Hot melt adhesive suitable for water-based coating waterproof membrane, and preparation method therefor and use thereof

Abstract

Disclosed in the present invention are a hot melt adhesive suitable for a water-based coating waterproof membrane, and a preparation method therefor and a use thereof. The waterproof membrane sequentially comprises a substrate, a connecting layer, and an anti-adhesive coating; the connecting layer is formed from the hot melt adhesive; the anti-adhesive coating is formed from a water-based resin emulsion; the hot melt adhesive comprises a plasticizer, a tackifying resin, a functional resin, and a thermoplastic elastomer; the functional resin contains one or more of abietic acid, Palustric acid, and pimaric acid; the carboxyl group content in the functional resin ranges from 0.90 mmol / g to 2.80 mmol / g; and a carboxyl group in the hot melt adhesive is used for chemical bonding with an amino group in the water-based resin emulsion. The hot melt adhesive of the present invention has a low surface contact angle and high surface energy, and the resin emulsion for forming the anti-adhesive coating can achieve good wetting on the surface, and exhibits stable adhesion to the coating, thereby ensuring that a full-adhesion structure is formed after pouring concrete on the water-based coating waterproof membrane.

Description

Hot melt adhesives suitable for water-based coating waterproof membranes, their preparation methods and applications Technical Field

[0001] This invention belongs to the field of adhesive technology and is applied to waterproof membranes. Specifically, it relates to a hot melt adhesive suitable for water-based coated waterproof membranes, a method for preparing the hot melt adhesive, and its application in waterproof membranes. Background Technology

[0002] Pre-applied waterproof membranes generally refer to membranes on which concrete is poured directly after a waterproof layer has been pre-applied. The membrane mainly consists of a main material, a bonding layer, a surface anti-adhesion (reducing) protective layer (excluding overlapping areas), and a release material (if needed). The bonding layer adheres well to the concrete layer after pouring, fundamentally preventing the risk of water seepage. Pre-applied waterproof membranes have low requirements for the substrate, requiring no leveling, are easy to install (direct overlap), and offer reliable adhesion. Currently, pre-applied waterproof membranes have become one of the main materials for underground waterproofing and are widely used in various building foundations and basement roofs both domestically and internationally.

[0003] The surface protective layer of waterproof membranes typically uses cement sand, artificial sand, quartz sand, or membrane-based silicone oil release materials. However, the use of membrane-based silicone oil release materials can cause secondary plastic pollution during construction, leading to unnecessary waste disposal problems. Various sand-based surface release materials are prone to shedding sand during production and transportation, and this sand shedding during construction can affect the overlapping edges, thus impacting the final waterproofing effect. Furthermore, membranes using sand-based protective layers are inherently heavy.

[0004] To address these issues, coated waterproof membranes have emerged, using coating materials to replace release liner or isolation sand to achieve a non-sticky protective layer. This non-sticky protective layer significantly reduces the weight of the waterproof membrane roll, greatly improving construction convenience.

[0005] The structure of coated waterproof membrane products mainly consists of three layers: substrate, connecting layer, and anti-adhesive coating layer. It forms a fully adhesive waterproof structure when bonded to the subsequently poured concrete. It mainly relies on the effective bonding between the surface coating and the concrete, and the intermediate connecting layer connects the coating and the substrate together. The adhesion between the self-adhesive and the substrate is currently at a very good level. Therefore, the cohesive force of the self-adhesive and the adhesion between it and the coating determine the waterproof effect of coated waterproof membrane.

[0006] Meanwhile, coating adhesion is often achieved through roller coating, spraying, and transfer printing during the production process. How to evenly and stably coat the self-adhesive surface determines the overall bonding performance of the subsequent roll material. Commonly used coatings for waterproof rolls are water-based, making the aforementioned problems even more difficult to solve.

[0007] Currently, commercially available hot melt adhesives for waterproof membranes are mainly used for bonding surface isolation sand. They have good initial adhesion, but these hot melt adhesives have low surface tension and a large surface contact angle, which makes it difficult for water-based emulsions to be well coated on the surface. After coating, roller marks and shrinkage marks are prone to appear. During production such as spraying, droplets are easily formed on the surface, which cannot be well wetted to form a coating film. This can lead to adhesive leakage on the surface of the pre-laid finished product, affecting the appearance of the coated membrane and the peeling from the subsequently poured concrete, ultimately resulting in poor product construction and waterproofing effect.

[0008] For example, patent CN116496714A, entitled "A Double-Sided Composite Polymer Waterproof Membrane, Preparation Method and Application," discloses a polymer pressure-sensitive adhesive that incorporates a fluorosiloxane adhesive aid. This adhesive not only allows for cold bonding with polymer sheets, creating a full bond between the two waterproof layers without water seepage, but also ensures long-term reliability of underground waterproofing since both waterproof layers are polymeric materials, eliminating material incompatibility. The patent also describes a double-sided composite polymer waterproof membrane that exhibits stronger adhesion, higher peel strength, and better water resistance to substrates such as cement mortar and concrete. However, the polymer pressure-sensitive adhesive mentioned in this patent primarily focuses on improving adhesion to substrates and concrete, without addressing the wetting effect of water-based materials on its surface. Furthermore, the improved adhesion relies on the fluorosiloxane adhesive aid. Strong adhesion, high peel strength, water resistance, and effective application to substrates via heat coating are all fundamental requirements for waterproof membrane adhesives.

[0009] For example, patent CN117285879A, entitled "A Pre-laid Waterproof Membrane and Its Preparation Method," describes a waterproof membrane comprising a substrate layer, an adhesive layer, and a protective coating layer stacked sequentially. Its focus is on adjusting the emulsion formula to improve wetting on the coated surface and bonding strength with concrete. However, the adhesive layer uses ordinary hot-melt pressure-sensitive adhesive. Ordinary hot-melt pressure-sensitive adhesives have low surface tension and a large surface contact angle, making them unsuitable for water-based protective coatings. The water-based protective coating cannot be fully wetted due to the surface effect of the hot-melt pressure-sensitive adhesive, resulting in shrinkage and missed areas. This leads to leakage of the hot-melt pressure-sensitive adhesive under the protective coating. Consequently, after drying, the unspread areas of the protective coating will adhere to the substrate layer when rolled up. Furthermore, the protective coating requires rapid UV curing after roller coating to achieve full film coverage, placing higher demands on the process.

[0010] The above background information is provided only to assist in understanding the inventive concept and technical solution of this invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed before the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0011] In view of this, in order to overcome the shortcomings of the prior art, the purpose of this invention is to provide an improved hot melt adhesive that is applicable to water-based coated waterproof membranes, has strong adhesion to the anti-stick coating and the substrate, and has a lower surface contact angle, which is more conducive to the application of the anti-stick coating.

[0012] To achieve the above objectives, the present invention adopts the following technical solution:

[0013] A hot melt adhesive suitable for water-based coated waterproof membranes, the waterproof membrane comprising a substrate, a bonding layer, and a non-stick coating, wherein the bonding layer is formed by the hot melt adhesive, and the non-stick coating is formed by an aqueous resin emulsion. The hot melt adhesive comprises a plasticizer, a tackifying resin, a functional resin, and a thermoplastic elastomer. The functional resin contains one or more of abietic acid (such as neoabietic acid, dehydroabietic acid, dihydroabietic acid, tetrahydroabietic acid), longleaf abietic acid, and piratic acid (such as L-pilocarboxylic acid, isopiratic acid). The carboxyl group content of the hot melt adhesive is 0.90 mmol / g to 2.80 mmol / g, and the carboxyl groups in the hot melt adhesive are used to form chemical bonds with the amino groups in the aqueous resin emulsion. The method for measuring the carboxyl group content is in accordance with EN 1240:2011 "Determination of hydroxyl value and / or hydroxyl content in adhesives". A low carboxyl content results in a larger surface contact angle (with water) after the hot melt adhesive film is formed. This leads to greater shrinkage after roller coating of the emulsion, and the emulsion film cannot completely cover the underlying hot melt adhesive. Furthermore, the low carboxyl content results in weak adhesion between the bonding layer and the anti-stick coating, leading to lower peel strength with the subsequently poured concrete. Conversely, a high carboxyl content can cause the adhesive to fail to meet standards in the water immersion treatment process with the subsequently poured concrete, and in more severe cases, it can lead to delamination after water immersion.

[0014] The hot melt adhesive of this invention has a small surface contact angle, resulting in better wetting of water-based resin emulsions and enabling full coating of the water-based resin emulsion to meet the application requirements of waterproof membranes. It uses a resin with a certain carboxyl content to achieve the predetermined surface contact angle. Furthermore, when applied to waterproof membranes in conjunction with a water-based anti-stick coating emulsion, the hot melt adhesive's various properties, adhesion to the anti-stick coating, and adhesion to concrete all meet the corresponding application requirements. The hot melt adhesive exhibits excellent surface wetting and film-forming adhesion.

[0015] According to some preferred embodiments of the invention, the surface contact angle of the connecting layer is ≤90°, preferably 65°~90°.

[0016] According to some preferred embodiments of the present invention, the aqueous resin emulsion contains amino groups, and the pH of the aqueous resin emulsion is 6 to 9.

[0017] According to some preferred embodiments of the present invention, the functional resin is one or more of rosin resin or its modified resin, terpene resin or its modified resin such as terpene phenolic resin. Modifications include maleic anhydride grafting, alkylation modification, hydroxylation modification, copolymerization modification, etc., to adjust the resin softening point, impart functional groups, and improve properties such as heat resistance and initial tack.

[0018] According to some preferred embodiments of the present invention, the softening point of the functional resin is 100°C to 130°C. This softening point of the functional resin results in better overall performance of the hot melt adhesive and better product performance when applied to waterproof materials.

[0019] According to some preferred embodiments of the invention, the plasticizer is a naphthenic oil and / or polyisobutylene.

[0020] According to some preferred embodiments of the present invention, the tackifying resin is one or more selected from C5 petroleum resin, hydrogenated petroleum resin, C9 petroleum resin, and C5 / C9 copolymer petroleum resin.

[0021] According to some preferred embodiments of the present invention, the thermoplastic elastomer is selected from one or more of styrene-isoprene-styrene triblock copolymer, styrene-butadiene-styrene triblock copolymer, and butyl rubber.

[0022] According to some preferred embodiments of the invention, the thermoplastic elastomer is a styrene-isoprene-styrene triblock copolymer with a diblock content in the range of 35%-45%. This diblock content of SIS results in better overall strength of the hot melt adhesive, manifested as better peel strength in waterproof membranes.

[0023] According to some preferred embodiments of the present invention, the hot melt adhesive comprises the following raw material components in parts by weight:

[0024] 16-25 parts plasticizer

[0025] 10-15 parts of tackifying resin

[0026] 28-33 parts of functional resin

[0027] 26-30 parts of thermoplastic elastomer.

[0028] According to some preferred embodiments of the present invention, the hot melt adhesive includes an antioxidant, which is one or more selected from hindered phenolic, phosphite, and thiophenolic antioxidants. Preferably, it is one or more selected from antioxidant 1010, antioxidant 168, and antioxidant 1076.

[0029] According to some preferred embodiments of the present invention, the hot melt adhesive includes an ultraviolet absorber, which is one or more selected from benzotriazole, benzophenone, and hindered amine ultraviolet absorbers.

[0030] According to some preferred embodiments of the present invention, the hot melt adhesive includes a filler, which is one or more selected from calcium carbonate, rutile titanium dioxide or its modified form, and kaolin inorganic filler.

[0031] In some embodiments, the hot melt adhesive suitable for water-based coated waterproof membranes includes plasticizers, tackifying resins, functional resins, thermoplastic elastomers, antioxidants, ultraviolet absorbers, and fillers.

[0032] Preferably, the hot melt adhesive comprises the following raw material components in parts by weight:

[0033] 16-25 parts plasticizer

[0034] 10-15 parts of tackifying resin

[0035] 28-33 parts of functional resin

[0036] 26-30 parts of thermoplastic elastomer

[0037] Antioxidant 0-3 parts

[0038] 0-3 parts of UV absorber

[0039] 0-2 parts of filler.

[0040] According to some preferred embodiments of the present invention, the aqueous resin emulsion includes a photocrosslinkable organosilicon resin emulsion; the organosilicon resin emulsion is prepared by first subjecting organosilicon polymer monomers to hydrolysis and polycondensation in the presence of a solvent, then subjecting them to end-capping reaction with an end-capping agent to obtain a prepolymer, then adding a photoinitiator and mixing, removing the solvent and emulsifying with water.

[0041] According to some preferred embodiments of the present invention, the aqueous resin emulsion includes a room temperature self-crosslinking acrylate resin emulsion; the room temperature self-crosslinking acrylate resin emulsion has a core-shell structure, wherein the core layer structure is obtained by polymerization of core layer monomers, and the shell layer is obtained by polymerization of shell layer monomers, wherein the shell layer monomers include room temperature self-crosslinking monomers, soft monomers, hard monomers, and hydrophilic monomers.

[0042] A water-based resin emulsion prepared by compounding a photocrosslinkable silicone resin emulsion with a room-temperature self-crosslinking acrylic resin emulsion exhibits excellent wetting and adhesion when applied to the hot melt adhesive of this invention. The coating emulsion contains functional groups such as amino, siloxane, isocyanate, and hydroxyl groups. The water-based anti-stick coating emulsion has a pH range of 6-9, primarily achieved by introducing amino-containing alkaline substances to adjust the overall pH value, hydrophilicity, and powder dispersibility of the emulsion. The pH value reflects the concentration or content of the main amino functional group. Besides the reaction between the carboxyl groups in the hot melt adhesive and the amino groups in the emulsion coating, a small portion of the isocyanate in the emulsion coating also reacts with the carboxyl groups in the hot melt adhesive to form amides, which further increase the adhesive strength between the hot melt adhesive and the coating.

[0043] The present invention also provides a method for preparing the hot melt adhesive as described above, comprising the following steps: heating and melting the substance and drawing a vacuum to obtain the hot melt adhesive.

[0044] In some embodiments, the method for preparing hot melt adhesive includes the following steps:

[0045] After adding plasticizer and filler to the reaction vessel, start stirring and heating, and set the reaction vessel temperature to 160-180℃.

[0046] After the materials in the reaction vessel are mixed evenly and the material temperature reaches 175-185℃, add thermoplastic elastomer, antioxidant, and ultraviolet absorber, continue stirring and draw a vacuum, and set the vacuum degree to ≤-0.08MPa.

[0047] After the thermoplastic elastomer is completely melted and mixed evenly, tackifying resin and functional resin are added to it while maintaining a vacuum state.

[0048] After all materials are melted and mixed evenly, a hot melt adhesive suitable for water-based coating waterproof membranes is obtained.

[0049] In this invention, the plasticizer, additives, and elastomer are first melted and stabilized before the resin is added. The entire process is carried out under vacuum to ensure that the raw materials are minimally affected by heat aging and to guarantee the strength of the adhesive. In contrast, the existing conventional preparation process involves stirring and melting the plasticizer, additives, and resin before adding the elastomer. This process is time-consuming, and the adhesive is prone to heat aging due to prolonged heating, which affects the overall strength of the adhesive.

[0050] The present invention also provides an application of the hot melt adhesive as described above in waterproof membranes, such as obtaining a water-based coated waterproof membrane, which sequentially includes a substrate, a bonding layer and an anti-stick coating. The bonding layer is formed by the hot melt adhesive described above, and the anti-stick coating is formed by a water-based resin emulsion. The substrate is preferably polyethylene (HDPE), polyolefin material (TPO) or polyvinyl chloride (PVC).

[0051] In some embodiments, the preparation method of water-based coated waterproof membrane includes the following steps:

[0052] The hot melt adhesive is heated and melted. After the material temperature reaches 160-165℃, it is placed in a coating equipment for coating. The coating thickness of the hot melt adhesive is 0.30mm~0.33mm.

[0053] After the hot melt adhesive coating is completed and the material passes through the heat preservation equipment, the water-based resin emulsion is coated. The coating thickness of the water-based resin emulsion is controlled at 80-150μm wet film. The heat preservation equipment is used to maintain the surface temperature of the hot melt adhesive at 70~80℃ to promote the bonding between the hot melt adhesive and the water-based resin emulsion.

[0054] After the water-based resin emulsion is coated, it is dried in hot air at a temperature of 60℃~80℃ to promote the reaction and combination of carboxyl and amino groups and accelerate the evaporation of water in the anti-stick coating for 5-10 minutes.

[0055] After passing through a drying device, the coating surface is fully dry, resulting in a water-based waterproof membrane.

[0056] Compared with existing traditional technologies, the advantages of this invention are as follows: The hot melt adhesive of this invention is used for water-based coating waterproof materials. It has a low surface contact angle and high surface energy. The water-based resin emulsion of the anti-stick coating can be well wetted on its surface, and at the same time, it has a stable adhesion to the coating. This ensures that the water-based coating waterproof membrane forms a fully bonded structure after the concrete is poured, and avoids water seepage. Attached Figure Description

[0057] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0058] Figure 1 is a schematic diagram of the cross-sectional structure of the water-based coating waterproof membrane in a preferred embodiment of the present invention;

[0059] Figure 2(a) is an enlarged view of the hot melt adhesive surface coated with water-based resin emulsion in Comparative Example 3 of the present invention;

[0060] Figure 2(b) is an enlarged view of the hot melt adhesive surface after being coated with water-based resin emulsion in Example 3 of the present invention;

[0061] The attached diagram is labeled as follows: concrete structure layer-1, anti-stick coating-2, connecting layer-3, and substrate-4. Detailed Implementation

[0062] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0063] The sources of raw materials used in the following embodiments are shown in Table 1 below:

[0064] Table 1 Raw Material List

[0065]

[0066] Common hot melt adhesives mainly contain polyisobutylene, petroleum resin, thermoplastic elastomers, and additives. Their raw materials are primarily isobutylene, C5 aliphatic structure, butadiene, styrene, and isoprene, all exhibiting weak polarity. Therefore, their surface polarity is poor, surface energy is low, and they are difficult to spread when coated with water-based emulsion materials. This invention improves the hot melt adhesive formulation of the bonding layer, giving it better wetting properties for the water-based resin emulsion of the anti-stick coating. This allows for better coating of the water-based resin emulsion onto the hot melt adhesive surface. Furthermore, the carboxyl groups in the hot melt adhesive form chemical bonds with the amino groups in the water-based resin emulsion, resulting in excellent adhesion between the anti-stick coating and the hot melt adhesive. After film formation, the hot melt adhesive effectively bonds the coating and the substrate, forming a fully bonded anti-stick coating.

[0067] The water-based coated waterproof membrane in this embodiment comprises, in sequence, a substrate, a bonding layer, and an anti-stick coating. The bonding layer is formed by hot melt adhesive, and the anti-stick coating is formed by curing a water-based resin emulsion. The substrate is polyethylene (HDPE), polyolefin material (TPO), or polyvinyl chloride (PVC), with a thickness of 1 mm. The water-based resin emulsion contains a large amount of amino groups, and its pH is 6-9. The surface contact angle of the bonding layer is ≤90°.

[0068] The waterborne resin emulsion for the anti-stick coating includes a photocrosslinkable silicone resin emulsion and a room-temperature self-crosslinking acrylate resin emulsion. The photocrosslinkable silicone resin emulsion is prepared by first hydrolyzing and polycondensing silicone monomers in the presence of a solvent, then reacting them with a capping agent to obtain a prepolymer, followed by adding a photoinitiator, mixing, removing the solvent, and emulsifying with water. The room-temperature self-crosslinking acrylate resin emulsion has a core-shell structure, with the core layer polymerized from core layer monomers and the shell layer polymerized from shell layer monomers. The shell layer monomers include room-temperature self-crosslinking monomers, soft monomers, hard monomers, and hydrophilic monomers. The composition and preparation method of the waterborne resin emulsion for the anti-stick coating in this embodiment refer to the description of the protective coating in patent CN202311577350.X.

[0069] The hot melt adhesive used in this embodiment for water-based coating waterproof membranes includes plasticizers, tackifying resins, functional resins, thermoplastic elastomers, and preferably, one or more of antioxidants, ultraviolet absorbers, and fillers.

[0070] The functional resin is one or more of rosin resin or its modified resin, terpene resin or its modified resin such as terpene phenolic resin. The functional resin contains one or more of abietic acid (such as neoabietic acid, dehydroabietic acid, dihydroabietic acid, tetrahydroabietic acid), longleaf abietic acid, and piratic acid (such as L-pilocarboxylic acid, isopiratic acid), with a carboxyl group content of 0.90 mmol / g to 2.80 mmol / g. The carboxyl groups in the hot melt adhesive are used to form chemical bonds with the amino groups in the aqueous emulsion. The method for measuring the carboxyl group content is in accordance with EN 1240:2011 "Determination of hydroxyl value and / or hydroxyl content in adhesives". The softening point of the functional resin is 100℃ to 130℃.

[0071] The plasticizer is naphthenic oil and / or polyisobutylene.

[0072] The tackifying resin is selected from one or more of the following: C5 petroleum resin, hydrogenated petroleum resin, C9 petroleum resin, and C5 / C9 copolymer petroleum resin.

[0073] The thermoplastic elastomer is one or more of styrene-isoprene-styrene triblock copolymer, styrene-butadiene-styrene triblock copolymer, and butyl rubber. Preferably, the thermoplastic elastomer is a styrene-isoprene-styrene triblock copolymer with a diblock content in the range of 35%-45%.

[0074] The antioxidant is selected from one or more of hindered phenolic, phosphite, and thiophenolic antioxidants. Preferably, it is selected from one or more of antioxidant 1010, antioxidant 168, and antioxidant 1076.

[0075] The ultraviolet absorber is selected from one or more of benzotriazole, benzophenone, and hindered amine ultraviolet absorbers.

[0076] The filler is selected from one or more of calcium carbonate, rutile titanium dioxide or its modified substances, and kaolin inorganic filler.

[0077] Preferably, the hot melt adhesive comprises the following raw material components in parts by weight:

[0078] 16-25 parts plasticizer

[0079] 10-15 parts of tackifying resin

[0080] 28-33 parts of functional resin

[0081] 26-30 parts of thermoplastic elastomer

[0082] Antioxidant 0-3 parts

[0083] 0-3 parts of UV absorber

[0084] 0-2 parts of filler.

[0085] The method for preparing the water-based coating waterproof membrane in this embodiment includes the following steps:

[0086] After adding plasticizer and filler to the reaction vessel, start stirring and heating, and set the reaction vessel temperature to 160-180℃.

[0087] After the materials in the reaction vessel are mixed evenly and the material temperature reaches 180℃, thermoplastic elastomer, antioxidant, and ultraviolet absorber are added. The stirring speed is maintained and a vacuum is drawn, with the vacuum degree set to ≤-0.08MPa.

[0088] After the thermoplastic elastomer is completely melted and mixed evenly, the tackifying resin and functional resin are slowly added while maintaining a vacuum state.

[0089] After all materials are melted and mixed evenly, a hot melt adhesive suitable for water-based coating waterproof membranes is obtained;

[0090] The hot melt adhesive is heated and melted. After the material temperature reaches 160℃, it is placed in a coating equipment for coating. The coating thickness of the hot melt adhesive is 0.30mm~0.33mm.

[0091] After the hot melt adhesive coating is completed and the material passes through the heat preservation equipment, the water-based resin emulsion is coated. The coating thickness of the water-based resin emulsion is controlled at 80-150μm wet film. The heat preservation equipment is used to maintain the surface temperature of the hot melt adhesive at 70~80℃ to promote the bonding between the hot melt adhesive and the water-based resin emulsion.

[0092] After the water-based resin emulsion is coated, it is dried in hot air at a temperature of 60℃~80℃ to promote the reaction and combination of carboxyl and amino groups and accelerate the evaporation of water in the anti-stick coating for 5-10 minutes.

[0093] After passing through a drying device, the coating surface is fully dry, resulting in a water-based waterproof membrane.

[0094] The hot melt adhesive for coated rolls prepared in this embodiment contains a large number of polar groups such as carboxyl, hydroxyl, epoxy, ether, acyl, sulfonic acid, phosphate, and sulfinic acid groups in its functional resin. The presence of these multiple polar groups increases the surface polarity of the hot melt adhesive, helping to reduce the surface contact angle. Simultaneously, the presence of carboxyl and hydroxyl groups enhances the surface energy of the hot melt adhesive, resulting in better hydrophilicity and a smaller surface contact angle. This leads to better wettability of the waterborne resin emulsion in the anti-stick coating on the hot melt adhesive surface. Furthermore, the presence of polar groups synergistically interacts with the monomer groups in the waterborne resin emulsion to form a stable chemical bond adhesive structure. Example 1

[0095] Referring to Table 2, the hot melt adhesive suitable for water-based coated waterproof membranes in this embodiment, by weight, comprises the following raw material components:

[0096] 18 parts naphthenic oil

[0097] 15 parts of tackifying resin

[0098] 31 parts of functional resin

[0099] 3 parts antioxidant

[0100] 3 parts of ultraviolet light absorber

[0101] 2 parts titanium dioxide

[0102] 28 parts of thermoplastic elastomer.

[0103] The tackifying resin is ordinary C5 petroleum resin HHC-1100. The functional resin is rosin terpene phenol resin T-105, with a carboxyl content of 0.963 mmol / g and a softening point of 106℃. The antioxidant is a 1:1 blend of 1076 and 168. The filler is Chemours titanium dioxide R-105. The thermoplastic elastomer is Jinhai Chenguang's JH-9163, with a diblock content of 38%.

[0104] The aforementioned hot melt adhesive is then coated onto a substrate, followed by coating with a water-based resin emulsion and drying to obtain a waterproof membrane. Example 2

[0105] Referring to Table 2, the hot melt adhesive for water-based coating waterproof membranes in this embodiment differs from that in Example 1 in that the rosin terpene phenol resin in this embodiment is T-901, with a carboxyl content of 1.43 mmol / g and a softening point of 124℃. Example 3

[0106] Referring to Table 2, the hot melt adhesive suitable for water-based coated waterproof membranes in this embodiment, by weight, comprises the following raw material components:

[0107] 21 parts naphthenic oil

[0108] 10 parts of tackifying resin

[0109] 32 parts of functional resin

[0110] 3 parts antioxidant

[0111] 3 parts of ultraviolet light absorber

[0112] 2 parts titanium dioxide

[0113] 29 parts of thermoplastic elastomer.

[0114] The tackifying resin is C5 hydrogenated petroleum resin H5-1001 with a softening point of 103℃. The functional resin is Eastman Poly-pale dimerized rosin with a carboxyl content of 2.763 mmol / g and a softening point of 103℃. The filler is Tryruti AQ51 rutile titanium dioxide from Liankai Chemicals. The thermoplastic elastomer is VECTOR 4116ND with a diblock content of 42%. Tryruti AQ51 is a rutile titanium dioxide that has undergone hydrophilic surface modification. The hydrophilic modification of the titanium dioxide helps to improve the overall surface contact angle. The anti-stick coating is a water-based resin emulsion, and the hydrophilic modified powder helps to coat the water-based emulsion on the hot melt adhesive surface.

[0115] The aforementioned hot melt adhesive is then coated onto a substrate, followed by coating with a water-based resin emulsion and drying to obtain a waterproof membrane.

[0116] In this embodiment, the surface contact angle (water) of the hot melt adhesive film is 65°. The water-based resin emulsion can be completely wetted and spread on the surface of the hot melt adhesive without any leakage, as shown in Figure 2(b). Example 4

[0117] Referring to Table 2, the difference between the hot melt adhesive for water-based coating waterproof membranes in this embodiment and that in Example 3 is that the thermoplastic elastomer in this embodiment is Jinhai Chenguang JH-9163, and its diblock content is 38%. Example 5

[0118] Referring to Table 2, the hot melt adhesive used in this embodiment for water-based coating waterproof membranes differs from that in Example 3 in that it uses a different filler. The filler in this embodiment is R-105, which is ordinary rutile titanium dioxide. Comparative Example 1

[0119] Referring to Table 2, the hot melt adhesive in this comparative example, by weight, comprises the following raw material components:

[0120] Naphthenic oil 4010 29 parts

[0121] 42 parts of ordinary C5 petroleum resin HHC-1100

[0122] Thermoplastic elastomer SIS-1170 28 parts

[0123] Antioxidant (1076 and 168 in a 1:1 ratio) 1 part.

[0124] This comparative example uses conventional hot melt adhesive. After the conventional hot melt adhesive is applied to the substrate, a sample is taken and water is used to test the surface contact angle. After the test, a water-based resin emulsion is rolled onto the surface. After the coating is completed, it is dried by blowing to prepare a water-based coating waterproof membrane.

[0125] The hot melt adhesive in this comparative example had a surface contact angle of 120° after film formation. When a water-based resin emulsion was roller-coated onto this surface, roller shrinkage occurred, causing the hot melt adhesive at the bottom to leak out. The water-based resin emulsion exhibited poor wetting properties on the hot melt adhesive surface. After the waterproof membrane dried and was rolled up, it could not be unrolled after a simulated transport test at 80℃ and a 5kg load. Shrinkage during the drying process of the hot melt adhesive surface coating led to adhesive leakage and adhesion, preventing normal unrolling and use. Comparative Example 2

[0126] The waterproof membrane used in this comparative example is the waterproof membrane disclosed in Example 1 of CN202311577350.X. Comparative Example 3

[0127] The difference between this comparative example and Example 1 is that the functional resin in this comparative example is rosin terpene phenol resin T-105, manufactured by Arakawa Chemicals, Japan, with a carboxyl content of 0.855 mmol / g and a softening point of 104℃.

[0128] The hot melt adhesive of this comparative example has a surface contact angle (water) of 115° after film formation. After the surface is coated with water-based resin emulsion, the shrinkage is large and the film cannot completely cover the bottom hot melt adhesive, as shown in Figure 2(a). When the film is unwound after being rolled up and placed for use again, it sticks and cannot be unwound. Comparative Example 4

[0129] The difference between this comparative example and Example 1 is that the functional resin in this comparative example is ARDYME R-115 polymeric rosin resin from Arakawa Chemicals of Japan, which has a carboxyl content of 3.1 mmol / g and a softening point of 115°C.

[0130] Table 2 Formulation Table

[0131] Example 6

[0132] This embodiment provides a method for preparing hot melt adhesive and water-based coating waterproof membrane based on the above embodiments, specifically including the following steps:

[0133] (1) After adding plasticizer and filler to the reaction vessel, start stirring and heating, and set the reaction vessel temperature to 160-180℃.

[0134] (2) After the materials in the reaction vessel are mixed evenly and the material temperature reaches 180°C, add thermoplastic elastomer, antioxidant and ultraviolet light absorber, speed up the stirring and draw a vacuum to set the vacuum degree to ≤-0.08MPa.

[0135] (3) After the thermoplastic elastomer is completely melted and mixed evenly, slowly add the tackifying resin and functional resin while keeping the vacuum state open.

[0136] (4) After 2 hours, wait for the material temperature to reach 160℃ before placing the coating equipment to coat the hot melt adhesive. The coating thickness of the hot melt adhesive is 0.30mm~0.33mm.

[0137] (5) After the hot melt adhesive is coated, it is kept at 70~80℃ by the heat preservation equipment; the water-based resin emulsion is coated and the thickness of the water-based resin emulsion coating is controlled at 80-150μm wet film.

[0138] (6) After the emulsion coating is completed, it is put into hot air drying, and the temperature is maintained at 60℃~80℃. After passing through the drying equipment, the coating surface is completely dry, and the finished water-based coating waterproof membrane is obtained. Results and Tests

[0139] The hot melt adhesives of the examples and comparative examples were applied to the substrate, and samples were taken to test their surface contact angles. After the tests, an aqueous emulsion was roller-coated at a wet film thickness of 120 μm per square meter. After roller coating, the film was dried with hot air and then rolled up. Peel tests with the subsequently poured concrete were then conducted, including untreated, water-immersed, heat-treated, UV-treated, and water-immersed peel tests. The test results are shown in Table 3. The peel tests were performed according to the method in GB / T 23457-2017, and the contact angle tests were performed according to the method for measuring the contact angle of plastic film with water in GB / T 30693-2014.

[0140] Table 3 Test Results

[0141]

[0142] The results from the examples and comparative examples show that increasing the use of functional resins with a certain range of carboxyl content can effectively reduce the surface water contact angle, allowing the water-based resin emulsion to better wet and spread on its surface. After comparison, the rolled materials were placed at 80℃ and subjected to a 5kg load test, and all could be unwound and used normally. As the acid value of the functional resin gradually increases within a certain range, its peel strength with the post-poured concrete after immersion in water gradually decreases, affecting its performance. Furthermore, a higher carboxyl content results in a lower than standard value peel strength with the post-poured concrete after immersion, or even peeling at the bonding surface. Meanwhile, the surface contact angle of the hot melt adhesive prepared with rutile titanium dioxide using hydrophilic surface modification treatment in Example 4 is significantly smaller than that of the hot melt adhesive prepared with ordinary rutile titanium dioxide in Example 5. The water-based emulsion exhibits poor wettability on the surface of the hot melt adhesive in Comparative Example 3, resulting in significant shrinkage after coating and inability to completely cover the underlying hot melt adhesive. After drying and winding, it adheres and cannot be unwound.

[0143] The anti-stick coating in this invention is located between the bonding layer of the hot melt adhesive and the concrete. Ideally, the water-based emulsion coating is fully spread on the surface of the hot melt adhesive, forming a full coating, and dries into a film to protect the intermediate hot melt adhesive while remaining non-adhesive. It can still bond with the concrete after pouring. The anti-stick coating serves to connect the waterproof membrane and the concrete. If the anti-stick coating cannot spread well on conventional hot melt adhesive and cannot form a full coating, firstly, after the waterproof membrane is rolled up, the hot melt adhesive will stick to the substrate, preventing the membrane from unrolling and rendering it unusable; secondly, it will cause gaps and weak adhesion between the waterproof membrane and the concrete.

[0144] The hot melt adhesive in the waterproof membrane of this invention contains polar groups such as carboxyl and hydroxyl groups, which allows the water-based anti-stick coating emulsion to wet better on its surface, resulting in a lower surface contact angle (θ≤90° with the water surface). Simultaneously, it reacts with the anti-stick coating emulsion to form a chemical bond structure for adhesion. This invention's hot melt adhesive, applicable to water-based coated waterproof membranes, is extruded and coated onto a substrate at 150℃-180℃. Then, the water-based resin emulsion of the anti-stick coating is roller-coated onto the hot melt adhesive surface. After roller-coating the anti-stick coating emulsion, hot air drying accelerates the condensation reaction rate of amino and carboxyl groups, and speeds up the evaporation of water in the emulsion and water produced by the condensation reaction. After hot air drying, all moisture in the anti-stick coating evaporates, achieving a completely dry coating without the need for UV curing. The surface anti-stick coating forms a dry film, which, through chemical bonding, forms a chemical bond with the hot melt adhesive, resulting in superior adhesion strength and peel force compared to traditional physical adhesion. The water-based coating waterproof membrane of this invention achieves excellent wetting properties of the surface water-based vertical emulsion on the hot melt adhesive surface, facilitating rapid film formation to create a good waterproof layer. This results in a fully bonded structure with the subsequently poured concrete, allowing for better application of the water-based resin emulsion. The improved wetting properties make it more suitable for roller coating and spraying of the water-based resin emulsion onto the hot melt adhesive layer. The hot melt adhesive of this invention contains a specific amount of carboxyl groups, improving the wetting of various water-based base anti-stick coating emulsions on its surface. Subsequent processes are simpler, requiring no ultraviolet irradiation or other steps; direct drying is sufficient.

[0145] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

[0146] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

Claims

1. A hot melt adhesive suitable for water-based coated waterproof membranes, the waterproof membrane comprising, in sequence, a substrate, a bonding layer, and an anti-stick coating, wherein the bonding layer is formed by the hot melt adhesive, and the anti-stick coating is formed by a water-based resin emulsion, characterized in that: The hot melt adhesive includes a plasticizer, a tackifying resin, a functional resin, and a thermoplastic elastomer. The functional resin contains one or more of abietic acid, longleaf abietic acid, and pithiazolic acid. The carboxyl group content of the functional resin is 0.90 mmol / g to 2.80 mmol / g. The carboxyl groups in the hot melt adhesive are used to form chemical bonds with the amino groups in the aqueous resin emulsion.

2. The hot melt adhesive according to claim 1, characterized in that: The surface contact angle of the connecting layer is ≤90°.

3. The hot melt adhesive of claim 1, wherein: The pH of the aqueous resin emulsion is 6-9.

4. The hot melt adhesive of claim 1, wherein: The functional resin is one or more of rosin resin or its modified resin, terpene resin or its modified resin.

5. The hot melt adhesive according to claim 1, characterized in that: The softening point of the functional resin is 100℃~130℃.

6. The hot melt adhesive of claim 1, wherein: The plasticizer is naphthenic oil and / or polyisobutylene.

7. The hot melt adhesive of claim 1, wherein: The tackifying resin is selected from one or more of C5 petroleum resin, hydrogenated petroleum resin, C9 petroleum resin, and C5 / C9 copolymer petroleum resin.

8. The hot melt adhesive of claim 1, wherein: The thermoplastic elastomer is selected from one or more of styrene-isoprene-styrene triblock copolymer, styrene-butadiene-styrene triblock copolymer, and butyl rubber.

9. The hot melt adhesive of claim 8, wherein: The thermoplastic elastomer is a styrene-isoprene-styrene triblock copolymer with a diblock content in the range of 35%-45%.

10. The hot melt adhesive of claim 1, wherein: The hot melt adhesive comprises the following raw material components by weight: 16-25 parts plasticizer 10-15 parts of tackifying resin 28-33 parts of functional resin 26-30 parts of thermoplastic elastomer.

11. The hot melt adhesive of claim 1, wherein: The hot melt adhesive includes an antioxidant, which is one or more selected from hindered phenolic, phosphite, and thiophenolic antioxidants.

12. The hot melt adhesive of claim 1, wherein: The hot melt adhesive includes a UV absorber, which is selected from one or more of benzotriazole, benzophenone, and hindered amine UV absorbers.

13. The hot melt adhesive of claim 1, wherein: The hot melt adhesive includes fillers, which are one or more selected from calcium carbonate, rutile titanium dioxide or its modified forms, and kaolin inorganic fillers.

14. The hot melt adhesive of claim 1, wherein: The aqueous resin emulsion includes a photocrosslinkable organosilicon resin emulsion; the organosilicon resin emulsion is prepared by first hydrolyzing and polycondensing organosilicon monomers in the presence of a solvent, then reacting them with a capping agent to obtain a prepolymer, then adding a photoinitiator and mixing, removing the solvent and emulsifying with water.

15. The hot melt adhesive according to claim 1, characterized in that: The aqueous resin emulsion includes a room-temperature self-crosslinking acrylic resin emulsion; the room-temperature self-crosslinking acrylic resin emulsion has a core-shell structure, the core layer structure is obtained by polymerization of core layer monomers, and the shell layer is obtained by polymerization of shell layer monomers, the shell layer monomers include room-temperature self-crosslinking monomers, soft monomers, hard monomers and hydrophilic monomers.

16. A method for preparing a hot melt adhesive as described in any one of claims 1-15, characterized in that: The process includes the following steps: heating and melting each substance and then drawing a vacuum, mixing them evenly to obtain the hot melt adhesive.

17. The application of a hot melt adhesive as described in any one of claims 1-15 in a waterproof membrane.

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