 is a linear or branched hydrocarbon chain segment with 7 - 25 carbon atoms, and one or more of the carbon atoms may be substituted with hydroxyl, carbonyl, urethane, and phenyl groups, etc., and a urethane-substituted hydrocarbon chain segment is preferred.

[0010] The hydrogen-containing silicone oil is a compound having the structure of formula (III), and the molar ratio of the hydrogen groups in the hydrogen-containing silicone oil to the vinyl groups in the vinyl silicone oil is 1.0 - 3.5:1.

[0011] Among them, (m + n) = 10 - 300 and is an integer.

[0012] The emulsifier is a non-ionic surfactant, and at least one of the non-ionic surfactants in the polyol type and the polyoxyethylene type can be selected. Polyol type, such as sorbitan esters, polyoxyethylene sorbitan esters, etc.; polyoxyethylene type, such as polyoxyethylene octyl phenyl ether, styrenated phenyl ether, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, alkylphenol polyoxyethylene ether, polyoxyethylene fatty alcohol ether, and isomeric alcohol polyoxyethylene ether, etc. Preferably, at least one non-ionic surfactant selected from polyoxyethylene alkyl ethers and polyoxyethylene phenyl ethers; more preferably, it is an isomeric tridecyl alcohol polyoxyethylene ether or a polyoxyethylene styrenated phenyl ether, etc. These non-ionic surfactants can be used alone or in combination of two or more. The individual non-ionic surfactant or a mixture of two or more non-ionic surfactants desirably has an HLB (hydrophilic-lipophilic balance) value of 10 to 15, such as polyether silicone, etc.

[0013] The water-soluble resin is at least one of polyvinyl alcohol, methyl cellulose, and alkyd resin. Among them, the degree of hydrolysis of polyvinyl alcohol can be selected as 80% - 98%, and at 20 °C, the polyvinyl alcohol compound can have a minimum viscosity of 5 cP in a 4% aqueous solution. The molecular weight of methyl cellulose can be selected as 1000 - 50000. Similarly to the non-ionic surfactant, the amount of the water-soluble resin is preferably the minimum amount sufficient to ensure the stability and substrate wettability of the obtained silicone emulsion composition.

[0014] Another object of the present invention is to provide a preparation method of the above-mentioned writable silicone emulsion release agent.

[0015] Specifically, a preparation method of a writable silicone emulsion release agent is provided. 20 - 40 parts of vinyl silicone oil, 1 - 20 parts of modified vinyl silicone oil, 0.5 - 8 parts of hydrogen-containing silicone oil, 0.5 - 3 parts of emulsifier, and 0.1 - 10 parts of water-soluble resin are used. The water-soluble resin is pre-dissolved in 10 - 50 parts of deionized water. The above components are fully dispersed and homogenized in a high-speed disperser, and then 30 - 50 parts of deionized water are added to obtain a writable emulsion release agent. Beneficial effects

[0016] The writable silicone emulsion release agent provided by the present invention can, on the one hand, obtain a moderate release force. On the other hand, it can achieve the writing effect of an oil-based pen on the release layer, precisely balancing the requirements of material writing, printing, and separation. The present invention introduces a benzene ring structure and a urethane fragment into the molecular system. The rigid planar structure of the benzene ring can enhance the π - π stacking interaction between molecules. The polar groups in the urethane fragment generate multiple interactions such as hydrogen bonds and van der Waals forces with the surface active sites of the substrate, significantly improving the adhesion and compatibility between the release agent and the substrate, enabling it to have a moderate adsorption and infiltration effect with components such as pigments and resins in the oil-based pen ink, achieving an excellent oil-based pen writing effect, and precisely balancing the requirements of the material in two key properties of writing, printing, and separation, opening up a new direction for the application of release materials in fields such as labels and packaging printing.

[0017] In the present invention, alkyl aromatic modified vinyl silicone oil is added to the conventional vinyl silicone oil component, and an emulsion release agent is prepared with hydrogen-containing silicone oil. Through high-temperature hydrosilylation curing, an alkyl aromatic modified silicone oil film coating can be obtained. This new type of release agent not only effectively overcomes the inherent defects of traditional release materials in key properties such as release property and writing and printing property, fully meets the stringent requirements for material versatility in the actual production process, but also highly conforms to the current global environmental protection trend, reduces the potential harm to the environment, and opens up a new path for the sustainable development of the release agent industry. Specific embodiments

[0018] The various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, characteristics, and implementation schemes of the present invention. Example 1

[0019] Mix 20 parts of vinyl silicone oil of formula (I) (x = 135, y = 0), 15 parts of octadecyl-modified vinyl silicone oil of formula (II) (q = 80, p = 20), where R1 is methyl and R2 is octadecyl carbamate propyl, 1.9 parts of hydrogen-containing silicone oil of formula (III), 0.5 part of emulsifier isomeric tridecyl alcohol polyoxyethylene ether 1380, 10 parts of polyvinyl alcohol aqueous solution (10% solid content), and 40 parts of deionized water evenly, heat up to 90 °C and disperse fully in a high-speed disperser to obtain emulsion release agent 1 with a solid content of about 44%. Example 2

[0020] Mix 20 parts of vinyl silicone oil of formula (I) (x = 135, y = 0), 15 parts of octadecyl-modified vinyl silicone oil of formula (II) (q = 80, p = 20), where R1 is methyl and R2 is octadecyl carbamate propyl, 1.9 parts of hydrogen-containing silicone oil of formula (III) (m = 100, n = 50), 0.5 part of emulsifier isomeric tridecyl alcohol polyoxyethylene ether 1380, 10 parts of polyvinyl alcohol aqueous solution (10% solid content), and 40 parts of deionized water evenly, heat up to 90 °C and disperse fully in a high-speed disperser to obtain emulsion release agent 2 with a solid content of about 44%. Example 3

[0021] Mix 20 parts of vinyl silicone oil of formula (I) (x = 135, y = 0), 5 parts of phenyl-modified vinyl silicone oil of formula (II) (q = 20, p = 5), where both R1 and R2 are phenyl, 15 parts of octadecyl-modified vinyl silicone oil (q = 80, p = 20), where R1 is methyl and R2 is octadecyl carbamate propyl, 3.1 parts of hydrogen-containing silicone oil of formula (III) (m = 100, n = 50), 0.5 part of emulsifier isomeric tridecyl alcohol polyoxyethylene ether (model 1380), 10 parts of polyvinyl alcohol aqueous solution (10% solid content), and 50 parts of deionized water evenly, heat up to 90 °C and disperse fully in a high-speed disperser to obtain emulsion release agent 3 with a solid content of about 43%. Example 4

[0022] Mix 20 parts of vinyl silicone oil of formula (I) (x = 400, y = 30), 15 parts of octadecyl-modified vinyl silicone oil of formula (II) (q = 80, p = 20), where R1 is methyl and R2 is octadecyl carbamate propyl, 7.5 parts of hydrogen-containing silicone oil of formula (III) (m = 100, n = 50), 0.5 part of emulsifier isomeric tridecyl alcohol polyoxyethylene ether 1380, 10 parts of polyvinyl alcohol aqueous solution (10% solid content), 3 parts of methyl cellulose aqueous solution (2% solid content), and 47 parts of deionized water evenly, heat up to 90 °C and disperse fully in a high-speed disperser to obtain emulsion release agent 4 with a solid content of about 43%. Example 5

[0023] Mix 20 parts of vinyl silicone oil of formula (I) (x = 400, y = 30), 15 parts of octadecylphenyl-modified vinyl silicone oil of formula (II) (q = 80, p = 20), where R1 is phenyl and R2 is octadecylcarbamate propyl, 7.5 parts of hydrogen-containing silicone oil of formula (III) (m = 100, n = 50), 0.5 part of emulsifier isomeric tridecanol polyoxyethylene ether 1380, 10 parts of polyvinyl alcohol aqueous solution (10% solid content), 1 part of methyl cellulose aqueous solution (2% solid content), and 49 parts of deionized water, stir evenly, heat up to 90 °C and disperse thoroughly in a high-speed disperser to obtain emulsion release agent 5 with a solid content of about 43%.

[0024] Comparative Example 1 Mix 40 parts of vinyl silicone oil (x = 135, y = 0), 2.5 parts of hydrogen-containing silicone oil (m = 100, n = 50), 0.5 part of emulsifier isomeric tridecanol polyoxyethylene ether 1380, 10 parts of polyvinyl alcohol aqueous solution (10% solid content), and 50 parts of deionized water, stir evenly, heat up to 90 °C and disperse thoroughly in a high-speed disperser to obtain emulsion release agent 6 with a solid content of about 43%.

[0025] Performance Test Respectively take 100 parts of the emulsion release agents in Examples 1 - 5 and Comparative Example 1, add 400 parts of deionized water, add 6 parts of emulsion platinum catalyst (such as YZ - 62B), stir evenly at room temperature, use a wire bar coater No. 1 bar to coat on the release paper, and cure under the curing conditions of 150 °C for 20 s to prepare for performance testing.

[0026] The room-temperature peel strength test method, the residual adhesion rate of the release agent, and the anchoring property test method are as follows respectively: I. Room-temperature peel strength test method of the release agent: Stick the TESA 7475 tape on the tested silicone-coated release paper according to the standard method, cut it into strips according to the tape shape, and then press it back and forth three times with a 2 kg rubber roller. Press the treated tape with a standard stainless steel bar of 50 g / cm 2 at room temperature for 20 h, place it at room temperature for 4 h, then test it with a release force tester. The tensile speed is 30 cm / min, and the tensile force at a tensile angle of 180 degrees is the room-temperature peel strength.

[0027] II. Aging peel strength test method of the release agent: Stick the TESA 7475 tape on the tested silicone-coated release paper according to the standard method, cut it into strips according to the tape shape, and then press it back and forth three times with a 2 kg rubber roller. Press the treated tape with a standard stainless steel bar of 50 g / cm 2The standard stainless steel strip is pressed at 70 °C for 20 h, placed at room temperature for 4 h, and then tested with a release force tester. The tensile speed is 30 cm / min, and the tensile force at a tensile angle of 180 degrees is the aging peel force.

[0028] III. Test method for the residual adhesion rate of the release agent: (1) Stick the Nitto 31B tape on the siliconized release paper to be tested according to the standard method, cut it into strips according to the tape shape, and then press it back and forth three times with a 2 kg rubber roller. Press the treated tape with a standard stainless steel strip of 20 g / cm 2 in an oven at 70 °C for 20 h, and take it out and place it for 1 h.

[0029] (2) Tear the Nitto 31B tape from the release paper and stick it on a clean PET film according to the standard method. After 1.5 h, test it with a release force tester. The tensile speed is 30 cm / min, and the tensile force at a tensile angle of 180 degrees is recorded. After repeating the experiment multiple times, find the average value of the release force values and record it as f2.

[0030] (3) Stick the Nitto 31B tape directly on a clean PET film according to the standard method. After 1.5 h, test it with a peel force tester. The tensile speed is 30 cm / min, and the tensile force at a tensile angle of 180 degrees is recorded. After repeating the experiment multiple times, find the average value of the peel force values and record it as f1.

[0031] (4) Residual adhesion rate = f2 / f1 × 100%.

[0032] IV. Test method for writability: Place the cured release paper on a horizontal table, and use a neutral pen to write on the release paper. Clear and continuous writing indicates good writability, broken strokes indicate average writability, and illegible writing indicates poor writability.

[0033] The performance test results of Examples 1 to 5 and the comparative example are as follows:

[0034] In summary, for the writable release paper obtained in Examples 1 - 5, the normal temperature peel force measured by the 180° peel method is all below 20 g / 25 mm, the aging peel force is basically between 25 g / 25 mm, the residual adhesion rate is above 85%, and the normal temperature peel force of Comparative Example 1 is 15 g / 25 mm, the aging peel force is 22 g / 25 mm, and the residual adhesion rate above 85% is not much different. However, the writability of Examples 1 - 5 has been improved, especially for Examples 3 - 5, which has been greatly improved.

[0035] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A writable silicone emulsion release agent, characterized in that, It is prepared from 20 - 40 parts of vinyl silicone oil, 1 - 20 parts of modified vinyl silicone oil, 0.5 - 8 parts of hydrogen-containing silicone oil, 0.5 - 3 parts of emulsifier, 0.1 - 10 parts of water-soluble resin and 40 - 100 parts of deionized water.

2. The writable silicone emulsion release agent according to claim 1, characterized in that, The modified vinyl silicone oil is a compound having the structure of formula (I): Among them, (x + y) = 10 - 500, and it is an integer.

3. The silicone emulsion release agent capable of being written according to claim 1, characterized in that, The modified vinyl silicone oil is a compound having the structure of formula (II): where (q + p) = 10 - 500, and is an integer; Wherein R1 is one of methyl and phenylmethylidene; R2 is a linear or branched hydrocarbon chain segment with 7 - 25 carbon atoms, and the carbon atoms may be substituted with one or more of hydroxyl, carbonyl, urethane, and phenyl.

4. The writable silicone emulsion release agent according to claim 1, characterized in that, The hydrogen-containing silicone oil is a compound having the structure of formula (III), and the molar ratio of the hydrogen groups in the hydrogen-containing silicone oil to the vinyl groups in the vinyl silicone oil is 1.0 - 3.5:1; Among them, (m + n) = 10 - 100 and is an integer.

5. The silicone emulsion release agent capable of being written according to claim 1, characterized in that, The emulsifier is a non-ionic surfactant, which is at least one of sorbitan esters, polyoxyethylene sorbitan esters, polyoxyethylene octyl phenyl ether, styrenated phenyl ether, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, alkylphenol polyoxyethylene ether, polyoxyethylene fatty alcohol ether, and isomeric alcohol polyoxyethylene ether.

6. The silicone emulsion release agent capable of being written according to claim 5, wherein, The emulsifier is a non-ionic surfactant including at least one selected from polyoxyethylene alkyl ethers and polyoxyethylene phenyl ethers.

7. The writable silicone emulsion release agent according to claim 5, characterized in that, The emulsifier is at least one of isomeric tridecanol polyoxyethylene ether and polyoxyethylene styrenated phenyl ether.

8. The writable silicone emulsion release agent according to claim 1, characterized in that, The water-soluble resin is at least one of polyvinyl alcohol, methyl cellulose, and alkyd resin.

9. The preparation method of the writable silicone emulsion release agent according to any one of claims 1-8, characterized in that, Dissolve 0.1 - 10 parts of the water-soluble resin in 10 - 50 parts of deionized water in advance. Then, disperse 20 - 40 parts of vinyl silicone oil, 1 - 20 parts of modified vinyl silicone oil, 0.5 - 8 parts of hydrogen-containing silicone oil, 0.5 - 3 parts of emulsifier, and the pre-dissolved water-soluble resin uniformly in a high-speed disperser. Add 30 - 50 parts of deionized water to obtain a writable emulsion release agent.

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