A hot-melt pressure-sensitive adhesive with good bonding effect and its preparation method

Abstract

The present invention discloses a hot melt pressure-sensitive adhesive with good adhesion effect and its preparation method, which relates to the technical field of hot melt pressure-sensitive adhesives. The preparation method of the present invention heats and melts SIS rubber in an aerobic environment to crack the macromolecular chains of SIS rubber, generating multiple molecular chains, thereby significantly improving the wettability and adsorption of the hot melt pressure-sensitive adhesive, and enabling the prepared hot melt pressure-sensitive adhesive to have a better adhesion effect on substrates such as PC plastics, PP plastics, aluminum plastic films, and metal plates.

Description

Technical Field

[0001] The present invention relates to the technical field of hot-melt pressure-sensitive adhesives, and specifically to a hot-melt pressure-sensitive adhesive with good bonding effect and a preparation method thereof. Background Art

[0002] Hot-melt pressure-sensitive adhesive (abbreviated as HMPSA) is a special type of pressure-sensitive adhesive, and its adhesiveness can be activated by applying a slight pressure. It is a polymer-based adhesive with the property of melting at high temperature and curing or remaining flowing when cooled. Hot-melt pressure-sensitive adhesives are widely used in many fields, including medical, packaging, automotive, electronics, etc.

[0003] The main components of hot-melt pressure-sensitive adhesives include synthetic rubber, tackifying resin, plasticizer, antioxidant, etc. Currently, the following method is usually used to prepare hot-melt pressure-sensitive adhesives: in a vacuum environment or under nitrogen protection, the synthetic rubber, tackifying resin, and plasticizer are mixed in proportion and heated and stirred at high temperature until completely melted; maintaining the vacuum environment or nitrogen protection, adding antioxidant and the remaining other raw materials to the melted mixture, and continuing to stir evenly to obtain the hot-melt pressure-sensitive adhesive.

[0004] In the above preparation method of hot-melt pressure-sensitive adhesives, in order to obtain a hot-melt pressure-sensitive adhesive with good high-temperature resistance, the entire preparation process needs to be carried out in a vacuum environment and under nitrogen protection, so as to reduce the oxidation of the synthetic rubber in the hot-melt pressure-sensitive adhesive by oxygen in the air, avoid thermal degradation of the hot-melt pressure-sensitive adhesive during heating and melting, thereby protecting the integrity of the rubber molecular chain, reducing molecular chain cleavage, and enabling the prepared hot-melt pressure-sensitive adhesive to have better high-temperature resistance. However, it is found in actual applications that the hot-melt pressure-sensitive adhesive prepared by melting rubber in a vacuum environment or under nitrogen protection has poor wettability and adsorption on substrates such as PC plastics, PP plastics, aluminum-plastic films, and metal plates (such as aluminum plates, steel plates), resulting in poor bonding effects on substrates such as PC plastics, PP plastics, aluminum-plastic films, and metal plates, and it is difficult to meet the application requirements. Summary of the Invention

[0005] In view of the above deficiencies of the prior art, the purpose of the present invention is to propose a preparation method of a hot-melt pressure-sensitive adhesive with good bonding effect. By heating and melting SIS rubber in an aerobic environment, the macromolecular chains of SIS rubber are cleaved to generate multiple molecular chains, thereby improving the wettability and adsorption of the hot-melt pressure-sensitive adhesive, and enabling the prepared hot-melt pressure-sensitive adhesive to have better bonding effects on substrates such as PC plastics, PP plastics, aluminum-plastic films, and metal plates.

[0006] Another object of the present invention is to provide a hot melt pressure sensitive adhesive with good bonding effect, which is prepared by the above preparation method. The hot melt pressure sensitive adhesive of the present invention has good adhesion to substrates such as PC plastics, PP plastics, aluminum plastic films and metal plates, and has a better bonding effect.

[0007] To achieve this purpose, the present invention adopts the following technical solutions:

[0008] A preparation method of a hot melt pressure sensitive adhesive with good bonding effect, comprising the following steps:

[0009] (1) In an aerobic environment, mineral oil and a first tackifying resin are mixed and then heated and stirred to melt at a first heating temperature to obtain a mixture A; styrene-isoprene block copolymer is added to the mixture A and heated and stirred at a second heating temperature until the styrene-isoprene block copolymer melts to obtain a mixture B;

[0010] (2) In a vacuum environment or under nitrogen protection, monomer resin is added to the mixture B and stirred evenly to obtain a mixture C;

[0011] (3) In a vacuum environment or under nitrogen protection, a second tackifying resin and an antioxidant are added to the mixture C and stirred evenly to obtain a hot melt pressure sensitive adhesive with good bonding effect.

[0012] Preferably, in step (1), the first heating temperature is 125-150 °C, and the second heating temperature is 170-220 °C;

[0013] After adding the styrene-isoprene block copolymer to the mixture A, the heating and stirring speed at the second heating temperature is 30-50 revolutions / min.

[0014] Preferably, step (1) includes the following operations: in an aerobic environment, calculated by mass, 13-17 parts of mineral oil and 5-11 parts of the first tackifying resin are mixed and then heated and stirred to melt at the first heating temperature to obtain a mixture A, and 27-33 parts of styrene-isoprene block copolymer are added to the mixture A and heated and stirred at the second heating temperature until the styrene-isoprene block copolymer melts to obtain a mixture B.

[0015] Preferably, in step (1), the viscosity of the mixture B is 21000-35000 mPa.s / 180 °C.

[0016] Preferably, in step (2), calculated by mass, the dosage of the monomer resin is 11-16 parts;

[0017] In step (3), the dosage of the second tackifying resin is 29-39 parts, and the dosage of the antioxidant is 0.5-1 part.

[0018] Preferably, the mineral oil includes naphthenic oil.

[0019] Preferably, the styrene-isoprene block copolymer includes 1106 rubber and 1126 rubber;

[0020] The mass ratio of the 1106 rubber to the 1126 rubber is 1:(0.8 - 1.2).

[0021] Preferably, both the first tackifying resin and the second tackifying resin include hydrogenated petroleum resin.

[0022] Preferably, the monomer resin includes α-methylstyrene monomer resin.

[0023] A hot melt pressure-sensitive adhesive with good adhesion effect is prepared by using the preparation method of the hot melt pressure-sensitive adhesive with good adhesion effect described above;

[0024] Calculated by mass parts, the raw materials of the hot melt pressure-sensitive adhesive include 13 - 17 parts of mineral oil, 5 - 11 parts of the first tackifying resin, 27 - 33 parts of styrene-isoprene block copolymer, 11 - 16 parts of monomer resin, 29 - 39 parts of the second tackifying resin, and 0.5 - 1 part of antioxidant.

[0025] The technical solution provided by the embodiment of the present application may include the following beneficial effects: This technical solution develops a new preparation method of hot melt pressure-sensitive adhesive. By melting styrene-isoprene block copolymer (SIS rubber) in an aerobic environment (i.e., non-vacuum and without nitrogen protection), the degree of curing of SIS rubber can be increased, the thermal degradation of rubber molecular chains can be accelerated, the compatibility between SIS rubber and resin materials in the formulation system can be improved, the adhesion of the hot melt pressure-sensitive adhesive to the substrate can be strengthened, and the adhesion effect can be significantly improved. Compared with the hot melt pressure-sensitive adhesive prepared by the conventional method of melting rubber under vacuum or nitrogen protection, the hot melt pressure-sensitive adhesive prepared by the method of melting SIS rubber in an aerobic environment using this technical solution has excellent adhesion effect on substrates such as PC plastic, PP plastic, aluminum-plastic film, and metal plate, and has better high-temperature fluidity and permeability. At the same time, through the selection and adjustment of formulation raw materials, this technical solution can ensure that the softening point of the prepared hot melt pressure-sensitive adhesive is also in a relatively high range, and the high-temperature resistance performance meets the daily application requirements. Detailed Embodiments

[0026] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure content of the present invention more thorough and comprehensive.

[0027] In the examples where specific technologies or conditions are not indicated, they shall be in accordance with the technologies or conditions described in the literature in this field or in accordance with the product specifications. Where the raw materials used are not indicated with the manufacturers, they are all conventional products that can be obtained through commercial procurement.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this invention belongs. The terms used herein in the specification of this invention are only for the purpose of describing specific embodiments and are not intended to limit the invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0029] The technical solution of the present invention will be further described below in conjunction with specific embodiments.

[0030] A preparation method of a hot-melt pressure-sensitive adhesive with good adhesion effect, comprising the following steps:

[0031] (1) In an aerobic environment, mineral oil and a first tackifying resin are mixed and then heated and stirred to melt at a first heating temperature to obtain a mixture A; a styrene-isoprene block copolymer is added to the mixture A and heated and stirred to melt the styrene-isoprene block copolymer at a second heating temperature to obtain a mixture B;

[0032] (2) In a vacuum environment or under nitrogen protection, a monomer resin is added to the mixture B and stirred evenly to obtain a mixture C;

[0033] (3) In a vacuum environment or under nitrogen protection, a second tackifying resin and an antioxidant are added to the mixture C and stirred evenly to obtain a hot-melt pressure-sensitive adhesive with good adhesion effect.

[0034] It should be noted that in order to solve the problem that the hot-melt pressure-sensitive adhesive prepared by the conventional preparation method has poor adhesion to substrates such as PC plastics, PP plastics and metal plates (such as aluminum plastic films), this technical solution develops a new preparation method for hot-melt pressure-sensitive adhesives. By melting styrene-isoprene block copolymer (SIS rubber) in an aerobic environment (i.e., non-vacuum and without nitrogen protection), the degree of curing of SIS rubber can be increased, the thermal degradation of rubber molecular chains can be accelerated, the compatibility between SIS rubber and resin materials in the formulation system can be effectively improved, the adhesion of the hot-melt pressure-sensitive adhesive to the substrate can be strengthened, and the adhesion effect can be significantly improved. Compared with the hot-melt pressure-sensitive adhesive prepared by the conventional method of melting rubber under vacuum or nitrogen protection, the hot-melt pressure-sensitive adhesive prepared by heating and melting SIS rubber in an aerobic environment according to this technical solution has better adhesion to substrates such as PC plastics, PP plastics, aluminum plastic films and metal plates (such as steel plates, aluminum plates), better high-temperature fluidity and better permeability. At the same time, through the selection of formulation raw materials and formulation adjustment, this technical solution can ensure that the softening point of the prepared hot-melt pressure-sensitive adhesive is also in a relatively high range, and the high-temperature resistance performance meets the daily application requirements.

[0035] Specifically, the conventional method of melting rubber by vacuum or nitrogen process to prepare hot-melt pressure-sensitive adhesive is mainly to protect the integrity of rubber molecular chains and avoid the cleavage of rubber molecular chains. However, the hot-melt pressure-sensitive adhesive prepared by this method has a large tensile strength, high viscosity and weak initial adhesion, poor wettability and weak peel strength to metal plates, PC substrates and PP substrates, and poor adhesion effect. In this technical solution, by heating and melting SIS rubber in an aerobic environment, SIS rubber is oxidized and degraded, and then the macromolecular chains of SIS rubber are cleaved to generate multiple molecular chains, so that the prepared hot-melt pressure-sensitive adhesive has low viscosity, low tensile strength and good initial adhesion, can improve the wettability and adsorption of the hot-melt pressure-sensitive adhesive, and thus improve the adhesion effect of the hot-melt pressure-sensitive adhesive to substrates such as metal plates, PC substrates and PP substrates.

[0036] Specifically, in step (1), in this technical solution, in an aerobic environment (such as in a normal air environment), heating and stirring are carried out to melt SIS rubber with the melted mineral oil and the first tackifying resin, which can cleave the macromolecular chains of SIS rubber to generate multiple molecular chains, thereby improving the wettability and adsorption of the hot-melt pressure-sensitive adhesive, and keeping the hot-melt pressure-sensitive adhesive with a certain strength. In steps (2) and (3), adding monomer resin, the second tackifying resin and antioxidant can strengthen and stabilize the structure, and improve the strength and high-temperature resistance performance of the hot-melt pressure-sensitive adhesive. In the final step of the preparation of this technical solution, adding 0.5-1 part of antioxidant can extend the service life and product stability of the hot-melt pressure-sensitive adhesive finished product. It should be noted that the antioxidant of this technical solution cannot be added in step (1). If the antioxidant is added in step (1), it will inhibit and slow down the cleavage of SIS rubber, which is not conducive to improving the adhesion effect of the hot-melt pressure-sensitive adhesive.

[0037] It should be noted that both the first tackifying resin and the second tackifying resin in this technical solution are tackifying resins and use the same material. In this technical solution, by first adding the first tackifying resin in step (1), the first tackifying resin and the mineral oil are used as dispersants, which can accelerate the melting and oxidative curing of the SIS rubber, facilitate the melting of the SIS rubber and maintain the bonding force. At the same time, adding the second tackifying resin in step (3) can improve the bonding force (bonding strength) of the hot melt pressure-sensitive adhesive.

[0038] It should be noted that if the formulation is adjusted to increase the mineral oil, decrease the rubber, and keep the tackifying resin unchanged in the formulation, although the viscosity and tensile strength of the hot melt pressure-sensitive adhesive are reduced and the wettability is improved, the self-strength of the prepared hot melt pressure-sensitive adhesive is insufficient and still cannot achieve a good bonding effect.

[0039] Furthermore, in step (1), the first heating temperature is 125 - 150 °C, and the second heating temperature is 170 - 220 °C;

[0040] After adding the styrene-isoprene block copolymer to mixture A, at the second heating temperature, the heating and stirring speed is 30 - 50 revolutions per minute.

[0041] By controlling the first heating temperature at 125 - 150 °C, the second heating temperature at 170 - 220 °C, and the stirring speed at 30 - 50 revolutions per minute when melting the SIS rubber, this technical solution can further crack the macromolecular chains of the SIS rubber, generate more multi-segment molecular chains, improve the wettability and adsorption of the hot melt pressure-sensitive adhesive, and thus further enhance the adhesion effect of the hot melt pressure-sensitive adhesive to substrates such as PC plastics, PP plastics, aluminum plastic films, and metal plates.

[0042] Furthermore, step (1) includes the following operations: in an aerobic environment, calculated by mass, 13 - 17 parts of mineral oil and 5 - 11 parts of the first tackifying resin are mixed, heated and stirred to melt at the first heating temperature to obtain mixture A, and 27 - 33 parts of the styrene-isoprene block copolymer are added to mixture A, and heated and stirred to melt the styrene-isoprene block copolymer at the second heating temperature to obtain mixture B.

[0043] By further limiting the dosages of the mineral oil, the first tackifying resin, and the SIS rubber in this technical solution, the melting and oxidative curing of the SIS rubber can be further accelerated, and thus the bonding effect of the hot melt pressure-sensitive adhesive to substrates such as PC plastics, PP plastics, aluminum plastic films, and metal plates can be further improved.

[0044] Specifically, the addition amount of the mineral oil in this technical solution is 13 to 17 parts, which can endow the hot melt pressure-sensitive adhesive with better wettability, thereby improving the adhesion of the hot melt pressure-sensitive adhesive and the bonding effect on the substrate. In this solution, the dosage of the styrene-isoprene block copolymer is 27 to 33 parts, which can provide a certain strength and stable structure for the hot melt pressure-sensitive adhesive. At the same time, the strength and adhesion of the hot melt pressure-sensitive adhesive are balanced, so that the hot melt pressure-sensitive adhesive has a good bonding effect on substrates such as PC / PP plastics, aluminum plastic films and metal plates, and avoids the situation where the adhesion of the hot melt pressure-sensitive adhesive is much greater than its strength, resulting in poor bonding effect of the hot melt pressure-sensitive adhesive; at the same time, avoiding the adhesion of the hot melt pressure-sensitive adhesive being much less than its strength will also lead to poor bonding effect of the hot melt pressure-sensitive adhesive.

[0045] Further explanation, in step (1), the viscosity of the mixture B is 21000 - 35000 mPa·s / 180 °C.

[0046] It is worth noting that in this technical solution, by controlling the stirring speed, heating temperature, and the dosages of the mineral oil, the first tackifying resin, and the SIS rubber, the mixture B after heating and stirring and melting is stabilized in a certain polymerization state. At this time, the viscosity of the mixture B is 21000 - 35000 mPa·s / 180 °C, so as to control the degree of oxidative degradation of the SIS rubber, and make the bonding effect of the prepared hot melt pressure-sensitive adhesive good. If the viscosity of the mixture B is lower than 21000 mPa·s / 180 °C, it is easy to cause too high an oxidation degree of the SIS rubber, and many molecular chains break, resulting in too low a tensile strength of the prepared hot melt pressure-sensitive adhesive, making it difficult to reach a level where the tensile strength and adhesion are similar, and leading to a poor bonding effect of the hot melt pressure-sensitive adhesive; if the viscosity of the mixture B is higher than 35000 mPa·s / 180 °C, at this time, the oxidation degree of the SIS rubber is too low, which is easy to cause too high a tensile strength of the prepared SIS rubber, far greater than the adhesion, and will also lead to a poor bonding effect.

[0047] Further explanation, in this technical solution, by controlling the viscosity of the mixture B to be 21000 - 35000 mPa·s / 180 °C, after adding the monomer resin, the second tackifying resin, and the antioxidant to the mixture B later, a hot melt pressure-sensitive adhesive product with a viscosity in the range of 14000 - 24000 mPa·s / 160 °C can be prepared. Based on the fact that the viscosity of the hot melt pressure-sensitive adhesive is closely related to its bonding performance, by controlling the viscosity of the hot melt pressure-sensitive adhesive product within the range of 14000 - 24000 mPa·s / 160 °C, the bonding strength and adhesion of the hot melt pressure-sensitive adhesive product can reach the best state, ensuring good bonding performance at the bonding part.

[0048] Further explanation, in step (2), calculated by mass parts, the dosage of the monomer resin is 11 - 16 parts;

[0049] In step (3), the dosage of the second tackifying resin is 29 to 39 parts, and the dosage of the antioxidant is 0.5 to 1 part.

[0050] In this technical solution, the dosage of the monomer resin is controlled at 11 to 16 parts (by mass), which can further improve the high-temperature resistance of the hot melt pressure-sensitive adhesive. At the same time, at this dosage, the compatibility between the monomer resin and the SIS rubber is good, and a hot melt pressure-sensitive adhesive with stable properties can be formed, avoiding delamination of the hot melt pressure-sensitive adhesive. In this technical solution, 29 to 39 parts of the second tackifying resin are added in step (3), so that the prepared hot melt pressure-sensitive adhesive has better adhesion and can achieve a better bonding effect.

[0051] In the final step of preparing this technical solution, 0.5 to 1 part of antioxidant is added, which can extend the service life of the hot melt pressure-sensitive adhesive product. It should be noted that the antioxidant of this technical solution cannot be added in step (1). If the antioxidant is added in step (1), it will inhibit and slow down the cracking of the SIS rubber, which is not conducive to improving the bonding effect of the hot melt pressure-sensitive adhesive.

[0052] Further explanation, the mineral oil includes naphthenic oil.

[0053] Preferably, the naphthenic oil is selected as Karamay KN4010.

[0054] Further explanation, the styrene-isoprene block copolymer includes 1106 rubber and 1126 rubber;

[0055] The mass ratio of the 1106 rubber to the 1126 rubber is 1:(0.8 to 1.2).

[0056] It is worth noting that the styrene-isoprene block copolymer of this technical solution includes two types of SIS rubbers, 1106 rubber and 1126 rubber. Both of these rubbers are produced by Baling Petrochemical, and both of these SIS rubbers contain diblocks, accounting for 17% and 50% of their respective rubbers, respectively, which can provide a certain degree of softness and elasticity for the hot melt pressure-sensitive adhesive.

[0057] Further explanation, both the first tackifying resin and the second tackifying resin include hydrogenated petroleum resin.

[0058] It is worth noting that the first tackifying resin and the second tackifying resin of this technical solution are the same, both are hydrogenated petroleum resins. For example, it can be a hydrogenated petroleum resin with 5 to 9 carbon atoms. Selecting hydrogenated petroleum resin can enhance the compatibility of the SIS rubber and reduce volatile organic compounds (VOC) and odor.

[0059] More preferably, both the first tackifying resin and the second tackifying resin in this technical solution are hydrogenated C5 petroleum resins. Selecting hydrogenated C5 petroleum resins can enhance the interaction between hydrogenated C5 petroleum resins and styrene-isoprene block copolymers, improve their compatibility, enhance the high-temperature resistance performance of the hot melt pressure-sensitive adhesive, and reduce the weakening effect of resin aging on the adhesive force.

[0060] In a preferred embodiment of the present invention, the hydrogenated C5 petroleum resin is Henghe H5-1001.

[0061] Further explanation, the hot melt pressure-sensitive adhesive of this technical solution is compounded with SIS rubber, naphthenic oil, monomer resin and hydrogenated petroleum resin, and at the same time, the SIS rubber is melted in an oxygen environment, so that the prepared hot melt pressure-sensitive adhesive has good effects when bonding metal plates, PP / PC materials, and has excellent high and low temperature resistance performance.

[0062] Further explanation, the monomer resin includes α-methylstyrene monomer resin.

[0063] The monomer resin material has a relatively high viscosity and softening point, so that the monomer resin can form stronger intermolecular interaction forces at high temperatures, improving the thermal stability of the hot melt pressure-sensitive adhesive.

[0064] Preferably, the monomer resin of this technical solution is α-methylstyrene monomer resin. More preferably, Exxon 5430 is selected. The softening point of Exxon 5430 is 140 °C, which can improve the high-temperature resistance performance of the hot melt pressure-sensitive adhesive, enabling the hot melt pressure-sensitive adhesive to work at a relatively high temperature.

[0065] Specifically, the antioxidant used in this technical solution is a commonly used antioxidant in the art, such as antioxidant 1010, antioxidant 168, antioxidant 264 or antioxidant 1035.

[0066] A hot melt pressure-sensitive adhesive with good bonding effect is prepared by using the preparation method of the hot melt pressure-sensitive adhesive with good bonding effect described above;

[0067] Calculated by mass parts, the raw materials of the hot melt pressure-sensitive adhesive include 13-17 parts of mineral oil, 5-11 parts of the first tackifying resin, 27-33 parts of styrene-isoprene block copolymer, 11-16 parts of monomer resin, 29-39 parts of the second tackifying resin, and 0.5-1 part of antioxidant.

[0068] The hot melt pressure-sensitive adhesive prepared by the method of melting SIS rubber in an aerobic environment in this technical solution has good adhesion to substrates such as PC plastics, PP plastics, aluminum plastic films and metal plates, and has good high-temperature fluidity and permeability.

[0069] Specifically, in a preferred embodiment of the present invention, a method for preparing a hot melt pressure-sensitive adhesive with good bonding effect includes the following steps:

[0070] (1) In an aerobic environment, put 13 - 17 parts of mineral oil (naphthenic oil) and 5 - 11 parts of the first tackifying resin (hydrogenated petroleum resin) into a reaction kettle (vertical stirring kettle), set the temperature of the heat transfer oil in the reaction kettle to 125 - 150 °C (i.e., the first heating temperature, at this time the material temperature is 125 - 130 °C), heat and stir for 10 - 30 min to melt the materials, obtaining mixture A; add 14 - 18 parts of 1106 rubber to mixture A, and set the temperature of the heat transfer oil to 170 - 220 °C (i.e., the second heating temperature, at this time the material temperature is 160 - 170 °C), heat and stir at a stirring speed of 30 - 50 revolutions per minute for 10 - 30 min, then add 13 - 15 parts of 1126 rubber, continue to stir for 10 - 30 min while maintaining the same stirring speed, stop heating, and continue to stir for 60 - 100 min to obtain mixture B;

[0071] (2) Under a vacuum environment or nitrogen protection, add 11 - 16 parts of monomer resin (Exxon 5430) to mixture B (at this time the material temperature is 150 - 160 °C), stir for 10 - 30 min until evenly stirred, obtaining mixture C;

[0072] (3) While maintaining the vacuum environment or nitrogen protection, add 29 - 39 parts of the second tackifying resin (hydrogenated petroleum resin) and 0.5 - 1 part of antioxidant to mixture C, stir for 25 - 45 min until evenly stirred, obtaining a hot melt pressure-sensitive adhesive with good bonding effect.

[0073] Example 1

[0074] The method for preparing a hot melt pressure-sensitive adhesive with good bonding effect in this example includes the following steps:

[0075] (1) In an aerobic environment, put 13 parts of mineral oil (naphthenic oil) and 11 parts of the first tackifying resin (hydrogenated petroleum resin) into a reaction kettle, set the temperature of the heat transfer oil in the reaction kettle to 130 °C (i.e., the first heating temperature), heat and stir for 15 min to obtain mixture A; add 16 parts of 1106 rubber to mixture A, and set the temperature of the heat transfer oil to 200 °C (i.e., the second heating temperature), heat and stir at a stirring speed of 40 revolutions per minute for 20 min, then add 14 parts of 1126 rubber, continue to stir for 20 min while maintaining the same stirring speed, stop heating, and continue to stir for 80 min to obtain mixture B;

[0076] (2) Under a vacuum environment, add 16 parts of monomer resin (Exxon 5430) to mixture B, stir for 20 min to obtain mixture C;

[0077] (3) Maintain a vacuum environment, add 29.3 parts of a second tackifying resin (hydrogenated C5 petroleum resin, Henghe H5-1001) and 0.7 part of an antioxidant to mixture C, and stir for 35 min to obtain a hot melt pressure-sensitive adhesive with good bonding effect.

[0078] Example 2

[0079] The preparation method of the hot melt pressure-sensitive adhesive with good bonding effect in this example includes the following steps:

[0080] (1) Under an aerobic environment, put 15 parts of mineral oil (naphthenic oil) and 10 parts of a first tackifying resin (hydrogenated petroleum resin) into a reaction kettle, set the temperature of the heat transfer oil in the reaction kettle to 128 °C (i.e., the first heating temperature), heat and stir for 15 min to obtain mixture A; add 18 parts of 1106 rubber to mixture A, and set the temperature of the heat transfer oil to 190 °C (i.e., the second heating temperature), heat and stir at a stirring speed of 40 r / min for 20 min, then add 15 parts of 1126 rubber, continue to stir at the same stirring speed for 20 min, stop heating, and continue to stir for 80 min to obtain mixture B;

[0081] (2) Under a vacuum environment, add 13 parts of a monomer resin (Exxon 5430) to mixture B and stir for 20 min to obtain mixture C;

[0082] (3) Maintain a vacuum environment, add 29.5 parts of a second tackifying resin (hydrogenated C5 petroleum resin, Henghe H5-1001) and 0.5 part of an antioxidant to mixture C, and stir for 35 min to obtain a hot melt pressure-sensitive adhesive with good bonding effect.

[0083] Example 3

[0084] The preparation method of the hot melt pressure-sensitive adhesive with good bonding effect in this example includes the following steps:

[0085] (1) Under an aerobic environment, put 17 parts of mineral oil (naphthenic oil) and 5 parts of a first tackifying resin (hydrogenated petroleum resin) into a reaction kettle, set the temperature of the heat transfer oil in the reaction kettle to 135 °C (i.e., the first heating temperature), heat and stir for 15 min to obtain mixture A; add 14 parts of 1106 rubber to mixture A, and set the temperature of the heat transfer oil to 210 °C (i.e., the second heating temperature), heat and stir at a stirring speed of 40 r / min for 20 min, then add 13 parts of 1126 rubber, continue to stir at the same stirring speed for 20 min, stop heating, and continue to stir for 80 min to obtain mixture B;

[0086] (2) Under a vacuum environment, add 11 parts of monomer resin (Exxon 5430) to mixture B and stir for 20 min to obtain mixture C;

[0087] (3) While maintaining the vacuum environment, add 39 parts of second tackifying resin (hydrogenated C5 petroleum resin, Ganga H5-1001) and 1 part of antioxidant to mixture C and stir for 35 min to obtain a hot melt pressure-sensitive adhesive with good bonding effect.

[0088] Comparative Example 1

[0089] The preparation method of the hot melt pressure-sensitive adhesive in this comparative example includes the following steps:

[0090] (1) Under a vacuum environment, put 13 parts of mineral oil (naphthenic oil) and 11 parts of first tackifying resin (hydrogenated petroleum resin) into the reaction kettle, set the temperature of the heat transfer oil in the reaction kettle to 130 °C (i.e., the first heating temperature), heat and stir for 15 min to obtain mixture A; add 16 parts of 1106 rubber to mixture A, and set the temperature of the heat transfer oil to 200 °C (i.e., the second heating temperature), heat and stir at a stirring speed of 40 r / min for 20 min, then add 14 parts of 1126 rubber and 0.7 part of antioxidant, continue to stir at the same stirring speed for 20 min, stop heating, and continue to stir for 80 min to obtain mixture B;

[0091] (2) Under a vacuum environment, add 16 parts of monomer resin (Exxon 5430) to mixture B and stir for 20 min to obtain mixture C;

[0092] (3) While maintaining the vacuum environment, add 29.3 parts of second tackifying resin (hydrogenated C5 petroleum resin, Ganga H5-1001) to mixture C and stir for 35 min to obtain the hot melt pressure-sensitive adhesive.

[0093] Comparative Example 2

[0094] The preparation method of the hot melt pressure-sensitive adhesive in this comparative example includes the following steps:

[0095] (1) Under a vacuum environment, put 15 parts of mineral oil (naphthenic oil) and 10 parts of first tackifying resin (hydrogenated petroleum resin) into the reaction kettle, set the temperature of the heat transfer oil in the reaction kettle to 128 °C (i.e., the first heating temperature), heat and stir for 15 min to obtain mixture A; add 18 parts of 1106 rubber to mixture A, and set the temperature of the heat transfer oil to 190 °C (i.e., the second heating temperature), heat and stir at a stirring speed of 40 r / min for 20 min, then add 15 parts of 1126 rubber and 0.5 part of antioxidant, continue to stir at the same stirring speed for 20 min, stop heating, and continue to stir for 80 min to obtain mixture B;

[0096] (2) In a vacuum environment, add 13 parts of monomer resin (Exxon 5430) to mixture B and stir for 20 min to obtain mixture C;

[0097] (3) While maintaining the vacuum environment, add 29.5 parts of the second tackifying resin (hydrogenated C5 petroleum resin, Ganga H5-1001) to mixture C and stir for 35 min to obtain the hot melt pressure-sensitive adhesive.

[0098] Comparative Example 3

[0099] The preparation method of the hot melt pressure-sensitive adhesive in this comparative example includes the following steps:

[0100] (1) In a vacuum environment, put 17 parts of mineral oil (naphthenic oil) and 5 parts of the first tackifying resin (hydrogenated petroleum resin) into the reaction kettle, set the temperature of the heat transfer oil in the reaction kettle to 135 °C (i.e., the first heating temperature), heat and stir for 15 min to obtain mixture A; add 14 parts of 1106 rubber to mixture A, and set the temperature of the heat transfer oil to 210 °C (i.e., the second heating temperature), heat and stir at a stirring speed of 40 rpm for 20 min, then add 13 parts of 1126 rubber and 1 part of antioxidant, continue to stir at the same stirring speed for 20 min, stop heating, and continue to stir for 80 min to obtain mixture B;

[0101] (2) In a vacuum environment, add 11 parts of monomer resin (Exxon 5430) to mixture B and stir for 20 min to obtain mixture C;

[0102] (3) While maintaining the vacuum environment, add 39 parts of the second tackifying resin (hydrogenated C5 petroleum resin, Ganga H5-1001) to mixture C and stir for 35 min to obtain the hot melt pressure-sensitive adhesive.

[0103] Specifically, the hot melt pressure-sensitive adhesives prepared in Examples 1-3 and Comparative Examples 1-3 were respectively subjected to performance tests. Among them, the test items and test methods are shown in Table 1 below.

[0104] Table 1 Test Items and Test Methods

[0105] Viscosity at 160℃ HG / T 3660-1999 Determination of the melt viscosity of hot melt adhesives Softening point GB / T 15332-1994 Determination of the softening point of hot melt adhesives Tensile strength GB / T 528-2009 Rubber, vulcanized or thermoplastic - Determination of tensile stress - strain properties Aluminum - plastic film peeling GB / T 2792-2014 Test method for peel strength of adhesive tapes Steel plate peeling GB / T 2792-2014 Test method for peel strength of adhesive tapes

[0106] Specifically, according to the test items and test methods in Table 1, the hot melt pressure-sensitive adhesives prepared in Examples 1-3 and Comparative Examples 1-3 were respectively subjected to performance tests, and the test results are shown in Table 2 below.

[0107] Table 2 Test Results

[0108]

[0109] From the test results of Table 2, it can be seen that since the SIS rubber is melted in step (1) of Example 1-3 under an aerobic environment, and no antioxidant is added in step (1), and an antioxidant is added in step (3), a hot melt pressure-sensitive adhesive with low viscosity, low tensile strength, and high peeling strength for substrates such as aluminum-plastic film and steel plate can be obtained. The viscosity of the hot melt pressure-sensitive adhesive obtained in Example 1-3 is 15973-17423 mPa.s / 160°C, the tensile strength is 3.5-3.9 Mpa, and the peeling strength for aluminum-plastic film and steel plate is 32.76-35.36 N / 25 mm. From the test results of Comparative Examples 1-3, it can be seen that the entire process of preparing the hot melt pressure-sensitive adhesive in Comparative Examples 1-3 is carried out under a vacuum environment, that is, the SIS rubber is melted in step (1) in Comparative Examples 1-3 under a vacuum environment, so that the hot melt pressure-sensitive adhesive obtained in Comparative Documents 1-3 has high viscosity, high tensile strength, and low peeling strength for substrates such as aluminum-plastic film and steel plate. The viscosity of the hot melt pressure sensitive adhesive prepared in Comparative Examples 1-3 is 35690-43569 mPa.s / 160°C, the tensile strength is 4.1-5.2 Mpa, and the peel strength to the aluminum-plastic film and the steel plate is 10.19-12.67. It can be seen that the peel strength of the hot melt pressure sensitive adhesive prepared in Examples 1-3 to substrates such as aluminum-plastic film and steel plate is much greater than the peel strength of the hot melt pressure sensitive adhesive prepared in Comparative Examples 1-3 to substrates such as aluminum-plastic film and steel plate. It can be seen that in Example 1-3, by melting the SIS rubber in an aerobic environment and oxidizing and cracking the SIS rubber, the bonding effect of the hot melt pressure sensitive adhesive to substrates such as aluminum-plastic film and metal plate can be significantly improved.

[0110] From the softening point test data of the hot melt pressure-sensitive adhesive in Examples 1-3 and Comparative Examples 1-3 in Table 2, it can be seen that the softening point of the hot melt pressure-sensitive adhesive prepared in Examples 1-3 is 108-113°C, and the softening point of the hot melt pressure-sensitive adhesive prepared in Comparative Examples 1-3 is 112-121°C. It can be seen that although the softening point of the hot melt pressure-sensitive adhesive prepared in Examples 1-3 is lower than that in Comparative Examples 1-3, the decline is relatively low, and the softening point can still reach 108-113°C, and still has better high temperature resistance and can meet conventional application requirements.

[0111] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without paying creative labor, and these methods will fall within the scope of protection of the present invention.

Claims

1. Preparation method of hot-melt pressure-sensitive adhesive with good bonding effect, characterized in that, it comprises the following steps: (1) Under aerobic environment, calculated by mass parts, mix 13 - 17 parts of mineral oil and 5 - 11 parts of the first tackifying resin, and heat and stir until melted at the first heating temperature to obtain mixture A. Add 27 - 33 parts of styrene-isoprene block copolymer to mixture A, and heat and stir at the second heating temperature until the styrene-isoprene block copolymer melts to obtain mixture B; (2) Under vacuum environment or nitrogen protection, add monomer resin to mixture B and stir evenly to obtain mixture C; (3) Under vacuum environment or nitrogen protection, add the second tackifying resin and antioxidant to mixture C and stir evenly to obtain hot-melt pressure-sensitive adhesive with good bonding effect; In step (1), the first heating temperature is 125 - 150 °C, and the second heating temperature is 160 - 220 °C; after adding the styrene-isoprene block copolymer to mixture A, the heating and stirring speed at the second heating temperature is 30 - 50 revolutions / min; In step (1), the viscosity of mixture B is 21000 - 35000 mPa·s / 180 °C; The monomer resin includes α-methylstyrene monomer resin.

2. The preparation method of hot-melt pressure-sensitive adhesive with good bonding effect according to claim 1, characterized in that, in step (2), calculated by mass parts, the dosage of the monomer resin is 11 - 16 parts; in step (3), the dosage of the second tackifying resin is 29 - 39 parts, and the dosage of the antioxidant is 0.5 - 1 part.

3. The preparation method of hot-melt pressure-sensitive adhesive with good bonding effect according to claim 1, characterized in that, the mineral oil includes naphthenic oil.

4. The preparation method of hot-melt pressure-sensitive adhesive with good bonding effect according to claim 1, characterized in that, the styrene-isoprene block copolymer includes 1106 rubber and 1126 rubber; the mass ratio of 1106 rubber to 1126 rubber is 1:(0.8 - 1.2).

5. The preparation method of hot-melt pressure-sensitive adhesive with good bonding effect according to claim 1, characterized in that, both the first tackifying resin and the second tackifying resin include hydrogenated petroleum resin.

6. A hot-melt pressure-sensitive adhesive with good bonding effect, characterized in that, it is prepared by using the preparation method of hot-melt pressure-sensitive adhesive with good bonding effect according to any one of claims 1 - 5; calculated by mass parts, the raw materials of the hot-melt pressure-sensitive adhesive include 13 - 17 parts of mineral oil, 5 - 11 parts of the first tackifying resin, 27 - 33 parts of styrene-isoprene block copolymer, 11 - 16 parts of monomer resin, 29 - 39 parts of the second tackifying resin and 0.5 - 1 part of antioxidant.

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