Silica gel combined type self-healing flexible robot skin and preparation method thereof

Abstract

The invention discloses silica gel combined type self-healing flexible robot skin and a preparation method thereof, and relates to the technical field of robot flexible materials. The method comprises the following steps: uniformly spraying a fluorine-containing self-healing waterborne polyurethane emulsion on the surface of a mold, and drying to obtain a fluorine-containing self-healing waterborne polyurethane film with the thickness of 0.04-0.06 mm; spraying a Karstedt platinum catalyst on the fluorine-containing self-healing waterborne polyurethane film, and then coating addition type double-component silica gel on the catalyst to obtain a semi-finished product; and spraying a waterborne polyurethane skin feeling treatment agent on the back surface of the semi-finished product to obtain the flexible robot skin. Resin used in the fluorine-containing double-bond waterborne polyurethane and the water-based skin feeling treating agent is polyether type waterborne polyurethane resin, after the fluorine-containing double-bond waterborne polyurethane is combined with the silica gel, operability of the surface of the silica gel is higher, the touch feeling is changed while the hand feeling of the silica gel is kept, the silica gel is highly similar to the human skin, and the skin feeling of the silica gel is improved. And the properties such as wear resistance and folding resistance can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of robot flexible materials, and in particular to a silicone-combined self-healing flexible robot skin and a preparation method thereof. Background Art

[0002] With the development of artificial intelligence technology, the market demand for robotic skin is becoming increasingly demanding. Existing silicone surface treatment methods mostly involve coating the surface with a special silane coupling agent to improve its stickiness and susceptibility to staining. However, such treated silicone surfaces feel hard and have poor physical properties such as wear resistance and folding resistance. Furthermore, because silane coupling agents contain silicon, they will still leak silicone oil over time.

[0003] Once the existing composite materials used to make robot skin are damaged, they cannot self-repair and need to be returned to the factory for repair or replacement, which is very inconvenient. Therefore, it is particularly important to develop a composite material that can cover the surface of silicone to improve the surface performance of silicone and can self-heal. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preparing a silicone-bonded self-healing flexible robot skin to solve the problem of oily surface and sticky feel of the silicone.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A method for preparing a silicone-bonded self-healing flexible robot skin comprises the following steps:

[0007] Step 1: spray the fluorine-containing self-healing water-based polyurethane emulsion evenly on the mold surface and dry it to obtain a fluorine-containing self-healing water-based polyurethane film with a thickness of 0.04-0.06 mm;

[0008] Step 2: spraying a Karstedt platinum catalyst on the fluorine-containing self-healing waterborne polyurethane film, and then coating the catalyst with an addition-type two-component silicone rubber to obtain a semi-finished product;

[0009] Step 3: Spray a skin-feel treatment agent on the back of the semi-finished product to obtain a flexible robot skin.

[0010] As a further embodiment of the present invention, in step 1, the fluorine-containing self-healing aqueous polyurethane emulsion is composed of the following components in parts by weight:

[0011] 100 parts of fluorine-containing self-healing water-based polyurethane;

[0012] 0.1-0.2 parts of leveling agent;

[0013] 0.5-1 part of water-based thickener;

[0014] Waterborne crosslinking agent 0.1-0.2 parts.

[0015] Further, the fluorine-containing self-healing waterborne polyurethane is KTJQ-792 of a fluorine-containing high self-healing double bond waterborne polyurethane type, and the solid content is 39-40%. The fluorine-containing self-healing waterborne polyurethane contains not only a fluorine functional group, but also a fluorine-containing nonionic emulsifier, so that it has strong hydrogen bonding, and the intermolecular force is very strong. In addition, a double sulfur bond is introduced into the main chain of the waterborne polyurethane, and the functional group has a weak bond energy, so it has a self-healing ability. In addition, the side chain contains a double bond, which can produce a carbon hydrogen addition reaction with silica gel, and can be combined with silica gel. Therefore, the material not only has high self-healing, but also can be combined with silica gel.

[0016] Further, the leveling agent is an organic silicon modified acrylic acid.

[0017] Further, the waterborne thickening agent is a waterborne nonionic associated thickening agent.

[0018] Further, the waterborne crosslinking agent is Wanhua Chemical HW-268.

[0019] As a further scheme of the present application, in step 1, the drying temperature is 70-80℃.

[0020] As a further scheme of the present application, in step 2, the spraying amount of Karstedt platinum gold catalyst is 3.5-4.5g / m 2 ; Karstedt platinum gold catalyst is a platinum (Pt) based homogeneous catalyst for silicon hydrogen addition reaction.

[0021] As a further scheme of the present application, in step 2, the addition type two-component silica gel is Smooth-On DragonSkin series 0 degree silica gel or 10 degree silica gel.

[0022] As a further scheme of the present application, in step 3, the skin feel treatment agent is composed of the following components by weight fraction:

[0023] Skin feel waterborne polyurethane resin 100 parts;

[0024] Waterborne color paste 5-10 parts;

[0025] Crosslinking agent 3-5 parts.

[0026] The spraying amount of the skin feel treatment agent is 8-10g / m 2 .

[0027] Further, the skin feel waterborne polyurethane resin is a polyether type waterborne polyurethane resin.

[0028] Further, the water-based color paste is LR series water-based color paste produced by Jiangsu Shinename Science and Technology, which has low VOC, excellent acid resistance, alkali resistance, light resistance and weather resistance and the like.

[0029] Further, the crosslinking agent is a carbodiimide crosslinking agent.

[0030] A silica gel combined self-healing flexible robot skin is prepared by the preparation method.

[0031] Compared with the prior art, the application has the following beneficial effects:

[0032] 1. The fluorine-containing self-healing water-based polyurethane used in the application introduces appropriate fluorine functional groups, has strong hydrogen bonding, and has strong intermolecular forces, so the film formed by the fluorine-containing water-based polyurethane is not easy to break, and a disulfide bond is also introduced, which makes the skin material have good self-healing ability because the bond energy is weak. The material has excellent heat resistance because it contains fluorine elements in the molecular chain. The main chain of the water-based polyurethane is composed of carbon, which is similar to the human body, and the modulus is low, so the hand feeling is soft, and the touch feeling is very close to the skin.

[0033] 2. The silica gel has high simulation in terms of human skin in appearance, but in the preparation process, a large amount of silicone oil is filled to maintain the softness of the silica gel, and the modulus is low, so the silica gel is easy to oil and easy to break. The fluorine-containing self-healing water-based polyurethane is combined with the silica gel, so that the silica gel surface is more resistant to dirt, the strength of the silica gel surface is enhanced, the cleaning of the silica gel surface is more convenient, and the self-repairing function is also provided.

[0034] 3. The resin used in the fluorine-containing water-based polyurethane and the water-based skin feel treatment agent is a polyether type water-based polyurethane resin, and after the fluorine-containing water-based polyurethane is combined with the silica gel, the operability of the silica gel surface is stronger, the softness of the silica gel is maintained, and the touch feeling of the silica gel surface is closer to human skin. Because it is a polyether type polyurethane, it also has the advantages of high strength, hydrolysis resistance and high resilience. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 A self-healing change diagram of a robot skin sample prepared in Example 3 of the application at different time periods (0 min-1h) is shown in the figure.

[0036] Figure 2 A cross-sectional view of the robot skin sample prepared in Example 3 of the application is shown in the figure. DETAILED DESCRIPTION

[0037] The specific embodiments of the application are described in detail below, but it should be understood that the protection scope of the application is not limited by the specific embodiments.

[0038] The terms used in the examples of this application are for the purpose of describing specific implementation rules only and are not intended to limit this application. The singular forms "a", "an", "the" and "the" used in the implementation rules of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0039] It should be understood that in the various embodiments of the present application, the size of the serial number of each process does not mean the order of execution. Some or all steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the implementation regulations of this application.

[0040] The weights of the relevant components mentioned in the examples of this application may not only refer to the specific content of each component, but also represent the weight ratio between the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the examples of this application, it is within the scope disclosed in the examples of this application. Specifically, the mass described in the examples of this application may be a mass unit known in the chemical industry, such as μg, mg, g, kg, etc.

[0041] Unless otherwise defined, all technical terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0042] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0043] In the following examples and comparative examples, the sources and types of the relevant raw materials are summarized in Table 1.

[0044] Table 1

[0045]

[0046]

[0047] The following is further explained with reference to specific embodiments.

[0048] Example 1

[0049] This embodiment provides a method for preparing a fluorine-containing self-healing aqueous polyurethane emulsion, comprising the following steps:

[0050] 0.1 parts of leveling agent, 1 part of water-based thickener, and 0.1 parts of water-based curing agent were added to 100 parts of fluorine-containing self-healing water-based polyurethane, and stirred and mixed evenly with a blender to obtain a fluorine-containing self-healing water-based polyurethane emulsion with a test viscosity of 150 cps.

[0051] Example 2

[0052] This embodiment provides a method for preparing a skin feel treatment agent, comprising the following steps:

[0053] 5 parts of water-based color paste and 3 parts of cross-linking agent were added to 100 parts of skin-feel water-based polyurethane resin, and the mixture was stirred and mixed evenly with a blender to obtain a skin-feel treatment agent.

[0054] Example 3

[0055] This embodiment provides a method for preparing a silicone-bonded self-healing flexible robot skin, comprising the following steps:

[0056] Step 1: The fluorine-containing self-healing water-based polyurethane emulsion prepared in Example 1 was evenly sprayed onto the mold using a spray gun and placed in an oven at 75° C. for drying to obtain a fluorine-containing self-healing water-based polyurethane film with a thickness of 0.04 mm;

[0057] Step 2: Spray Karstedt platinum catalyst on the surface of the fluorine-containing self-healing water-based polyurethane film on the mold, with a spraying amount of 4g / m 2 , used for the reaction and combination of polyurethane and silicone; mix the 0-degree silicone A and B components in a ratio of 100:100 (weight ratio) evenly, pour into the mold, and naturally cure at room temperature (25°C) and humidity 50±5% to obtain a semi-finished product;

[0058] Step 3: Take the finished product out of the mold, take it out and spray the skin feel treatment agent prepared in Example 2 on the back side of the fluorine-containing self-healing water-based polyurethane film (away from the silicone surface) at a spraying amount of 8g / m 2 , and dried in an oven at 100°C to obtain a flexible robotic skin.

[0059] Example 4

[0060] This embodiment provides a method for preparing a silicone-bonded self-healing flexible robot skin, comprising the following steps:

[0061] Step 1: The fluorine-containing self-healing water-based polyurethane emulsion prepared in Example 1 was evenly sprayed onto the mold using a spray gun and placed in an oven at 75° C. for drying to obtain a fluorine-containing self-healing water-based polyurethane film with a thickness of 0.04 mm;

[0062] Step 2: Spray Karstedt catalyst on the surface of the fluorine-containing self-healing water-based polyurethane film on the mold with a spraying amount of 4g / m 2, for polyurethane and silica gel reaction combination; 10 degree silica gel A, B component is mixed uniformly in the proportion of 100:100 (weight ratio), poured into the mold, and naturally cured under the condition of room temperature (25℃) and humidity 50±5%, to obtain a semi-finished product;

[0063] Step 3: The finished product was taken out of the mold, and the skin feel treatment agent prepared in Example 2 was sprayed on the back of the fluorine self-healing waterborne polyurethane film (away from the silica gel surface), with a spraying amount of 9 g / m 2 , and dried in a 100℃ oven to obtain a flexible robot skin.

[0064] Example 5

[0065] This example provides a preparation method of a silica gel combined type self-healing flexible robot skin, which is different from Example 3 in that in Step 3, the skin feel treatment agent prepared in Example 2 is sprayed at a spraying amount of 10 g / m 2 , and the remaining steps and parameters remain the same.

[0066] Comparative Example 1

[0067] This comparative example provides a preparation method of a robot skin, comprising the following steps:

[0068] Step 1: 0.1 parts of a leveling agent, 1 part of a waterborne thickening agent, and 0.1 parts of a waterborne curing agent were added to 100 parts of a waterborne polyurethane prepared in Example 1 of the patent document CN115044003B, and uniformly sprayed on a mold using an airbrush. The mold was placed in a 75℃ oven for drying, to obtain a waterborne polyurethane film with a thickness of 0.04mm;

[0069] Step 2: Karstedt platinum gold catalyst was sprayed on the surface of the waterborne polyurethane on the mold, with a spraying amount of 4 g / m 2 , and the remaining steps and parameters remain the same.

[0070] Step 3: The finished product was taken out of the mold, and the skin feel treatment agent prepared in Example 2 was sprayed on the back of the waterborne polyurethane film (away from the silica gel surface), with a spraying amount of 10 g / m 2 , and dried in a 100℃ oven to obtain a robot skin.

[0071] Comparative Example 2

[0072] This comparative example provides a preparation method of a robot skin, comprising the following steps:

[0073] Step 1: Add 0.1 parts of a leveling agent, 1 part of a water-based thickener, and 0.1 parts of a water-based curing agent to 100 parts of a water-based polyurethane having a solid content of 40% prepared in Example 1 of patent document CN119682333B, spray the mixture evenly onto a mold using a spray gun, and dry the mixture in an oven at 75°C to obtain a water-based polyurethane film having a thickness of 0.04 mm;

[0074] Step 2: Spray Karstedt platinum catalyst on the surface of the water-based polyurethane film on the mold, with a spraying amount of 4g / m 2 ; Mix the 0-degree silica gel A and B components in a ratio of 100:100 (weight ratio) and pour them into a mold. Naturally cure them at room temperature (25°C) and humidity 50±5% to obtain a semi-finished product;

[0075] Step 3: Take the finished product out of the mold and spray the skin feel treatment agent prepared in Example 2 on the back of the waterborne polyurethane film (away from the silicone surface) at a spraying amount of 8 g / m 2 , and dried in an oven at 100°C to obtain the robotic skin.

[0076] Performance testing:

[0077] (1) The self-healing performance of the flexible robot skin prepared in Examples 3-5 and Comparative Examples 1-2 was tested. The specific test method was as follows: a small cut was made on the surface of the prepared flexible robot skin sample with a knife, and the sample was placed at 150°C for 1 hour to detect the self-healing ability of the fracture. The test results are summarized in Table 2.

[0078] Table 2

[0079]

[0080]

[0081] In addition, the self-healing condition of the sample of Example 3 was tested at 0 min, 30 min and 1 h respectively. The changes in the self-healing condition of the sample in different time periods are shown in FIG. Figure 1 ,from Figure 1 It can be seen that the fracture of the sample gradually heals within 1 hour. The cross section of the fractured sample is as follows: Figure 2 As shown, from Figure 2 It can be seen that the structure of the skin sample is specifically a bottom silicone layer, a middle layer (black part) resin layer, and a top layer of flexible treatment layer. While maintaining the feel of silicone, further surface treatment makes the touch highly similar to human skin.

[0082] (2) Basic performance tests were performed on the flexible robot skins prepared in Examples 3-5 and Comparative Examples 1-2. The test reference standards for the test contents are shown in Table 3, and the test results are summarized in Table 4.

[0083] Table 3

[0084] Test standards Test reference standards Constant temperature and humidity 70℃×95％×7W QB / T4671-2014 Martindale wear-resistant 500,000 QB / T5253.1-2018 Alcohol color fastness test 99% alcohol 20 times GB / T5712-1997 Smell test \ QB / T5447-2019 Folding resistance at room temperature 1 million GB / T39368-2020 Low temperature folding resistance -10℃ 100,000 GB / T39368-2020 Hardness \ QB / T5155-2017 Peel strength 200mm / min GB / T8808-1988 Heat resistant 100℃ / 24h ISO17228:2015

[0085] Table 4

[0086]

[0087]

[0088] As can be seen from Table 4, Example 3 and Example 4 use two-component addition type silicone gels of different hardness, which have certain differences in softness and peel strength, but both maintain excellent levels in self-healing ability and self-cleaning ability of the silicone gel surface; the skin feel treatment agent in Example 3-5 is sprayed at a dosage of 8-10 g / m 2 and all remain good hand feeling within the range.

[0089] Comparative Example 3 and Comparative Example 1, when the fluorine-containing self-healing waterborne polyurethane is replaced by a fluorine-containing ordinary polyether resin, the sample performance is relatively poor, because the double bond end contained in the fluorine-containing self-healing resin forms a dense film through silicon hydrogen addition with the chemical bond of the silicone gel, effectively preventing silicone oil from overflowing, and having excellent heat resistance and oil resistance. In the peel test, the failure occurs in the silicone gel layer, proving the chemical bonding of the silicon hydrogen addition reaction, which is superior to the strength of the material itself.

[0090] Comparative Example 3 and Comparative Example 2, when only the fluorine-containing self-healing waterborne polyurethane is replaced by an ordinary double bond resin, the sample performance is relatively poor, because the fluorine-containing waterborne polyurethane main chain contains an appropriate amount of fluorine functional groups, which have strong hydrogen bonding, so that the intermolecular force is very strong, and therefore it is not easy to break, and a double sulfur group is introduced into the waterborne polyurethane main chain, and this functional group has a weak bond energy, so it has self-healing ability.

[0091] It should be noted that the relational terms herein such as first and second and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any such actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0092] The above disclosure is only several specific embodiments of the present application, but the embodiments of the present application are not limited thereto, and any changes that can be thought of by those skilled in the art shall fall within the protection scope of the present application.

Claims

1. A method for preparing a silicone-bonded self-healing flexible robot skin, characterized in that: The following steps are involved: Step 1: spray the fluorine-containing self-healing water-based polyurethane emulsion evenly on the mold surface and dry it to obtain a fluorine-containing self-healing water-based polyurethane film with a thickness of 0.04-0.06 mm; Step 2: spraying a Karstedt platinum catalyst on the fluorine-containing self-healing waterborne polyurethane film, and then coating the catalyst with an addition-type two-component silicone rubber to obtain a semi-finished product; Step 3: Spray a skin-feel treatment agent on the back of the semi-finished product to obtain a flexible robot skin.

2. The method for preparing the silicone-bonded self-healing flexible robot skin according to claim 1, characterized in that: In step 1, the fluorine-containing self-healing water-based polyurethane emulsion is composed of the following components in parts by weight: 100 parts of fluorine-containing self-healing water-based polyurethane; 0.1-0.2 parts of leveling agent; 0.5-1 part of water-based thickener; 0.1-0.2 parts of water-based crosslinking agent.

3. The method for preparing the silicone-bonded self-healing flexible robot skin according to claim 2, characterized in that: The leveling agent is silicone modified acrylic.

4. The method for preparing the silicone-bonded self-healing flexible robot skin according to claim 2, characterized in that: The aqueous thickener is an aqueous nonionic associative thickener.

5. The method for preparing the silicone-bonded self-healing flexible robot skin according to claim 2, characterized in that: The water-based crosslinking agent was Wanhua Chemical HW-268.

6. The method for preparing the silicone-bonded self-healing flexible robot skin according to claim 1, characterized in that: In step 1, the drying temperature is 70-80°C.

7. The method for preparing the silicone-bonded self-healing flexible robot skin according to claim 1, characterized in that: In step 2, the spraying amount of platinum catalyst is 3.5-4.5g / m 2 .

8. The method for preparing the silicone-bonded self-healing flexible robot skin according to claim 1, characterized in that: In step 3, the skin feel treatment agent is composed of the following components in parts by weight: 100 parts of skin-feeling waterborne polyurethane resin; 5-10 parts of water-based color paste; 3-5 parts of cross-linking agent. The spraying amount of skin-feel treatment agent is 8-10g / m 2 .

9. The method for preparing the silicone-bonded self-healing flexible robot skin according to claim 8, characterized in that: The skin-feeling water-based polyurethane resin is a polyether-type water-based polyurethane resin; the cross-linking agent is a carbodiimide cross-linking agent.

10. A silicone-bonded self-healing flexible robot skin, characterized in that: Prepared by the preparation method according to claim 1.

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