Rubber type pressure-sensitive adhesive, adhesive tape and preparation method

Abstract

The invention discloses a rubber type pressure-sensitive adhesive, an adhesive tape and a preparation method. The rubber type pressure-sensitive adhesive comprises the following components in parts by weight: 100 parts of rubber, 3-30 parts of modified polyether polyol, 30-130 parts of tackifying resin, 1-5 parts of an antioxidant, 1-30 parts of a cross-linking agent and a proper amount of a solvent. The formula of the rubber type pressure-sensitive adhesive is innovatively designed, the adhesive force of the pressure-sensitive adhesive to a base material is improved by utilizing the modified polyether polyol containing epoxy groups, and the polyurethane formed by the reaction of the modified polyether polyol and isocyanate is utilized to form network crosslinking with the rubber; meanwhile, the reaction between isocyanate and rubber is utilized to further enhance the net-shaped cross-linked structure, so that the cohesive force of the pressure-sensitive adhesive is remarkably improved, the adhesive force of the rubber type pressure-sensitive adhesive to substrates such as PET (Polyethylene Terephthalate), PP (Polypropylene), PE (Polyethylene) and PVC (Polyvinyl Chloride) is greatly improved, and the rubber type pressure-sensitive adhesive can be directly coated on the substrates to obtain excellent anchoring force.

Description

Technical Field

[0001] This invention belongs to the field of pressure-sensitive adhesive technology, specifically relating to a rubber-type pressure-sensitive adhesive, tape, and preparation method. Background Technology

[0002] Rubber-type pressure-sensitive adhesives are made from natural or synthetic rubber with appropriate amounts of tackifying resins, softeners, fillers, solvents, etc. They have good resilience, flexibility, initial tack, weather resistance, and environmental friendliness, and are widely used in tapes for various applications.

[0003] However, rubber-based pressure-sensitive adhesives have insufficient adhesion to film substrates such as PET, PP, PVC, and PE. Tapes made by direct coating have a high probability of delamination. The usual solution is to pre-treat the adhesive surface of the above film substrates with a primer or corona treatment. Both primer coating and corona treatment place higher demands on coating equipment and processing methods, increase the number of steps, and seriously restrict production efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a rubber-type pressure-sensitive adhesive, tape, and preparation method. This rubber-type pressure-sensitive adhesive can be directly coated on substrates such as PET, PP, PE, and PVC. It can achieve good anchoring force without the need for a primer corona treatment, is not easy to fall off, reduces processing steps, and improves quality stability and production efficiency.

[0005] To achieve the above objectives, a specific embodiment of the present invention provides the following technical solution:

[0006] A rubber-type pressure-sensitive adhesive, comprising the following components by weight: 100 parts rubber, 3-30 parts modified polyether polyol, 30-130 parts tackifying resin, 1-5 parts antioxidant, 1-30 parts crosslinking agent, and an appropriate amount of solvent.

[0007] In one or more embodiments of the present invention, the modified polyether polyol is a polyether polyol containing epoxy groups.

[0008] In one or more embodiments of the present invention, the modified polyether polyol is at least one of Cardolite® NX-9008 and SIMALINE™ IE 2002.

[0009] In one or more embodiments of the present invention, the rubber is natural rubber or a mixture of natural rubber and SIS thermoplastic elastomer; and / or,

[0010] The crosslinking agent is at least one of TDI, MDI, and HDI.

[0011] In one or more embodiments of the present invention, the tackifying resin is at least one selected from C5 petroleum resin, C9 petroleum resin, terpene resin, and rosin resin; and / or,

[0012] The softening point of the tackifying resin is 75℃-120℃.

[0013] In one or more embodiments of the present invention, the rubber-type pressure-sensitive adhesive further comprises less than or equal to 10 parts by weight of filler, wherein the filler is at least one of calcium carbonate, zinc oxide, titanium dioxide, and silica, and the particle size of the filler is 1000 mesh to 5000 mesh.

[0014] In one or more embodiments of the present invention, the rubber-type pressure-sensitive adhesive further comprises less than or equal to 30 parts by weight of rubber oil, wherein the rubber oil is at least one of naphthenic oil, polyisobutylene, and liquid rubber.

[0015] Another specific embodiment of the present invention provides the following technical solution:

[0016] A method for preparing a rubber-type pressure-sensitive adhesive involves dispersing rubber, modified polyether polyol, tackifying resin, antioxidant, and crosslinking agent in a solvent, mixing them thoroughly, and obtaining the rubber-type pressure-sensitive adhesive.

[0017] Another specific embodiment of the present invention provides the following technical solution:

[0018] An adhesive tape comprising a substrate layer and a pressure-sensitive adhesive layer stacked sequentially, the pressure-sensitive adhesive layer being formed of a rubber-based pressure-sensitive adhesive.

[0019] In one or more embodiments of the present invention, the substrate layer is any one of PET, PP, PVC, and PE.

[0020] Compared with existing technologies, this invention innovatively designs a rubber-based pressure-sensitive adhesive formulation. It utilizes modified polyether polyols containing epoxy groups to improve the adhesion of the pressure-sensitive adhesive to the substrate. The polyurethane formed by the reaction of the modified polyether polyol with isocyanate forms a network crosslink with the rubber. At the same time, the reaction between isocyanate and rubber further enhances the network crosslink structure, significantly improving the cohesive force of the pressure-sensitive adhesive. This greatly improves the adhesion of the rubber-based pressure-sensitive adhesive to substrates such as PET, PP, PE, and PVC, allowing the rubber-based pressure-sensitive adhesive to be directly coated onto the substrate to obtain excellent anchoring force. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the tape structure in one embodiment of the present invention.

[0023] Explanation of key figure labels:

[0024] 1. Substrate layer; 2. Pressure-sensitive adhesive layer. Detailed Implementation

[0025] To enable those skilled in the art to better understand the technical solutions in this disclosure, the technical solutions in the embodiments of this disclosure are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this disclosure.

[0026] A specific embodiment of the present invention provides a rubber-type pressure-sensitive adhesive, which comprises the following components by weight: 100 parts rubber, 3-30 parts modified polyether polyol, 30-130 parts tackifying resin, 1-5 parts antioxidant, 1-30 parts crosslinking agent, and an appropriate amount of solvent.

[0027] Furthermore, the rubber is natural rubber or a mixture of natural rubber and SIS thermoplastic elastomer, preferably natural rubber.

[0028] Furthermore, the modified polyether polyol is a polyether polyol containing epoxy groups, which can improve the adhesion of pressure-sensitive adhesives to low surface energy substrates such as PET, PP, PE, and PVC, and is especially suitable for improving the adhesion of pressure-sensitive adhesives to PVC and PET.

[0029] The modified polyether polyol is specifically at least one of Cardolite® NX-9008 and SIMALINE™ IE 2002. Cardolite® NX-9008 is a trifunctional polyether polyol based on cashew nutshell oil from Cardolite, with a hydroxyl value of 300-380 mg KOH / g and a viscosity of 2,000-4,000 cP@25°C. SIMALINE™ IE 2002 is a modified polymer containing epoxy groups and active hydroxyl groups produced by SEPPIC, France, with a hydroxyl value of 230 mg KOH / g, a functionality of 2, a molecular weight of approximately 485, a water content of <0.2%, and a viscosity of 2,100 cP@50°C. Selecting the above polyether polyols can significantly improve the adhesion of the pressure-sensitive adhesive to the substrate and increase the adhesive strength of the pressure-sensitive adhesive.

[0030] Using too little modified polyether polyol will not significantly improve the performance of pressure-sensitive adhesive, while using too much will make the adhesive harden, affecting its pressure sensitivity and also having a significant impact on release.

[0031] Furthermore, the tackifying resin is one or a mixture or modified mixture of C5 petroleum resin, C9 petroleum resin, terpene resin, and rosin resin. The softening point of the tackifying resin is preferably 75℃-120℃. Selecting the above-mentioned tackifying resin can effectively improve the cohesion and tack of the pressure-sensitive adhesive and optimize the adhesion performance of the pressure-sensitive adhesive to the substrate.

[0032] Furthermore, antioxidants help improve the stability and weather resistance of pressure-sensitive adhesives. Specifically, antioxidants such as 1010 antioxidant can be selected.

[0033] Furthermore, the crosslinking agent is an isocyanate, specifically at least one of TDI (toluene diisocyanate), MDI (diphenylmethane diisocyanate), and HDI (hexamethylene diisocyanate). In the pressure-sensitive adhesive system, the isocyanate groups in the isocyanate can react with the hydroxyl groups in the modified polyether polyol to form polyurethane. On one hand, the polyurethane formed in the system can form a network crosslink with the rubber; on the other hand, the isocyanate can also react with the active groups in the rubber to further strengthen the network structure, thereby increasing the cohesive force of the pressure-sensitive adhesive. Simultaneously, the epoxy groups in the polyether polyol improve the adhesion of the pressure-sensitive adhesive to the substrate, resulting in excellent adhesion performance.

[0034] Furthermore, the solvent is toluene.

[0035] Furthermore, the rubber-type pressure-sensitive adhesive also includes 10 parts by weight of filler, wherein the filler is at least one selected from calcium carbonate, zinc oxide, titanium dioxide, and silica, and the particle size of the filler is 1000 mesh-5000 mesh, preferably 1500 mesh-3000 mesh. Adding an appropriate amount of filler further improves the mechanical properties of the pressure-sensitive adhesive.

[0036] Furthermore, the rubber-based pressure-sensitive adhesive also includes less than or equal to 30 parts by weight of rubber oil, which is at least one of naphthenic oil, polyisobutylene, and liquid rubber. By adding an appropriate amount of rubber oil, the viscosity of the pressure-sensitive adhesive is improved, its processability is optimized, and its adhesion to the substrate is enhanced.

[0037] Another specific embodiment of the present invention provides a method for preparing a rubber-based pressure-sensitive adhesive, which specifically includes the following steps:

[0038] First, dissolve the components other than the crosslinking agent—rubber, modified polyether polyol, tackifying resin, and antioxidant—in a solvent to prepare a solution with a certain solid content. Then, add the crosslinking agent before coating (to avoid pre-mixing the adhesive and curing it, which would prevent coating). After mixing evenly, a rubber-type pressure-sensitive adhesive is obtained.

[0039] Another specific embodiment of the present invention provides an adhesive tape, such as Figure 1 As shown, the tape includes a substrate layer 1 and a pressure-sensitive adhesive layer 2 stacked sequentially, the pressure-sensitive adhesive layer 2 being formed of a rubber-type pressure-sensitive adhesive.

[0040] Specifically, the substrate layer can be any of PET, PP, PVC, or PE. Depending on the actual needs, a release layer is provided on the side of the substrate layer facing away from the pressure-sensitive adhesive layer. The release layer is formed by a release agent (such as an organosilicon release agent: dimethyl silicone oil, methyl phenyl silicone oil), which plays a role in isolation and protection, preventing the tape from sticking together. The surface of the substrate can be corona treated or not.

[0041] In the specific preparation process, a rubber-based pressure-sensitive adhesive is coated onto a substrate, with a dry coating weight of 5 g / m². 2 -50g / m 2 Then dry at 110℃ for 4-5 minutes.

[0042] The present invention will be further described in detail below with reference to specific embodiments.

[0043] The raw materials used in this invention are: natural rubber with a Mooney value of 60±5; C5 petroleum resin is 3204C5 petroleum resin produced by Ningbo Jinhai Chenguang; polyisobutylene is Daelim PB1300 from South Korea; isocyanate is PM-200 and MDI polymerized by Yantai Wanhua.

[0044] Example 1

[0045] The rubber-type pressure-sensitive adhesive in this embodiment comprises, by weight, 100 parts natural rubber, 100 parts C5 petroleum resin, 10 parts 1500-mesh calcium carbonate, 5 parts polyisobutylene, 10 parts NX-9008 polyether polyol, 1 part 1010 antioxidant, 10 parts isocyanate and an appropriate amount of toluene.

[0046] During preparation, dissolve all materials except isocyanate in toluene, stir until homogeneous, and prepare a 30% solid content solution. Add isocyanate before coating, stir until homogeneous, and ensure coating is completed within 1 hour.

[0047] The prepared rubber-type pressure-sensitive adhesive was coated onto a 25μm thick PET substrate with an adhesive application rate of 25g / m². 2 The tape was dried at 110℃ for 5 minutes.

[0048] Examples 2-5

[0049] The preparation of rubber-type pressure-sensitive adhesives in Examples 2-5 is basically the same as that in Example 1. The difference lies in the slight difference in the types and amounts of each raw material component, as shown in Table 1. The proportions in Table 1 are dry weight proportions.

[0050] Table 1. Raw material composition of rubber-type pressure-sensitive adhesives in Examples 1-5

[0051] Raw materials (parts by weight) Example 1 Example 2 Example 3 Example 4 Example 5 Natural rubber 100 100 100 100 100 C5 petroleum resin 100 100 100 100 100 Calcium carbonate 10 10 10 10 10 Polyisobutylene 5 5 5 5 5 NX-9008 polyether polyol 10 5 50 10 0 IE 2002 polyether polyol 0 0 0 0 10 1010 Antioxidant 1 1 1 1 1 Isocyanates 10 3 30 10 10 Toluene Appropriate amount Appropriate amount Appropriate amount Appropriate amount Appropriate amount Coated substrate 25μm PET 25μm PET 25μm PET 100μm PVC 100μm PVC <![CDATA[Coating amount (dry weight g / m 2 )]]> 25.00 25.00 25.00 25.00 25.00

[0052] Comparative Example 1

[0053] The rubber-type pressure-sensitive adhesive in this comparative example, by weight, includes 100 parts natural rubber, 100 parts C5 petroleum resin, 10 parts 1500-mesh calcium carbonate, 5 parts polyisobutylene, 1 part 1010 antioxidant, 0.3 parts isocyanate, and an appropriate amount of toluene.

[0054] During preparation, dissolve all materials except isocyanate in toluene, stir until homogeneous, and prepare a 30% solid content solution. Add isocyanate before coating, stir until homogeneous, and ensure coating is completed within 1 hour.

[0055] The prepared rubber-type pressure-sensitive adhesive was coated onto a 25μm thick PET substrate with an adhesive application rate of 25g / m². 2 The tape was dried at 110℃ for 5 minutes.

[0056] Comparative Example 2

[0057] The rubber-type pressure-sensitive adhesive in this comparative example, by weight, includes 100 parts natural rubber, 100 parts C5 petroleum resin, 10 parts 1500-mesh calcium carbonate, 5 parts polyisobutylene, 1 part 1010 antioxidant, 0.3 parts isocyanate, and an appropriate amount of toluene.

[0058] During preparation, dissolve all materials except isocyanate in toluene, stir until homogeneous, and prepare a 30% solid content solution. Add isocyanate before coating, stir until homogeneous, and ensure coating is completed within 1 hour.

[0059] The prepared rubber-type pressure-sensitive adhesive was coated onto a 100μm thick PVC substrate with an adhesive application rate of 25g / m².2 The tape was dried at 110℃ for 5 minutes.

[0060] Comparative Example 3

[0061] The rubber-type pressure-sensitive adhesive in this comparative example, by weight, includes 100 parts natural rubber, 100 parts C5 petroleum resin, 10 parts 1500-mesh calcium carbonate, 5 parts polyisobutylene, 10 parts NX-9008 polyether polyol, 1 part 1010 antioxidant, 0.3 parts isocyanate and an appropriate amount of toluene.

[0062] During preparation, dissolve all materials except isocyanate in toluene, stir until homogeneous, and prepare a 30% solid content solution. Add isocyanate before coating, stir until homogeneous, and ensure coating is completed within 1 hour.

[0063] The prepared rubber-type pressure-sensitive adhesive was coated onto a 25μm thick PET substrate with an adhesive application rate of 25g / m². 2 The tape was dried at 110℃ for 5 minutes.

[0064] The preparation of rubber-type pressure-sensitive adhesives in Comparative Examples 1-3 is basically the same as that in Example 1. The difference lies in the slight difference in the types and amounts of each raw material component, as shown in Table 2. The proportions in Table 2 are dry weight proportions.

[0065] Table 2 Raw material composition of rubber-type pressure-sensitive adhesives in Comparative Examples 1-3

[0066] Raw materials (parts by weight) Comparative Example 1 Comparative Example 2 Comparative Example 3 Natural rubber 100 100 100 C5 petroleum resin 100 100 100 Calcium carbonate 10 10 10 Polyisobutylene 5 5 5 NX-9008 polyether polyol 0 0 10 IE 2002 polyether polyol 0 0 0 1010 Antioxidant 1 1 1 Isocyanates 0.3 0.3 0.3 Toluene Appropriate amount Appropriate amount Appropriate amount Coated substrate 25μm PET 100μm PVC 25μm PET <![CDATA[Coating amount (dry weight g / m 2 )]]> 25.00 25.00 25.00

[0067] The coated and dried tapes from each embodiment and comparative example were adhered to the release surface of the release paper and cut into 25mm*25cm experimental samples for testing peel force, heat resistance test of stainless steel plate bonding at 100℃ for 1H and 110℃ for 1H to verify the presence of residual adhesive, and adhesion test (using standard adhesive to bond the adhesive surface and removing it to test the delamination). The results are shown in Table 3.

[0068] Table 3 Performance Test Results

[0069] Test Project Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Example 2 Example 3 Example 4 Example 5 180° peel force (ASTM D3300 N / inch) 9.8 6.5 8.9 5.2 6.8 2.5 3.6 3.5 1H Hot Tear on 100℃ Stainless Steel Sheet No residue No residue Residual glue No residue No residue No residue No residue No residue 1H Hot Tear on 110℃ Stainless Steel Sheet Residual glue Residual glue Residual glue No residue No residue No residue No residue No residue Viscosity test Degumming Degumming Degumming No glue separation No glue separation No glue separation No glue separation No glue separation

[0070] As can be seen from Table 3, compared with Comparative Example 1 and Comparative Example 2, the rubber-type pressure-sensitive adhesive in the embodiments of the present invention exhibits excellent adhesion to film substrates such as PET and PVC, indicating that the adhesion performance of the rubber-type pressure-sensitive adhesive can be effectively improved by using NX-9008 polyether polyol and IE 2002 polyether polyol.

[0071] In Comparative Example 3, the rubber-type pressure-sensitive adhesive showed poor adhesion to the substrate. Analysis suggests that the amount of crosslinking agent affects the formation of the network structure in the system. Insufficient amount will affect the reaction between the crosslinking agent and the modified polyether polyol, thereby reducing the performance of the rubber-type pressure-sensitive adhesive.

[0072] It will be apparent to those skilled in the art that this disclosure is not limited to the details of the exemplary embodiments described above, and that this disclosure can be implemented in other specific forms without departing from the spirit or essential characteristics of this disclosure. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of this disclosure is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this disclosure.

[0073] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A rubber-based pressure-sensitive adhesive, characterized in that, The rubber-type pressure-sensitive adhesive comprises the following components in parts by weight: 100 parts rubber, 3-30 parts modified polyether polyol, 30-130 parts tackifying resin, 1-5 parts antioxidant, 1-30 parts crosslinking agent, and an appropriate amount of solvent.

2. The rubber-type pressure-sensitive adhesive according to claim 1, characterized in that, The modified polyether polyol is a polyether polyol containing epoxy groups.

3. The rubber-type pressure-sensitive adhesive according to claim 2, characterized in that, The modified polyether polyol is at least one of Cardolite® NX-9008 and SIMALINE™ IE 2002.

4. The rubber-type pressure-sensitive adhesive according to claim 1, characterized in that, The rubber is natural rubber or a mixture of natural rubber and SIS thermoplastic elastomer; and / or, The crosslinking agent is at least one of TDI, MDI, and HDI.

5. The rubber-type pressure-sensitive adhesive according to claim 1, characterized in that, The tackifying resin is at least one of C5 petroleum resin, C9 petroleum resin, terpene resin, and rosin resin; and / or, The softening point of the tackifying resin is 75℃-120℃.

6. The rubber-type pressure-sensitive adhesive according to claim 1, characterized in that, The rubber-type pressure-sensitive adhesive also includes less than or equal to 10 parts by weight of filler, wherein the filler is at least one of calcium carbonate, zinc oxide, titanium dioxide, and silica, and the particle size of the filler is 1000 mesh to 5000 mesh.

7. The rubber-type pressure-sensitive adhesive according to claim 1, characterized in that, The rubber-type pressure-sensitive adhesive also includes less than or equal to 30 parts by weight of rubber oil, wherein the rubber oil is at least one of naphthenic oil, polyisobutylene, and liquid rubber.

8. A method for preparing the rubber-type pressure-sensitive adhesive according to claim 1, characterized in that, Rubber, modified polyether polyol, tackifying resin, antioxidant and crosslinking agent are dispersed in a solvent and mixed to obtain rubber-type pressure-sensitive adhesive.

9. A type of adhesive tape, characterized in that, The tape comprises a substrate layer and a pressure-sensitive adhesive layer stacked sequentially, wherein the pressure-sensitive adhesive layer is formed of the rubber-type pressure-sensitive adhesive as described in claim 1.

10. The tape according to claim 9, characterized in that, The substrate layer is any one of PET, PP, PVC, and PE.

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