Shoe sole bonding reaction type polyurethane hot melt adhesive and preparation method thereof

Abstract

The invention discloses a shoe sole bonding reaction type polyurethane hot melt adhesive and a preparation method thereof. The polyurethane hot melt adhesive is prepared from the following raw materials in parts by weight: 10-15 parts of EVA thermoplastic resin, 40-60 parts of polyester polyol, 20-30 parts of petroleum resin, 5-15 parts of polyether glycol, 10-20 parts of isocyanate, 1-10 parts of thermoplastic acrylic resin, 1-5 parts of a silane coupling agent, 0.01-0.1 part of a stabilizer and 0.05-0.5 part of a catalyst. The content of NCO in the shoe sole bonding reaction type polyurethane hot melt adhesive is 1.4%-3.2%. The adhesive provided by the invention has the characteristics of strong initial adhesion and strong bonding force, improves the production efficiency, has good flexibility and tolerance, and can simultaneously meet the use requirements of bonding polyurethane soles, EVA soles and PVC soles with various uppers.

Description

Technical Field

[0001] The invention relates to the technical field of polyurethane hot melt adhesives, and in particular to a sole bonding reactive polyurethane hot melt adhesive which can be used for bonding polyurethane soles, EVA soles and PVC soles to various shoe uppers, and a preparation method thereof. Background Art

[0002] Sole bonding mainly involves the bonding of polyurethane-based soles, EVA-based soles, and PVC-based soles with various types of uppers. Among them, the core of sole bonding lies in choosing the right glue and mastering the correct operation method. The glues developed for sole bonding mainly include water-based laminating glue and hot melt glue. Soles bonded with hot melt glue have more advantages than water-based glue. Hot melt glue does not produce harmful gas volatilization during the compounding process and is friendly to the human body and the environment. Hot melt glue provides high bonding strength, which can ensure a close bond between the sole and the upper layers of materials, thereby improving the overall durability of the shoe. The hot melt adhesive film has good resistance to daily chemicals and good water washability, which extends the service life of the shoe. Hot melt adhesive bonding reduces production steps and improves production efficiency.

[0003] However, existing hot melt adhesives generally have problems such as long open time and poor bonding strength.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The purpose of the present invention is to provide a sole bonding reactive polyurethane hot melt adhesive and a preparation method thereof, which has the characteristics of short open time and strong bonding strength, can improve production efficiency, reduce production costs, and solve the technical problems of long open time and poor bonding strength in the prior art.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] A reactive polyurethane hot melt adhesive for bonding soles, wherein the NCO% content of the hot melt adhesive is 1.4%-3.2%, and the hot melt adhesive is mainly prepared from the following raw materials in parts by weight: 10-15 parts of EVA thermoplastic resin, 40-60 parts of polyester polyol, 20-30 parts of petroleum resin, 5-15 parts of polyether diol, 10-20 parts of isocyanate, 1-10 parts of thermoplastic acrylic resin, 1-5 parts of silane coupling agent, 0.01-0.1 parts of stabilizer and 0.05-0.5 parts of catalyst.

[0008] Preferably, in the above hot melt adhesive, the VA content of the EVA thermoplastic resin is 20-40%.

[0009] Preferably, in the above hot melt adhesive, the polyester polyol has a hydroxyl value of 20 to 180 mgKOH / g, an acid value of 0.1 to 3 mgKOH / g, and a number average molecular weight of 500 to 9000;

[0010] The polyester polyol is any one of aliphatic polyester polyol and polyaromatic acid-neopentyl glycol ester diol.

[0011] Preferably, in the above hot melt adhesive, the aliphatic polyester polyol used in the polyester polyol is synthesized from a diol and a polybasic carbon chain dibasic acid, has a hydroxyl value of 10 to 40 mgKOH / g, and a number average molecular weight in the range of 2000 to 8000;

[0012] The aromatic acid in the polyaromatic acid-neopentyl glycol ester diol used in the polyester polyol is at least one of terephthalic acid, isophthalic acid, phthalic acid and phthalic anhydride.

[0013] Preferably, in the above hot melt adhesive, the petroleum resin is at least one of C9 petroleum resin and C5 petroleum resin.

[0014] Preferably, in the above hot melt adhesive, the polyether diol is a polyether diol with a propylene oxide structure as the main chain, a hydroxyl value of 30 to 120 mgKOH / g, and a number average molecular weight of 1000 to 4000.

[0015] Preferably, in the above hot melt adhesive, the isocyanate is at least one of 4,4'-diphenylmethane diisocyanate, diphenylmethane-2,4-diisocyanate, 1,5-naphthalene diisocyanate, p-toluenesulfonyl isocyanate, and 4,4-dicyclohexylmethane diisocyanate.

[0016] Preferably, in the above hot melt adhesive, the thermoplastic acrylic resin has a Tg point of 30° C. to 80° C. and a molecular weight of 20,000 to 80,000, and the synthetic monomer of the thermoplastic acrylic resin includes at least one of methyl methacrylate and n-butyl methacrylate.

[0017] Preferably, in the above hot melt adhesive, the silane coupling agent is at least one of vinyl triethoxy silane, vinyl trimethoxy silane and vinyl tri (β-methoxyethoxy) silane.

[0018] A method for preparing the sole bonding reactive polyurethane hot melt adhesive of the present invention comprises the following steps:

[0019] Step 1, according to the formula of the sole bonding reactive polyurethane hot melt adhesive described in any one of claims 1 to 9, weigh EVA thermoplastic resin, polyester polyol, petroleum resin, polyether diol, isocyanate, thermoplastic acrylic resin, silane coupling agent, stabilizer and catalyst;

[0020] Step 2, adding the polyether diol, petroleum resin and EVA thermoplastic resin into a reaction kettle, controlling the temperature between 100 and 140° C., maintaining the pressure between -0.06 and -0.095 MPa, stirring to melt and dehydrating for 1 to 2 hours;

[0021] Step 3, adding the polyester polyol and the thermoplastic acrylic resin into the reactor, controlling the temperature between 100 and 120° C., maintaining the pressure between -0.06 and -0.095 MPa, stirring to melt and dehydrating for 1 to 2 hours, then cooling to 60 to 85° C., adding the silane coupling agent, catalyst, stabilizer and isocyanate into the reactor, maintaining the temperature between 80 and 100° C., maintaining the vacuum degree between -0.06 and -0.095 MPa, and stirring to react for 0.5 to 1 hour;

[0022] Step 4, stopping stirring, degassing for 10 to 20 minutes, filtering, and discharging the material to obtain the sole bonding reactive polyurethane hot melt adhesive according to any one of claims 1 to 9.

[0023] Compared with the prior art, the sole bonding reactive polyurethane hot melt adhesive and the preparation method thereof provided by the present invention have the following beneficial effects:

[0024] The hot melt adhesive is obtained by using a specific ratio of isocyanate, polyester polyol, polyether diol, thermoplastic acrylic and EVA thermoplastic resin and petroleum resin in combination with a specific amount of stabilizer, catalyst and silane coupling agent, and adopting a special preparation method; the single-component moisture-curing reactive polyurethane hot melt adhesive for sole bonding not only has excellent initial adhesion and good lasting adhesion, and has extremely low odor, but also can be quickly cured, and its water resistance and chemical resistance meet the requirements of polyurethane soles, EVA soles and PVC soles bonding applications. DETAILED DESCRIPTION

[0025] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in combination with the specific content of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, which does not constitute a limitation of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0026] First, the terms that may be used in this article are explained as follows:

[0027] The term “and / or” means that either or both of them can be realized at the same time. For example, X and / or Y means both “X” or “Y” and “X and Y”.

[0028] The terms "include", "comprises", "contains", "has" or other descriptions with similar semantics should be interpreted as non-exclusive inclusion. For example, including certain technical feature elements (such as raw materials, components, ingredients, carriers, dosage forms, materials, dimensions, parts, components, mechanisms, devices, steps, procedures, methods, reaction conditions, processing conditions, parameters, algorithms, signals, data, products or products, etc.) should be interpreted as including not only certain technical feature elements explicitly listed, but also other technical feature elements known in the art that are not explicitly listed.

[0029] The term "consisting of..." means excluding any technical feature elements not explicitly listed. If this term is used in a claim, it will make the claim closed, so that it does not contain technical feature elements other than the technical feature elements explicitly listed, except for the conventional impurities related to them. If this term only appears in a clause of a claim, it only limits the elements explicitly listed in the clause, and the elements recorded in other clauses are not excluded from the overall claim.

[0030] The term "parts by mass" refers to the mass ratio relationship between multiple components. For example, if it is described that component X is x parts by mass and component Y is y parts by mass, then the mass ratio of component X to component Y is x:y. 1 part by mass can represent any mass, for example, 1 part by mass can be represented as 1 kg or 3.1415926 kg. The sum of the parts by mass of all components is not necessarily 100 parts, but can be greater than 100 parts, less than 100 parts or equal to 100 parts. Unless otherwise specified, the parts, proportions and percentages described herein are all measured by mass.

[0031] When concentration, temperature, pressure, size or other parameters are expressed in the form of a numerical range, the numerical range should be understood to specifically disclose all ranges formed by the pairing of any upper limit, lower limit, and preferred value in the numerical range, regardless of whether the range is explicitly stated; for example, if a numerical range of "2 to 8" is stated, the numerical range should be interpreted as including ranges such as "2 to 7", "2 to 6", "5 to 7", "3 to 4 and 6 to 7", "3 to 5 and 7", "2 and 5 to 7", etc. Unless otherwise specified, the numerical ranges stated herein include both their end values ​​and all integers and fractions within the numerical range.

[0032] The scheme provided by the present invention is described in detail below. The contents not described in detail in the embodiments of the present invention belong to the prior art known to professionals in the field. If the specific conditions are not specified in the embodiments of the present invention, they are carried out according to the conventional conditions in the field or the conditions recommended by the manufacturer. If the manufacturers are not specified in the reagents or instruments used in the embodiments of the present invention, they are all conventional products that can be purchased commercially.

[0033] The embodiment of the present invention provides a sole bonding reactive polyurethane hot melt adhesive, which is used for bonding polyurethane soles, EVA soles and PVC soles to various uppers. The NCO% content in the hot melt adhesive is 1.4% to 3.2%, and the hot melt adhesive is mainly made of the following raw materials in parts by weight: 10 to 15 parts of EVA thermoplastic resin, 40 to 60 parts of polyester polyol, 20 to 30 parts of petroleum resin, 5 to 15 parts of polyether diol, 10 to 20 parts of isocyanate, 1 to 10 parts of thermoplastic acrylic resin, 1 to 5 parts of silane coupling agent, 0.01 to 0.1 parts of stabilizer and 0.05 to 0.5 parts of catalyst; wherein the VA content of the EVA thermoplastic resin is 20 to 40%.

[0034] Specifically, the sole bonding reactive polyurethane hot melt adhesive may include the following embodiments:

[0035] (1) The isocyanate is at least one of 4,4'-diphenylmethane diisocyanate, diphenylmethane-2,4-diisocyanate, 1,5-naphthalene diisocyanate, p-toluenesulfonyl isocyanate, and 4,4-dicyclohexylmethane diisocyanate. The above isocyanates have high reactivity, and the polyurethane material synthesized from alicyclic isocyanates and aromatic isocyanates has higher strength, wear resistance, and heat resistance.

[0036] (2) The polyester polyol can be aliphatic polyester polyol, which is mainly synthesized from diol and polybasic carbon chain dibasic acid. The hydroxyl value of the aliphatic polyester polyol is 10-40 mgKOH / g, and the number average molecular weight ranges from 2000 to 8000. The diol used is a highly crystalline polyester diol, such as polyadipate-1,6-hexanediol ester diol and polyadipate-ethylene glycol-neopentyl glycol-1,6-hexanediol ester diol, which can effectively shorten the open time while improving the initial adhesion of the polyurethane hot melt adhesive.

[0037] (3) The polyether diol is a polypropylene oxide ether diol with a propylene oxide structure as the main chain, a hydroxyl value of 30 to 120 mgKOH / g, and a number average molecular weight of 1000 to 4000. The polyether diol has good solubility for thermoplastic acrylic resin, which makes the colloid have better fluidity in the molten state.

[0038] (4) The thermoplastic acrylic resin is mainly synthesized by copolymerization of methyl methacrylate and n-butyl methacrylate.

[0039] (5) The EVA thermoplastic resin is mainly copolymerized with ethylene and vinyl ester, and has the characteristics of good elasticity, good flexibility, good cold resistance, and acid and alkali corrosion resistance.

[0040] (6) The petroleum resin is at least one of C9 petroleum resin and C5 petroleum resin. Petroleum resin, as a tackifying resin, can increase the compatibility of the reaction system, has good solubility in EVA thermoplastic particles, has the characteristics of adjustable viscosity and thermal stability, and is low in price. After adding petroleum resin, the glue has high peel strength, good quick adhesion, stable bonding performance, water resistance, ethanol resistance, chemical resistance, and chemical stability to acids and alkalis;

[0041] (7) The stabilizer is phosphoric acid, which can effectively inhibit the violent reaction and prevent the occurrence of explosion.

[0042] (8) The catalyst is at least one of dibutyltin dilaurate, stannous octoate, triethylenediamine, and dimorpholine diethyl ether.

[0043] (9) The silane coupling agent is at least one of vinyltriethoxysilane, vinyltrimethoxysilane and vinyltri(β-methoxyethoxy)silane.

[0044] (10) The NCO% content of the reactive polyurethane hot melt adhesive for sole bonding provided by the present invention is 1.5% to 4.5%. This specific NCO% content can avoid the generation of excessive CO2 during the curing process of the adhesive layer due to excessively high NCO% and the resulting presence of more bubbles in the adhesive layer. The lower limit value of NCO% can ensure that the adhesive layer has sufficient NCO groups to react and cross-link with moisture in the air and hydroxyl groups on the surface of the substrate, thereby achieving a higher final adhesive layer body strength and forming sufficient chemical bonds with the substrate, that is, achieving a higher final bonding strength.

[0045] Furthermore, the present invention also provides a method for preparing the above-mentioned sole bonding reactive polyurethane hot melt adhesive, which may include the following steps:

[0046] Step 1, according to the formula of the above-mentioned sole bonding reactive polyurethane hot melt adhesive, weigh isocyanate, polyester polyol, polyether diol, thermoplastic acrylic resin, EVA thermoplastic resin, petroleum resin, silane coupling agent, stabilizer, and catalyst;

[0047] Step 2, adding the polyether diol, petroleum resin and EVA thermoplastic resin into a reaction kettle, controlling the temperature between 100 and 140° C., maintaining the pressure between -0.06 and -0.095 MPa, stirring to melt and dehydrating for 1 to 2 hours;

[0048] Step 3, adding the polyester polyol and the thermoplastic acrylic resin into the reactor, controlling the temperature between 100 and 120° C., maintaining the pressure between -0.06 and -0.095 MPa, stirring to melt and dehydrating for 1 to 2 hours, then cooling to 60 to 85° C., adding the silane coupling agent, the catalyst, the stabilizer and the isocyanate into the reactor, maintaining the temperature between 80 and 100° C., maintaining the vacuum degree between -0.06 and -0.095 MPa, and stirring to react for 0.5 to 1 hour;

[0049] Step 4, stop stirring, degas for 10 to 20 minutes, filter, and discharge the material to obtain the above-mentioned sole bonding reactive polyurethane hot melt adhesive.

[0050] Compared with the prior art, the sole bonding reactive polyurethane hot melt adhesive and the preparation method thereof provided by the present invention have at least the following advantages:

[0051] (1) The shoe sole bonding reactive polyurethane hot melt adhesive provided by the present invention uses a prepolymer method to adjust the molecular weight distribution of the synthesized polyurethane resin, which can greatly improve the initial viscosity and wettability of the polyurethane hot melt adhesive to the bonding surface.

[0052] (2) The acrylic and EVA resin structures used in the sole bonding reactive polyurethane hot melt adhesive provided by the present invention have excellent chemical resistance, and the adhesive has good elasticity and flexibility, which increases the overall durability of the polyurethane hot melt adhesive;

[0053] (3) The polyester polyol used in the present invention can be polyaromatic acid-neopentyl glycol ester diol or aliphatic polyester polyol ester diol, which is synthesized from aromatic acid or polycarbon chain dibasic acid and polycarbon chain diol. Since it has a regular structure of a carbon chain or aromatic ring with more than six members, the prepared polyurethane hot melt adhesive has a fast crystallization speed and good hydrolysis resistance, which can meet the requirement of short open time for polyurethane sole bonding.

[0054] (4) The inexpensive petroleum resin used in the reactive polyurethane hot melt adhesive for sole bonding provided by the present invention improves the initial adhesion and bonding strength of the adhesive.

[0055] (5) Compared with the prior art, the reactive polyurethane hot melt adhesive for sole bonding provided by the present invention has the characteristics of short open time, high initial adhesion, high bonding strength, strong crack resistance and low cost.

[0056] In summary, it can be seen that the embodiments of the present invention have the characteristics of short open time and strong bonding force, and have a high degree of crack resistance, which increases the service life of the shoes, can reduce the production cost of sole bonding, and improve production efficiency.

[0057] In order to more clearly demonstrate the technical solution and technical effects provided by the present invention, the solution provided by the embodiment of the present invention is described in detail with specific embodiments below.

[0058] First, the raw materials used in the following examples and comparative examples are described:

[0059] MDI-100 refers to 4,4'-diphenylmethane diisocyanate;

[0060] PAA-4000 refers to poly(1,6-hexanediol adipate) with a number average molecular weight of 4000;

[0061] PNA-2000 refers to poly(neopentyl phthalate) glycol with a number average molecular weight of 2000;

[0062] PNH-5500S refers to poly(adipic acid-ethylene glycol-neopentyl glycol-1,6-hexanediol) ester diol, with a number average molecular weight of 5500;

[0063] PPG-1000 refers to a polyether diol with propylene oxide as the main chain and a number average molecular weight of 1000;

[0064] Example 1

[0065] This embodiment provides a sole bonding reactive polyurethane hot melt adhesive, and the preparation method thereof comprises the following steps:

[0066] Step 1A, add 50 kg of PPG-1000, 100 kg of EVA thermoplastic resin and 150 kg of petroleum resin SK120 into a reactor, open the vacuum to -0.06 to -0.095 MPa, control the temperature between 100 and 140° C., stir to melt and dehydrate for 1 to 2 hours;

[0067] Step 2A, adding 100 kg of PAA-4000, 180 kg of PNA-2000, 200 kg of PNH-5500S and 30 kg of acrylic resin into the reactor, controlling the temperature between 100 and 120° C., maintaining the pressure between -0.06 and -0.095 MPa, stirring to melt and dehydrating for 1 to 2 hours;

[0068] Step 3A, add 0.2 kg of catalyst, 1 kg of stabilizer and 20 kg of silane coupling agent KH550 into the reactor and stir evenly, add 115 kg of MDI-100 into the reactor, maintain the temperature at 80-100° C., maintain the vacuum degree at -0.06-0.095 MPa, and stir the reaction for 0.5-1 h;

[0069] Step 4A, stopping stirring, degassing for 10 to 20 minutes, filtering, and discharging, thereby preparing a reactive polyurethane hot melt adhesive for bonding soles.

[0070] Example 2

[0071] This embodiment provides a sole bonding reactive polyurethane hot melt adhesive, and the preparation method thereof comprises the following steps:

[0072] Step 1B, add 45 kg of PPG-1000, 100 kg of EVA thermoplastic resin and 200 kg of petroleum resin SK120 into the reactor, open the vacuum to -0.06 to -0.095 MPa, control the temperature between 100 and 140° C., stir to melt and dehydrate for 1 to 2 hours;

[0073] Step 2B, add 120kg of PAA-4000, 150kg of PNA-2000, 220kg of PNH-5500S and 20kg of acrylic resin into the reactor, control the temperature between 100 and 120° C., maintain the pressure between -0.06 and -0.095 MPa, stir to melt and dehydrate for 1 to 2 hours;

[0074] Step 3B, add 0.2 kg of catalyst, 1 kg of stabilizer and 15 kg of silane coupling agent KH550 into the reactor and stir evenly, add 135 kg of MDI-100 into the reactor, maintain the temperature at 80-100° C., maintain the vacuum degree at -0.06-0.095 MPa, and stir the reaction for 0.5-1 h;

[0075] Step 4B, stopping stirring, degassing for 10 to 20 minutes, filtering, and discharging the material, thereby obtaining a reactive polyurethane hot melt adhesive for bonding soles.

[0076] Example 3

[0077] This embodiment provides a sole bonding reactive polyurethane hot melt adhesive, and the preparation method thereof comprises the following steps:

[0078] Step 1C, add 55 kg of PPG-1000, 80 kg of EVA thermoplastic resin and 220 kg of petroleum resin SK120 into the reactor, open the vacuum to -0.06 to -0.095 MPa, control the temperature between 100 and 140° C., stir to melt and dehydrate for 1 to 2 hours;

[0079] Step 2C, add 130 kg of PAA-4000, 160 kg of PNA-2000, 220 kg of PNH-5500S and 20 kg of acrylic resin into the reactor, control the temperature between 100 and 120° C., maintain the pressure between -0.06 and -0.095 MPa, stir to melt and dehydrate for 1 to 2 hours;

[0080] Step 3C, add 0.2 kg of catalyst, 1 kg of stabilizer and 15 kg of silane coupling agent KH550 into the reactor and stir evenly, add 115 kg of MDI-100 into the reactor, maintain the temperature at 80 to 100 ° C, maintain the vacuum degree at -0.06 to -0.095 MPa, and stir the reaction for 0.5 to 1 hour;

[0081] Step 4C, stopping stirring, degassing for 10 to 20 minutes, filtering, and discharging the material, thereby obtaining a reactive polyurethane hot melt adhesive for bonding soles.

[0082] Comparative Example 1

[0083] A commercially available sole bonding reactive polyurethane hot melt adhesive was selected as a comparative example.

[0084] Performance Testing

[0085] The following parallel comparative performance tests were conducted on the shoe sole bonding reactive polyurethane hot melt adhesives prepared in Examples 1, 2 and 3 of the present invention and the shoe sole bonding reactive polyurethane hot melt adhesives available on the market under the same conditions:

[0086] (1) Rotational viscosity: The rotational viscosity at 120°C was measured using a CAP2000 cone-plate viscometer to characterize fluidity.

[0087] (2) Open time: Tested by the sticker method, characterized by the time it takes for the kraft paper to not stick.

[0088] (3) Shear force: In an environment of (RT: 25°C, RH: 50%), the prepared hot melt adhesive was used to bond long polyurethane soles, EVA soles and PVC soles, and the shear force was tested after bonding for 10 min, 30 min, 1 h, 2 h, 5 h and 24 h. Five samples were tested for each and the average value was taken after the test.

[0089] Table 1 is a summary of the test results

[0090]

[0091]

[0092] It can be seen from Table 1 above that compared with the comparative example, the shoe sole bonding reactive polyurethane hot melt adhesive of the embodiment of the present invention has a short open time, moderate viscosity, good hot melt fluidity, and good initial bonding strength and final bonding strength.

[0093] In summary, the sole bonding reactive polyurethane hot melt adhesive described in the embodiment of the present invention can be used for bonding and laminating polyurethane soles, EVA soles and PVC soles with upper substrates, and can meet the use requirements of sole bonding.

[0094] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims. The information disclosed in the background technology section of this article is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or in any form that the information constitutes prior art known to those skilled in the art.

Claims

1. A reactive polyurethane hot melt adhesive for bonding soles, characterized in that: The hot melt adhesive has an NCO% content of 1.4% to 3.2%, and is mainly made of the following raw materials in parts by weight: 10 to 15 parts of EVA thermoplastic resin, 40 to 60 parts of polyester polyol, 20 to 30 parts of petroleum resin, 5 to 15 parts of polyether diol, 10 to 20 parts of isocyanate, 1 to 10 parts of thermoplastic acrylic resin, 1 to 5 parts of silane coupling agent, 0.01 to 0.1 parts of stabilizer and 0.05 to 0.5 parts of catalyst.

2. The reactive polyurethane hot melt adhesive for sole bonding according to claim 1, characterized in that: The VA content of the EVA thermoplastic resin is 20-40%.

3. The reactive polyurethane hot melt adhesive for sole bonding according to claim 1 or 2, characterized in that: The polyester polyol has a hydroxyl value of 20 to 180 mgKOH / g, an acid value of 0.1 to 3 mgKOH / g, and a number average molecular weight of 500 to 9000; The polyester polyol is any one of aliphatic polyester polyol and polyaromatic acid-neopentyl glycol ester diol.

4. The reactive polyurethane hot melt adhesive for sole bonding according to claim 2, characterized in that: The aliphatic polyester polyol used in the polyester polyol is synthesized from diol and polybasic carbon chain dibasic acid, has a hydroxyl value of 10 to 40 mgKOH / g, and a number average molecular weight in the range of 2000 to 8000; The aromatic acid in the polyaromatic acid-neopentyl glycol ester diol used in the polyester polyol is at least one of terephthalic acid, isophthalic acid, phthalic acid and phthalic anhydride.

5. The reactive polyurethane hot melt adhesive for sole bonding according to claim 1 or 2, characterized in that: The petroleum resin is at least one of C9 petroleum resin and C5 petroleum resin.

6. The reactive polyurethane hot melt adhesive for sole bonding according to claim 1 or 2, characterized in that: The polyether diol is a polyether diol with a propylene oxide structure as the main chain, a hydroxyl value of 30 to 120 mgKOH / g, and a number average molecular weight of 1000 to 4000.

7. The reactive polyurethane hot melt adhesive for sole bonding according to claim 1 or 2, characterized in that: The isocyanate is at least one of 4,4'-diphenylmethane diisocyanate, diphenylmethane-2,4-diisocyanate, 1,5-naphthalene diisocyanate, p-toluenesulfonyl isocyanate, and 4,4-dicyclohexylmethane diisocyanate.

8. The reactive polyurethane hot melt adhesive for sole bonding according to claim 1 or 2, characterized in that: The Tg point of the thermoplastic acrylic resin is 30° C. to 80° C., and the molecular weight is 20,000 to 80,000. The synthetic monomer of the thermoplastic acrylic resin includes at least one of methyl methacrylate and n-butyl methacrylate.

9. The reactive polyurethane hot melt adhesive for sole bonding according to claim 1 or 2, characterized in that: The silane coupling agent is at least one of vinyl triethoxy silane, vinyl trimethoxy silane and vinyl tri (β-methoxyethoxy) silane.

10. A method for preparing the reactive polyurethane hot melt adhesive for bonding soles according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1, according to the formula of the sole bonding reactive polyurethane hot melt adhesive described in any one of claims 1 to 9, weigh EVA thermoplastic resin, polyester polyol, petroleum resin, polyether diol, isocyanate, thermoplastic acrylic resin, silane coupling agent, stabilizer and catalyst; Step 2, adding the polyether diol, petroleum resin and EVA thermoplastic resin into a reaction kettle, controlling the temperature between 100 and 140° C., maintaining the pressure between -0.06 and -0.095 MPa, stirring to melt and dehydrating for 1 to 2 hours; Step 3, adding the polyester polyol and the thermoplastic acrylic resin into the reactor, controlling the temperature between 100 and 120° C., maintaining the pressure between -0.06 and -0.095 MPa, stirring to melt and dehydrating for 1 to 2 hours, then cooling to 60 to 85° C., adding the silane coupling agent, catalyst, stabilizer and isocyanate into the reactor, maintaining the temperature between 80 and 100° C., maintaining the vacuum degree between -0.06 and -0.095 MPa, and stirring to react for 0.5 to 1 hour; Step 4, stopping stirring, degassing for 10 to 20 minutes, filtering, and discharging the material to obtain the sole bonding reactive polyurethane hot melt adhesive according to any one of claims 1 to 9.

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