A strong and durable adhesive and preparation method thereof

Abstract

The invention relates to a strong-adhesive and durable self-adhesive label and a preparation method thereof. The self-adhesive label comprises a surface material layer, an adhesive layer and a release layer which are arranged in sequence; the adhesive layer is composed of the following raw materials in parts by weight: 20-30 parts of waterborne polyurethane, 20-40 parts of hydroxy acrylic resin, 8-20 parts of epoxy soybean oil, 0.1-0.5 parts of a composite antioxidant, and 2-5 parts of an initiator; wherein the composite antioxidant is a composition of tea polyphenol palmitate, tea polyphenol and butylated hydroxyanisole in a mass ratio of 1: (0.5-0.8): (0.3-0.5); the tea polyphenol palmitate, tea polyphenol and butylated hydroxyanisole are added in a specific dosage ratio to produce a synergistic effect, thereby effectively promoting the bonding performance and durability of the self-adhesive label.

Description

Technical Field

[0001] The invention relates to the technical field of self-adhesive stickers, and in particular to a strong-adhesive and durable self-adhesive sticker and a preparation method thereof. Background Art

[0002] Acrylic pressure-sensitive adhesive (APSA) has the advantages of excellent bonding performance, good aging resistance, low cost, stable performance, and simple synthesis process. Due to its excellent performance, it is widely used in self-adhesive tapes, labels, medicine, home care, automotive parts and other fields. However, the application field of APSA is still relatively narrow, and most products have poor heat resistance and cannot be used under high temperature conditions. Waterborne polyurethane (WPU) is becoming a research hotspot for waterborne pressure-sensitive adhesives with its outstanding advantages such as oil resistance, impact resistance, wear resistance, low temperature resistance and high elasticity, but its application is limited by its shortcomings such as poor initial viscosity and water resistance. Epoxidized soybean oil is a renewable resource derived from vegetable oils and fats, is biodegradable, and is environmentally friendly. The use of epoxidized soybean oil can reduce dependence on petroleum resources and reduce the environmental burden of products. However, due to the presence of residual double bonds and a large number of ester bonds, its bonding strength is unsatisfactory and it is prone to aging during storage and application. Summary of the invention

[0003] In view of the problems of insufficient initial viscosity and water resistance of WPU, insufficient heat resistance and flexibility of acrylate, and the negative impact of epoxidized soybean oil on aging resistance and adhesion retention, the purpose of the present invention is to overcome the shortcomings of the prior art and provide a strong and durable self-adhesive label and a preparation method thereof, wherein the self-adhesive label has good environmental friendliness, bonding performance, durability, low temperature resistance and high temperature resistance.

[0004] To achieve the above object, the technical solution adopted by the present invention is:

[0005] In the first aspect, the present invention provides a strong and durable self-adhesive label, comprising a surface material layer, an adhesive layer and a release layer arranged in sequence; the adhesive layer is composed of the following raw materials in parts by weight: 20-30 parts of water-based polyurethane, 20-40 parts of hydroxy acrylic resin, 8-20 parts of epoxy soybean oil, 0.1-0.5 parts of composite antioxidant, and 2-5 parts of initiator; wherein the composite antioxidant is a composition of tea polyphenol palmitate, tea polyphenols and butylated hydroxyanisole in a mass ratio of 1: (0.5-0.8): (0.3-0.5).

[0006] Preferably, the initiator is ammonium persulfate and / or potassium persulfate.

[0007] Preferably, the mass ratio of waterborne polyurethane, hydroxylated acrylic resin and epoxylated soybean oil is 1:(1.2-1.5):(0.4-0.7). More preferably, the mass ratio of waterborne polyurethane, hydroxylated acrylic resin and epoxylated soybean oil is 1:1.5:0.5.

[0008] Preferably, the composite antioxidant is a composition of tea polyphenol palmitate, tea polyphenols and butylated hydroxyanisole in a mass ratio of 1:0.6:0.4.

[0009] Preferably, the waterborne polyurethane is F0409 produced by Shenzhen Yoshida Chemical Co., Ltd.

[0010] Preferably, the hydroxylated acrylic resin is 587 from BASF AG.

[0011] Preferably, the release layer is a PET release film layer.

[0012] In a second aspect, the present invention provides a method for preparing the strong and durable self-adhesive adhesive, comprising the following steps:

[0013] S1, mixing waterborne polyurethane, hydroxyl acrylic resin, epoxy soybean oil and composite antioxidant, heating to 60-70°C and keeping warm for 1-2h, then dropping initiator, keeping warm for 30-60min, cooling down to obtain adhesive;

[0014] S2, coating the adhesive on the surface of the surface material layer, curing to form an adhesive layer, covering the surface of the adhesive layer with a release film to form a release layer, and obtaining the strong and durable self-adhesive label.

[0015] Preferably, the curing temperature of step S2 is 70-80° C. and the curing time is 20-30 min.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The self-adhesive adhesive of the present invention is a pressure-sensitive adhesive composed of a surface material layer, an adhesive layer and a release layer, wherein the adhesive layer is made of water-based polyurethane, hydroxyl acrylic resin, epoxy soybean oil, a composite antioxidant and an initiator, and the adhesive layer combines the advantages of water-based polyurethane, hydroxyl acrylic resin and epoxy soybean oil, such as environmental friendliness, water resistance and heat resistance, and a composite antioxidant is added to the adhesive layer, and the composite antioxidant is composed of tea polyphenol palmitate, tea polyphenol and butyl hydroxyanisole in a specific dosage ratio, has a synergistic effect, and can further improve the bonding performance, aging resistance and durability of the pressure-sensitive adhesive. DETAILED DESCRIPTION

[0018] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0019] The sources of materials in the following examples and comparative examples are as follows:

[0020] Waterborne polyurethane: The manufacturer is Shenzhen Yoshida Chemical Co., Ltd., brand number F0409;

[0021] Hydroxylated acrylic resin: the manufacturer is BASF AG, brand number 587;

[0022] Epoxidized soybean oil: The manufacturer is Guangzhou Yuanda New Materials Co., Ltd., and the epoxy value is 6.3;

[0023] Tea polyphenol palmitate: The manufacturer is Hebei Qiansheng Biotechnology Co., Ltd., purity 99%;

[0024] Tea polyphenols: Manufacturer: Nanjing Songguan Biotechnology Co., Ltd., purity 99%

[0025] Butylated hydroxyanisole: manufacturer is Guangdong Wengjiang Chemical Reagent Co., Ltd., product number PA05324;

[0026] Unless otherwise specified, other materials, reagents, etc. used in the examples and comparative examples can be obtained from commercial sources.

[0027] Example 1

[0028] A strong and durable self-adhesive label comprises a surface material layer, an adhesive layer and a release layer which are arranged in sequence; the adhesive layer is composed of the following raw materials in parts by weight: 20 parts of waterborne polyurethane, 30 parts of hydroxy acrylic resin, 10 parts of epoxy soybean oil, 0.3 parts of a composite antioxidant, and 4 parts of an initiator; wherein the composite antioxidant is a composition of tea polyphenol palmitate, tea polyphenol and butylated hydroxyanisole in a mass ratio of 1:0.6:0.4, and the initiator is ammonium persulfate; the surface material layer is a PET film layer, and the release layer is a PET release film layer.

[0029] The method for preparing the strong and durable self-adhesive sticker comprises the following steps:

[0030] S1, mixing waterborne polyurethane, hydroxyl acrylic resin, epoxy soybean oil and composite antioxidant, heating to 65°C for 1.5 hours, then dropping initiator, keeping the temperature for 40 minutes, cooling to obtain adhesive;

[0031] S2. Apply the adhesive on the surface of the surface material layer, and cure it at 75° C. for 25 min to form an adhesive layer with a thickness of 50 μm. Cover the surface of the adhesive layer with a PET release film to form a release layer to obtain the strong and durable self-adhesive label.

[0032] Example 2

[0033] A strong and durable self-adhesive label comprises a surface material layer, an adhesive layer and a release layer which are arranged in sequence; the adhesive layer is composed of the following raw materials in parts by weight: 20 parts of waterborne polyurethane, 24 parts of hydroxy acrylic resin, 8 parts of epoxy soybean oil, 0.1 parts of a composite antioxidant, and 2 parts of an initiator; wherein the composite antioxidant is a composition of tea polyphenol palmitate, tea polyphenol and butylated hydroxyanisole in a mass ratio of 1:0.5:0.3, and the initiator is potassium persulfate; the surface material layer is a PET film layer, and the release layer is a PET release film layer.

[0034] The method for preparing the strong and durable self-adhesive sticker comprises the following steps:

[0035] S1, mixing waterborne polyurethane, hydroxyl acrylic resin, epoxy soybean oil and composite antioxidant, heating to 60°C and keeping the temperature for 2 hours, then dropping initiator, keeping the temperature for 60 minutes, cooling down, and obtaining adhesive;

[0036] S2. Apply the adhesive on the surface of the surface material layer, and cure it at 70° C. for 20 min to form an adhesive layer with a thickness of 50 μm. Cover the surface of the adhesive layer with a PET release film to form a release layer to obtain the strong and durable self-adhesive label.

[0037] Example 3

[0038] A strong and durable self-adhesive label comprises a surface material layer, an adhesive layer and a release layer which are arranged in sequence; the adhesive layer is composed of the following raw materials in parts by weight: 30 parts of waterborne polyurethane, 40 parts of hydroxy acrylic resin, 20 parts of epoxy soybean oil, 0.5 parts of composite antioxidant, and 5 parts of initiator; wherein the composite antioxidant is a composition of tea polyphenol palmitate, tea polyphenol and butylated hydroxyanisole in a mass ratio of 1:0.8:0.5; the initiator is potassium persulfate, the surface material layer is a PET film layer, and the release layer is a PET release film layer.

[0039] The method for preparing the strong and durable self-adhesive sticker comprises the following steps:

[0040] S1, mixing waterborne polyurethane, hydroxyl acrylic resin, epoxy soybean oil and composite antioxidant, heating to 70°C for 1 hour, then dropping initiator, keeping the temperature for 30 minutes, cooling down to obtain adhesive;

[0041] S2, coating the adhesive on the surface of the surface material layer, curing at 80° C. for 20 min to form an adhesive layer with a thickness of 50 μm, covering the surface of the adhesive layer with a PET release film to form a release layer, and obtaining the strong and durable self-adhesive label.

[0042] Example 4

[0043] The difference between Example 4 and Example 1 is that the total mass of the waterborne polyurethane, hydroxylated acrylic resin and epoxyd soybean oil remains unchanged, and the mass ratio of the waterborne polyurethane, hydroxylated acrylic resin and epoxyd soybean oil is 1:1.2:0.4.

[0044] Example 5

[0045] The difference between Example 5 and Example 1 is that the total mass of the waterborne polyurethane, hydroxylated acrylic resin and epoxyd soybean oil remains unchanged, and the mass ratio of the waterborne polyurethane, hydroxylated acrylic resin and epoxyd soybean oil is 1:1:0.5.

[0046] Example 6

[0047] The difference between Example 6 and Example 1 is that the total mass of the waterborne polyurethane, hydroxylated acrylic resin and epoxyd soybean oil remains unchanged, and the mass ratio of the waterborne polyurethane, hydroxylated acrylic resin and epoxyd soybean oil is 1:1:1.

[0048] Comparative Example 1

[0049] The difference between Comparative Example 1 and Example 1 is that no composite antioxidant is added in Comparative Example 1.

[0050] Comparative Example 2

[0051] The difference between Comparative Example 2 and Example 1 is that the added amount of the composite antioxidant remains unchanged, tea polyphenol palmitate is not added, and tea polyphenol and butylated hydroxyanisole in a mass ratio of 0.6:0.4 are used as the composite antioxidant.

[0052] Comparative Example 3

[0053] The difference between Comparative Example 3 and Example 1 is that the added amount of the composite antioxidant remains unchanged, tea polyphenols are not added, and tea polyphenol palmitate and butylated hydroxyanisole in a mass ratio of 1:0.4 are used as the composite antioxidant.

[0054] Comparative Example 4

[0055] The difference between Comparative Example 4 and Example 1 is that the added amount of the composite antioxidant remains unchanged, butylated hydroxyanisole is not added, and tea polyphenol palmitate and tea polyphenol in a mass ratio of 1:0.6 are used as the composite antioxidant.

[0056] Comparative Example 5

[0057] The difference between Comparative Example 5 and Example 1 is that the added amount of the composite antioxidant remains unchanged, and the composite antioxidant is a composition of tea polyphenol palmitate, tea polyphenols and butylated hydroxyanisole in a mass ratio of 0.6:1:0.4.

[0058] Comparative Example 6

[0059] The difference between Comparative Example 6 and Example 1 is that the added amount of the composite antioxidant remains unchanged, and the composite antioxidant is a composition of tea polyphenol palmitate, tea polyphenols and butylated hydroxyanisole in a mass ratio of 0.4:0.6:1.

[0060] Comparative Example 7

[0061] The difference between Comparative Example 7 and Example 1 is that the added amount of the composite antioxidant remains unchanged, and the composite antioxidant is a composition of tea polyphenol palmitate, tea polyphenols and butylated hydroxyanisole in a mass ratio of 1:0.4:0.6.

[0062] Performance Testing

[0063] The following tests were performed on the adhesive labels of Examples 1-6 and Comparative Examples 1-7:

[0064] 1. Adhesion performance test

[0065] The adhesion test was conducted according to GB / T 4851-2014, and the 180° peel strength test was conducted according to GB / T 2792-2014. The test substrate was a stainless steel plate.

[0066] 2. Durability test

[0067] High temperature and high humidity adhesion performance (referred to as 60 / 90 adhesion): The aging box is set at 60°C and 90% humidity, and a 1kg weight is used to carry out adhesion test.

[0068] High temperature and high humidity aging peel strength attenuation test (referred to as 60 / 90 aging): According to the test standard, the adhesive layer of the self-adhesive sticker is attached to a stainless steel plate and placed in an aging box for aging at 60°C and 90% humidity. After 1000 hours, the self-adhesive sticker and the steel plate are removed and the peel strength test is performed after cooling to room temperature. See Table 1 for specific data.

[0069] Table 1 Adhesion performance test and durability test data of each group of samples

[0070]

[0071] As can be seen from Table 1 and Examples 1-6, when the mass ratio of waterborne polyurethane, hydroxyl acrylic resin and epoxy soybean oil is within the range of 1:(1.2-1.5):(0.4-0.7), the adhesive properties and durability of the self-adhesive can reach a better level.

[0072] It can be seen from Example 1 and Comparative Examples 1-4 that the present invention can synergistically improve the adhesive performance and durability of the self-adhesive sticker by adding tea polyphenol palmitate, tea polyphenol and butylated hydroxyanisole in a specific dosage ratio as a composite antioxidant.

[0073] It can be seen from Example 1 and Comparative Examples 5-7 that when the composite antioxidant is a composition of tea polyphenol palmitate, tea polyphenols and butylated hydroxyanisole in a mass ratio of 1: (0.5-0.8): (0.3-0.5), the adhesive properties and durability of the self-adhesive label have better levels.

[0074] In summary, the adhesive layer of the self-adhesive label in the present invention is made of water-based polyurethane, hydroxyl acrylic resin, epoxy soybean oil, composite antioxidant, and initiator. The adhesive layer combines the advantages of water-based polyurethane, hydroxyl acrylic resin, and epoxy soybean oil, such as environmental friendliness, water resistance, and heat resistance. The added composite antioxidant is composed of tea polyphenol palmitate, tea polyphenols, and butylated hydroxyanisole in a specific dosage ratio, which can produce a synergistic effect, thereby effectively promoting the bonding performance and durability of the self-adhesive label.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A strong and durable self-adhesive sticker, characterized in that: It comprises a surface material layer, an adhesive layer and a release layer which are arranged in sequence; the adhesive layer is composed of the following raw materials in parts by weight: 20-30 parts of waterborne polyurethane, 20-40 parts of hydroxy acrylic resin, 8-20 parts of epoxy soybean oil, 0.1-0.5 parts of composite antioxidant, and 2-5 parts of initiator; wherein the composite antioxidant is a composition of tea polyphenol palmitate, tea polyphenol and butylated hydroxyanisole in a mass ratio of 1: (0.5-0.8): (0.3-0.5).

2. The strong and durable adhesive label as claimed in claim 1, characterized in that: The surface material layer is a PET film layer.

3. The strong and durable adhesive label as claimed in claim 1, characterized in that: The initiator is ammonium persulfate and / or potassium persulfate.

4. The strong and durable adhesive label as claimed in claim 1, characterized in that: The mass ratio of waterborne polyurethane, hydroxy acrylic resin and epoxy soybean oil is 1:(1.2-1.5):(0.4-0.7).

5. The strong and durable adhesive label as claimed in claim 1, characterized in that: The composite antioxidant is a composition of tea polyphenol palmitate, tea polyphenol and butylated hydroxyanisole in a mass ratio of 1:0.6:0.

4.

6. The strong and durable adhesive label as claimed in claim 1, characterized in that: The waterborne polyurethane is F0409 produced by Shenzhen Yoshida Chemical Co., Ltd.

7. The strong and durable adhesive label as claimed in claim 1, characterized in that: The hydroxylated acrylic resin is 587 produced by BASF.

8. The strong and durable adhesive label as claimed in claim 1, characterized in that: The release layer is a PET release film layer.

9. The method for preparing the strong and durable self-adhesive sticker according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1, mixing waterborne polyurethane, hydroxyl acrylic resin, epoxy soybean oil and composite antioxidant, heating to 60-70°C and keeping warm for 1-2h, then dropping initiator, keeping warm for 30-60min, cooling down to obtain adhesive; S2, coating the adhesive on the surface of the surface material layer, curing to form an adhesive layer, covering the surface of the adhesive layer with a release film to form a release layer, and obtaining the strong and durable self-adhesive label.

10. The method for preparing a strong and durable self-adhesive sticker according to claim 9, characterized in that: The curing temperature of step S2 is 70-80° C. and the curing time is 20-30 minutes.

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