Creep-resistant degradable environment-friendly SIS hot melt adhesive and preparation method thereof

Abstract

The invention relates to the technical field of hot melt adhesives, in particular to a creep-resistant degradable environment-friendly SIS hot melt adhesive and a preparation method thereof. The SIS hot melt adhesive comprises the following raw materials: 40-50 parts of SIS resin, 10-20 parts of tackifying resin, 5-10 parts of a plasticizer and 1-3 parts of an antioxidant. The preparation method comprises the following steps: taking the SIS resin, the tackifying resin, the plasticizer and the antioxidant, heating, raising the temperature, continuously stirring, raising the temperature to 150-180 DEG C after the SIS resin is completely molten, stopping stirring until a system is completely molten and becomes a uniform viscous state, and discharging while the system is hot, so as to obtain the creep-resistant degradable environment-friendly SIS hot melt adhesive. The prepared SIS hot melt adhesive can meet the diversified requirements of creep resistance and environmental protection performance in the fields of automobiles, household appliances, digital products and the like, and has a relatively good application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of hot melt adhesives, and in particular to a creep-resistant, degradable and environmentally friendly SIS hot melt adhesive and a preparation method thereof. Background Art

[0002] In the field of modern adhesive technology, hot melt adhesives based on thermoplastic elastomers are an important type of functional adhesive. When the hot melt adhesive is in a molten state, it can be easily coated. As the temperature drops, the hot melt adhesive hardens and crystallizes, achieving a fast and strong bonding effect. During the peeling process, the hot melt adhesive can quickly detach from the surface of the adhered object without generating residual pollution. As an important thermoplastic elastomer, SIS hot melt adhesive (styrene-isoprene-styrene block copolymer) has multiple advantages due to its unique microscopic phase separation structure: at room temperature, the polystyrene hard segment forms physical cross-linking points to provide sufficient cohesive strength, while the polyisoprene soft segment gives the material excellent flexibility and initial adhesion. This structural feature makes SIS hot melt adhesive widely used in industries such as packaging, hygiene materials, and automobiles. In addition, compared with traditional thermosetting adhesives, SIS hot melt adhesive also has the advantages of simple production process, excellent environmental performance, and outstanding cost-effectiveness.

[0003] However, the structural characteristics of SIS resins result in significant creep resistance deficiencies under long-term stress loads, severely restricting the application of SIS hot-melt adhesives in high-end applications. For example, in automotive headlight bonding, creep at high temperatures can cause the adhesive layer to soften and fail; in refrigerated packaging, creep at low temperatures can cause the adhesive layer to crack and fall apart; and in hygiene applications, sustained stress at human body temperature can cause the bond to gradually loosen and shift. Therefore, research into modifying the creep resistance of SIS hot-melt adhesives has become a key development direction in the adhesives industry.

[0004] Patent application number CN202311779239.9 discloses an acrylate-modified polyurethane hot melt adhesive and its preparation method and application. A difunctional acrylate monomer, a polyol compound, a polyisocyanate compound, a catalyst, and a modifying agent are mixed and stirred at a certain temperature to obtain a polyurethane hot melt adhesive with excellent creep resistance and a fast curing speed. Patent application number CN202311767573.2 discloses a low-odor, high-heat-resistant creep water-based polyurethane hot melt adhesive and its preparation method. Polyester polyol, polyether polyol, isocyanate, a catalyst, and a modifying agent are added to a reaction device for reaction polymerization to obtain a low-odor, high-heat-resistant creep water-based polyurethane hot melt adhesive. The heat creep water-based polyurethane hot melt adhesive prepared in the above technical solution requires the preparation of a first intermediate, a second intermediate, and a third intermediate. The reaction steps are multiple and the equipment and production process requirements are strict, which is not conducive to industrial production. Therefore, it is necessary to develop an environmentally friendly SIS hot melt adhesive with simple process, high stability, good creep resistance, and biodegradability. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention provides a creep-resistant, degradable and environmentally friendly SIS hot melt adhesive and a preparation method thereof.

[0006] The technical solutions of the present invention are as follows:

[0007] First, the present invention provides: creep-resistant, degradable and environmentally friendly SIS hot melt adhesive, which comprises the following raw materials by weight: 40-50 parts of SIS resin, 10-20 parts of tackifying resin, 5-10 parts of plasticizer and 1-3 parts of antioxidant.

[0008] In some specific embodiments, the SIS resin includes a block-modified SIS resin, and the preparation steps of the block-modified SIS resin include:

[0009] Add cyclohexane solvent and styrene monomer to the polymerization bottle; add cyclohexane solvent and isoprene to ampoule A, add cyclohexane solvent and styrene to ampoule B, and seal the polymerization bottle, ampoule A and ampoule B;

[0010] The polymerization bottle is preheated, an anionic initiator is added, and the reaction is carried out; the mixture in ampoule bottle A is added to the polymerization bottle, and the reaction is carried out; the aryl ester ether prepolymer and the catalyst are added, and the reaction is carried out; the mixture in ampoule bottle B is added to the polymerization bottle, and the reaction is carried out; the product is taken out, the reaction is terminated, and the block-modified SIS resin is obtained by drying.

[0011] In some specific embodiments, the amount of catalyst added is 0.1-0.5 g.

[0012] In some specific embodiments, the anionic initiator includes one or more of n-butyllithium, phenyllithium, and triethylamine.

[0013] In some specific embodiments, the catalyst includes one or more of tetraphenylphosphonium bromide, triphenylethylphosphonium bromide, and tetrabutylammonium bromide.

[0014] In some specific embodiments, when preparing the block-modified SIS resin, the preheating temperature is 30-80°C.

[0015] In some specific embodiments, the aryl ester ether prepolymer includes a borane-containing aryl ester ether prepolymer, and the preparation steps of the borane-containing aryl ester ether prepolymer include:

[0016] Epichlorohydrin, bisphenol A polyoxyethylene ether, tri-sec-butylborane, and tetramethylammonium bromide are introduced into nitrogen, stirred for reaction, cooled, and a sodium hydroxide aqueous solution is added dropwise, the reaction is continued, and heated to obtain borane bisphenol diglycidyl ether; borane bisphenol diglycidyl ether, adipic acid, tetraphenylphosphonium bromide, and ethylene glycol methyl ether acetate are introduced into nitrogen, reacted, cooled, washed, and dried to obtain an aryl ester ether prepolymer.

[0017] It should be noted that the aforementioned technical solution introduces aryl ester ether blocks into the SIS resin matrix, forming strong dipole interactions with the SIS molecular chains, limiting molecular chain slippage and deformation, and imparting excellent creep resistance to the hot melt adhesive while maintaining high bond strength and heat resistance. The ether bonds in the aryl ester ether blocks readily break under acidic conditions, making the SIS hot melt adhesive biodegradable under specific conditions. SIS hot melt adhesives can meet diverse creep resistance and environmental performance requirements in the automotive, home appliance, and digital product sectors, offering promising application prospects.

[0018] In some specific embodiments, the amount of tri-sec-butylborane added is 0.5-1 g.

[0019] In some specific embodiments, when preparing the block-modified SIS resin, the reaction temperature is 60-150°C.

[0020] In some specific embodiments, the tackifying resin includes one or more of C5 hydrogenated petroleum resin, C9 hydrogenated petroleum resin and terpene resin.

[0021] In some specific embodiments, the plasticizer includes one or more of naphthenic oil, white mineral oil, and liquid paraffin; the antioxidant includes one or more of antioxidant 1010, antioxidant 168, and antioxidant trisnonylphenyl phosphite.

[0022] Secondly, the invention provides a method for preparing the creep-resistant, degradable and environmentally friendly SIS hot melt adhesive according to the aforementioned method. SIS resin, tackifying resin, plasticizer and antioxidant are taken, heated and stirred continuously. After the SIS resin is completely melted, the temperature is raised to 150-180°C until the system is completely melted and becomes uniformly viscous. Stirring is stopped and the material is discharged while hot to obtain the creep-resistant, degradable and environmentally friendly SIS hot melt adhesive.

[0023] The beneficial effects of the present invention are:

[0024] (1) The present invention achieves "rigid anchoring" of the SIS molecular chain by introducing an aromatic ester ether structure, limiting the sliding and deformation of the SIS molecular chain when subjected to stress, significantly improving the creep resistance of the hot melt adhesive, and the modified group is block-bonded with the SIS main chain, avoiding phase separation caused by traditional physical blending.

[0025] (2) The ether bonds in the aromatic ester ethers undergo specific cleavage in a weakly acidic environment, achieving controllable degradation of the adhesive layer integrity, thereby providing a degradable bonding solution for hot melt adhesives in the fields of medical consumables and environmentally friendly packaging.

[0026] (3) The SIS hot melt adhesive prepared by the present invention is more environmentally friendly than solvent-based hot melt adhesive, and has a simple process, no VOC emissions during the preparation process, moderate raw material costs, and is suitable for industrial production. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0028] In the present invention, unless otherwise specified, all parts are by weight, and the equipment and raw materials used are commercially available or commonly used in the art. The methods in the following examples are all conventional methods in the art unless otherwise specified.

[0029] Ampoule A and ampoule B are both ampoules, and are named as such in order to distinguish the two ampoules.

[0030] The tackifying resins used below include C5 hydrogenated petroleum resin, C9 hydrogenated petroleum resin, and terpene resin, all of which are produced by Henghe Materials Technology Co., Ltd.

[0031] Example 1

[0032] Preparation of a creep-resistant, degradable and environmentally friendly SIS hot melt adhesive, the specific steps are as follows:

[0033] 100 mL of epichlorohydrin, 5 g of bisphenol A polyoxyethylene ether, 0.5 g of tri-sec-butylborane, and 0.01 g of tetramethylammonium bromide were added to a round-bottom flask, purged with nitrogen, and stirred at 110°C for 30 min. The temperature was then lowered to 80°C, and 5 mL of a 40 wt% aqueous sodium hydroxide solution was added dropwise. The reaction was continued for 1 h. The mixture was then transferred to a rotary evaporator and heated to remove the epichlorohydrin to obtain borane bisphenol diglycidyl ether.

[0034] 1.2 g of the above-prepared borane bisphenol diglycidyl ether, 0.4 g of adipic acid, 0.2 g of tetraphenylphosphonium bromide, and 20 mL of ethylene glycol methyl ether acetate were added to a 100 mL reaction bottle, nitrogen was introduced, and the mixture was reacted at 130° C. for 2 h. The mixture was cooled to room temperature, washed with excess ethanol, and dried to obtain an aryl ester ether prepolymer.

[0035] Add 200 mL of cyclohexane solvent and 50 mL of styrene monomer to a 500 mL polymerization bottle; add 40 mL of cyclohexane solvent and 20 mL of isoprene to a 100 mL ampoule A, and add 40 mL of cyclohexane solvent and 20 mL of styrene to a 100 mL ampoule B. Seal the polymerization bottle, ampoule A, and ampoule B with nitrogen and set aside. Preheat the polymerization bottle in a 60°C water bath for 30 minutes. Add 1 mL of n-butyl lithium via syringe and let react for 1 hour. Add the mixture in ampoule A to the polymerization bottle and let react for 1 hour. Add 5 mL of the previously prepared aryl ester ether prepolymer and 0.1 g of tetraphenylphosphonium bromide and let react for 1 hour. Add the mixture in ampoule B to the polymerization bottle and let react for 1 hour. Remove the product, add excess ethanol to terminate the reaction, and thoroughly dry to obtain a block-modified SIS resin.

[0036] 40 parts of block-modified SIS resin, 10 parts of C5 hydrogenated petroleum resin, 5 parts of cyclohexane oil and 1 part of antioxidant 1010 were added to a ceramic crucible. The heating jacket was turned on to increase the temperature and stir continuously. After the SIS resin was completely melted, the temperature was raised to 150°C until the system was completely melted and became uniformly viscous. Stirring was stopped, and the material was discharged while hot for performance testing.

[0037] Example 2

[0038] Preparation of a creep-resistant, degradable and environmentally friendly SIS hot melt adhesive, the specific steps are as follows:

[0039] 100 mL of epichlorohydrin, 5 g of bisphenol A polyoxyethylene ether, 0.6 g of tri-sec-butylborane, and 0.01 g of tetramethylammonium bromide were added to a round-bottom flask and purged with nitrogen. The mixture was stirred and reacted at 110°C for 30 min. The temperature was then lowered to 80°C, and 5 mL of a 40 wt% aqueous sodium hydroxide solution was added dropwise. The reaction was continued for 1 h. The mixture was then transferred to a rotary evaporator and heated to remove the epichlorohydrin to obtain borane bisphenol diglycidyl ether.

[0040] 1.2 g of the above-prepared borane bisphenol diglycidyl ether, 0.4 g of adipic acid, 0.2 g of tetraphenylphosphonium bromide, and 20 mL of ethylene glycol methyl ether acetate were added to a 100 mL reaction bottle, nitrogen was introduced, and the mixture was reacted at 130° C. for 2 h. The mixture was cooled to room temperature, washed with excess ethanol, and dried to obtain an aryl ester ether prepolymer.

[0041] Add 200 mL of cyclohexane solvent and 50 mL of styrene monomer to a 500 mL polymerization bottle; add 40 mL of cyclohexane solvent and 20 mL of isoprene to a 100 mL ampoule A, and add 40 mL of cyclohexane solvent and 20 mL of styrene to a 100 mL ampoule B. Seal the polymerization bottle, ampoule A, and ampoule B with nitrogen and set aside. Preheat the polymerization bottle in a 60°C water bath for 30 minutes. Add 1.4 mL of phenyllithium via syringe and let react for 1 hour. Add the mixture in ampoule A to the polymerization bottle and let react for 1 hour. Add 6 mL of the previously prepared aryl ester ether prepolymer and 0.2 g of triphenylethylphosphonium bromide and let react for 1 hour. Add the mixture in ampoule B to the polymerization bottle and let react for 1 hour. Remove the product, add excess ethanol to terminate the reaction, and thoroughly dry to obtain a block-modified SIS resin.

[0042] 42 parts of block-modified SIS resin, 12 parts of C9 hydrogenated petroleum resin, 6 parts of white mineral oil and 1.4 parts of antioxidant 168 were added to a ceramic crucible. The heating jacket was turned on to increase the temperature while stirring continuously. After the SIS resin was completely melted, the temperature was raised to 160°C until the system was completely melted and became uniformly viscous. Stirring was stopped, and the material was discharged while hot for performance testing.

[0043] Example 3

[0044] Preparation of a creep-resistant, degradable and environmentally friendly SIS hot melt adhesive, the specific steps are as follows:

[0045] 100 mL of epichlorohydrin, 5 g of bisphenol A polyoxyethylene ether, 0.7 g of tri-sec-butylborane, and 0.01 g of tetramethylammonium bromide were added to a round-bottom flask and purged with nitrogen. The mixture was stirred and reacted at 110°C for 30 min. The temperature was then lowered to 80°C, and 5 mL of a 40 wt% aqueous sodium hydroxide solution was added dropwise. The reaction was continued for 1 h. The mixture was then transferred to a rotary evaporator and heated to remove the epichlorohydrin to obtain borane bisphenol diglycidyl ether.

[0046] 1.2 g of the above-prepared borane bisphenol diglycidyl ether, 0.4 g of adipic acid, 0.2 g of tetraphenylphosphonium bromide, and 20 mL of ethylene glycol methyl ether acetate were added to a 100 mL reaction bottle, nitrogen was introduced, and the mixture was reacted at 130° C. for 2 h. The mixture was cooled to room temperature, washed with excess ethanol, and dried to obtain an aryl ester ether prepolymer.

[0047] Add 200 mL of cyclohexane solvent and 50 mL of styrene monomer to a 500 mL polymerization bottle; add 40 mL of cyclohexane solvent and 20 mL of isoprene to a 100 mL ampoule A, and add 40 mL of cyclohexane solvent and 20 mL of styrene to a 100 mL ampoule B. Seal the polymerization bottle, ampoule A, and ampoule B with nitrogen and set aside. Preheat the polymerization bottle in a 60°C water bath for 30 minutes. Add 1.8 mL of triethylamine via syringe and let react for 1 hour. Add the mixture in ampoule A to the polymerization bottle and let react for 1 hour. Add 7 mL of the previously prepared aryl ester ether prepolymer and 0.3 g of triphenylethylphosphonium bromide and let react for 1 hour. Add the mixture in ampoule B to the polymerization bottle and let react for 1 hour. Remove the product, add excess ethanol to terminate the reaction, and thoroughly dry to obtain a block-modified SIS resin.

[0048] Add 44 parts of block-modified SIS resin, 16 parts of terpene resin, 7 parts of liquid paraffin and 1.8 parts of antioxidant TNPP (trinonylphenyl phosphite) into a ceramic crucible, turn on the heating jacket to increase the temperature and stir continuously. After the SIS resin is completely melted, raise the temperature to 165°C until the system is completely melted and becomes uniformly viscous. Stop stirring, discharge the material while hot, and conduct performance testing.

[0049] Example 4

[0050] Preparation of a creep-resistant, degradable and environmentally friendly SIS hot melt adhesive, the specific steps are as follows:

[0051] 100 mL of epichlorohydrin, 5 g of bisphenol A polyoxyethylene ether, 0.8 g of tri-sec-butylborane, and 0.01 g of tetramethylammonium bromide were added to a round-bottom flask and purged with nitrogen. The mixture was stirred and reacted at 110°C for 30 minutes. The temperature was then lowered to 80°C, and 5 mL of a 40 wt% aqueous sodium hydroxide solution was added dropwise. The reaction was continued for 1 hour. The mixture was then transferred to a rotary evaporator and heated to remove the epichlorohydrin to obtain borane bisphenol diglycidyl ether.

[0052] 1.2 g of the above-prepared borane bisphenol diglycidyl ether, 0.4 g of adipic acid, 0.2 g of tetraphenylphosphonium bromide, and 20 mL of ethylene glycol methyl ether acetate were added to a 100 mL reaction bottle, nitrogen was introduced, and the mixture was reacted at 130° C. for 2 h. The mixture was cooled to room temperature, washed with excess ethanol, and dried to obtain an aryl ester ether prepolymer.

[0053] Add 200 mL of cyclohexane solvent and 50 mL of styrene monomer to a 500 mL polymerization bottle; add 40 mL of cyclohexane solvent and 20 mL of isoprene to a 100 mL ampoule A, and add 40 mL of cyclohexane solvent and 20 mL of styrene to a 100 mL ampoule B. Seal the polymerization bottle, ampoule A, and ampoule B with nitrogen and set aside. Preheat the polymerization bottle in a 60°C water bath for 30 minutes. Add 2.4 mL of n-butyl lithium via syringe and let react for 1 hour. Add the mixture in ampoule A to the polymerization bottle and let react for 1 hour. Add 8 mL of the previously prepared aryl ester ether prepolymer and 0.4 g of tetrabutylammonium bromide and let react for 1 hour. Add the mixture in ampoule B to the polymerization bottle and let react for 1 hour. Remove the product, add excess ethanol to terminate the reaction, and thoroughly dry to obtain a block-modified SIS resin.

[0054] 48 parts of block-modified SIS resin, 18 parts of C5 hydrogenated petroleum resin, 8 parts of cyclohexane oil and 2.4 parts of antioxidant 1010 were added to a ceramic crucible. The heating jacket was turned on to increase the temperature while stirring continuously. After the SIS resin was completely melted, the temperature was raised to 170°C until the system was completely melted and became uniformly viscous. Stirring was stopped, and the material was discharged while hot for performance testing.

[0055] Example 5

[0056] Preparation of a creep-resistant, degradable and environmentally friendly SIS hot melt adhesive, the specific steps are as follows:

[0057] 100 mL of epichlorohydrin, 5 g of bisphenol A polyoxyethylene ether, 1 g of tri-sec-butylborane, and 0.01 g of tetramethylammonium bromide were added to a round-bottom flask, purged with nitrogen, and stirred at 110°C for 30 min. The temperature was then lowered to 80°C, and 5 mL of a 40 wt% aqueous sodium hydroxide solution was added dropwise. The reaction was continued for 1 h. The mixture was then transferred to a rotary evaporator and heated to remove the epichlorohydrin to obtain borane bisphenol diglycidyl ether.

[0058] 1.2 g of the above-prepared borane bisphenol diglycidyl ether, 0.4 g of adipic acid, 0.2 g of tetraphenylphosphonium bromide, and 20 mL of ethylene glycol methyl ether acetate were added to a 100 mL reaction bottle, nitrogen was introduced, and the mixture was reacted at 130° C. for 2 h. The mixture was cooled to room temperature, washed with excess ethanol, and dried to obtain an aryl ester ether prepolymer.

[0059] Add 200 mL of cyclohexane solvent and 50 mL of styrene monomer to a 500 mL polymerization bottle; add 40 mL of cyclohexane solvent and 20 mL of isoprene to a 100 mL ampoule A, and add 40 mL of cyclohexane solvent and 20 mL of styrene to a 100 mL ampoule B. Seal the polymerization bottle, ampoule A, and ampoule B with nitrogen and set aside. Preheat the polymerization bottle in a 60°C water bath for 30 minutes. Add 3 mL of phenyllithium via syringe and let react for 1 hour. Add the mixture in ampoule A to the polymerization bottle and let react for 1 hour. Add 10 mL of the previously prepared aryl ester ether prepolymer and 0.5 g of tetraphenylphosphonium bromide and let react for 1 hour. Add the mixture in ampoule B to the polymerization bottle and let react for 1 hour. Remove the product, add excess ethanol to terminate the reaction, and thoroughly dry to obtain a block-modified SIS resin.

[0060] Add 50 parts of block-modified SIS resin, 20 parts of C9 hydrogenated petroleum resin, 10 parts of cyclohexane oil and 3 parts of antioxidant 1010 into a ceramic crucible, turn on the heating jacket to increase the temperature and stir continuously. After the SIS resin is completely melted, raise the temperature to 180°C until the system is completely melted and becomes uniformly viscous. Stop stirring, discharge the material while hot, and conduct performance testing.

[0061] Comparative Example 1

[0062] A SIS hot melt adhesive was prepared. In this comparative example, unlike Example 1, butyl vinyl ether was used instead of bisphenol A polyoxyethylene ether. The specific steps are as follows:

[0063] 100 mL of epichlorohydrin, 5 g of butyl vinyl ether, 0.5 g of tri-sec-butylborane, and 0.01 g of tetramethylammonium bromide were added to a round-bottom flask, purged with nitrogen, and stirred at 110°C for 30 min. The temperature was then lowered to 80°C, and 5 mL of a 40 wt% aqueous sodium hydroxide solution was added dropwise. The reaction was continued for 1 h. The mixture was then transferred to a rotary evaporator and heated to remove the epichlorohydrin to obtain borane bisphenol diglycidyl ether.

[0064] 1.2 g of the above-prepared borane bisphenol diglycidyl ether, 0.4 g of adipic acid, 0.2 g of tetraphenylphosphonium bromide, and 20 mL of ethylene glycol methyl ether acetate were added to a 100 mL reaction bottle, nitrogen was introduced, and the mixture was reacted at 130° C. for 2 h. The mixture was cooled to room temperature, washed with excess ethanol, and dried to obtain a butyl vinyl ester ether prepolymer.

[0065] Add 200 mL of cyclohexane solvent and 50 mL of styrene monomer to a 500 mL polymerization bottle; add 40 mL of cyclohexane solvent and 20 mL of isoprene to a 100 mL ampoule A, and add 40 mL of cyclohexane solvent and 20 mL of styrene to a 100 mL ampoule B. Seal the polymerization bottle, ampoule A, and ampoule B with nitrogen and set aside. Preheat the polymerization bottle in a 60°C water bath for 30 minutes. Add 1 mL of n-butyl lithium via syringe and let react for 1 hour. Add the mixture in ampoule A to the polymerization bottle and let react for 1 hour. Add 5 mL of the previously prepared aryl ester ether prepolymer and 0.1 g of tetraphenylphosphonium bromide and let react for 1 hour. Add the mixture in ampoule B to the polymerization bottle and let react for 1 hour. Remove the product, add excess ethanol to terminate the reaction, and thoroughly dry to obtain a block-modified SIS resin.

[0066] 40 parts of block-modified SIS resin, 10 parts of C5 hydrogenated petroleum resin, 5 parts of cyclohexane oil and 1 part of antioxidant 1010 were added to a ceramic crucible. The heating jacket was turned on to increase the temperature and stir continuously. After the SIS resin was completely melted, the temperature was raised to 150°C until the system was completely melted and became uniformly viscous. Stirring was stopped, and the material was discharged while hot for performance testing.

[0067] Comparative Example 2

[0068] A SIS hot melt adhesive was prepared. In this comparative example, unlike Example 2, the aryl ester ether polymer was directly hot melt blended with the SIS matrix. The specific steps are as follows:

[0069] 100mL epichlorohydrin, 5g bisphenol A polyoxyethylene ether, 0.6g tri-sec-butylborane, 0.01g tetramethylammonium bromide are added to a round-bottomed flask, passed into nitrogen, and stirred for 30min at 110 ℃.Then be cooled to 80 ℃, drip 5mL sodium hydroxide aqueous solution with a concentration of 40wt%, continue the reaction for 1h, be transferred to a rotary evaporator, heat and remove epichlorohydrin to obtain borane bisphenol diglycidyl ether. 1.2g borane bisphenol diglycidyl ether prepared above, 0.4g adipic acid, 0.2g tetraphenylphosphonium bromide, 20mL ethylene glycol methyl ether acetate are added in a 100mL reaction flask, passed into nitrogen, reacted for 2h at 130 ℃, cooled to room temperature, washed with excessive ethanol, and dried to obtain aryl ester ether prepolymer.

[0070] In a 100 mL polymerization bottle equipped with reflux condenser and heating and stirring, 6 mL of the above-prepared aryl ester ether prepolymer, 0.2 g of triphenylethylphosphonium bromide, and 1 g of succinic acid were added. The mixture was evacuated, nitrogen was introduced, 50 mL of cyclohexane solvent was added, and the mixture was heated to 130 ° C. and stirred for 8 h. Excess methanol was added to terminate the reaction, and the mixture was washed with ethanol 3 times to obtain an aryl ester ether polymer.

[0071] Add 200 mL of cyclohexane solvent and 50 mL of styrene monomer to a 500 mL polymerization bottle; add 40 mL of cyclohexane solvent and 20 mL of isoprene to a 100 mL ampoule A, and add 40 mL of cyclohexane solvent and 20 mL of styrene to a 100 mL ampoule B. Seal the polymerization bottle and ampoules with nitrogen and set aside. Preheat the polymerization bottle in a 60°C water bath for 30 minutes, add 1.4 mL of phenyllithium via syringe, and react for 1 hour. Add the mixture in ampoule A to the polymerization bottle and react for 1 hour; then add the mixture in ampoule B to the polymerization bottle and react for 1 hour. Remove the product, add excess ethanol to terminate the reaction, and thoroughly dry to obtain SIS resin.

[0072] Add 42 parts of SIS resin, 5 parts of aromatic ester ether polymer, 12 parts of C9 hydrogenated petroleum resin, 6 parts of white mineral oil and 1.4 parts of antioxidant 168 into a ceramic crucible, turn on the heating jacket to increase the temperature and stir continuously. After the SIS resin is completely melted, raise the temperature to 160°C until the system is completely melted and becomes uniformly viscous. Stop stirring, discharge the material while hot, and conduct performance testing.

[0073] Comparative Example 3

[0074] A SIS hot melt adhesive was prepared. In this comparative example, unlike Example 3, a commercially available SIS resin was used. The specific steps are as follows:

[0075] 44 parts of SIS resin (brand YH-1105, Baling Petrochemical), 16 parts of terpene resin, 7 parts of liquid paraffin and 1.8 parts of antioxidant TNPP were added to a ceramic crucible. The heating jacket was turned on to increase the temperature and stir continuously. After the SIS resin was completely melted, the temperature was raised to 165°C until the system was completely melted and became uniformly viscous. Stirring was stopped, and the material was discharged while hot for performance testing.

[0076] The finished products of Examples 1-5 and Comparative Examples 1-3 were evaluated.

[0077] 1) The evaluation method is as follows:

[0078] The initial tack is tested according to GB / T 31125-2014 Test method for initial tack of adhesive tapes - Ring method.

[0079] The holding force is tested according to GB / T 4851-2014 Test method for holding force of adhesive tapes.

[0080] The 180° peel strength is tested according to GB / T 2792-2014 Test method for peel strength of adhesive tapes.

[0081] The creep resistance test method is as follows: SIS hot melt adhesive is heated to 160°C, stirred evenly, and applied to two ABS plastic sheets. The adhesive is then heated in a 60°C oven for 5 minutes. After removal from the oven, the two plastic sheets are firmly bonded together to form a piece. The piece is then allowed to stand for 10 minutes before being placed in a 60°C oven and heated continuously for 15 minutes. A 1kg weight is vertically applied to one of the plastic sheets in the oven. The oven door is closed and the time it takes for the weight to fall is observed and recorded at 60°C. If the weight does not fall after 20 minutes, the distance traveled is recorded.

[0082] The evaluation results are shown in Table 1.

[0083] Table 1 Evaluation results of various examples and comparative examples

[0084]

[0085] Result analysis: It can be seen from Example 1 and Comparative Example 1 that the present invention introduces aromatic ester ethers through block polymerization. The high rigidity of aromatic ester ethers themselves can effectively improve the initial adhesion, holding time and 180° peel strength of the pressure-sensitive adhesive, and the creep resistance is significantly improved.

[0086] It can be seen from Example 2 and Comparative Example 2 that when the aromatic ester ether is polymerized alone and then added to the SIS hot melt adhesive system, the bonding strength and creep resistance are greatly reduced. This is because the non-blocked aromatic ester ether has poor compatibility with the SIS matrix, and direct hot melt blending is prone to phase separation, which affects the modification effect.

[0087] It can be seen from Example 3 and Comparative Example 3 that, compared with ordinary SIS hot melt adhesive, the modified SIS hot melt adhesive prepared in the present invention has excellent bonding strength and higher creep resistance.

[0088] 2) The evaluation method is as follows:

[0089] The degradation performance test method is as follows: the SIS hot melt adhesive prepared in each embodiment and comparative example is evenly coated on the release paper using an integrated coating tester, and then placed in an environmental box with an ambient temperature of 25°C and a humidity of 50% RH to fully cure for 48 hours. The adhesives are uniformly cut into 100 mm × 100 mm sizes and then buried in the same acidic soil at a depth of 50 mm. Samples are dug out regularly, thoroughly cleaned and dried, and then weighed to record the remaining mass of the samples.

[0090] The evaluation results are shown in Table 2.

[0091] Table 2 Evaluation results of degradation performance of various examples and comparative examples

[0092]

[0093] Result analysis:

[0094] It can be seen from Example 1 and Comparative Example 1 that replacing the aromatic ester ether prepolymer with butyl vinyl ether has no significant effect on the degradation performance of the hot melt adhesive, indicating that the degradation performance is mainly caused by the breakage of the ether bond in the aromatic ester ether and has little effect on the aromatic functional group.

[0095] It can be seen from Example 2 and Comparative Example 2 that when the aromatic ester ether polymer is directly added to the hot melt adhesive system, the degradation performance of the hot melt adhesive is significantly reduced. The main reason is that the ether bond breakage of the aromatic ester ether polymer cannot cause the destruction of the hot melt adhesive matrix.

[0096] It can be seen from Example 3 and Comparative Example 3 that the performance of conventional SIS hot melt adhesive in acidic soil is relatively stable, and there is no obvious damage to the structure after 180 days of embedding, the mass percentage is above 96%, and there is basically no degradation phenomenon.

[0097] The above embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and replacements made by technicians in this field on the basis of the present invention fall within the scope of protection required by the present invention.

Claims

1. Creep-resistant, degradable and environmentally friendly SIS hot melt adhesive, characterized by: The raw materials are as follows, counted by weight: 40-50 parts of SIS resin, 10-20 parts of tackifying resin, 5-10 parts of plasticizer, and 1-3 parts of antioxidant.

2. The creep-resistant, degradable and environmentally friendly SIS hot melt adhesive according to claim 1, characterized in that: SIS resin includes block-modified SIS resin. The preparation steps of the block-modified SIS resin include: Add cyclohexane solvent and styrene monomer to the polymerization bottle; add cyclohexane solvent and isoprene to ampoule A, add cyclohexane solvent and styrene to ampoule B, and seal the polymerization bottle, ampoule A and ampoule B; The polymerization bottle is preheated, an anionic initiator is added, and the reaction is carried out; the mixture in ampoule bottle A is added to the polymerization bottle, and the reaction is carried out; the aryl ester ether prepolymer and the catalyst are added, and the reaction is carried out; the mixture in ampoule bottle B is added to the polymerization bottle, and the reaction is carried out; the product is taken out, the reaction is terminated, and the block-modified SIS resin is obtained by drying.

3. The creep-resistant, degradable and environmentally friendly SIS hot melt adhesive according to claim 2, characterized in that: The amount of catalyst added is 0.1-0.5g.

4. The creep-resistant, degradable and environmentally friendly SIS hot melt adhesive according to claim 2, characterized in that: The anionic initiator includes one or more of n-butyl lithium, phenyl lithium and triethylamine.

5. The creep-resistant, degradable and environmentally friendly SIS hot melt adhesive according to claim 2, characterized in that: The catalyst comprises one or more of tetraphenylphosphonium bromide, triphenylethylphosphonium bromide and tetrabutylammonium bromide.

6. The creep-resistant, degradable and environmentally friendly SIS hot melt adhesive according to claim 2, characterized in that: The aryl ester ether prepolymer includes a borane-containing aryl ester ether prepolymer, and the preparation steps of the borane-containing aryl ester ether prepolymer include: Epichlorohydrin, bisphenol A polyoxyethylene ether, tri-sec-butylborane, and tetramethylammonium bromide are introduced into nitrogen, stirred for reaction, cooled, and a sodium hydroxide aqueous solution is added dropwise, the reaction is continued, and heated to obtain borane bisphenol diglycidyl ether; borane bisphenol diglycidyl ether, adipic acid, tetraphenylphosphonium bromide, and ethylene glycol methyl ether acetate are introduced into nitrogen, reacted, cooled, washed, and dried to obtain an aryl ester ether prepolymer.

7. The creep-resistant, degradable and environmentally friendly SIS hot melt adhesive according to claim 6, characterized in that: The amount of tri-sec-butylborane added is 0.5-1 g.

8. The creep-resistant, degradable and environmentally friendly SIS hot melt adhesive according to claim 1, characterized in that: The tackifying resin includes one or more of C5 hydrogenated petroleum resin, C9 hydrogenated petroleum resin and terpene resin.

9. The creep-resistant, degradable and environmentally friendly SIS hot melt adhesive according to claim 1, characterized in that: The plasticizer includes one or more of naphthenic oil, white mineral oil and liquid paraffin; the antioxidant includes one or more of antioxidant 1010, antioxidant 168 and antioxidant trisnonylphenyl phosphite.

10. The method for preparing the creep-resistant, degradable and environmentally friendly SIS hot melt adhesive according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: taking SIS resin, tackifying resin, plasticizer, and antioxidant, heating and stirring continuously, and after the SIS resin is completely melted, heating to 150-180°C until the system is completely melted and becomes uniformly viscous, stopping stirring, and discharging the material while hot to obtain creep-resistant, degradable, and environmentally friendly SIS hot melt adhesive.

Images