Water-based adhesive, preparation method thereof and EVA foam gum

Abstract

The invention relates to the technical field of EVA foam gum, and discloses a water-based adhesive, a preparation method thereof and EVA foam gum, the EVA foam gum is prepared by coating kraft paper with the water-based adhesive prepared by the invention, drying and transferring to EVA foam, and the water-based adhesive comprises the following components in parts by weight: 50-400 parts of 2-ethylhexyl acrylate; 0 to 400 parts of n-butyl acrylate; 5-15 parts of acrylic acid or methacrylic acid; 5 to 20 parts of hydroxyethyl acrylate; 20 to 70 parts of methyl methacrylate or methyl acrylate; 0.05 to 0.1 part of dodecanethiol; 0.05 to 1 part of a silane coupling agent; 3-5 parts of an anionic emulsifier; 1-3 parts of a nonionic emulsifier; 0.5-2 parts of a reactive emulsifier; 400 to 600 parts of deionized water; 3-5 parts of ammonium persulfate; and 0.2-1 part of sodium bicarbonate. Experiments show that the scheme provided by the invention can ensure that the EVA foam gum has the properties of high adhesive force, no warping of a curved surface, high-temperature stripping force and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of EVA foam adhesive, and in particular relates to a water-based adhesive and a preparation method thereof, and EVA foam adhesive. Background Art

[0002] The main functions of EVA (ethylene-vinyl acetate copolymer) foam include shockproof, cushioning, protection and sound insulation. It is known for its excellent elasticity and softness. It can effectively absorb and disperse external impact and protect products from damage. EVA foam tape is widely used in new energy vehicles and consumer electronics. The surface polarity of EVA is low and it is not easy to adhere. Some EVA foams have pores, and the adhesive backing is very easy to fall off during application.

[0003] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a water-based adhesive and a preparation method thereof, and an EVA foam adhesive, aiming to solve the problem that the existing EVA foam adhesive is easy to warp and fall off.

[0005] The technical solution of the present invention is as follows:

[0006] A water-based adhesive, wherein the water-based adhesive comprises, by weight:

[0007] 50-400 parts of isooctyl acrylate;

[0008] 0-400 parts of n-butyl acrylate;

[0009] Acrylic acid or methacrylic acid 5-15 parts;

[0010] Hydroxyethyl acrylate 5-20 parts;

[0011] 20-70 parts of methyl methacrylate or methyl acrylate;

[0012] Dodecanethiol 0.05-0.1 part;

[0013] Silane coupling agent 0.05-1 part;

[0014] 3-5 parts of anionic emulsifier;

[0015] 1-3 parts of nonionic emulsifier;

[0016] Reactive emulsifier 0.5-2 parts;

[0017] 400-600 parts of deionized water;

[0018] 3-5 parts of ammonium persulfate;

[0019] Sodium bicarbonate 0.2-1 part.

[0020] The water-based adhesive, wherein the anionic emulsifier is one or more of sodium dodecyl sulfonate, ester succinate and fatty alcohol polyoxyethylene ether salt; the nonionic emulsifier is one or two of alkyl benzene ether polyoxyethylene ether and fatty alcohol polyoxyethylene ether; the reactive emulsifier is Aidico SR-10.

[0021] A method for preparing the water-based adhesive according to the present invention, comprising the steps of:

[0022] Weigh isooctyl acrylate, n-butyl acrylate, acrylic acid / methacrylic acid, hydroxyethyl acrylate, methyl methacrylate / methyl acrylate, dodecanethiol, silane coupling agent, anionic emulsifier, nonionic emulsifier, reactive emulsifier, deionized water, ammonium persulfate and sodium bicarbonate according to weight parts;

[0023] Add 97-100% by weight of anionic emulsifier, nonionic emulsifier, reactive emulsifier and sodium bicarbonate, 20-40% by weight of deionized water into a pre-emulsification kettle, mix and stir evenly, and add all isooctyl acrylate, n-butyl acrylate, acrylic acid / methacrylic acid, hydroxyethyl acrylate, methyl methacrylate / methyl acrylate, dodecanethiol, and silane coupling agent and stir evenly to prepare a pre-emulsion;

[0024] Add the remaining deionized water, anionic emulsifier, nonionic emulsifier, reactive emulsifier and sodium bicarbonate into the reaction kettle, raise the temperature to 82-86° C., then add 3-10% by weight of pre-emulsion and 30-70% by weight of ammonium persulfate;

[0025] Then, the remaining pre-emulsion and ammonium persulfate are added dropwise into the reactor, and the addition is completed within 3-4 hours. After the addition is completed, the mixture is kept warm for 30-60 minutes, then cooled to 70-75°C, and the residue is treated. Finally, the mixture is cooled to below 45°C, a defoamer, a wetting agent, and a preservative are added, and the material is neutralized to obtain a water-based adhesive.

[0026] The EVA foam adhesive backing is prepared by coating the water-based adhesive prepared by the present invention on kraft paper and transferring the water-based adhesive to the EVA foam after drying.

[0027] Beneficial effect: The EVA foam back glue provided by the present invention is prepared by coating the water-based adhesive prepared by the present invention on kraft paper and transferring it to the EVA foam after drying. The water-based adhesive includes, by weight: 50-400 parts of isooctyl acrylate; 0-400 parts of n-butyl acrylate; 5-15 parts of acrylic acid or methacrylic acid; 5-20 parts of hydroxyethyl acrylate; 20-70 parts of methyl methacrylate or methyl acrylate; 0.05-0.1 parts of dodecanethiol; 0.05-1 parts of silane coupling agent; 3-5 parts of anionic emulsifier; 1-3 parts of nonionic emulsifier; 0.5-2 parts of reactive emulsifier; 400-600 parts of deionized water; 3-5 parts of ammonium persulfate; 0.2-1 parts of sodium bicarbonate. It is found through experiments that the scheme of the present invention can ensure high adhesion of the EVA foam back glue, no warping of the curved surface, and high-temperature peeling strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The present invention is a flow chart of a method for preparing a water-based adhesive. DETAILED DESCRIPTION

[0029] The present invention provides a water-based adhesive and a preparation method thereof, and an EVA foam adhesive. To make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" or "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0031] The invention provides an EVA foam adhesive. The EVA foam adhesive is prepared by coating a water-based adhesive on kraft paper and transferring the water-based adhesive to the EVA foam after drying. The water-based adhesive comprises, by weight, 50-400 parts of isooctyl acrylate, 0-400 parts of n-butyl acrylate, 5-15 parts of acrylic acid or methacrylic acid, 5-20 parts of hydroxyethyl acrylate, 20-70 parts of methyl methacrylate or methyl acrylate, 0.05-0.1 parts of dodecanethiol, 0.05-1 parts of silane coupling agent, 3-5 parts of anionic emulsifier, 1-3 parts of nonionic emulsifier, 0.5-2 parts of reactive emulsifier, 400-600 parts of deionized water, 3-5 parts of ammonium persulfate and 0.2-1 parts of sodium bicarbonate.

[0032] Specifically, the EVA foam back glue of the present invention is made by uniformly coating the water-based adhesive on 70g kraft paper (release force 13g-18g), with a dry glue weight of 50g / ㎡, drying at 105°C for 3-6min, and then transferring it to the EVA foam. In the present invention, the combination of anionic emulsifiers, nonionic emulsifiers and reactive emulsifiers can effectively improve the mechanical stability of the product and the wetting of kraft paper (release force 13g-18g), and adapt to different coating methods and coating speeds; by controlling the proportion of hard monomers such as methyl methacrylate / methyl acrylate, the product's room temperature viscosity and temperature-resistant viscosity are improved, thereby improving the toughness of the product; by using functional monomers with functional groups such as acrylic acid / methacrylic acid, hydroxyethyl acrylate, isooctyl acrylate, and n-butyl acrylate, the degree of crosslinking and adhesion to the substrate are increased; by using silane coupling agents to promote monomer crosslinking, the product's water resistance and impact resistance are improved. By proportioning the above components, the present invention can ensure that the EVA foam backing adhesive has high adhesion, no warping of the curved surface, and high-temperature peeling performance.

[0033] In some embodiments, Figure 1 As shown, the preparation method of the water-based adhesive comprises the following steps:

[0034] S10, weighing isooctyl acrylate, n-butyl acrylate, acrylic acid / methacrylic acid, hydroxyethyl acrylate, methyl methacrylate / methyl acrylate, dodecanethiol, silane coupling agent, anionic emulsifier, nonionic emulsifier, reactive emulsifier, deionized water, ammonium persulfate and sodium bicarbonate in parts by weight;

[0035] S20, adding 97-100% by weight of anionic emulsifier, nonionic emulsifier, reactive emulsifier and sodium bicarbonate, 20-40% by weight of deionized water to a pre-emulsification kettle, mixing and stirring evenly, and adding all of isooctyl acrylate, n-butyl acrylate, acrylic acid / methacrylic acid, hydroxyethyl acrylate, methyl methacrylate / methyl acrylate, dodecanethiol, and silane coupling agent and stirring evenly to prepare a pre-emulsion;

[0036] S30, adding the remaining deionized water, anionic emulsifier, nonionic emulsifier, reactive emulsifier and sodium bicarbonate into the reaction kettle, heating to 82-86° C., and then adding 3-10% by weight of pre-emulsion and 30-70% by weight of ammonium persulfate;

[0037] S40, then start dripping the remaining pre-emulsion and ammonium persulfate in the reactor, dripping within 3-4 hours, after dripping, keep warm for 30-60min, then cool to 70-75℃, do residual single treatment, finally cool to below 45℃, add defoamer, wetting agent, preservative, neutralize and discharge, and obtain water-based adhesive. The water-based adhesive prepared by the present invention can effectively improve the adhesion of EVA foam adhesive and ensure that the curved surface does not warp after being used to prepare EVA foam adhesive.

[0038] The present invention will be further explained below by means of specific embodiments:

[0039] Example 1

[0040] A method for preparing an EVA foam adhesive comprises the following steps:

[0041] Weigh 400 parts of isooctyl acrylate, 40 parts of butyl acrylate, 5 parts of acrylic acid, 10 parts of hydroxyethyl acrylate, 30 parts of methyl methacrylate, 0.1 parts of dodecanethiol, 5 parts of anionic emulsifier, 1 part of nonionic emulsifier, 0.5 parts of reactive emulsifier, 500 parts of deionized water, 3 parts of ammonium persulfate and 1 part of sodium bicarbonate by weight;

[0042] Preparation of pre-emulsion: add 5 parts of anionic emulsifier, 1 part of nonionic emulsifier, 0.8 parts of sodium bicarbonate, and 140 parts of deionized water into a pre-emulsification kettle, mix and stir evenly, and add all of isooctyl acrylate, acrylic acid, hydroxyethyl acrylate, methyl methacrylate, and dodecanethiol and stir evenly to prepare a pre-emulsion;

[0043] Add the remaining 250 parts of deionized water, 1 part of reactive emulsifier, and the remaining sodium bicarbonate into the reaction kettle, raise the temperature to 80° C., then add 5% by weight of the above pre-emulsion and 2 parts of ammonium persulfate;

[0044] After the temperature reaches the highest, it drops back to 86°C, and the remaining pre-emulsion and ammonium persulfate are added dropwise, and the addition is completed within 3-4 hours; after the addition is completed, the temperature is kept for 30 minutes, and then the residue is treated and the temperature is lowered to below 45°C, a defoamer, a wetting agent, and a preservative are added, and the material is neutralized to obtain the water-based adhesive;

[0045] The prepared water-based adhesive was coated on 70g kraft paper (release force 13g-18g), dried at 105°C for 3min, the dry adhesive weight was 50g / ㎡, and covered on the corona EVA substrate to obtain the EVA foam backing adhesive.

[0046] Example 2

[0047] A method for preparing an EVA foam adhesive comprises the following steps:

[0048] Weigh 400 parts of n-butyl acrylate, 50 parts of isooctyl acrylate, 10 parts of acrylic acid, 15 parts of hydroxyethyl acrylate, 70 parts of methyl methacrylate, 0.1 parts of dodecanethiol, 1 part of silane coupling agent, 5 parts of anionic emulsifier, 3 parts of nonionic emulsifier, 0.5 parts of reactive emulsifier, 500 parts of deionized water, 5 parts of ammonium persulfate and 0.7 parts of sodium bicarbonate by weight;

[0049] Preparation of pre-emulsion: add 5 parts of anionic emulsifier, 3 parts of nonionic emulsifier, 0.5 parts of reactive emulsifier, 0.3 parts of sodium bicarbonate, and 140 parts of deionized water into a pre-emulsification kettle, mix and stir evenly, and add all of n-butyl acrylate, isooctyl acrylate, acrylic acid, hydroxyethyl acrylate, methyl methacrylate, silane coupling agent, and dodecanethiol, stir evenly to prepare a pre-emulsion;

[0050] Add the remaining 250 parts of deionized water into the reactor, heat it to 80° C., then add 5% by weight of the pre-emulsion and 2 parts of ammonium persulfate;

[0051] After the temperature reaches the highest, it drops back to 86°C, and the remaining pre-emulsion and ammonium persulfate are added dropwise, and the addition is completed within 3-4 hours; after the addition is completed, the temperature is kept for 30 minutes, and then the residue is treated and the temperature is lowered to below 45°C, a defoamer, a wetting agent, and a preservative are added, and the material is neutralized to obtain the water-based adhesive;

[0052] The prepared water-based adhesive was coated on 70g kraft paper (release force 13g-18g), dried at 105°C for 3min, the dry adhesive weight was 50g / ㎡, and covered on the corona EVA substrate to obtain the EVA foam backing adhesive.

[0053] Example 3

[0054] A method for preparing an EVA foam adhesive comprises the following steps:

[0055] Weigh 300 parts of isooctyl acrylate, 150 parts of n-butyl acrylate, 15 parts of acrylic acid, 10 parts of hydroxyethyl acrylate, 40 parts of methyl methacrylate, 0.3 parts of silane coupling agent, 0.05 parts of dodecanethiol, 600 parts of deionized water, 4 parts of ammonium persulfate and 1 part of sodium bicarbonate by weight;

[0056] Preparation of pre-emulsion: add 4 parts of anionic emulsifier, 1.5 parts of nonionic emulsifier, 0.8 parts of sodium bicarbonate, and 140 parts of deionized water into a pre-emulsification kettle, mix and stir evenly, and add all of n-butyl acrylate, isooctyl acrylate, acrylic acid, hydroxyethyl acrylate, methyl methacrylate, silane coupling agent, and dodecanethiol, stir evenly to prepare a pre-emulsion;

[0057] Add the remaining 250 parts of deionized water into the reactor, heat it to 80° C., then add 5% by weight of the pre-emulsion and 2 parts of ammonium persulfate;

[0058] After the temperature reaches the highest, it drops back to 86°C, and the remaining pre-emulsion and ammonium persulfate are added dropwise, and the addition is completed within 3-4 hours; after the addition is completed, the temperature is kept for 30 minutes, and then the residue is treated and the temperature is lowered to below 45°C, a defoamer, a wetting agent, and a preservative are added, and the material is neutralized to obtain the water-based adhesive;

[0059] The prepared water-based adhesive was coated on 70g kraft paper (release force 13g-18g), dried at 105°C for 3min, the dry adhesive weight was 50g / ㎡, and covered on the corona EVA substrate to obtain the EVA foam backing adhesive.

[0060] Example 4

[0061] A method for preparing an EVA foam adhesive comprises the following steps:

[0062] Weigh 200 parts of isooctyl acrylate, 250 parts of n-butyl acrylate, 15 parts of acrylic acid, 20 parts of hydroxyethyl acrylate, 20 parts of methyl methacrylate, 0.1 parts of silane coupling agent, 0.1 parts of dodecanethiol, 600 parts of deionized water, 6 parts of ammonium persulfate and 1 part of sodium bicarbonate by weight;

[0063] Preparation of pre-emulsion: add 5 parts of anionic emulsifier, 2.5 parts of nonionic emulsifier, 1 part of sodium bicarbonate, and 140 parts of deionized water into a pre-emulsification kettle, mix and stir evenly, and add all of n-butyl acrylate, isooctyl acrylate, acrylic acid, hydroxyethyl acrylate, methyl methacrylate, silane coupling agent, and dodecanethiol, stir evenly to prepare a pre-emulsion;

[0064] Add the remaining 300 parts of deionized water into the reactor, raise the temperature to 80° C., then add 3% by weight of the above pre-emulsion and 3 parts of ammonium persulfate;

[0065] After the temperature reaches the highest, it drops back to 86°C, and the remaining pre-emulsion and ammonium persulfate are added dropwise, and the addition is completed within 3-4 hours; after the addition is completed, the temperature is kept for 30 minutes, and then the residue is treated and the temperature is lowered to below 45°C, a defoamer, a wetting agent, and a preservative are added, and the material is neutralized to obtain the water-based adhesive;

[0066] The prepared water-based adhesive was coated on 70g kraft paper (release force 13g-18g), dried at 105°C for 3min, the dry adhesive weight was 50g / ㎡, and covered on the corona EVA substrate to obtain the EVA foam backing adhesive.

[0067] Test Example 1

[0068] According to the test method of GB / T 2792-2014 "Test method for peel strength of adhesive tape", the water-based acrylic EVA foam tapes of Examples 1-4 were tested for 180° peel strength.

[0069] Test method: After the 175X25 (mm) test strip is placed under standard conditions of 23℃±2℃, 50%RH±5%RH for 24 hours, it is attached to a clean standard steel plate, and pressed once in each direction with a test roller at a speed of 10mm / S, placed for 20 minutes, and peeled 180° at a peeling speed of 300mm / min. Three test strips are made, and the average value is taken. The results are shown in Table 1.

[0070] Table 1 Peel strength test results

[0071]

[0072]

[0073] It can be seen from the data in Table 1 that the 180° peel strength of the EVA foam adhesive prepared by the present invention is greater than 5N / 25mm, indicating that the EVA foam adhesive of the present invention has better high adhesion.

[0074] Test Example 2

[0075] According to the test method of GB / T 4851-2014 "Test method for holding adhesiveness of adhesive tapes", the holding adhesiveness of the water-based acrylic EVA foam tapes of Examples 1-4 was tested.

[0076] After the 175X25 (mm) test strip is placed under the standard conditions of 23℃±2℃, 50%RH±5%RH for 24 hours, the sample material is removed, the adhesive surface is facing outward, three test strips are made, and they are placed on the steel plate for 20 minutes, and a 1kg weight is hung below for testing. The numbers are recorded and the average value is taken. The results are shown in Table 2.

[0077] Table 2 Adhesion test results

[0078] project Adhesion Example 1 15 Example 2 20 Example 3 ＞24H Example 4 ＞24H

[0079] It can be seen from the data in Table 2 that the EVA foam adhesive prepared in the embodiments of the present invention has a holding force of at least 15 hours, and the holding forces of Examples 3-4 are all greater than 24 hours, indicating that the holding force of the EVA foam adhesive of the present invention is improved.

[0080] Test Example 3

[0081] A sample of 25 mm×200 mm was randomly taken from the tapes prepared in Examples 1-4, the waste material was removed, and the sample was attached to a 6-inch paper tube in a circular shape (360°) with a tight fit without bubbles. The warping was observed on 1 / 3 / 7 days, respectively. The test results are shown in Table 3.

[0082] Table 3 Warping test results

[0083] project 1D 3D 7D Example 1 No curling No curling Warping Example 2 No curling No curling Warping Example 3 No curling No curling Slightly warped Example 4 No curling No curling Warping

[0084] It can be seen from the data in Table 3 that the EVA foam adhesive prepared in the embodiment of the present invention only starts to warp or slightly warp on the 7th day, indicating that the EVA foam adhesive of the present invention has a better anti-warping effect.

[0085] Based on this, in order to improve the product's warpage resistance and adhesion to non-polar substrates, different proportions of high softening point (softening point 125° C.) rosin or modified rosin resin esterified with alcohols were added to modify the product on the basis of Example 3 to form Examples 5-9.

[0086] Example 5

[0087] A method for preparing an EVA foam adhesive comprises the following steps:

[0088] Weigh 300 parts of isooctyl acrylate, 150 parts of n-butyl acrylate, 15 parts of acrylic acid, 10 parts of hydroxyethyl acrylate, 40 parts of methyl methacrylate, 0.3 parts of silane coupling agent, 0.05 parts of dodecanethiol, 600 parts of deionized water, 4 parts of ammonium persulfate and 1 part of sodium bicarbonate by weight;

[0089] Preparation of pre-emulsion: add 4 parts of anionic emulsifier, 1.5 parts of nonionic emulsifier, 0.8 parts of sodium bicarbonate, and 140 parts of deionized water into a pre-emulsification kettle, mix and stir evenly, and add all of n-butyl acrylate, isooctyl acrylate, acrylic acid, hydroxyethyl acrylate, methyl methacrylate, silane coupling agent, and dodecanethiol, stir evenly to prepare a pre-emulsion;

[0090] Add the remaining 250 parts of deionized water into the reactor, heat it to 80° C., then add 5% by weight of the pre-emulsion and 2 parts of ammonium persulfate;

[0091] After the temperature reaches the highest, it drops back to 86°C, and the remaining pre-emulsion and ammonium persulfate are added dropwise, and the addition is completed within 3-4 hours; after the addition is completed, the temperature is kept for 30 minutes, and then the residue is treated and the temperature is lowered to below 45°C, a defoamer, a wetting agent, and a preservative are added, and the material is neutralized to obtain the water-based adhesive;

[0092] The prepared water-based adhesive is mixed with a high softening point (softening point 125°C) rosin resin accounting for 5% of the water-based adhesive, coated on 70g kraft paper (release force 13g-18g), dried at 105°C for 3min, the dry adhesive weight is 50g / ㎡, and covered on a corona EVA substrate to obtain EVA foam backing adhesive.

[0093] Example 6

[0094] A method for preparing an EVA foam adhesive comprises the following steps:

[0095] Weigh 300 parts of isooctyl acrylate, 150 parts of n-butyl acrylate, 15 parts of acrylic acid, 10 parts of hydroxyethyl acrylate, 40 parts of methyl methacrylate, 0.3 parts of silane coupling agent, 0.05 parts of dodecanethiol, 600 parts of deionized water, 4 parts of ammonium persulfate and 1 part of sodium bicarbonate by weight;

[0096] Preparation of pre-emulsion: add 4 parts of anionic emulsifier, 1.5 parts of nonionic emulsifier, 0.8 parts of sodium bicarbonate, and 140 parts of deionized water into a pre-emulsification kettle, mix and stir evenly, and add all of n-butyl acrylate, isooctyl acrylate, acrylic acid, hydroxyethyl acrylate, methyl methacrylate, silane coupling agent, and dodecanethiol, stir evenly to prepare a pre-emulsion;

[0097] Add the remaining 250 parts of deionized water into the reactor, heat it to 80° C., then add 5% by weight of the pre-emulsion and 2 parts of ammonium persulfate;

[0098] After the temperature reaches the highest, it drops back to 86°C, and the remaining pre-emulsion and ammonium persulfate are added dropwise, and the addition is completed within 3-4 hours; after the addition is completed, the temperature is kept for 30 minutes, and then the residue is treated and the temperature is lowered to below 45°C, a defoamer, a wetting agent, and a preservative are added, and the material is neutralized to obtain the water-based adhesive;

[0099] The prepared water-based adhesive is mixed with modified rosin resin esterified with alcohol accounting for 10% of the water-based adhesive, coated on 70g kraft paper (release force 13g-18g), dried at 105°C for 3min, the dry adhesive weight is 50g / ㎡, and covered on a corona EVA substrate to obtain EVA foam backing adhesive.

[0100] Example 7

[0101] A method for preparing an EVA foam adhesive comprises the following steps:

[0102] Weigh 300 parts of isooctyl acrylate, 150 parts of n-butyl acrylate, 15 parts of acrylic acid, 10 parts of hydroxyethyl acrylate, 40 parts of methyl methacrylate, 0.3 parts of silane coupling agent, 0.05 parts of dodecanethiol, 600 parts of deionized water, 4 parts of ammonium persulfate and 1 part of sodium bicarbonate by weight;

[0103] Preparation of pre-emulsion: add 4 parts of anionic emulsifier, 1.5 parts of nonionic emulsifier, 0.8 parts of sodium bicarbonate, and 140 parts of deionized water into a pre-emulsification kettle, mix and stir evenly, and add all of n-butyl acrylate, isooctyl acrylate, acrylic acid, hydroxyethyl acrylate, methyl methacrylate, silane coupling agent, and dodecanethiol, stir evenly to prepare a pre-emulsion;

[0104] Add the remaining 250 parts of deionized water into the reactor, heat it to 80° C., then add 5% by weight of the pre-emulsion and 2 parts of ammonium persulfate;

[0105] After the temperature reaches the highest, it drops back to 86°C, and the remaining pre-emulsion and ammonium persulfate are added dropwise, and the addition is completed within 3-4 hours; after the addition is completed, the temperature is kept for 30 minutes, and then the residue is treated and the temperature is lowered to below 45°C, a defoamer, a wetting agent, and a preservative are added, and the material is neutralized to obtain the water-based adhesive;

[0106] The prepared water-based adhesive is mixed with modified rosin resin esterified with alcohol accounting for 15% of the water-based adhesive, coated on 70g kraft paper (release force 13g-18g), dried at 105°C for 3min, the dry adhesive weight is 50g / ㎡, and covered on a corona EVA substrate to obtain EVA foam backing adhesive.

[0107] Example 8

[0108] A method for preparing an EVA foam adhesive comprises the following steps:

[0109] Weigh 300 parts of isooctyl acrylate, 150 parts of n-butyl acrylate, 15 parts of acrylic acid, 10 parts of hydroxyethyl acrylate, 40 parts of methyl methacrylate, 0.3 parts of silane coupling agent, 0.05 parts of dodecanethiol, 600 parts of deionized water, 4 parts of ammonium persulfate and 1 part of sodium bicarbonate by weight;

[0110] Preparation of pre-emulsion: add 4 parts of anionic emulsifier, 1.5 parts of nonionic emulsifier, 0.8 parts of sodium bicarbonate, and 140 parts of deionized water into a pre-emulsification kettle, mix and stir evenly, and add all of n-butyl acrylate, isooctyl acrylate, acrylic acid, hydroxyethyl acrylate, methyl methacrylate, silane coupling agent, and dodecanethiol, stir evenly to prepare a pre-emulsion;

[0111] Add the remaining 250 parts of deionized water into the reactor, heat it to 80° C., then add 5% by weight of the pre-emulsion and 2 parts of ammonium persulfate;

[0112] After the temperature reaches the highest, it drops back to 86°C, and the remaining pre-emulsion and ammonium persulfate are added dropwise, and the addition is completed within 3-4 hours; after the addition is completed, the temperature is kept for 30 minutes, and then the residue is treated and the temperature is lowered to below 45°C, a defoamer, a wetting agent, and a preservative are added, and the material is neutralized to obtain the water-based adhesive;

[0113] The prepared water-based adhesive is mixed with modified rosin resin esterified with alcohol accounting for 20% of the water-based adhesive, coated on 70g kraft paper (release force 13g-18g), dried at 105°C for 3min, the dry adhesive weight is 50g / ㎡, and covered on a corona EVA substrate to obtain EVA foam backing adhesive.

[0114] Example 9

[0115] A method for preparing an EVA foam adhesive comprises the following steps:

[0116] Weigh 300 parts of isooctyl acrylate, 150 parts of n-butyl acrylate, 15 parts of acrylic acid, 10 parts of hydroxyethyl acrylate, 40 parts of methyl methacrylate, 0.3 parts of silane coupling agent, 0.05 parts of dodecanethiol, 600 parts of deionized water, 4 parts of ammonium persulfate and 1 part of sodium bicarbonate by weight;

[0117] Preparation of pre-emulsion: add 4 parts of anionic emulsifier, 1.5 parts of nonionic emulsifier, 0.8 parts of sodium bicarbonate, and 140 parts of deionized water into a pre-emulsification kettle, mix and stir evenly, and add all of n-butyl acrylate, isooctyl acrylate, acrylic acid, hydroxyethyl acrylate, methyl methacrylate, silane coupling agent, and dodecanethiol, stir evenly to prepare a pre-emulsion;

[0118] Add the remaining 250 parts of deionized water into the reactor, heat it to 80° C., then add 5% by weight of the pre-emulsion and 2 parts of ammonium persulfate;

[0119] After the temperature reaches the highest, it drops back to 86°C, and the remaining pre-emulsion and ammonium persulfate are added dropwise, and the addition is completed within 3-4 hours; after the addition is completed, the temperature is kept for 30 minutes, and then the residue is treated and the temperature is lowered to below 45°C, a defoamer, a wetting agent, and a preservative are added, and the material is neutralized to obtain the water-based adhesive;

[0120] The prepared water-based adhesive is mixed with modified rosin resin esterified with alcohol accounting for 25% of the water-based adhesive, coated on 70g kraft paper (release force 13g-18g), dried at 105°C for 3min, the dry adhesive weight is 50g / ㎡, and covered on a corona EVA substrate to obtain EVA foam backing adhesive.

[0121] The EVA foam adhesives prepared in Examples 5-9 were tested for peeling force, holding force, and lamination. The results are shown in Table 4.

[0122] project 180° peel force Adhesion 7D Fit Example 5 (5% resin) 7.5N / 25mm ＞24H No curling Example 6 (10% resin) 8N / 25mm ＞24H No curling Example 7 (15% resin) 9.5N / 25mm ＞24H No curling Example 8 (20% resin) 11N / 25mm ＞24H No curling Example 9 (25% resin) 11.2N / 25mm ＞24H No curling

[0123] From the data in Table 4, it can be seen that adding high softening point (softening point 125°C) rosin or modified rosin resin esterified with alcohols to the water-based adhesive can improve the product's anti-warping ability and peeling strength; especially after adding 20% ​​of the resin, the product's anti-warping ability and peeling strength can be significantly improved, further improving the product's adaptability.

[0124] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A water-based adhesive, characterized in that: The water-based adhesive comprises, by weight: 50-400 parts of isooctyl acrylate; 0-400 parts of n-butyl acrylate; Acrylic acid or methacrylic acid 5-15 parts; Hydroxyethyl acrylate 5-20 parts; 20-70 parts of methyl methacrylate or methyl acrylate; Dodecanethiol 0.05-0.1 part; Silane coupling agent 0.05-1 part 3-5 parts of anionic emulsifier; 1-3 parts of nonionic emulsifier; Reactive emulsifier 0.5-2 parts; 400-600 parts of deionized water; 3-5 parts of ammonium persulfate; Sodium bicarbonate 0.2-1 part.

2. The water-based adhesive according to claim 1, characterized in that: The anionic emulsifier is one or more of sodium dodecyl sulfonate, ester succinate and fatty alcohol polyoxyethylene ether salt; the nonionic emulsifier is one or two of alkyl benzene ether polyoxyethylene ether and fatty alcohol polyoxyethylene ether; the reactive emulsifier is Aidico SR-10.

3. A method for preparing the water-based adhesive as claimed in claim 1 or 2, characterized in that: Includes steps: Weigh isooctyl acrylate, n-butyl acrylate, acrylic acid / methacrylic acid, hydroxyethyl acrylate, methyl methacrylate / methyl acrylate, dodecanethiol, silane coupling agent, anionic emulsifier, nonionic emulsifier, reactive emulsifier, deionized water, ammonium persulfate and sodium bicarbonate according to weight parts; Add 97-100% by weight of anionic emulsifier, nonionic emulsifier, reactive emulsifier and sodium bicarbonate, 20-40% by weight of deionized water into a pre-emulsification kettle, mix and stir evenly, and add all isooctyl acrylate, n-butyl acrylate, acrylic acid / methacrylic acid, hydroxyethyl acrylate, methyl methacrylate / methyl acrylate, dodecanethiol, and silane coupling agent and stir evenly to prepare a pre-emulsion; Add the remaining deionized water, anionic emulsifier, nonionic emulsifier, reactive emulsifier and sodium bicarbonate into the reaction kettle, raise the temperature to 82-86° C., then add 3-10% by weight of pre-emulsion and 30-70% by weight of ammonium persulfate; Then, the remaining pre-emulsion and ammonium persulfate are added dropwise into the reactor, and the addition is completed within 3-4 hours. After the addition is completed, the mixture is kept warm for 30-60 minutes, then cooled to 70-75°C, and the residue is treated. Finally, the mixture is cooled to below 45°C, a defoamer, a wetting agent, and a preservative are added, and the material is neutralized to obtain a water-based adhesive.

4. An EVA foam adhesive, characterized in that: The EVA foam backing adhesive is prepared by coating the water-based adhesive prepared in claim 3 on kraft paper and transferring the dried adhesive to the EVA foam.

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