Low-temperature-resistant hot-melt pressure-sensitive adhesive and preparation method thereof

Abstract

The invention discloses a low-temperature-resistant hot-melt pressure-sensitive adhesive and a preparation method thereof in the technical field of hot-melt pressure-sensitive adhesives. The low-temperature-resistant hot-melt pressure-sensitive adhesive is prepared from the following raw materials in parts by weight: 50 to 80 parts of thermoplastic elastomer, 20 to 40 parts of tackifier, 0.1 to 1 part of antioxidant, 0.1 to 1 part of ultraviolet light absorber and 10 to 30 parts of filler. And the thermoplastic elastomer is a polystyrene-isoprene-styrene block copolymer and a polyacrylate thermoplastic elastomer. The hot-melt pressure-sensitive adhesive disclosed by the invention does not contain an organic solvent, so that the pollution of a traditional solvent type pressure-sensitive adhesive to the environment in the production and use processes is avoided, and the hot-melt pressure-sensitive adhesive accords with the current development trend of green chemistry; as flammable and explosive organic solvents are not used, the hot-melt pressure-sensitive adhesive disclosed by the invention has higher safety in storage and use processes, and the risks of fire disasters and explosions are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of hot-melt pressure-sensitive adhesives, in particular to a low-temperature resistant hot-melt pressure-sensitive adhesive and a preparation method thereof. Background Art

[0002] The full name of pressure-sensitive adhesive is pressure-sensitive adhesive, also commonly known as self-adhesive, or simply pressure-sensitive adhesive. Pressure-sensitive adhesive products include three categories: pressure-sensitive adhesive tape, pressure-sensitive adhesive label paper, and pressure-sensitive film. Their full names are pressure-sensitive adhesive tape, pressure-sensitive adhesive label paper, and pressure-sensitive adhesive sheet, commonly known as tape, self-adhesive label paper, and pressure-sensitive film. This component is adjusted to achieve better performance of the product.

[0003] Hot-melt pressure-sensitive adhesives have been widely used in packaging, labeling, sanitary products and other fields due to their advantages such as fast curing, no solvent emission, environmental protection and safety. However, the existing hot-melt pressure-sensitive adhesives have poor bonding performance in low-temperature environments and are prone to peeling or cracking, which limits their application in some special environments. In modern industrial production and daily life, pressure-sensitive adhesives are widely used in various fields as an important adhesive material. Summary of the invention

[0004] The object of the present invention is to provide a low-temperature resistant hot-melt pressure-sensitive adhesive and a preparation method thereof, so as to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a low-temperature resistant hot-melt pressure-sensitive adhesive, comprising the following weight portions of a raw thermoplastic elastomer: 50-80 parts, a tackifier: 20-40 parts, an antioxidant: 0.1-1 parts, an ultraviolet absorber: 0.1-1 parts, and a filler: 10-30 parts.

[0006] As a further solution of the present invention: the thermoplastic elastomer is a polystyrene-isoprene-styrene block copolymer and a polyacrylate thermoplastic elastomer.

[0007] As a further solution of the present invention: the tackifier is rosin ester and petroleum resin, the antioxidant is phenol and amine antioxidant, the ultraviolet absorber is benzotriazole and hydroxybenzoate, and the filler is talc, calcium carbonate and diatomaceous earth.

[0008] A method for preparing a low-temperature resistant hot-melt pressure-sensitive adhesive comprises the above-mentioned low-temperature resistant hot-melt pressure-sensitive adhesive and the following steps:

[0009] S100: Raw material preparation: prepare thermoplastic elastomer, tackifier, antioxidant, UV absorber and filler according to the formula ratio;

[0010] S200: Mixing raw materials: Mix all prepared raw materials in proportion to ensure that the ingredients are evenly distributed;

[0011] S300: Melt mixing: melt the mixture at a temperature of 160-200°C, and use an extruder or other mixing equipment to fully stir to ensure that all ingredients are completely blended together;

[0012] S400: Extrusion molding: The melt-mixed material is extruded through an extruder to form a continuous long strip;

[0013] S500: Cooling and pelletizing: The extruded long strip material is cooled and then cut into particles of the required size by a pelletizer:

[0014] S600: Packaging and storage: Pack the prepared low-temperature resistant hot-melt pressure-sensitive adhesive particles and store them in a dry and ventilated environment, avoiding moisture and direct sunlight.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] Environmental protection: The hot-melt pressure-sensitive adhesive of the present invention does not contain organic solvents, thus avoiding the pollution of the environment caused by the traditional solvent-based pressure-sensitive adhesive during production and use, and conforms to the current development trend of green chemistry.

[0017] Safety: Since no flammable and explosive organic solvents are used, the hot-melt pressure-sensitive adhesive of the present invention has higher safety during storage and use, and reduces the risk of fire and explosion.

[0018] Excellent performance: By optimizing the formula and preparation process, the hot-melt pressure-sensitive adhesive of the present invention has excellent bonding performance, low-temperature resistance and aging resistance, and can meet the needs of various complex application scenarios.

[0019] Cost-effectiveness: Compared with similar imported products, the hot-melt pressure-sensitive adhesive of the present invention has lower costs while ensuring performance, thereby improving market competitiveness.

[0020] Wide application: The hot-melt pressure-sensitive adhesive of the present invention is suitable for various fields, such as packaging, labeling, advertising, etc., and has broad market prospects and application potential. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] The terms "first", "second", etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated before and after are in an "or" relationship.

[0023] In this embodiment: a low-temperature resistant hot-melt pressure-sensitive adhesive comprises the following parts by weight: a raw thermoplastic elastomer: 50-80 parts, a tackifier: 20-40 parts, an antioxidant: 0.1-1 parts, an ultraviolet absorber: 0.1-1 parts, and a filler: 10-30 parts.

[0024] The thermoplastic elastomer is a polystyrene-isoprene-styrene block copolymer and a polyacrylate thermoplastic elastomer.

[0025] The tackifiers are rosin esters and petroleum resins, the antioxidants are phenolic and amine antioxidants, the UV absorbers are benzotriazoles and hydroxybenzoic acid esters, and the fillers are talc, calcium carbonate and diatomaceous earth.

[0026] A method for preparing a low-temperature resistant hot-melt pressure-sensitive adhesive comprises the above-mentioned low-temperature resistant hot-melt pressure-sensitive adhesive and the following steps:

[0027] S100: Raw material preparation: prepare thermoplastic elastomer (such as SIS or polyacrylate), tackifier (such as rosin ester or petroleum resin), antioxidant (such as phenol or amine), UV absorber (such as benzotriazole or hydroxybenzoate) and filler (such as talc, calcium carbonate or diatomaceous earth) according to the formula ratio;

[0028] S200: Mixing raw materials: Mix all prepared raw materials in proportion to ensure that the ingredients are evenly distributed. This step can be carried out using a high-speed stirrer to ensure uniform mixing;

[0029] S300: Melt mixing: melt the mixture at a temperature of 160-200°C, and use an extruder or other mixing equipment to fully stir to ensure that all ingredients are completely blended together;

[0030] S400: Extrusion molding: The melted and mixed materials are extruded through an extruder to form a continuous long strip. The temperature and pressure need to be controlled during the extrusion process to ensure the uniformity and quality of the product;

[0031] S500: Cooling and pelletizing: The extruded long strip material is cooled and then cut into pellets of the required size by a pelletizer. The cooling process can be done by air cooling or water cooling, and the specific choice depends on product requirements and production efficiency;

[0032] S600: Packaging and storage: Package the prepared low-temperature resistant hot-melt pressure-sensitive adhesive particles and store them in a dry and ventilated environment, avoiding moisture and direct sunlight.

[0033] Embodiment 1:

[0034] Formula: 60 parts of SIS, 30 parts of rosin ester tackifier, 0.5 parts of phenolic antioxidant, 0.5 parts of benzotriazole ultraviolet absorber, and 20 parts of talc.

[0035] Preparation method: After mixing the above raw materials, melt mixing at 180°C, extrusion molding, cooling and pelletizing.

[0036] Performance test: Adhesion performance test was carried out at -20℃, and the result showed that the bonding strength was 4.5N / cm 2 , the peel strength is 1.2N / cm.

[0037] Embodiment 2:

[0038] Formula: 70 parts of polyacrylate thermoplastic elastomer, 25 parts of petroleum resin tackifier, 0.3 parts of amine antioxidant, 0.7 parts of hydroxybenzoate ultraviolet absorber, and 15 parts of calcium carbonate.

[0039] Preparation method: After mixing the above raw materials, melt mixing at 160°C, extrusion molding, cooling and pelletizing.

[0040] Performance test: Adhesion performance test was carried out at -30℃, and the result showed that the bonding strength was 4.0N / cm 2 , the peel strength is 1.0N / cm.

[0041] Embodiment 3:

[0042] Formula: 65 parts of SIS, 20 parts of rosin ester tackifier, 10 parts of petroleum resin tackifier, 0.4 parts of phenolic antioxidant, 0.6 parts of benzotriazole ultraviolet absorber, and 25 parts of diatomaceous earth.

[0043] Preparation method: After mixing the above raw materials, melt mixing at 190°C, extrusion molding, cooling and pelletizing.

[0044] Performance test: The bonding performance test was carried out at -25℃, and the results showed that the bonding strength was 4.2N / cm 2 , the peel strength is 1.1N / cm.

[0045] Embodiment 4:

[0046] Formula: 55 parts of polyacrylate thermoplastic elastomer, 35 parts of rosin ester tackifier, 0.2 parts of amine antioxidant, 0.8 parts of hydroxybenzoate ultraviolet absorber, and 20 parts of talc.

[0047] Preparation method: After mixing the above raw materials, melt mixing at 170°C, extrusion molding, cooling and pelletizing.

[0048] Performance test: The bonding performance test was carried out at -15℃, and the results showed that the bonding strength was 4.8N / cm 2 , the peel strength is 1.3N / cm.

[0049] Embodiment 5:

[0050] Formula: 60 parts of SIS, 25 parts of rosin ester tackifier, 15 parts of petroleum resin tackifier, 0.6 parts of phenolic antioxidant, 0.4 parts of benzotriazole ultraviolet absorber, and 30 parts of calcium carbonate.

[0051] Preparation method: After mixing the above raw materials, melt mixing at 185°C, extrusion molding, cooling and pelletizing.

[0052] Performance test: Adhesion performance test was carried out at -20℃, and the result showed that the bonding strength was 4.6N / cm 2 , the peel strength is 1.15N / cm.

[0053] Embodiment 6:

[0054] Formula: 65 parts of polyacrylate thermoplastic elastomer, 20 parts of rosin ester tackifier, 10 parts of petroleum resin tackifier, 0.5 parts of amine antioxidant, 0.5 parts of hydroxybenzoic acid ester ultraviolet absorber, and 15 parts of diatomaceous earth.

[0055] Preparation method: After mixing the above raw materials, melt mixing at 165°C, extrusion molding, cooling and pelletizing.

[0056] Performance test: Adhesion performance test was carried out at -30℃, and the result showed that the bonding strength was 4.1N / cm 2 , the peel strength is 1.05N / cm.

[0057] Embodiment 7:

[0058] Formula: 70 parts of SIS, 30 parts of rosin ester tackifier, 0.4 parts of phenolic antioxidant, 0.6 parts of benzotriazole ultraviolet absorber, and 20 parts of talc.

[0059] Preparation method: After mixing the above raw materials, melt mixing at 195°C, extruding and molding, cooling and pelletizing.

[0060] Performance test: Adhesion performance test was carried out at -25℃, and the result showed that the bonding strength was 4.3N / cm 2 , the peel strength is 1.1N / cm.

[0061] By comparing the above embodiments, the following conclusions can be drawn:

[0062] Different types and proportions of thermoplastic elastomers have a significant effect on the low temperature resistance of pressure sensitive adhesives. Both SIS and polyacrylate thermoplastic elastomers can provide good low temperature resistance, but the specific effect varies depending on the type and amount used.

[0063] The type and amount of tackifier have an important influence on the adhesive properties of pressure-sensitive adhesives. Both rosin ester and petroleum resin tackifiers can improve the initial tack and sustained tack of pressure-sensitive adhesives, but the specific effect needs to be adjusted according to actual needs.

[0064] The addition of antioxidants and UV absorbers can help improve the aging resistance of pressure-sensitive adhesives, thereby extending their service life. However, excessive use may have a negative impact on other properties of pressure-sensitive adhesives.

[0065] The type and amount of fillers also have a certain impact on the performance of pressure-sensitive adhesives. Fillers such as talcum powder, calcium carbonate and diatomaceous earth can adjust the viscosity and fluidity of pressure-sensitive adhesives, while improving their bonding strength and stability at low temperatures. However, excessive use of fillers may reduce the flexibility and coatability of pressure-sensitive adhesives.

[0066] Selection and influence of thermoplastic elastomers: SIS vs. polyacrylate thermoplastic elastomers: In the examples, both SIS and polyacrylate thermoplastic elastomers are used. Both have their own advantages in bonding performance under low temperature environment, but overall, SIS performs slightly better at lower temperatures. For example, in Examples 1 and 7, the bonding strength of the pressure-sensitive adhesive using SIS at -20°C and -25°C is 4.5N / cm 2 and 4.3N / cm 2 In Examples 2 and 6, the bonding strength of the polyacrylate pressure-sensitive adhesive at the same temperature is 4.0 N / cm 2 and 4.1N / cm 2 .

[0067] Type and proportion of tackifier: Effect of rosin ester tackifier: Rosin ester tackifier shows good bonding performance in many examples. In Examples 1, 3, 4, 5 and 7, the proportion of rosin ester tackifier ranges from 20% to 35%, and the bonding strength is 4.0 N / cm 2 Up to 4.8N / cm 2 It shows its effectiveness in different ratios.

[0068] Auxiliary effect of petroleum resin tackifier: In Examples 3, 4, 5 and 6, petroleum resin tackifier is used as an auxiliary tackifier in combination with rosin ester tackifier to enhance the adhesive properties of the pressure-sensitive adhesive. In particular, in Example 4, the proportion of petroleum resin tackifier reaches the highest (35%), and the bonding strength also reaches 4.8N / cm 2 , which is the highest value among all the embodiments.

[0069] Stability contribution of antioxidants and UV absorbers: Comparison of phenolic antioxidants and amine antioxidants: Different types of antioxidants, including phenols and amines, were used in the examples. Although both can provide certain antioxidant protection, no significant performance differences were shown in the specific examples. However, considering long-term stability, it is necessary to add an appropriate amount of antioxidant. The role of UV absorbers: Benzotriazole and hydroxybenzoate UV absorbers are used in the examples to help improve the weather resistance of pressure-sensitive adhesives in outdoor environments. Although the effect may not be obvious in the short term, these additives are indispensable for long-term applications.

[0070] Effect and Optimization of Fillers: Comparison of Talc, Calcium Carbonate and Diatomaceous Earth: The use of three fillers in different examples shows their different effects on the performance of pressure-sensitive adhesives. Talc was used in Examples 1, 3, 5 and 7, providing good bonding performance and stability. Calcium carbonate was used in Example 5 and also showed good performance. Diatomaceous earth was used in Examples 3 and 6, and although it performed well in some cases, the overall effect was slightly inferior to talc.

[0071] According to the above embodiment formula content and comparison report, the optimal ratio scheme is selected as follows:

[0072] The best ratio scheme:

[0073] Thermoplastic elastomer: 60 parts SIS

[0074] Tackifier: 30 parts rosin ester tackifier + 10 parts petroleum resin tackifier

[0075] Antioxidant: 0.4 parts phenolic antioxidant

[0076] UV absorber: 0.6 parts of benzotriazole UV absorber

[0077] Filler: 25 parts talc

[0078] Reasons for selection:

[0079] Selection of thermoplastic elastomer: SIS has slightly better bonding performance than polyacrylates in low temperature environments, so 60 parts of SIS was selected as the base.

[0080] Optimization of tackifiers: Combined with the data in the comparison report, the combination of rosin ester tackifiers and petroleum resin tackifiers can provide the best bonding performance. In this solution, 30 parts of rosin ester tackifiers and 10 parts of petroleum resin tackifiers were selected to balance initial tack and sustained tack.

[0081] Appropriate addition of antioxidants and UV absorbers: Considering long-term stability, 0.4 parts of phenolic antioxidants and 0.6 parts of benzotriazole UV absorbers were selected to provide sufficient antioxidant protection and ensure the weather resistance of the pressure-sensitive adhesive.

[0082] Fine adjustment of filler: Talc powder showed good performance in most embodiments, especially in improving bonding strength and stability. Therefore, 25 parts of talc powder were selected as filler.

[0083] As an improvement direction in this field:

[0084] Raw material selection and ratio optimization

[0085] Thermoplastic elastomer: 60 parts of SIS (styrene-isoprene-styrene block copolymer) was selected as the base material. SIS has good bonding properties and flexibility in low temperature environments.

[0086] Tackifier: A combination of 30 parts of rosin ester tackifier and 10 parts of petroleum resin tackifier is used. Rosin ester tackifier provides good initial adhesion, while petroleum resin tackifier enhances the lasting adhesion. The combination of the two can significantly improve the overall bonding performance of the pressure-sensitive adhesive.

[0087] Antioxidant: Add 0.4 parts of phenolic antioxidant to inhibit free radical reactions, slow down the oxidative degradation process, and improve the aging resistance of the pressure-sensitive adhesive.

[0088] UV absorber: Add 0.6 parts of benzotriazole UV absorber to effectively absorb UV rays, prevent photo-oxidation, and extend the service life of the pressure-sensitive adhesive.

[0089] Filler: Using 25 parts of talcum powder as filler can not only adjust the viscosity and fluidity, but also improve the bonding strength and stability of the pressure-sensitive adhesive.

[0090] Preparation process optimization

[0091] Melt mixing: Add the raw materials in the above proportions into a high-speed mixing device and melt mix at a temperature of 160°C to 190°C. Ensure that all components are fully integrated to form a uniform mixture.

[0092] Extrusion granulation: The melt-mixed materials are granulated through an extruder, and the extrusion temperature and speed are controlled to obtain granular hot-melt pressure-sensitive adhesive products.

[0093] Cooling and pelletizing: The extruded hot-melt pressure-sensitive adhesive strip is cooled and then cut into pellets of the required size for easy storage and use.

[0094] Performance testing and tuning

[0095] Adhesion performance test: The prepared hot melt pressure sensitive adhesive is subjected to adhesion performance test, including initial adhesion, sustained adhesion and peel strength. According to the test results, the type and proportion of the tackifier can be appropriately adjusted to achieve the best adhesion effect.

[0096] Low temperature resistance test: Test the pressure sensitive adhesive in different low temperature environments to evaluate its low temperature resistance. If necessary, adjust the type and amount of thermoplastic elastomer to improve low temperature resistance.

[0097] Aging resistance test: The aging resistance of the pressure sensitive adhesive is evaluated through accelerated aging test. According to the test results, the amount or type of antioxidant and UV absorber can be adjusted to improve the aging resistance.

[0098] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0099] The embodiments of the present application are described above, but the present application is not limited to the above-mentioned specific implementation modes. The above-mentioned specific implementation modes are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A low temperature resistant hot melt pressure sensitive adhesive, characterized in that: The invention comprises the following parts by weight: 50-80 parts of a raw material thermoplastic elastomer, 20-40 parts of a tackifier, 0.1-1 parts of an antioxidant, 0.1-1 parts of an ultraviolet absorber and 10-30 parts of a filler.

2. The low temperature resistant hot melt pressure sensitive adhesive according to claim 1, characterized in that: The thermoplastic elastomer is a polystyrene-isoprene-styrene block copolymer and a polyacrylate thermoplastic elastomer.

3. The low temperature resistant hot melt pressure sensitive adhesive according to claim 1, characterized in that: The tackifiers are rosin esters and petroleum resins, the antioxidants are phenolic and amine antioxidants, the ultraviolet absorbers are benzotriazoles and hydroxybenzoic acid esters, and the fillers are talcum powder, calcium carbonate and diatomaceous earth.

4. A method for preparing a low-temperature resistant hot-melt pressure-sensitive adhesive, characterized in that: The method comprises the low temperature resistant hot melt pressure sensitive adhesive according to claim 1 to claim 3 and the following steps: S100: Raw material preparation: prepare thermoplastic elastomer, tackifier, antioxidant, UV absorber and filler according to the formula ratio; S200: Mixing raw materials: Mix all prepared raw materials in proportion to ensure that the ingredients are evenly distributed; S300: Melt mixing: melt the mixture at a temperature of 160-200°C, and use an extruder or other mixing equipment to fully stir to ensure that all ingredients are completely blended together; S400: Extrusion molding: The melt-mixed material is extruded through an extruder to form a continuous long strip; S500: Cooling and pelletizing: The extruded long strip material is cooled and then cut into particles of the required size by a pelletizer: S600: Packaging and storage: Pack the prepared low-temperature resistant hot-melt pressure-sensitive adhesive particles and store them in a dry and ventilated environment, avoiding moisture and direct sunlight.