Hot melt pressure sensitive adhesive for adhesive bandages and process for the preparation thereof

Abstract

The present application relates to the technical field of adhesive, especially to the field of IPC C09J7, more particularly to a hot melt pressure sensitive adhesive for adhesive plaster and a preparation method thereof. The hot melt pressure sensitive adhesive component comprises 15-40 parts of main polymer, 45-60 parts of petroleum resin, 20-40 parts of filling oil, 5-20 parts of liquid rubber and 0.1-5 parts of auxiliary agent. The weight ratio of the main polymer and the liquid rubber is 3: (1-2), which can effectively improve the peeling strength (24N / in) and the bonding performance (22N / in) of the pressure sensitive adhesive 2 ); polyisobutylene comprises PB950 (Daling) and PB1300 (Daling), and the weight ratio of the PB950 (Daling) and the PB1300 (Daling) is 1: (2-4), which can balance the initial adhesion and the peeling strength, and can also reduce the residual glue rate between the skin, and is suitable for the adhesive plaster glue layer.

Description

Technical Field

[0001] This invention relates to the field of adhesive technology, particularly to the field of IPC C09J7, and more specifically, to a hot melt pressure-sensitive adhesive for bandages and its preparation method. Background Technology

[0002] Currently, the market size for adhesive bandages in my country exceeds 900 million pieces, with an annual market size of approximately 300 to 400 million yuan and an annual growth rate of around 10%, indicating a relatively rapid growth. Therefore, adhesive bandages have a huge consumer market in my country. Currently, the adhesives used in adhesive bandages on the market are typically hot-melt pressure-sensitive adhesive and natural rubber. Natural rubber production requires a large amount of solvent, posing certain risks and causing environmental pollution. Hot-melt pressure-sensitive adhesive, on the other hand, is increasingly favored due to its environmentally friendly nature. However, adhesive bandages made with hot-melt pressure-sensitive adhesive have several problems: prolonged exposure to air inevitably leads to contact with the adhesive tape or contamination with dust or water, thus failing to achieve the desired wound protection. Furthermore, prolonged application can result in adhesive residue near the wound. Additionally, if the product is not applied firmly or in the wrong position, excessive force during removal can pull on the wound, affecting healing.

[0003] CN110724480A discloses a sweat-resistant and waterproof hot-melt pressure-sensitive adhesive for adhesive bandages, comprising the following raw materials in parts by weight: 30-40 parts of styrene-based resin, 14-18 parts of filler, 18-22 parts of petroleum resin, 5-7 parts of dispersant, and 1-3 parts of antioxidant. The hot-melt pressure-sensitive adhesive prepared by this invention shows good waterproof and breathable properties in waterproof and breathable tests; however, it exhibits low peel strength in a 180° peel strength test, which somewhat affects its long-term durability. Summary of the Invention

[0004] The first aspect of the present invention provides a hot melt pressure-sensitive adhesive for adhesive bandages, comprising, by weight: 15-40 parts of a main polymer, 45-60 parts of petroleum resin, 20-40 parts of filler oil, 5-20 parts of liquid rubber, and 0.1-5 parts of additives.

[0005] The weight ratio of the main polymer to the liquid rubber is 3:(1-2), which can effectively improve the peel strength and adhesion performance of the pressure-sensitive adhesive. This may be because a certain microphase region exists during the mixing process of the main polymer, and the specific low molecular weight polyisobutylene can effectively improve the wettability between the three phases. Further research found that the molecular weight of the liquid rubber is 800-2000, which can further improve the holding power of the pressure-sensitive adhesive. Reducing the relative molecular mass of polyisobutylene will lead to an increase in initial tack and peel strength, but a decrease in shear strength, while increasing... The high molecular weight polyisobutylene content in the system reduces the fluidity of the adhesive and weakens the initial tack. The polyisobutylene includes PB950 (Daelin) and PB1300 (Daelin), with a weight ratio of PB950 (Daelin) to PB1300 (Daelin) of 1:(2-4). This not only balances initial tack and peel strength but also reduces residual adhesive with the skin. It may also improve the wax fog point of petroleum resin, thereby improving the compatibility of petroleum resin with the polar molecules in the hot-melt pressure-sensitive adhesive and enhancing the cohesive properties of the hot-melt pressure-sensitive adhesive. However, when the content of low molecular weight polyisobutylene increases, certain defects appear in the continuous polymer network structure of the system, leading to a decrease in cohesive strength. When peel force is generated, the structure of the hot-melt pressure-sensitive adhesive is easily damaged, resulting in excessive residual adhesive in the macroscopic mechanical properties.

[0006] The weight ratio of the main polymer to the liquid rubber is 3:(1-2).

[0007] Preferably, the weight ratio of the main polymer to the liquid rubber is 7:3.

[0008] The liquid rubber includes at least one of polyisobutylene, polyacrylonitrile, and polyisoprene.

[0009] Preferably, the liquid rubber comprises polyisobutylene.

[0010] The molecular weight of the liquid rubber is 800-2000.

[0011] Preferably, the molecular weight of the liquid rubber is 900-1300.

[0012] More preferably, the polyisobutylene includes at least one of PB950 (Daelim), PB1300 (Daelim), and H100 (Ineos).

[0013] Preferably, the polyisobutylene comprises PB950 (Dalin) and PB1300 (Dalin), and the weight ratio of PB950 (Dalin) to PB1300 (Dalin) is 1:(2-4).

[0014] More preferably, the weight ratio of PB950 (Dalin) to PB1300 (Dalin) is 1:3, and both PB950 (Dalin) and PB1300 (Dalin) are purchased from Guangzhou Yehusheng Chemical Co., Ltd.

[0015] The main polymer includes at least one of styrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS), styrene-ethylene-butene-styrene (SEBS), and styrene-ethylene-propylene-styrene (SEPS).

[0016] The main polymers include styrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS), and styrene-ethylene-butene-styrene (SEBS), wherein the weight ratio of SIS, SBS, and SEBS is 1:(0.8-1.5):(0.7-1.2).

[0017] Preferably, the weight ratio of SIS, SBS, and SEBS is 1:1:1.

[0018] Preferably, the styrene content in the SEBS is 25-32 wt%, and the melt flow rate (200℃, 5 kg) is 0.1-1 g / 10 min.

[0019] More preferably, the styrene content in the SEBS is 30wt%, the melt flow rate (200℃, 5kg) is 0.25g / 10min, and it is purchased from Baling Petrochemical, grade: YH-501.

[0020] The SBS melt flow rate (200℃, 5kg) is 7-12g / 10min.

[0021] More preferably, the SBS melt flow rate (200°C, 5kg) is 11g / 10min (BASF, Germany, model: 684D NW).

[0022] The styrene content in the SIS is 12-20 wt%, and the melt flow rate (200℃, 5kg) is 8-14 g / 10min.

[0023] Preferably, the SIS includes two grades, YH-1106 and YH-1126, and the weight ratio of YH-1106 to YH-1126 is 1:(1-3).

[0024] More preferably, the weight ratio of YH-1106 to YH-1126 is 1:1.5, the styrene content of YH-1106 is 15wt%, and the melt flow rate is 12g / 10min; the styrene content of SISYH-1126 is 16wt%, and the melt flow rate is 10g / 10min, both of which are purchased from Baling Petrochemical.

[0025] The kinematic viscosity (40℃) of the filler oil is 140-180 mmHg. 2 / s.

[0026] The filler oil includes one or more of paraffin oil, naphthenic oil, and white mineral oil.

[0027] Preferably, the filler oil comprises a naphthenic oil with a kinematic viscosity (40°C) of 160.6 mm. 2 / s, purchased from Jinan Shanhai Chemical Technology Co., Ltd., model: KN4010.

[0028] The petroleum resin includes one or more of C5 petroleum resin, hydrogenated C5 petroleum resin, C9 petroleum resin, hydrogenated C9 petroleum resin, DCPD resin, C5C9 petroleum resin, and terpene phenolic resin.

[0029] Preferably, the petroleum resin includes hydrogenated C5 petroleum resin and hydrogenated C9 petroleum resin, wherein the weight ratio of hydrogenated C5 petroleum resin to hydrogenated C9 petroleum resin is 1:(3-6).

[0030] More preferably, the weight ratio of the hydrogenated C5 petroleum resin to the hydrogenated C9 petroleum resin is 1:4, the hydrogenated C5 petroleum resin is designated as H5 1001, and the hydrogenated C9 petroleum resin is designated as HM-1000, both of which are purchased from Henghe Materials Technology Co., Ltd.

[0031] The weight ratio of petroleum resin to filler oil is 1:(0.4-0.8).

[0032] Preferably, the weight ratio of the petroleum resin to the filler oil is 24:11.

[0033] The additives include at least one of the following: fluorescent masking agents, ultraviolet absorbers, antioxidants, and anti-yellowing agents.

[0034] Preferably, the adjuvant includes an antioxidant.

[0035] The antioxidants include hindered phenolic antioxidants.

[0036] The hindered phenolic antioxidants include at least one of antioxidant 1010, antioxidant 1076, antioxidant 1024, and antioxidant 1098.

[0037] Preferably, the hindered phenolic antioxidant includes antioxidant 1010, purchased from Jiyi Holdings Group, model: JYANOX-1010.

[0038] The second aspect of the present invention provides a method for preparing a hot melt pressure-sensitive adhesive for adhesive bandages, comprising the following steps: adding a main polymer and additives to a mixing tank and heating and stirring until melted; after stirring thoroughly, adding petroleum resin, filler oil and liquid rubber; and stirring under vacuum to obtain the adhesive.

[0039] Beneficial effects:

[0040] 1. The weight ratio of the main polymer to the liquid rubber is 3:(1-2), which can effectively improve the peel strength (24 N / in) and adhesion performance (22 N / in) of the pressure-sensitive adhesive. 2 ).

[0041] 2. The polyisobutylene includes PB950 (Dalin) and PB1300 (Dalin), and the weight ratio of PB950 (Dalin) and PB1300 (Dalin) is 1:(2-4), which can balance the initial tack and peel strength, and also reduce the residual adhesive rate with the skin, making it suitable for use in the adhesive layer of bandages.

[0042] 3. The weight ratio of petroleum resin to filler oil is 1:(0.4-0.8), which can further improve the adhesion of the pressure-sensitive adhesive.

[0043] 4. The weight ratio of SIS, SBS and SEBS is 1:(0.8-1.5):(0.7-1.2), which can improve the peel strength and holding power of the pressure-sensitive adhesive. Detailed Implementation

[0044] Example 1

[0045] A hot melt pressure-sensitive adhesive for bandages, comprising, by weight: 28 parts of main polymer, 48 parts of petroleum resin, 22 parts of filler oil, 12 parts of liquid rubber, and 0.15 parts of additives.

[0046] The main polymer is styrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS), or styrene-ethylene-butene-styrene (SEBS), and the weight ratio of SIS, SBS, and SEBS is 1:1:1.

[0047] The SEBS contained 30 wt% styrene and had a melt flow rate (200℃, 5 kg) of 0.25 g / 10 min. It was purchased from Baling Petrochemical, grade YH-501.

[0048] The SBS melt flow rate (200℃, 5kg) was 11g / 10min, purchased from BASF Germany, model: 684DNW.

[0049] The SIS is of two grades, YH-1106 and YH-1126, with a weight ratio of YH-1106 to YH-1126 of 1:1.5. YH-1106 has a styrene content of 15 wt% and a melt flow rate of 12 g / 10 min; SISYH-1126 has a styrene content of 16 wt% and a melt flow rate of 10 g / 10 min. Both were purchased from Baling Petrochemical.

[0050] The filler oil is a naphthenic oil with a kinematic viscosity (40°C) of 160.6 mm. 2 / s, purchased from Jinan Shanhai Chemical Technology Co., Ltd., model: KN4010.

[0051] The adjuvant is an antioxidant, which is a hindered phenolic antioxidant, specifically Antioxidant 1010, purchased from Jiyi Holdings Group, model: JYANOX-1010.

[0052] The petroleum resins are hydrogenated C5 petroleum resin and hydrogenated C9 petroleum resin, with a weight ratio of 1:4. The hydrogenated C5 petroleum resin is designated as H5 1001, and the hydrogenated C9 petroleum resin is designated as HM-1000. Both are purchased from Henghe Materials Technology Co., Ltd.

[0053] The liquid rubber is polyisobutylene, and the polyisobutylene is PB950 (Dalin) and PB1300 (Dalin), with a weight ratio of PB950 (Dalin) to PB1300 (Dalin) of 1:3, both purchased from Guangzhou Yehusheng Chemical Co., Ltd.

[0054] A method for preparing a hot melt pressure-sensitive adhesive for bandages includes the following steps: adding the main polymer and additives into a mixing tank, heating to 135°C and stirring until melted, adding petroleum resin, filler oil and liquid rubber, and stirring under vacuum (maintaining the vacuum degree at 0.1 MPa) to obtain the adhesive.

[0055] The stirring speed is 400 rpm.

[0056] Example 2

[0057] The specific implementation method is the same as in Example 1; the difference is that in Example 2, the main polymer consists of 26 parts and the liquid rubber consists of 14 parts.

[0058] Example 3

[0059] The specific implementation method is the same as in Example 1; the difference is that the weight ratio of PB950 (Dalin) and PB1300 (Dalin) in Example 3 is 1:3.

[0060] Comparative Example 1

[0061] The specific implementation method is the same as in Example 1; the difference is that the main polymer in Comparative Example 1 consists of 23 parts and the liquid rubber consists of 17 parts.

[0062] Comparative Example 2

[0063] The specific implementation method is the same as in Example 1; the difference is that the weight ratio of PB950 (Dailing) and PB1300 (Dailing) in Comparative Example 2 is 1:1.

[0064] Comparative Example 3

[0065] The specific implementation method is the same as in Example 1; the difference is that the polyisobutylene described in Comparative Example 3 is only PB1300 (Daelin).

[0066] Performance testing methods

[0067] The hot melt pressure-sensitive adhesives obtained in the examples and comparative examples were subjected to performance tests, and the test data are listed in Table 1.

[0068] 1. Peel strength: The 180° peel force was tested according to GB / T 2792-1998, with an adhesive application amount of 55 gsm.

[0069] 2. Holding power: The test was conducted in accordance with GB / T 4851-1998, and the displacement (mm) was recorded after 30 minutes.

[0070] 3. Ring-shaped initial tack: Tested according to GB / T 31125-2014.

[0071] 4. Human body patch test: 20 participants, 3-hour application time, application location: skin surface of the middle forearm, peeled off at 180°. If there is no adhesive residue on the skin surface of any of the 20 participants, it is considered qualified; otherwise, it is considered unqualified.

[0072] Performance test data

[0073] Table 1

[0074] Peel strength (N / in) Holding power (mm) <![CDATA[Ring tack force (N / in 2 )]]> patch test Example 1 24 18 22 qualified Example 2 23 20 21 qualified Example 3 23 21 20 qualified Comparative Example 1 17 22 19 qualified Comparative Example 2 19 20 18 Unqualified Comparative Example 3 24 17 16 Unqualified

Claims

1. A hot melt pressure-sensitive adhesive for use in adhesive bandages, characterized in that, By weight, the components include: 15-40 parts of main polymer, 45-60 parts of petroleum resin, 20-40 parts of filler oil, 5-20 parts of liquid rubber, and 0.1-5 parts of additives. The weight ratio of the main polymer to the liquid rubber is 3:(1-2). The liquid rubber includes polyisobutylene, which includes PB950 and PB1300, and the weight ratio of PB950 to PB1300 is 1:(2-4). The main polymer comprises SIS, SBS, and SEBS, wherein the weight ratio of SIS, SBS, and SEBS is 1:(0.8-1.5):(0.7-1.2).

2. The hot melt pressure-sensitive adhesive for adhesive bandages according to claim 1, characterized in that, The filler oil includes one or more of paraffin oil, naphthenic oil, and white mineral oil.

3. The hot melt pressure-sensitive adhesive for bandages according to claim 2, characterized in that, The petroleum resin includes one or more of C5 petroleum resin, hydrogenated C5 petroleum resin, C9 petroleum resin, hydrogenated C9 petroleum resin, DCPD resin, C5C9 petroleum resin, and terpene phenolic resin.

4. The hot melt pressure-sensitive adhesive for adhesive bandages according to claim 3, characterized in that, The weight ratio of the petroleum resin to the filler oil is 1:(0.4-0.8).

5. A hot melt pressure-sensitive adhesive for adhesive bandages according to claim 1 or 4, characterized in that, The additives include at least one of the following: fluorescent masking agents, ultraviolet absorbers, antioxidants, and anti-yellowing agents.

6. A method for preparing the hot melt pressure-sensitive adhesive for adhesive bandages according to claim 1, characterized in that, The process includes the following steps: adding the main polymer and additives into a mixing tank, heating and stirring until melted, then adding petroleum resin, filler oil and liquid rubber, and stirring under vacuum to obtain the final product.