Anti-aging detachable rubber pressure-sensitive adhesive and preparation method thereof

Abstract

The invention relates to the technical field of pressure-sensitive adhesives, and discloses an anti-aging detachable rubber type pressure-sensitive adhesive and a preparation method thereof.The rubber type pressure-sensitive adhesive is prepared from, by mass, 100 parts of matrix rubber, 20-50 parts of tackifying resin, 40-70 parts of plasticizer, 1-3 parts of anti-aging agent, 4-10 parts of reinforcing filler and 0-8 parts of special auxiliaries. The anti-aging detachable rubber pressure-sensitive adhesive prepared by the technical scheme has excellent anti-aging and adhesive properties, can be detached without residues after being used, and meets the use requirements in the fields of battery assembly, mold sealing and the like.

Description

Technical Field

[0001] The invention relates to the technical field of pressure-sensitive adhesives, and in particular to an aging-resistant and detachable rubber-type pressure-sensitive adhesive and a preparation method thereof. Background Art

[0002] Rubber-based pressure-sensitive adhesive (PSA) is mainly based on natural rubber or synthetic rubber, and is prepared by adding auxiliary ingredients such as tackifying resins, fillers, and antioxidants. Rubber-based pressure-sensitive adhesives have the following characteristics: (1) High holding power: Due to the high molecular weight of rubber and the low glass transition temperature, rubber-based pressure-sensitive adhesives have good compatibility with tackifying resins and exhibit good holding performance. (2) Excellent low-temperature performance: It can still maintain good flexibility and adhesion at low temperatures. (3) Quick adhesion and adhesion: It can generate strong adhesion at the moment of contact and further enhance over time. Therefore, rubber-based pressure-sensitive adhesives are widely used in various fields such as pressure-sensitive tapes, labels, and medical patches, especially in application scenarios that require good initial adhesion and long-lasting adhesion.

[0003] The common rubber-type pressure-sensitive adhesives on the market will leave residues on the substrate after use, resulting in the substrate being unable to be reused or difficult to clean. In response to the above problems, Chinese patent CN202110867536 A discloses a removable hot-melt pressure-sensitive adhesive and a preparation method thereof, which reduces the viscosity of the hot-melt adhesive while achieving the removability of the pressure-sensitive adhesive. Its bonding performance makes it difficult to perfectly bond complex substrates, and it is easy to become detached from the bond. With the application and promotion of rubber-type pressure-sensitive adhesives in the fields of battery assembly and mold sealing, there is an urgent need for a rubber-type pressure-sensitive adhesive with high aging resistance and no residue after disassembly after use. Summary of the invention

[0004] The present invention aims to provide an aging-resistant and detachable rubber-type pressure-sensitive adhesive and a preparation method thereof, so as to solve the problem that the rubber-type pressure-sensitive adhesive in the prior art cannot take into account both the adhesion and aging resistance as well as the removability after bonding.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: an aging-resistant and detachable rubber-type pressure-sensitive adhesive, which comprises, by mass, 100 parts of base rubber, 20-50 parts of tackifying resin, 40-70 parts of plasticizer, 1-3 parts of antioxidant, 4-10 parts of reinforcing filler, and 0-8 parts of special additives.

[0006] Preferably, as an improvement, the base rubber is a hydrogenated styrene-butadiene block copolymer obtained by hydrogenating a special linear SBS.

[0007] Preferably, as an improvement, the tackifying resin is at least one of C5 petroleum resin, hydrogenated terpene resin and rosin resin.

[0008] Preferably, as an improvement, the plasticizer is at least one of cycloalkane oil, white oil and paraffin oil.

[0009] Preferably, as an improvement, the antioxidant is at least one of N-phenyl-N / -isopropyl-p-phenylenediamine, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, and 2-mercaptobenzimidazole.

[0010] Preferably, as an improvement, the reinforcing filler is at least one of ultrafine silica and carbon black.

[0011] Preferably, as an improvement, the special additive is obtained by addition reaction of ethyl isocyanate acrylate and hydroxyl-terminated polyolefin, and the mass ratio of ethyl isocyanate acrylate and hydroxyl-terminated polyolefin is 1:1.

[0012] Preferably, as an improvement, the method for preparing the special additive comprises the following steps:

[0013] S1, mixing ethyl isocyanate acrylate and hydroxyl-terminated polyolefin in a mass ratio of 1:1;

[0014] S2, heating the system to 150°C and reacting for 2 minutes;

[0015] S3. Add organic tin to continue the reaction. The reaction time is 10 min.

[0016] Preferably, as an improvement, a method for preparing an aging-resistant and detachable rubber-type pressure-sensitive adhesive is characterized by comprising the following steps:

[0017] Step 1: weigh the raw materials according to the proportion and set the mixing temperature to 150°C;

[0018] Step 2: Add the base rubber into the internal mixer and heat and soften for 1-3 minutes;

[0019] Step 3: Add the tackifier and special additives into the internal mixer and mix for 1-3 minutes;

[0020] Step 4: Continue to add plasticizer, antioxidant and carbon black, and mix for 4-8 minutes;

[0021] Step 5: Extrusion through screw.

[0022] Preferably, as an improvement, in step five, the screw extrusion conditions are: extrusion temperature 110-150°C, extrusion rate 2-4m / min, and extruder head pressure 5-7MPa.

[0023] The principle and advantages of this solution are: in practical application, in this technical solution, the formula composition of the rubber-type pressure-sensitive adhesive is optimized and upgraded through structural and component analysis in view of the problem that the adhesion, aging resistance and removability after bonding of the rubber-type pressure-sensitive adhesive in the prior art cannot be taken into account. The SEBS rubber obtained by hydrogenation of special linear SBS is used as the base rubber, which has good compatibility with the saturated tackifier. After adding the tackifier, the bonding performance of the material can be improved to a certain extent; and there is no double bond in the SEBS molecular chain, which has good stability and aging resistance. Special additives are creatively added to the formula of the pressure-sensitive adhesive. The special additives and the tackifying resin are mixed and reacted at 150°C to form an ester group, and have good compatibility with rubber. Therefore, while increasing the strength of the colloid, the adhesion is also improved. The raw materials used are all in a saturated state and have excellent aging performance. In the technical research and development stage, how to achieve the residue-free disassembly of the colloid on the substrate is one of the research and development difficulties of this technical solution. In the test stage, the colloid often breaks during disassembly, and the broken colloid remains on the substrate to pollute the substrate. This problem was solved by developing the special additive mentioned in the present invention through structural and component analysis.

[0024] In summary, the beneficial effects of this technical solution are:

[0025] 1. In this technical solution, by optimizing the base rubber and combining it with the use of a tackifier, the two can work together to improve the bonding performance of the material while ensuring good stability and aging resistance. The colloid will not age even when the glue is applied for a long time at a temperature above 100°C. It can also be disassembled without residue while achieving sealing and high bonding strength.

[0026] 2. In the present technical solution, the molecular chain of the special additive used is a straight chain with a low molecular weight and contains carbonyl, carboxyl and cyano groups with strong polarity. The additive has a high degree of bonding with the tackifying resin and can greatly improve the cohesive strength of the colloid to prevent the colloid from breaking and remaining on the substrate during disassembly. In terms of process, a high-temperature mixing preparation process is adopted. After cooling, it has a certain cold viscosity but the adhesion is not strong. It is easy to store and transport, and does not require high storage and transportation vessels and conditions.

[0027] 3. In this technical solution, there is an obvious synergistic strengthening effect between SEBS, saturated tackifying resin and special additives: first, SEBS and saturated tackifying resin have high compatibility, and strong van der Waals forces are formed between molecules, which improves the stability and weather resistance of the material; secondly, the special additives have good compatibility with SEBS and tackifying resin, and the hydroxyl and cyano groups in the special additives also provide bonding groups for the colloid, which work together to strengthen the bonding performance of the colloid. At a high temperature of 150°C, after the special additives are combined with the tackifying resin and the base rubber, the cohesive strength of the colloid is enhanced, making it difficult for the colloid to break during disassembly.

[0028] 4. In this technical solution, the rubber-type pressure-sensitive adhesive does not use toxic or harmful substances, and will not decompose toxic small molecules at high temperatures; and there is no solvent in the raw materials, which is safe and environmentally friendly.

[0029] 5. The aging-resistant and removable rubber-type pressure-sensitive adhesive prepared by this technical solution has excellent aging resistance and bonding properties, and can be disassembled with almost no residue after use, meeting the use requirements in the fields of battery assembly, mold sealing, etc. DETAILED DESCRIPTION

[0030] The following is further described in detail through specific implementations, but the implementation of the present invention is not limited thereto. Unless otherwise specified, the technical means used in the following implementations are conventional means well known to those skilled in the art; the experimental methods used are all conventional methods; the materials, reagents, etc. used can all be obtained from commercial channels.

[0031] An aging-resistant and detachable rubber-type pressure-sensitive adhesive comprises, by weight, 100 parts of base rubber, 20-50 parts of tackifying resin, 40-70 parts of plasticizer, 1-3 parts of antioxidant, 4-10 parts of reinforcing filler and 0-8 parts of special additives.

[0032] The base rubber is SEBS (hydrogenated styrene-butadiene block copolymer), which is obtained by hydrogenating special linear SBS.

[0033] The tackifying resin is at least one of C5 petroleum resin, hydrogenated terpene resin and rosin resin.

[0034] The plasticizer is at least one of cycloparaffin oil, white oil and paraffin oil.

[0035] The antioxidant is at least one of N-phenyl-N / -isopropyl-p-phenylenediamine, 2,2,4-trimethyl-1,2-dihydroquinoline polymer and 2-mercaptobenzimidazole.

[0036] The reinforcing filler is at least one of ultrafine white carbon black and carbon black.

[0037] The special additive is a compound with a linear molecular chain, a low molecular weight, and containing carbonyl, carboxyl and cyano groups with strong polarity; the preparation method of the special additive comprises the following steps:

[0038] S1, ethyl isocyanate acrylate The hydroxyl-terminated polyolefins are mixed in a mass ratio of 1:1;

[0039] S2, heating the system to 150°C and reacting for 2 minutes;

[0040] S3. Add organic tin and continue the reaction for 10 minutes to obtain a mixture containing a large amount of the following structure, which is a special auxiliary agent.

[0041] A method for preparing an aging-resistant and detachable rubber-type pressure-sensitive adhesive comprises the following steps:

[0042] Step 1: Weigh various raw materials according to the proportion and set the temperature of the internal mixer to 150°C;

[0043] Step 2: Add the base rubber into the internal mixer and heat and soften for 1-3 minutes;

[0044] Step 3: Add the tackifier and special additives into the internal mixer and mix for 1-3 minutes;

[0045] Step 4: Continue to add plasticizer, antioxidant and carbon black, and mix for 4-8 minutes;

[0046] Step 5: Extruding by screw, the screw extrusion conditions are: extrusion temperature 110-150°C, extrusion rate 2-4m / min, and extruder head pressure 5-7MPa.

[0047] Examples and Comparative Examples

[0048] Each embodiment and comparative example prepares a rubber-type pressure-sensitive adhesive according to the method generally described in the above scheme. The difference between each embodiment and comparative example lies in the type and amount of raw materials added, as shown in Table 1:

[0049] Table 1

[0050]

[0051]

[0052] The performance of the rubber-type pressure-sensitive adhesives prepared in the above embodiments and comparative examples was tested, and each group was repeated three times. The specific test methods and test results are shown in Table 2:

[0053] Table 2

[0054]

[0055] From the data in Table 2, it can be seen that, by comparing Example 1, Example 2 and Example 3, the use of different plasticizers will directly affect the mechanical properties of the pressure-sensitive adhesive. When white oil and paraffin oil are used as plasticizers, the mechanical properties are significantly reduced, but there is basically no effect on the bonding properties of the substrate. Therefore, cycloalkane oil is used as the plasticizer.

[0056] Compared with Example 1, Example 4 uses a mixture of terpene resin and hydrogenated petroleum resin, and after the total amount of plasticizer is reduced, there is no significant effect on the bonding performance. However, the aging resistance of the material deteriorates after the addition of terpene resin.

[0057] Comparing Example 5 and Example 6, after adding the special additive in Example 6, no colloid residue appeared on the rough substrate surface during disassembly, indicating that the addition of the special additive increased the strength of the glue and also increased the compatibility of the tackifying resin and the base rubber.

[0058] Comparing Example 6, Example 7 and Example 8, respectively, 20 parts, 30 parts and 40 parts of hydrogenated petroleum resin, it can be clearly observed that when the hydrogenated petroleum resin is 40 parts, the bonding performance is excellent, but a small amount of colloid remains on the rough substrate during disassembly. Relatively speaking, when the hydrogenated petroleum resin is 500 parts, the bonding performance is excellent, and no residue will appear during disassembly.

[0059] Through comparative analysis of eight embodiments, it is found that the colloid bonding performance, aging resistance and detachability of Embodiment 7 all meet the requirements envisioned by the present invention.

[0060] Comparative Example 1

[0061] The difference between Comparative Example 1 and Example 1 is that cyclohexane oil, paraffin oil and white oil are mixed and added in a weight ratio of 1:1:1. The preparation process is as follows: the temperature of the kneader is set to 150°C, the base rubber is added to the kneader to soften for 3 minutes, the tackifier and special additives are added and kneaded for 1-3 minutes, the plasticizer, antioxidant and carbon black are continuously added and kneaded for 4-8 minutes, and the mixture is extruded through a screw after being kneaded evenly.

[0062] Comparative Example 2

[0063] The difference between Comparative Example 2 and Example 4 is that the amount of cyclohexane oil is increased. The preparation process is as follows: the kneading machine temperature is set to 150° C., the base rubber is added to the kneading machine to soften for 3 minutes, the tackifier and the special additive are added and kneaded for 1-3 minutes, the plasticizer, the antioxidant and the carbon black are continuously added and kneaded for 4-8 minutes, and the mixture is extruded through a screw after being kneaded evenly.

[0064] Comparative Example 3

[0065] The difference between Comparative Example 3 and Examples 5 and 6 is that tripropylene glycol diacrylate is added. The preparation process is as follows: the kneading machine temperature is set to 150° C., the base rubber is added to the kneading machine to soften for 3 minutes, the tackifier and the special additive are added and kneaded for 1-3 minutes, the plasticizer, antioxidant, tripropylene glycol diacrylate and carbon black are continuously added and kneaded for 4-8 minutes, and the mixture is extruded through a screw after being kneaded evenly.

[0066] Comparative Example 4

[0067] The difference between Comparative Example 4 and Example 7 is that no antioxidant is added. The preparation process is as follows: the kneading machine temperature is set to 150° C., the base rubber is added to the kneading machine to soften for 3 minutes, the tackifier and the special additive are added and kneaded for 1-3 minutes, the plasticizer, antioxidant, special additive and carbon black are continuously added and kneaded for 4-8 minutes, and the mixture is extruded through a screw after being uniformly kneaded.

[0068] Comparative Example 5

[0069] The difference between Comparative Example 5 and Example 1 is that ordinary SBS base rubber without hydrogenation treatment is used. The preparation process is as follows: the kneading machine temperature is set to 150° C., the base rubber is added to the kneading machine to soften for 3 minutes, the tackifier and special additives are added and kneaded for 1-3 minutes, the plasticizer, antioxidant, special additives and carbon black are continuously added and kneaded for 4-8 minutes, and the mixture is extruded through a screw after being uniformly kneaded.

[0070] The specific raw material compositions of Comparative Examples 1 to 4 are shown in Table 3:

[0071] Table 3

[0072]

[0073] The pressure-sensitive adhesives prepared in the above-mentioned comparative examples were subjected to performance tests, and the specific test results are detailed in Table 4: Compared with Example 1, Example 2 and Example 3, Comparative Example 1 mixed three plasticizers, and the tensile properties and bonding properties of the pressure-sensitive adhesive of the present invention were reduced. Compared with Example 4, Comparative Example 2 increased the amount of plasticizer, resulting in a decrease in hardness and softening point, low adhesion, and oil seepage. Compared with Examples 5 and 6, Comparative Example 3 added an auxiliary agent to enhance cohesion, and after the common tripropylene glycol diacrylate on the market, some residues would appear on the substrate with a rough surface of the bonding, and the disassembly integrity was not high. Compared with Example 5, Comparative Example 4 did not add an antioxidant, and the aging resistance of the product was reduced. Comparative Example 5 used ordinary SBS base rubber that had not been hydrogenated, resulting in a significant decrease in mechanical strength and aging resistance.

[0074] Table 4

[0075]

[0076] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. An aging-resistant and detachable rubber-type pressure-sensitive adhesive, characterized in that: Calculated by mass, it includes 100 parts of base rubber, 20-50 parts of tackifying resin, 40-70 parts of plasticizer, 1-3 parts of antioxidant, 4-10 parts of reinforcing filler and 0-8 parts of special additives.

2. The aging-resistant and detachable rubber-type pressure-sensitive adhesive according to claim 1, characterized in that: The base rubber is a hydrogenated styrene-butadiene block copolymer obtained by hydrogenating a special linear SBS.

3. The aging-resistant and detachable rubber-type pressure-sensitive adhesive according to claim 2, characterized in that: The tackifying resin is at least one of C5 petroleum resin, hydrogenated terpene resin and rosin resin.

4. The aging-resistant and detachable rubber-type pressure-sensitive adhesive according to claim 3, characterized in that: The plasticizer is at least one of cycloalkane oil, white oil and paraffin oil.

5. The aging-resistant and detachable rubber-type pressure-sensitive adhesive according to claim 4, characterized in that: The antioxidant is at least one of N-phenyl-N / -isopropyl-p-phenylenediamine, 2,2,4-trimethyl-1,2-dihydroquinoline polymer and 2-mercaptobenzimidazole.

6. The aging-resistant and detachable rubber-type pressure-sensitive adhesive according to claim 5, characterized in that: The reinforcing filler is at least one of ultrafine white carbon black and carbon black.

7. The aging-resistant and detachable rubber-type pressure-sensitive adhesive according to claim 6, characterized in that: The special additive is obtained by addition reaction of ethyl isocyanate acrylate and terminal hydroxyl polyolefin, and the mass ratio of ethyl isocyanate acrylate to terminal hydroxyl polyolefin is 1:

1.

8. The aging-resistant and detachable rubber-type pressure-sensitive adhesive according to claim 7, characterized in that: The preparation method of the special additive comprises the following steps: S1, mixing ethyl isocyanate acrylate and hydroxyl-terminated polyolefin in a mass ratio of 1:1; S2, heating the system to 150°C and reacting for 2 minutes; S3. Add organic tin to continue the reaction. The reaction time is 10 min.

9. The method for preparing an aging-resistant and detachable rubber-type pressure-sensitive adhesive according to any one of claims 1 to 8, characterized in that: The steps include: Step 1: weigh the raw materials according to the proportion and set the mixing temperature to 150°C; Step 2: Add the base rubber into the internal mixer and heat and soften for 1-3 minutes; Step 3: Add the tackifier and special additives into the internal mixer and mix for 1-3 minutes; Step 4: Continue to add plasticizer, antioxidant and carbon black, and mix for 4-8 minutes; Step 5: Extrusion through screw.

10. The method for preparing an aging-resistant and detachable rubber-type pressure-sensitive adhesive according to claim 9, characterized in that: In step 5, the screw extrusion conditions are: extrusion temperature 110-150° C., extrusion rate 2-4 m / min, and extruder head pressure 5-7 MPa.

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