A rubber release agent and a method of making

Abstract

The present application provides a kind of rubber release agent and preparation method, and the rubber release agent includes: water, lignin, bentonite, fatty acid salt and emulsifier.The present application utilizes the multiple phenolic hydroxyl functional groups in lignin, ensures that these phenolic hydroxyl groups can ion exchange and electrostatic adsorption with bentonite and fatty acid salt, form a stable suspension, ensure the dispersion stability of release agent;In addition, through the viscosity of bentonite and the benzene ring structure inside the lignin molecule, π-π interaction force and van der waals force occur between the rubber surface and aromatic substances, and the adhesion effect on the rubber surface is enhanced.After drying, the abundant phenolic hydroxyl functional groups of lignin itself will also repel the charge, and bentonite and fatty acid salt will also play a better release and anti-sticking effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rubber processing, and more particularly to a rubber release agent and a preparation method thereof. BACKGROUND

[0002] During the production, processing and use of rubber products, due to their unique self-adhesion, especially in summer or after extrusion, they are prone to caking or sticking to the storage container. In order to prevent the above-mentioned situation from occurring, it is necessary to apply a rubber release agent to the surface of the rubber product. However, the current rubber release agent has poor affinity on the surface of the rubber, and the rubber release agent is prone to be scattered during the production of the rubber, and the rubber release agent after drying has a white appearance, so further improvement and development are needed. SUMMARY

[0003] In view of the various deficiencies of the prior art, in order to solve the above-mentioned problems, the present application provides a rubber release agent and a preparation method thereof, and provides the following technical solutions:

[0004] A rubber release agent, comprising: water, lignin, bentonite, fatty acid salt and emulsifier.

[0005] Further, the water, lignin, bentonite, fatty acid salt and emulsifier are included in an amount of 40-60 parts by mass, 6-15 parts by mass, 20-38 parts by mass, 8-18 parts by mass and 0.5-5 parts by mass, respectively.

[0006] Further, the mass usage ratio of the lignin to the bentonite is 1:2-3.5.

[0007] Further, the mass usage ratio of the lignin to the fatty acid salt is 0.5-2:1.

[0008] Further, the emulsifier is a polyhydric alcohol fatty acid ester emulsifier.

[0009] Further, the release agent further comprises a dispersant, a stabilizer and a bactericide.

[0010] Further, the dispersant, the stabilizer and the bactericide are included in an amount of 1-5 parts by mass, 1-8 parts by mass and 0.5-3 parts by mass, respectively.

[0011] In addition, the present application also provides a preparation method of the above-mentioned rubber release agent, wherein the dispersant and the lignin are added to water at a temperature of 55-65℃, and stirred for 10-25 minutes, then the fatty acid salt is added again, and after being heated to 66-75℃, it is stirred again, then the bentonite is added, and after being stirred for 40-70 minutes, the emulsifier and the stabilizer are added, and after being stirred again for 30-60 minutes, the temperature is lowered to 20-35℃, then the bactericide is added to obtain the release agent.

[0012] Due to the adoption of the above technical solutions, the present application has the following beneficial technical effects:

[0013] 1、The present application utilizes the multiple hydroxyl functional groups in lignin to ensure that these hydroxyl groups can ion exchange and electrostatic adsorption with bentonite and fatty acid salt to form a stable suspension, ensuring that the release agent is dispersed stably.

[0014] 2、The present application utilizes the viscosity of bentonite and the benzene ring structure inside the lignin molecule to generate π-π interaction force and van der Waals force with aromatic substances on the surface of the rubber, enhancing the adhesion effect on the surface of the rubber. After drying, the abundant hydroxyl functional groups of lignin repel each other and cooperate with bentonite and fatty acid salt to achieve better release and anti-sticking effect. DETAILED DESCRIPTION

[0015] In order to make the personnel in the art better understand the technical solutions of the present application, the technical solutions of the present application will be described clearly and completely below in combination with the embodiments of the present application. Based on the embodiments in the present application, other similar embodiments obtained by the personnel in the art without making creative efforts should all belong to the scope of protection of the present application.

[0016] A rubber release agent, comprising: water, lignin, bentonite, fatty acid salt and emulsifier. Lignin is applied to the rubber release agent for the first time. Lignin cooperates with bentonite and fatty acid salt. Lignin contains multiple hydroxyl functional groups, which form stable complexes with metal ions in water. At the same time, these hydroxyl groups can ensure ion exchange and electrostatic adsorption with bentonite and fatty acid salt to form a stable suspension, ensuring that the release agent is dispersed stably. In addition, lignin contains benzene ring structure. Lignin generates π-π interaction force and van der Waals force with aromatic substances on the surface of the rubber, enhancing the adhesion effect on the surface of the rubber. At the same time, after drying, the abundant hydroxyl functional groups of lignin repel each other and cooperate with bentonite and fatty acid salt to achieve better release and anti-sticking effect on the rubber.

[0017] Example 1

[0018] In a three-necked flask, add 50 parts of deionized water, start the heating mantle and turn on the stirring device, control the speed at 500 rpm / min, at 65°C, add 3 parts of 40% polycarboxylic acid ammonium salt aqueous solution (aqueous wetting dispersant), 10 parts of lignin, stir for 25 minutes, add 18 parts of zinc fatty acid, heat to 75°C, control the stirring speed at 800 rpm / min for 30 minutes, make the mixture uniform, stop heating, add bentonite 30 parts in turn, continue stirring for 70 minutes, add cyclodextrin stabilizer 4 parts, triglycerol oleate 2 parts, control the stirring speed at 600 rpm / min, after stirring for 70 minutes, cool to 35°C, adjust the stirring speed to 300 rpm / min, add isothiazolinone compound (bactericide) 2 parts, 2-methyl-5-chloro-4-isothiazolin-3-one (CMI): 2-methyl-4-isothiazolin-3-one (MI) = 3:1, antifoaming agent 2 parts, to eliminate foam. The product is packed into a plastic bucket through a funnel and sealed.

[0019] Example 2

[0020] In a three-necked flask, add 50 parts of deionized water, start the heating mantle and turn on the stirring device, control the speed at 500 rpm / min, at 65°C, add 3 parts of 40% polycarboxylic acid ammonium salt aqueous solution (aqueous wetting dispersant), 10 parts of lignin, stir for 25 minutes, add 18 parts of zinc fatty acid, heat to 75°C, control the stirring speed at 800 rpm / min for 30 minutes, make the mixture uniform, stop heating, add bentonite 30 parts in turn, continue stirring for 70 minutes, add cyclodextrin stabilizer 4 parts, triglycerol oleate 2 parts, control the stirring speed at 600 rpm / min, after stirring for 70 minutes, cool to 35°C, adjust the stirring speed to 300 rpm / min, add isothiazolinone compound (bactericide) 2 parts, 2-methyl-5-chloro-4-isothiazolin-3-one (CMI): 2-methyl-4-isothiazolin-3-one (MI) = 3:1, antifoaming agent 2 parts, to eliminate foam. The product is packed into a plastic bucket through a funnel and sealed.

[0021] Example 3

[0022] In a three-necked flask, add 45 parts of deionized water, start the heating mantle and turn on the stirring device, control the speed at 500 rpm / min, at 55°C, add 4 parts of 40% polycarboxylic acid ammonium salt aqueous solution (aqueous wetting dispersant), 12 parts of lignin, stir for 25 minutes, add 10 parts of zinc fatty acid, heat to 66°C, control the stirring speed at 800 rpm / min for 30 minutes, make the mixture uniform, stop heating, add bentonite 34 parts in turn, continue stirring for 40 minutes, add cyclodextrin stabilizer 6 parts, triglycerol oleate 5 parts, control the stirring speed at 600 rpm / min, after stirring for 30 minutes, cool to 20°C, adjust the stirring speed to 300 rpm / min, add isothiazolinone compound (bactericide) 3 parts, 2-methyl-5-chloro-4-isothiazolin-3-one (CMI): 2-methyl-4-isothiazolin-3-one (MI) = 3:1, antifoaming agent 1 part, to eliminate foam. The product is packed into a plastic bucket through a funnel and sealed.

[0023] Example 4

[0024] In a three-necked flask, add 45 parts of deionized water, start the heating mantle and turn on the stirring device, control the speed at 500 rpm / min, at 55°C, add 4 parts of 40% polycarboxylic acid ammonium salt aqueous solution (aqueous wetting dispersant), 12 parts of lignin, stir for 25 minutes, add 10 parts of zinc fatty acid, heat to 66°C, control the stirring speed at 800 rpm / min for 30 minutes, make the mixture uniform, stop heating, add bentonite 34 parts in turn, continue stirring for 40 minutes, add cyclodextrin stabilizer 6 parts, triglycerol oleate 5 parts, control the stirring speed at 600 rpm / min, after stirring for 30 minutes, cool to 20°C, adjust the stirring speed to 300 rpm / min, add isothiazolinone compound (bactericide) 3 parts, 2-methyl-5-chloro-4-isothiazolin-3-one (CMI): 2-methyl-4-isothiazolin-3-one (MI) = 3:1, antifoaming agent 1 part, to eliminate foam. The product is packed into a plastic bucket through a funnel and sealed.

[0025] Example 5

[0026] In a three-necked flask, 55 parts of deionized water was added, the heating mantle was started to heat and the stirring device was started, the stirring speed was controlled at 500 rpm / min, at 55°C, 2 parts of 40% polycarboxylic acid ammonium salt aqueous solution (aqueous wetting dispersant), 8 parts of lignin were added, stirring for 25 minutes, 16 parts of calcium fatty acid was added, the temperature was raised to 66°C, the stirring speed was controlled at 800 rpm / min, stirring for 30 minutes, making it mix evenly, stopping heating, 34 parts of bentonite was added in turn, continue stirring for 40 minutes, 2 parts of cyclodextrin stabilizer, 4 parts of triacylglycerol oleate were added, the stirring speed was controlled at 600 rpm / min, after stirring for 30 minutes, the temperature was lowered to 20°C, the stirring speed was adjusted to 300 rpm / min, 1 part of isothiazolinone compound (bactericide) was added, in which 2-methyl-5-chloro-4-isothiazolin-3-one (CMI) : 2-methyl-4-isothiazolin-3-one (MI) = 3:1, 1.8 parts of defoaming agent was added to eliminate foam. The product was packed into a plastic bucket through a funnel and sealed with a lid.

[0027] Comparative Example 1

[0028] The ZD-C model of Rhein Chemie was selected as the rubber release agent.

[0029] Comparative Example 2

[0030] Dimethyl silicone oil was selected as the rubber release agent.

[0031] Comparative Example 3

[0032] Compared with Example 1, no lignin was added, and the other steps were the same as Example 1.

[0033] Comparative Example 4

[0034] Compared with Example 1, lignin 3 parts, bentonite 50 parts, calcium fatty acid 1 part, and the other steps were the same as Example 1.

[0035] 1. Release agent performance test:

[0036] The rubber release agents prepared in Examples 1-5 and Comparative Examples 1-4 were diluted with water according to the dilution ratio of 1:5, 1:10 and 1:20 respectively, and stirred with a stirrer for 15 minutes to make them mix evenly for standby use. The tire side vulcanized and promoted after mixing was mixed by a kneader for 120 seconds and a roll mill for 300 seconds, the film temperature was controlled at 90±2°C, and the roll gap was adjusted to 1.5±0.2 mm to produce the film, which was covered with clean release film on both sides for standby use. The film was cut into 100 mm*30 mm pieces with scissors, and the release film was torn off. The film was coated with the release agent diluent of Examples 1-5 and Comparative Examples 1-4 in turn, and the film was naturally air-dried to record the drying time. Each 2 pieces of film were placed together and evenly pressed with a pressure of 10 MPa, and the film peeling effect evaluation test was carried out after 24 h and 48 h, and the test results are shown in Table 1.

[0037] Table 1 Isolation performance results of rubber isolation agent dilutions of Examples 1-5 and Comparative Examples 1-4 on rubber sheets

[0038]

[0039]

[0040]

[0041] As can be seen from the above Table 1, the rubber isolation agent obtained by the present Examples 1-5 is coated on the rubber sheets, and the appearance of the rubber sheets is a misty rubber sheet, and there is substantially no white powder in the appearance, while the rubber isolation agent of Comparative Example 1 is coated on the rubber sheets, and the appearance of the rubber sheets is a white powder rubber sheet, and there is a part of white isolation agent powder enrichment on the surface of the rubber sheets after the isolation agent is dried, and the white powder enrichment produces the following hazards: 1. The isolation powder of the rubber sheets is easy to fall off in the manufacturing transfer process, and the isolation dust floe is easy to float on site, which is not friendly to the site operation environment, and can cause product delamination, air bubbles and other problems caused by the adhesion of the rubber. 2. The isolation agent cannot be uniformly dispersed, and is floating on the isolation liquid surface of the dipping tank, and a hard isolation agent layer is formed on the surface of the rubber sheets. The isolation agent can cause the isolation performance to decrease due to the difference in the concentration of the product components in the later use, and can cause the rubber sheets to be bonded, thereby affecting the quality of the rubber and causing waste. The isolation agents of the present Examples 1-5 do not affect the appearance of the rubber sheets, and do not produce dust aggregation phenomenon, and the surface state of the rubber after coating and drying the rubber isolation agent is excellent. In terms of the drying time of the rubber sheets, as the dilution ratio increases, the drying time of the rubber sheets gradually increases, when the dilution ratio is 1:5, the drying time of the rubber sheets in Example 3 is only 5 minutes and 9 seconds, compared with other examples and comparative examples, when the dilution ratio is 1:10, the drying time of the rubber sheets in Example 3 is only 6 minutes and 19 seconds, compared with other examples and comparative examples, when the dilution ratio is 1:20, the drying time of the rubber sheets in Example 1 is only 6 minutes and 39 seconds, compared with other examples and comparative examples. It is worth mentioning that the isolation agents obtained by the present Examples 1-5 are coated on the rubber sheets, and the isolation effect is excellent within 48 hours, and there is no rubber sheet bonding, while Comparative Examples 1-3 all have rubber sheet bonding within 48 hours when the dilution ratio is 1:20, which also proves that the isolation performance of the present application is better than that of general products.

[0042] 2. Effect of rubber isolation agent on the properties of rubber

[0043] The green tire was mixed for 120 seconds by a kneader, and was mixed for 300 seconds by an open mill. The temperature of the green tire was controlled at 90±2℃, and the roll gap was adjusted at 8-10mm. The green tire was cut into 100*50mm pieces by a scissors, and the release film was removed. Three pieces of the green tire were coated with the release agent prepared in Example 1-5 and Comparative Example 1-4, respectively. The release agent was diluted with water at a ratio of 1:5, and was dried. The coated green tire was vulcanized together with the steel wire to test the pull-out force of the steel wire. Rheology: 151℃*40min, ML1+4100℃; T5 127℃; Tensile strength, elongation: 151℃*30min.

[0044] Table 2: Test results of the rubber release agent of Example 1-5 and Comparative Example 1-4 on the fusion performance of the green tire

[0045]

[0046] As shown in Table 2, the rubber release agent of the present application has good compatibility with rubber, and the components of the rubber release agent are better integrated with rubber, which has little effect on the physical properties of the rubber compound, and basically does not affect the pull-out force of the steel wire after the use of the release agent. In addition, the rubber release agent is different, and the size of the pull-out force of the steel wire is different. The pull-out force of the steel wire of each example is greater than that of the comparative example, which indicates that the rubber release agent of the present application improves the compatibility of the steel wire and the rubber compound after being added. Specifically, by adjusting the ratio of lignin and bentonite in the present application, the compatibility with rubber is further improved.

[0047] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity. The skilled person should consider the specification as a whole, and the technical solutions in each example can be combined appropriately to form other embodiments that can be understood by the skilled person.

Claims

1. A rubber release agent characterized by, It comprises: water, lignin, bentonite, fatty acid salt and emulsifier; The mass ratio of lignin and bentonite is 1:2-3.5; The mass ratio of lignin and fatty acid salt is 0.5-2:1; According to the mass fraction, it comprises water 40-60 parts, lignin 6-15 parts, bentonite 20-38 parts, fatty acid salt 8-18 parts and emulsifier 0.5-5 parts.

2. A rubber release agent according to claim 1, wherein The emulsifier is polyol fatty acid ester emulsifier.

3. A rubber release agent according to claim 1, wherein The release agent also comprises dispersant, stabilizer and bactericide.

4. A rubber release agent according to claim 3, wherein According to the mass fraction, the dispersant is 1-5 parts, the stabilizer is 1-8 parts and the bactericide is 0.5-3 parts.

5. A process for the preparation of a rubber release agent as claimed in any one of claims 1 to 4, characterised in that, In water with a temperature of 55-65℃, add dispersant and lignin, stir for 10-25 minutes, then add fatty acid salt again, heat to 66-75℃, then stir again, then add bentonite, stir for 40-70 minutes after adding bentonite, then add emulsifier, stabilizer, stir again for 30-60 minutes, then cool to 20-35℃, then add bactericide to obtain rubber release agent.

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