Heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive and preparation method thereof

Abstract

The invention relates to the field of adhesives, in particular to the field of C09J, and specifically relates to a heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive and a preparation method thereof. The hot-melt pressure-sensitive adhesive is prepared from the following raw materials: TPE, tackifying resin, a softening agent and a heat-resistant agent; wherein the TPE comprises SIS and SBS, the tackifying resin comprises hydrogenated C5 petroleum resin, and the heat-resistant agent comprises nano aluminum oxide; the mass ratio of the TPE to the tackifying resin to the softening agent is (15-20): (50-55): (25-35). The prepared hot-melt pressure-sensitive adhesive is excellent in water resistance and heat resistance, has high bonding strength even after being aged, and is particularly suitable for being applied to sanitary care products such as paper diapers.

Description

Technical Field

[0001] The present invention relates to the field of adhesives, in particular to the field of C09J, and specifically to a heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive and a preparation method thereof. Background Art

[0002] Diapers have been widely used in the nursing field due to their convenience, safety and non-irritation. The raw materials of diapers mainly include antibacterial non-woven fabrics, water-absorbing particles and adhesives. During normal use, diapers will absorb a large amount of liquid, but as the humidity of the use environment increases, the bonding performance of the adhesive in the diapers will also be obviously affected to a certain extent. In addition, during the processing and transportation process, the bonding strength of the adhesive will be affected by the temperature, especially at high temperatures, it is easy to lose adhesion, which will directly affect the user's product experience.

[0003] Patent document CN113736401A discloses a highly heat-resistant one-component adhesive, whose preparation raw materials mainly include modified bismaleimide resin and epoxy resin; Patent document CN112920366A discloses a highly heat-resistant elastic water-based polyurethane adhesive, whose main preparation raw materials include polyurethane; Compared with epoxy resin system adhesives and polyurethane system adhesives, adhesives prepared with styrene thermoplastic elastomers as raw materials have better weather resistance, elasticity, and toughness, and the products are easier to process. At present, there are relatively few reports on the preparation of heat-resistant and moisture-resistant adhesives with styrene thermoplastic elastomers.

[0004] Therefore, it is of great research value to provide a hot melt pressure sensitive adhesive that still has excellent bonding properties under water and high temperature conditions. Summary of the invention

[0005] In order to solve the above technical problems, the first aspect of the present invention provides a heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive, the raw materials for preparing the hot-melt pressure-sensitive adhesive include: TPE (thermoplastic elastomer), tackifying resin, softener, and heat-resistant agent.

[0006] As an implementable case, the mass ratio of the TPE, tackifying resin and softener is (15-20): (50-55): (25-35).

[0007] As an implementable case, the TPE is a styrene-based thermoplastic elastomer, and the styrene-based thermoplastic elastomer includes at least two of SBS (styrene-butadiene-styrene block copolymer), SEBS (styrene-ethylene-butylene-styrene block copolymer), SIS (styrene-isoprene-styrene block copolymer), and SEPS (styrene-ethylene-propylene-styrene block copolymer).

[0008] The amount of tackifying resin used in the present invention is significantly excessive compared to the thermoplastic elastomer, which can ensure that the hot melt pressure-sensitive adhesive has a more excellent use effect. First of all, the compatibility between the tackifying resin and TPE is excellent. Even if the amount of tackifying resin used is significantly excessive compared to TPE, the raw materials can still be normally miscible and the product can still be prepared normally; secondly, the tackifying resin has a certain heat resistance and can withstand certain high temperature conditions, so that the hot melt pressure-sensitive adhesive still has good stability and bonding performance at high temperatures. At the same time, the tackifying resin has excellent water resistance, ensuring that the hot melt pressure-sensitive adhesive can still maintain excellent bonding performance after contacting water or being damp, which is particularly suitable for care products such as diapers; most importantly, the curing speed of the tackifying resin is relatively fast. In the TPE system, it can significantly shorten the preparation cycle and improve production efficiency. In addition, the amount of softener used in the present invention is also higher than that of TPE. The softener can improve the flexibility of the hot melt pressure-sensitive adhesive, making it easier to process and shape, making the product more suitable for the application of care products. In addition, the softener can reduce the viscosity of TPE and tackifying resin after compounding, further improving the processing stability of the product. Finally, from the cost perspective, the cost of the softener is lower than that of TPE and tackifying resin, which can significantly reduce the production cost. Therefore, TPE is preferred in the present invention, and the mass ratio of tackifying resin to softener is (15-20): (50-55): (25-35), which can further improve the heat resistance and moisture resistance of the hot melt pressure-sensitive adhesive while ensuring that the product has excellent bonding performance, and can also reduce production costs.

[0009] As an implementable case, the TPE is SBS and SIS; the mass ratio of SBS to SIS is (10-15): (5-10).

[0010] As an implementable example, the SBS includes a linear SBS and / or a star SBS.

[0011] Furthermore, the SBS is a linear SBS.

[0012] As an implementable example, the S / B block ratio of the linear SBS is (28-30):(70-72).

[0013] Furthermore, the S / B block ratio of the linear SBS is 30:70, and the brand is YH-188.

[0014] As an implementable case, the SIS includes one or more of a linear SIS, a star SIS or a coupled linear SIS.

[0015] Furthermore, the SIS is a linear SIS.

[0016] As an practicable example, the S / I block ratio of the linear SIS is (15-20):(80-85).

[0017] Furthermore, the S / I block ratio of the linear SIS is 16:84, and the brand is YH-1126.

[0018] The compounding ratio of linear SBS and linear SIS has a significant effect on heat resistance. Generally speaking, when the linear SBS content is high, the hot melt pressure-sensitive adhesive has higher viscosity and strength, but lower hardness, elasticity and heat resistance; when the linear SIS content is high, the heat resistance, elasticity and flexibility are better, but the strength and durability will decrease accordingly; for linear SBS, when the S / B block ratio increases within a certain range, the proportion of hard segment polystyrene increases, which helps to form more physical cross-linking points, thereby improving the heat resistance of the material; however, too high S / B block ratio may cause the hot melt pressure-sensitive adhesive to become too rigid, which in turn reduces its heat resistance. For linear SIS, as the S / I block ratio increases, the hardness of linear SIS will increase, the melt flow rate (MFR) will decrease, and the heat resistance will improve, but too high S / I block ratio may cause the hot melt pressure-sensitive adhesive to become too rigid, which is also not conducive to its application in diapers. Therefore, the present invention prefers linear SBS with an S / B block ratio of (28-30): (70-72) and linear SIS with an S / I block ratio of (15-20): (80-85); linear SBS and linear SIS are compounded in a mass ratio of (10-15): (5-10) to achieve an optimal balance between high adhesion, heat resistance and moisture resistance.

[0019] As an implementable case, the tackifying resin includes: one or more of terpene phenol resin, petroleum resin, rosin resin, and modified rosin resin.

[0020] Furthermore, the tackifying resin is petroleum resin.

[0021] As an implementable case, the petroleum resin includes: one or more of C5 petroleum resin, hydrogenated C5 petroleum resin, C9 petroleum resin, and hydrogenated C9 petroleum resin.

[0022] Furthermore, the petroleum resin is a hydrogenated C5 petroleum resin; as an implementable case, the brand of the hydrogenated C5 petroleum resin includes LH 100-1.

[0023] As an implementable example, the softener includes cyclohexane oil and / or white mineral oil.

[0024] Furthermore, the softener is cyclohexane oil; the kinematic viscosity of cyclohexane oil at 40° C. is 120-140 cSt; and the brand includes KN4010.

[0025] As an implementable case, the heat-resistant agent includes: one or more of aluminum oxide, boron nitride, aluminum nitride, zinc oxide, magnesium oxide, silicon carbide, silicon nitride, and quartz powder.

[0026] As an implementable case, the particle size of the heat-resistant agent is 10-100 nm.

[0027] Furthermore, the heat-resistant agent is aluminum oxide with a particle size of 30-60 nm.

[0028] Furthermore, the alumina is nano alumina; the brands of nano alumina include: JC-SP50W, which can be purchased from Shenzhen Jingcai Chemical Co., Ltd.

[0029] Due to its high specific surface area and activity, nano-alumina has high thermal stability and can maintain stable structure and performance at high temperatures. When nano-alumina is added to hot-melt pressure-sensitive adhesive as a heat-resistant agent, it can form a strong bond with the tackifying resin and TPE in the hot-melt pressure-sensitive adhesive, forming a dense protective layer on the surface, which not only enhances the cohesion and moisture resistance of the hot-melt pressure-sensitive adhesive, but also improves the adhesion between it and the adherend, so that the hot-melt pressure-sensitive adhesive can still maintain good bonding performance in high temperature and humid environments.

[0030] As an implementable case, the raw materials for preparing the hot melt pressure-sensitive adhesive may also include: one of an antioxidant, a plasticizer, an anti-UV agent, an antibacterial agent, an antistatic agent, a dispersant, and a lubricant; these may be added as needed according to the actual performance requirements of the product.

[0031] Furthermore, the raw materials for preparing the hot melt pressure-sensitive adhesive also include an antioxidant, and the antioxidant includes one or more of antioxidant 1010, antioxidant 168, antioxidant 264, antioxidant 2246, antioxidant 330, and antioxidant DNP.

[0032] The second aspect of the present invention provides a method for preparing a heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive, comprising:

[0033] S1. Pour 40-60% of the total amount of softener into a stirring tank, add heat-resistant agent and TPE in sequence, and stir at high speed in a constant temperature oil bath at 120-180°C and 1000-2000rpm;

[0034] S2. When the raw materials are completely melted, add tackifying resin and the remaining softener, evacuate, and continue stirring for 1-2 hours;

[0035] S3, end the reaction, discharge the material, and that's it.

[0036] Beneficial Effects

[0037] (i) In the present invention, linear SIS and linear SBS are preferably compounded in a specific mass ratio, which can ensure that the hot melt pressure-sensitive adhesive has excellent bonding properties and has certain heat and moisture resistance.

[0038] (ii) The present invention further limits the S / B block ratio of SBS to (28-30): (70-72), and the S / I block ratio of SIS to (15-20): (80-85), which can achieve an optimal balance between bonding performance, heat resistance, and moisture resistance. At the same time, after the hot-melt pressure-sensitive adhesive is used, the mechanical strength is moderate, which is more suitable for the application of sanitary care products such as diapers.

[0039] (III) In the present invention, the mass ratio of the raw material TPE, the tackifying resin and the softener is preferably (15-20): (50-55): (25-35), which can further improve the heat resistance and moisture resistance of the hot melt pressure-sensitive adhesive while ensuring the bonding performance of the product, thereby reducing the production cost.

[0040] (IV) In order to further improve the heat resistance of the hot melt pressure sensitive adhesive, the present invention selects nano-alumina as a heat-resistant agent. The use of nano-alumina can also improve the aging resistance of the product.

[0041] (V) The hot melt pressure-sensitive adhesive provided by the present invention has a relatively simple preparation method. It can be prepared by simply adding the various preparation raw materials into the reaction system in a certain order at a certain temperature. No additional organic solvent is required, which is green and environmentally friendly. In addition, the preparation raw materials are all conventional commercially available raw materials, and the product is expected to be promoted on a large scale. DETAILED DESCRIPTION

[0042] Example 1

[0043] The first aspect of this example provides a heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive, the raw materials for its preparation include, by weight: 12 parts of SBS, 5 parts of SIS, 52 parts of tackifying resin, 29.7 parts of softener, 0.3 parts of antioxidant, and 1 part of heat-resistant agent.

[0044] The SBS is of grade YH-188, purchased from Yueyang Baling Petrochemical; the SIS is of grade YH-1126, purchased from Yueyang Baling Petrochemical; the tackifying resin is hydrogenated C5 petroleum resin, of grade LH100-1, purchased from Lanzhou Petrochemical; the softener is cyclohexane oil, of grade KN4010, purchased from Karamay; the antioxidant is antioxidant 1010, a common commercial product; the heat-resistant agent is nano-alumina, with a particle size of 30-60nm, of grade JC-SP50W, purchased from Shenzhen Jingcai Chemical Co., Ltd.

[0045] The second aspect of this example provides a method for preparing a heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive, comprising:

[0046] S1. Pour 50% of the total amount of softener into a stirring tank, add heat resistant agent, SBS, SIS and antioxidant in sequence, and then stir at high speed in a constant temperature oil bath at 160°C and 2000rpm for 30min;

[0047] S2. When the raw materials are completely melted, add tackifying resin and the remaining softener, evacuate the mixture to a vacuum pressure of -87 kPa, and continue stirring for 2 h;

[0048] S3, end the reaction, discharge the material, and keep the temperature at 25°C for 24 hours.

[0049] Example 2

[0050] The first aspect of this example provides a heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive, the raw materials for its preparation include, by weight: 10 parts of SBS, 10 parts of SIS, 51 parts of tackifying resin, 25.7 parts of softener, 0.3 parts of antioxidant, and 5 parts of heat-resistant agent.

[0051] The SBS is of grade YH-188, purchased from Yueyang Baling Petrochemical; the SIS is of grade YH-1126, purchased from Yueyang Baling Petrochemical; the tackifying resin is hydrogenated C5 petroleum resin, of grade LH 100-1, purchased from Lanzhou Petrochemical; the softener is cyclohexane oil, of grade KN4010, purchased from Karamay; the antioxidant is antioxidant 1010, a common commercial product; the heat-resistant agent is nano-alumina, with a particle size of 30-60nm, of grade JC-SP50W, purchased from Shenzhen Jingcai Chemical Co., Ltd.

[0052] The second aspect of this example provides a method for preparing a heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive, comprising:

[0053] S1. Pour 50% of the total amount of softener into a stirring tank, add heat resistant agent, SBS, SIS and antioxidant in sequence, and then stir at high speed in a constant temperature oil bath at 160°C and 2000rpm for 30min;

[0054] S2. When the raw materials are completely melted, add tackifying resin and the remaining softener, evacuate the mixture to a vacuum pressure of -87 kPa, and continue stirring for 2 h;

[0055] S3, end the reaction, discharge the material, and keep the temperature at 25°C for 24 hours.

[0056] Example 3

[0057] The first aspect of this example provides a heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive, the raw materials for its preparation include, by weight: 10 parts of SBS, 8 parts of SIS, 51 parts of tackifying resin, 27.7 parts of softener, 0.3 parts of antioxidant, and 3 parts of heat-resistant agent.

[0058] The SBS is of grade YH-188, purchased from Yueyang Baling Petrochemical; the SIS is of grade YH-1126, purchased from Yueyang Baling Petrochemical; the tackifying resin is hydrogenated C5 petroleum resin, of grade LH 100-1, purchased from Lanzhou Petrochemical; the softener is cyclohexane oil, of grade KN4010, purchased from Karamay; the antioxidant is antioxidant 1010, a common commercial product; the heat-resistant agent is nano-alumina, with a particle size of 30-60nm, of grade JC-SP50W, purchased from Shenzhen Jingcai Chemical Co., Ltd.

[0059] The second aspect of this example provides a method for preparing a heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive, comprising:

[0060] S1. Pour 50% of the total amount of softener into a stirring tank, add heat resistant agent, SBS, SIS and antioxidant in sequence, and then stir at high speed in a constant temperature oil bath at 160°C and 2000rpm for 30min;

[0061] S2. When the raw materials are completely melted, add tackifying resin and the remaining softener, evacuate the mixture to a vacuum pressure of -87 kPa, and continue stirring for 2 h;

[0062] S3, end the reaction, discharge the material, and keep the temperature at 25°C for 24 hours.

[0063] Comparative Example 1

[0064] In the first aspect of this example, a hot melt pressure-sensitive adhesive is provided, and the raw materials for its preparation include, by weight: 12 parts of SBS, 5 parts of SIS, 52 parts of tackifying resin, 30.7 parts of softener, and 0.3 parts of antioxidant.

[0065] The SBS is of grade YH-188, purchased from Yueyang Baling Petrochemical; the SIS is of grade YH-1126, purchased from Yueyang Baling Petrochemical; the tackifying resin is hydrogenated C5 petroleum resin, grade LH 100-1, purchased from Lanzhou Petrochemical; the softener is cyclohexane oil, grade KN4010, purchased from Karamay; the antioxidant is antioxidant 1010, a common commercially available product.

[0066] The second aspect of this example provides a method for preparing a hot melt pressure-sensitive adhesive, comprising:

[0067] S1. Pour 50% of the total amount of softener into a stirring tank, add SBS, SIS and antioxidant in sequence, and then stir at high speed in a constant temperature oil bath at 160°C and 2000rpm for 30min;

[0068] S2. When the raw materials are completely melted, add tackifying resin and the remaining softener, evacuate the mixture to a vacuum pressure of -87 kPa, and continue stirring for 2 h;

[0069] S3, end the reaction, discharge the material, and keep the temperature at 25°C for 24 hours.

[0070] Comparative Example 2

[0071] In the first aspect of this example, a hot melt pressure-sensitive adhesive is provided, and the raw materials for its preparation include, by weight: 10 parts of SBS, 8 parts of SIS, 51 parts of tackifying resin, 30.7 parts of softener, and 0.3 parts of antioxidant.

[0072] The SBS is of grade YH-188, purchased from Yueyang Baling Petrochemical; the SIS is of grade YH-1126, purchased from Yueyang Baling Petrochemical; the tackifying resin is hydrogenated C5 petroleum resin, grade LH 100-1, purchased from Lanzhou Petrochemical; the softener is cyclohexane oil, grade KN4010, purchased from Karamay; the antioxidant is antioxidant 1010, a common commercially available product.

[0073] The second aspect of this example provides a method for preparing a hot melt pressure-sensitive adhesive, comprising:

[0074] S1. Pour 50% of the total amount of softener into a stirring tank, add SBS, SIS and antioxidant in sequence, and then stir at high speed in a constant temperature oil bath at 160°C and 2000rpm for 30min;

[0075] S2. When the raw materials are completely melted, add tackifying resin and the remaining softener, evacuate the mixture to a vacuum pressure of -87 kPa, and continue stirring for 2 h;

[0076] S3, end the reaction, discharge the material, and keep the temperature at 25°C for 24 hours.

[0077] Comparative Example 3

[0078] In the first aspect of this example, a hot melt pressure-sensitive adhesive is provided, and the raw materials for its preparation include, by weight: 10 parts of SBS, 8 parts of SIS, 51 parts of tackifying resin, 30.7 parts of softener, and 0.3 parts of antioxidant.

[0079] The SBS is of grade YH-188, purchased from Yueyang Baling Petrochemical; the SIS is of grade YH-1126, purchased from Yueyang Baling Petrochemical; the tackifying resin is hydrogenated C5 petroleum resin, grade LH 100-1, purchased from Lanzhou Petrochemical; the softener is cyclohexane oil, grade KN4010, purchased from Karamay; the antioxidant is antioxidant 1010, a common commercially available product.

[0080] The second aspect of this example provides a method for preparing a hot melt pressure-sensitive adhesive, comprising:

[0081] S1. Pour 50% of the total amount of softener into a stirring tank, add SBS, SIS and antioxidant in sequence, and then stir at high speed in a constant temperature oil bath at 160°C and 2000rpm for 30min;

[0082] S2. When the raw materials are completely melted, add tackifying resin and the remaining softener, evacuate the mixture to a vacuum pressure of -87 kPa, and continue stirring for 2 h;

[0083] S3, end the reaction, discharge the material, and keep the temperature at 25°C for 24 hours.

[0084] Performance Evaluation

[0085] 1. Viscosity and softening point: The viscosity and softening point of the hot melt pressure sensitive adhesives of Examples 1 to 3 and Comparative Examples 1 to 3 were tested according to HG / T 3660-1999 and GB / T 15332-1994 (ring and ball method) standards, respectively. The results are shown in Table 1.

[0086] Specifically, 100 g of the hot melt pressure-sensitive adhesives of Examples 1 to 3 and Comparative Examples 1 to 3 were placed in different beakers, and placed in an oven at 160° C., and the viscosity and softening point were tested after 12 h, 24 h, and 48 h.

[0087] Table 1

[0088]

[0089] 2. Peel strength: According to GB / T 2792-1998 standard, apply 2g / m between the base material hot air non-woven fabric and the cast film. 2 The hot melt pressure-sensitive adhesives of Examples 1 to 3 and Comparative Examples 1 to 3 were tested using a tensile testing machine after the hot melt pressure-sensitive adhesives were cured; the results are shown in Table 2.

[0090] 3. Wet peel strength: According to GB / T 2792-1998 standard, 2g / m2 is coated between the hot air non-woven fabric and the cast film. 2 The hot melt pressure-sensitive adhesives of Examples 1 to 3 and Comparative Examples 1 to 3 were soaked in room temperature water for 5 min and dried for 1 min after being cured, and then tested using a tensile testing machine; the results are shown in Table 2.

[0091] 4. Peel strength after aging: According to GB / T 2792-1998 standard, 2g / m2 is coated between the hot air non-woven fabric and the cast film. 2 The hot melt pressure-sensitive adhesives of Examples 1 to 3 and Comparative Examples 1 to 3 were cured and placed in an oven at 58°C. The viscosity was tested after 30d, 60d, and 90d, and a tensile testing machine was used to test the viscosity. The results are shown in Table 2.

[0092] Table 2

[0093]

[0094]

Claims

1. A heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive, characterized in that: The preparation raw materials include: TPE, tackifying resin, softener and heat-resistant agent.

2. The heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive according to claim 1, characterized in that: The mass ratio of the TPE, tackifying resin and softener is (15-20): (50-55): (25-35).

3. The heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive according to claim 2, characterized in that: The TPE is a styrene-based thermoplastic elastomer, and the styrene-based thermoplastic elastomer includes at least two of SBS, SEBS, SIS, and SEPS.

4. The heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive according to claim 3, characterized in that: The TPE comprises SBS and SIS; the mass ratio of SBS to SIS is (10-15):(5-10).

5. The heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive according to claim 1, characterized in that: The tackifying resin includes one or more of terpene phenol resin, petroleum resin, rosin resin and modified rosin resin.

6. The heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive according to claim 5, characterized in that: The petroleum resin includes one or more of C5 petroleum resin, hydrogenated C5 petroleum resin, C9 petroleum resin and hydrogenated C9 petroleum resin.

7. The heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive according to claim 1, characterized in that: The softener includes naphthenic oil and / or white mineral oil.

8. A heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive according to any one of claims 1 to 7, characterized in that: The heat-resistant agent includes one or more of aluminum oxide, boron nitride, aluminum nitride, zinc oxide, magnesium oxide, silicon carbide, silicon nitride, and quartz powder.

9. The heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive according to claim 8, characterized in that: The particle size of the heat-resistant agent is 10-100 nm.

10. A method for preparing the heat-resistant and moisture-resistant hot-melt pressure-sensitive adhesive according to any one of claims 1 to 9, characterized in that: include: S1. Pour 40-60% of the total amount of softener into a stirring tank, add heat-resistant agent and TPE in sequence, and then stir at high speed in a constant temperature oil bath at 120-180°C and 1000-2000rpm; S2. When the raw materials are completely melted, add tackifying resin and the remaining softener, evacuate the mixture, and continue stirring for 1-2 hours; S3, end the reaction, discharge the material, and that's it.

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