Anti-wrinkle hot-melt pressure-sensitive adhesive for polyethylene base material and preparation method of anti-wrinkle hot-melt pressure-sensitive adhesive

Abstract

The invention relates to the technical field of pressure-sensitive adhesives, and particularly discloses an anti-wrinkle hot-melt pressure-sensitive adhesive for a polyethylene base material and a preparation method of the anti-wrinkle hot-melt pressure-sensitive adhesive. The invention relates to an anti-wrinkle hot-melt pressure-sensitive adhesive for a polyethylene base material. The anti-wrinkle hot-melt pressure-sensitive adhesive comprises a thermoplastic copolymer, mineral oil, tackifying resin and an antioxidant, the tackifying resin is formed by mixing C5 petroleum resin, rosin resin, terpene resin and maleic anhydride grafted polyethylene; the preparation method comprises the following steps: mixing and melting the mineral oil, 10-30wt% of the tackifying resin and the antioxidant, adding the thermoplastic copolymer, stirring and mixing, finally adding the residual tackifying resin, stirring and mixing to obtain the anti-wrinkle hot-melt pressure-sensitive adhesive for the polyethylene base material. The anti-wrinkle hot-melt pressure-sensitive adhesive for the polyethylene base material has relatively high bonding strength, and after the anti-wrinkle hot-melt pressure-sensitive adhesive is applied to polyethylene film packaging, a polyethylene film has good anti-wrinkle capability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pressure-sensitive adhesive, more particularly, it relates to an anti-wrinkle hot melt pressure-sensitive adhesive for polyethylene substrates and a preparation method thereof. BACKGROUND

[0002] Hot melt pressure-sensitive adhesive (HMPSA) is an environmentally friendly adhesive which is solid at room temperature, can be coated after melting into a fluid state by heating, and has pressure-sensitive adhesion without solvent or water evaporation after cooling. It has the advantages of 100% solid content, no volatile organic compounds (VOC), and high production efficiency of hot melt adhesive, and the convenient characteristics of instant adhesion and pressure adhesion of pressure-sensitive adhesive, and is widely used in packaging, labeling, medical health, automobile manufacturing, building materials and textiles and other fields.

[0003] Polyethylene film is a thermoplastic plastic film made of polyethylene resin, which has the characteristics of non-toxicity, chemical corrosion resistance, etc., and is widely used in food packaging, agricultural covering and other fields. Whether polyethylene film is used as a self-supporting bag, a composite film inner layer heat sealing material, or a temporary protective film for industrial coiled material, polyethylene film needs to form effective and reliable adhesion with various surfaces (such as paperboard, plastic, metal, glass, etc.).

[0004] However, polyethylene film itself is a typical difficult-to-adhere material, with low surface energy (usually only 31-33 dynes / cm), strong chemical inertness, and a weak boundary layer on the surface, which makes it difficult for many adhesives to achieve good wetting and form strong adhesion on its surface. When traditional pressure-sensitive adhesives are used to bond PE film, they often face the problems of poor holding power and easy interface peeling. SUMMARY

[0005] In order to improve the bonding strength to polyethylene film, the present application provides an anti-wrinkle hot melt pressure-sensitive adhesive for polyethylene substrates and a preparation method thereof.

[0006] In the first aspect, the present application provides an anti-wrinkle hot melt pressure-sensitive adhesive for polyethylene substrates, which adopts the following technical scheme: An anti-wrinkle hot melt pressure-sensitive adhesive for polyethylene substrates comprises the following components by weight: Thermoplastic copolymer 10-40 parts Mineral oil 10-30 parts Tackifying resin 30-60 parts Antioxidant 0.1-1.5 parts The tackifying resin is composed of C5 petroleum resin, rosin resin, terpene resin, and maleic anhydride grafted polyethylene.

[0007] The tackifying resin is composed of C5 petroleum resin: rosin resin: terpene resin: maleic anhydride grafted polyethylene mixed in a weight ratio of 2:1:1:1.

[0008] By adopting the above technical scheme, the C5 petroleum resin, rosin resin, terpene resin, and maleic anhydride grafted polyethylene are compounded, on the one hand, the C5 petroleum resin has good compatibility with the thermoplastic copolymer, which can effectively reduce the melt viscosity of the pressure-sensitive adhesive and improve the initial tack; on the other hand, the rosin resin and the terpene resin act as high-efficiency tackifiers and cooperate with the C5 resin, so that the prepared pressure-sensitive adhesive has good viscoelasticity and cohesive strength, the flowability and stress dispersion capacity are optimal when attached, and the adhesion strength and high-low temperature performance of the pressure-sensitive adhesive are improved; finally, the anhydride groups of the maleic anhydride grafted polyethylene can form strong interaction with the surface of the polar base material, which is equivalent to increasing many “anchoring points” between the adhesive layer and the base material, the adhesive layer is more firmly fixed by the anchoring points, and the overall shrinkage is prevented, thereby preventing wrinkles.

[0009] Preferably, the anti-wrinkle hot melt pressure-sensitive adhesive for polyethylene base material comprises the following components in weight fractions: Thermoplastic copolymer 20-30 parts Mineral oil 10-30 parts Tackifying resin 40-60 parts Antioxidant 0.3-1.0 parts.

[0010] By adopting the above technical scheme, the weight fractions of the components are further optimized, and the prepared pressure-sensitive adhesive has higher loop initial tack and peeling force, and the adhesion strength of the pressure-sensitive adhesive is effectively improved.

[0011] Preferably, the weight ratio of the thermoplastic copolymer, the mineral oil, and the tackifying resin is 1:(0.83-1.0):(1.0-2.0).

[0012] Preferably, the weight ratio of the thermoplastic copolymer, the mineral oil, and the tackifying resin is 1:0.83:1.50.

[0013] By adopting the above technical scheme, since the thermoplastic copolymer, the mineral oil, and the tackifying resin are compounded in the above weight ratio, the resin can be uniformly dissolved in the soft segment, which provides excellent wettability (tackiness) and does not seriously damage the physical crosslinking network formed by the hard segment, thereby achieving a good balance between tackiness and cohesive strength, which is conducive to improving the adhesion strength of the pressure-sensitive adhesive to the polyethylene film and improving the wrinkling of the polyethylene film.

[0014] Preferably, the thermoplastic copolymer is one or more of styrene-isoprene block copolymer, styrene-butadiene block copolymer, hydrogenated styrene-isoprene block copolymer, and hydrogenated styrene-butadiene block copolymer.

[0015] Preferably, the thermoplastic copolymer is composed of styrene-isoprene block copolymer and styrene-butadiene block copolymer mixed at a weight ratio of 5:1.

[0016] By adopting the above technical scheme, since the styrene-isoprene block copolymer and the styrene-butadiene block copolymer are compounded at a weight ratio of 5:1, the high content of the styrene-isoprene block copolymer can improve the compatibility of the styrene-butadiene block copolymer in the pressure-sensitive adhesive raw material system, and the mixed system formed can obtain a more balanced combination of peel strength and tack force than pure styrene-isoprene block copolymer or pure styrene-butadiene block copolymer, and the performance short board of the single system is improved. Therefore, when the pressure-sensitive adhesive is applied to a polyethylene film, the polyethylene film has good wrinkle resistance due to its excellent adhesion and strength.

[0017] Preferably, the mineral oil is naphthenic oil or white mineral oil.

[0018] Preferably, the antioxidant is a sterically hindered phenolic antioxidant.

[0019] In a second aspect, the application provides a preparation method of an anti-wrinkle hot melt pressure-sensitive adhesive for a polyethylene substrate, which adopts the following technical scheme: A preparation method of an anti-wrinkle hot melt pressure-sensitive adhesive for a polyethylene substrate, comprising the following steps: S1: After the mineral oil, 10-30wt% tackifying resin and antioxidant are mixed, they are first heated and melted at 110-130℃ and 10-15r / min for 20-30min, then the thermoplastic copolymer is added, and they are stirred and mixed at 15-20r / min and -0.8-1.0MPa for 60-80min to obtain a melted mixture; S2: The remaining tackifying resin is added to the melted mixture, and they are stirred and mixed at 140-150℃, 20-30r / min and -0.8-1.0MPa for 40-60min to obtain an anti-wrinkle hot melt pressure-sensitive adhesive for a polyethylene substrate.

[0020] By adopting the above technical scheme, the mineral oil and part of the tackifying resin and the antioxidant are first heated and melted, and then mixed with the thermoplastic copolymer, which can effectively improve the compatibility of various components and is beneficial to improve the bonding strength and anti-wrinkle performance of the anti-wrinkle hot melt pressure-sensitive adhesive for a polyethylene substrate.

[0021] In summary, the application has the following beneficial effects: 1、Due to the application adopts C5 petroleum resin, rosin resin, terpene resin, maleic anhydride grafted polyethylene, the compatibility of the mixed system formed by each raw material is excellent, the pressure sensitive adhesive formed has low melt viscosity, viscoelasticity and anchoring performance, can wet the polyethylene film substrate faster, improve the bonding strength of the polyethylene film, effectively improve the polyethylene substrate creping; 2、In the application, high content of styrene-isoprene block copolymer and styrene-butadiene block copolymer are preferably used to promote the compatibility of styrene-butadiene block copolymer in each raw material, the pressure sensitive adhesive formed has balanced peel strength and holding power, is more easily wetted and adhered on the surface of the polyethylene film, so that the polyethylene film has good anti-wrinkling ability; 3、The method of the application, each component is mixed by step, which can effectively improve the compatibility of various components, and is beneficial to improve the bonding strength and anti-wrinkling performance of the anti-wrinkling hot melt pressure sensitive adhesive for polyethylene substrate. DETAILED DESCRIPTION

[0022] The application will be further described in detail below in combination with examples.

[0023] The raw materials in the examples of the application are all commercially available, except for the following special descriptions. Styrene-isoprene block copolymer, brand YH-1126, purchased from Sinopec; Styrene-butadiene block copolymer, brand YH-792E, purchased from Sinopec; Naphthenic oil, Kunlun lubricating oil, brand 4010; C5 petroleum resin, Eastman, brand C-125W; Rosin resin, Komag, brand 146; Terpene resin, Okamura, brand 803L; Maleic anhydride grafted polyethylene (MAH-g-PE); Hindered phenolic antioxidant, Liyanlong, brand 1010. Performance detection

[0024] The pressure sensitive adhesive prepared in the examples and comparative examples of the application is used as a sample to detect viscosity, ring initial adhesion, 180° peel strength and anti-wrinkling ability, and the detection method is as follows: (1) Viscosity detection: first, set the temperature of the viscometer (model DV2T, purchased from Brookfield, USA) to the detection temperature 180℃; then add the sample (11g±0.5g) into the sample tube of the viscometer, heat the sample to balance with the detection temperature, and keep the sample temperature uniform; finally, vertically immerse the rotor into the center of the sample, set the rotor speed to 20r / min, start the viscometer, and record the viscosity data after the reading is stable.

[0025] (2) Ring tack detection: refer to GB / T 31125-2014 "Adhesive tape tack test method ring method".

[0026] (3) 180° peel force detection: refer to GB / T 2792-2014 "Adhesive tape peel strength test method".

[0027] (4) Wrinkle resistance detection: cut the coated sample substrate into the same size (20cm*20cm), and place it in a constant temperature and humidity chamber (temperature 23℃±2℃, humidity 50%±5% respectively), and record the surface wrinkle change of the substrate every day. Example Examples 1-3

[0028] A kind of anti-wrinkle hot melt pressure sensitive adhesive for polyethylene substrate, the components and their corresponding weight (kg) are shown in the following table.

[0029]

[0030] The preparation method of the above anti-wrinkle hot melt pressure sensitive adhesive for polyethylene substrate includes the following steps: S1: mix mineral oil, 25 kg tackifying resin and antioxidant, first melt at 110℃, 15r / min for 20min, then add thermoplastic copolymer, stir and mix at 20r / min, -1.0MPa for 70min, to get the melted mixture; S2: add the remaining tackifying resin to the melted mixture, stir and mix at 150℃, 30r / min, 1.0MPa for 50min, to get the anti-wrinkle hot melt pressure sensitive adhesive for polyethylene substrate.

[0031] The viscosity, ring tack, 180° peel force and wrinkle resistance of the anti-wrinkle hot melt pressure sensitive adhesive for polyethylene substrate prepared in examples 1-3 were detected, and the detection results are shown in the following table.

[0032]

[0033] Through data analysis of the above table, it can be seen that examples 1, 2 and 3 have no wrinkles after 30 days, but compared with example 1, the peel force of examples 2 and 3 is smaller. Therefore, it is shown that in the preparation of the anti-wrinkle hot melt pressure sensitive adhesive for polyethylene substrate, when the weight ratio of thermoplastic copolymer, mineral oil and tackifying resin is 1:0.38:1.50, the peel force of the pressure sensitive adhesive can be improved. The reason may be that the product of example 2 is too dry, resulting in insufficient peel force, and the content of thermoplastic polymer in example 3 is too high, resulting in weak adhesion. Example 4

[0034] A wrinkle-resistant hot melt pressure-sensitive adhesive for polyethylene substrates, which differs from Example 1 in that the thermoplastic copolymer is composed of styrene-isoprene block copolymer (SIS) and styrene-butadiene block copolymer (SBS) mixed at a weight ratio of 5:1. Example 5

[0035] A wrinkle-resistant hot melt pressure-sensitive adhesive for polyethylene substrates, which differs from Example 1 in that the thermoplastic copolymer is composed of styrene-isoprene block copolymer (SIS) and styrene-butadiene block copolymer (SBS) mixed at a weight ratio of 1:5.

[0036] The viscosity, loop tack, 180° peel force and wrinkle resistance of the wrinkle-resistant hot melt pressure-sensitive adhesive for polyethylene substrates prepared in Examples 4 and 5 were detected, and the detection results are shown in the following table.

[0037]

[0038] Through data analysis of the above table, it can be seen that compared with Example 1, the peel force of Examples 4 and 5 is reduced, and wrinkles start to appear after 14 days. This indicates that when the thermoplastic copolymer is composed of styrene-isoprene block copolymer (SIS) and styrene-butadiene block copolymer (SBS) mixed at a weight ratio of 2:1 in the preparation of the wrinkle-resistant hot melt pressure-sensitive adhesive for polyethylene substrates, the peel force and wrinkle resistance of the pressure-sensitive adhesive can be improved. The reason for this may be that the adhesion of Examples 4 and 5 is weak, the peel force is weak, and therefore the wrinkle resistance is not improved enough, and the wrinkling time does not meet the expected value. Comparative Example

[0039] Comparative Example 1 A pressure-sensitive adhesive, which differs from Example 1 in that the tackifying resin is composed of C5 petroleum resin: rosin resin: terpene resin: maleic anhydride grafted polyethylene mixed at a weight ratio of 3:0:1:1.

[0040] Comparative Example 2 A pressure-sensitive adhesive, which differs from Example 1 in that the tackifying resin is composed of C5 petroleum resin: rosin resin: terpene resin: maleic anhydride grafted polyethylene mixed at a weight ratio of 3:1:0:1.

[0041] Comparative Example 3 A pressure-sensitive adhesive, which differs from Example 1 in that the tackifying resin is composed of C5 petroleum resin: rosin resin: terpene resin: maleic anhydride grafted polyethylene mixed at a weight ratio of 3:1:1:0.

[0042] The viscosity, loop tack, 180° peel force and wrinkle resistance of the wrinkle-resistant hot melt pressure-sensitive adhesive for polyethylene substrates prepared in Comparative Examples 1 to 3 were detected, and the detection results are shown in the following table.

[0043]

[0044] Through data analysis of the above table, compared with Example 1, Comparative Examples 1 and 2 began to wrinkle after 7 days, especially Comparative Example 3, which began to wrinkle after 3 days. It is shown from the table that, in the preparation of the anti-wrinkle hot melt pressure-sensitive adhesive for polyethylene substrates, the tackifying resin is composed of C5 petroleum resin, rosin resin, terpene resin and maleic anhydride grafted polyethylene, which can improve the anti-wrinkle ability of the pressure-sensitive adhesive.

[0045] The specific embodiments are only an explanation of the present application, which is not a limitation of the present application, and those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. An anti-wrinkle hot melt pressure sensitive adhesive for polyethylene substrates, characterized by, Components in the following weight parts are included: thermoplastic copolymer 10-40 parts mineral oil 10-30 parts tackifying resin 30-60 parts antioxidant 0.1-1.5 parts. The tackifying resin is composed of C5 petroleum resin, rosin resin, terpene resin, and maleic anhydride grafted polyethylene.

2. The anti-wrinkle hot melt pressure sensitive adhesive for polyethylene substrates according to claim 1, characterized by, Components in the following weight parts are included: thermoplastic copolymer 20-30 parts mineral oil 10-30 parts tackifying resin 40-60 parts antioxidant 0.3-1.0 parts.

3. The anti-wrinkle hot melt pressure sensitive adhesive for polyethylene substrates according to claim 2, characterized in that, The tackifying resin is composed of C5 petroleum resin: rosin resin: terpene resin: maleic anhydride grafted polyethylene in a weight ratio of 2:1:1:

1.

4. The anti-wrinkle hot melt pressure sensitive adhesive for polyethylene substrates according to claim 2, characterized by, The weight ratio of the thermoplastic copolymer, mineral oil, and tackifying resin is 1:(0.83-1.0):(1.0-2.0).

5. The anti-wrinkle hot melt pressure sensitive adhesive for polyethylene substrates according to claim 4, characterized in that, The weight ratio of the thermoplastic copolymer, mineral oil, and tackifying resin is 1:0.83:1.

50.

6. The anti-wrinkle hot melt pressure sensitive adhesive for polyethylene substrates according to claim 1, characterized in that, The thermoplastic copolymer is one or more of styrene-isoprene block copolymer, styrene-butadiene block copolymer, hydrogenated styrene-isoprene block copolymer, and hydrogenated styrene-butadiene block copolymer.

7. The anti-wrinkle hot melt pressure sensitive adhesive for polyethylene substrates according to claim 6, characterized in that, The thermoplastic copolymer is composed of styrene-isoprene block copolymer and styrene-butadiene block copolymer in a weight ratio of 5:

1.

8. The process for preparing an anti-wrinkle hot-melt pressure sensitive adhesive for polyethylene substrates according to any one of claims 1 to 7, characterized in that, The following steps are included: S1: After mixing the mineral oil, 10-30 wt% tackifying resin, and antioxidant, first melt at 110-130℃, 10-15 r / min for 20-30 min, then add the thermoplastic copolymer, and stir mix at 15-20 r / min, -0.8-1.0 MPa for 60-80 min to obtain a melted mixture; S2: Add the remaining tackifying resin to the melted mixture, and stir mix at 140-150℃, 20-30 r / min, -0.8-1.0 MPa for 40-60 min to obtain an anti-wrinkle hot melt pressure-sensitive adhesive for polyethylene substrates.

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