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CN-121991620-A - Copolyester hot melt adhesive for laser edge sealing and preparation method thereof

CN121991620ACN 121991620 ACN121991620 ACN 121991620ACN-121991620-A

Abstract

The invention discloses a copolyester hot melt adhesive for laser edge sealing and a preparation method thereof, and the copolyester hot melt adhesive comprises, by mass, 51% -56% of dibasic acid, 40% -45% of dihydric alcohol, 0.1% -1.5% of laser absorbent, 0.025% -0.06% of catalyst, 0.01% -0.03% of heat stabilizer, 0.1% -1% of antioxidant, 0.2% -0.5% of trimethylolpropane, 0-0.3% of inorganic hardening agent, and one or more of cesium tungsten bronze or lanthanide series hexaboride, wherein the particle size is 30-80 nm, and the specific surface area is 20-50 m 2 /g. The invention utilizes in-situ polymerization to lead the laser absorbent to uniformly enter the hot melt adhesive so as to achieve the effect of absorbing laser melting, and simultaneously introduces polar monomers, hardening agents and reasonable material proportion to prepare the copolyester hot melt adhesive with heat resistance and high peeling strength for laser edge sealing.

Inventors

  • DU MIN
  • MENG HAICHENG

Assignees

  • 上海东睿新材料股份有限公司

Dates

Publication Date
20260508
Application Date
20260122

Claims (10)

  1. 1. The copolyester hot melt adhesive for laser edge sealing is characterized by comprising, by mass, 51% -56% of dibasic acid, 40% -45% of dihydric alcohol, 0.1% -1.5% of laser absorbent, 0.025% -0.06% of catalyst, 0.01% -0.03% of heat stabilizer, 0.1% -1% of antioxidant, 0.2% -0.5% of trimethylolpropane and 0% -0.3% of inorganic hardening agent; The laser absorber is one or more of cesium tungsten bronze or lanthanide series hexaboride, the particle size is 30-80 nm, and the specific surface area is 20-50 m 2 /g.
  2. 2. The copolyester hot melt adhesive according to claim 1, wherein said lanthanide hexaboride is at least one of lanthanum hexaboride, neodymium hexaboride and persimmon hexaboride.
  3. 3. The copolyester hot melt adhesive according to claim 1, wherein the molar ratio of the dibasic acid to the dihydric alcohol is 1 (1.4-1.5), and the dibasic acid is a mixture of aromatic dibasic acid and aliphatic dibasic acid according to the molar ratio of (0.90-0.98) to (0.02-0.1).
  4. 4. The copolyester hot melt adhesive according to claim 3, wherein the aromatic dibasic acid is one or more of terephthalic acid, isophthalic acid-5-sodium sulfonate, isophthalic acid and phthalic acid, and the aliphatic dibasic acid is one or more of 1, 4-succinic acid, 1, 6-adipic acid, sebacic acid and dodecanedioic acid.
  5. 5. The copolyester hot melt adhesive according to claim 1, wherein the dihydric alcohol is one or more of ethylene glycol, 1, 3-malonic acid, 1, 4-butanediol, diethylene glycol, 1, 4-cyclohexanedimethanol, and 1, 6-hexanediol.
  6. 6. The copolyester hot melt adhesive according to claim 1, wherein the catalyst is one or more of tetrabutyl titanate, antimony trioxide and dibutyltin dilaurate.
  7. 7. The copolyester hot melt adhesive according to claim 1, wherein the heat stabilizer is triphenyl phosphate or/and trimethyl phosphate, and the antioxidant is a compound of hindered phenol antioxidant 1010 and phosphite antioxidant 168 according to a mass ratio of 1 (1-1.2).
  8. 8. The copolyester hot melt adhesive according to claim 1, wherein the inorganic hardening agent is wollastonite of 800-1500 meshes or/and talcum powder of 1000-1500 meshes.
  9. 9. The method for preparing the copolyester hot melt adhesive for laser edge sealing according to any one of claims 1 to 8, which is characterized by comprising the following steps: S1, mixing trimethylolpropane, a laser absorbent and dihydric alcohol accounting for 20% -35% of the formula, and dispersing uniformly at a high speed to obtain a dispersion liquid A; S2, under the action of a catalyst, reacting the dispersion liquid A, the residual dihydric alcohol and the dibasic acid at 170-195 ℃ for 40-60 min, and then at 195-220 ℃ for 120-180 min, wherein when the distilled water amount is 95% or more of the theoretical water yield, the esterification reaction is finished to obtain an esterified liquid B; And S3, introducing nitrogen into the esterification liquid B, pressing the esterification liquid B into a polycondensation reaction kettle, simultaneously adding a heat stabilizer, an antioxidant and an inorganic hardening agent, reacting for 50-70 min at the temperature of 200-230 ℃ and the vacuum degree of 1000-500 Pa, heating to 235-238 ℃ and the vacuum degree of 50-100 Pa, continuing to react, detecting that the melt index is qualified, introducing nitrogen, simultaneously releasing the vacuum, blanking while the material is hot, and granulating and drying.
  10. 10. The method for preparing the copolyester hot melt adhesive for laser edge sealing according to claim 9, wherein the melt index of the copolyester hot melt adhesive at 160 ℃ and 2.16kg is 35-40 g/10min.

Description

Copolyester hot melt adhesive for laser edge sealing and preparation method thereof Technical Field The invention belongs to the technical field of polyester hot melt adhesives, and particularly relates to a copolyester hot melt adhesive for laser edge sealing and a preparation method thereof. Background The laser edge sealing technology is an emerging technology in recent years, and the edge sealing tape pre-coated with hot melt adhesive is instantaneously irradiated by laser to melt the adhesive layer and combine the adhesive layer with the plate base material. The technology has the characteristics of high processing efficiency, attractive glue line, suitability for plates with complex shapes, environmental protection and the like. The core of the laser edge sealing method is to develop special hot melt adhesive. The hot melt adhesive has high-efficiency absorption and conversion capability to near infrared laser (the common wavelength is about 940-1060 nm), can be used for instantly melting and wetting a substrate, and has excellent bonding strength and heat resistance. At present, the conventional method for preparing the laser edge sealing hot melt adhesive is to compound a laser absorbent with pre-synthesized PA, TPU, EVA and other resins through blending. However, the method has the defects of uneven dispersion (the laser absorbent is easy to agglomerate in melt blending, the uniformity of the product performance is affected, the local melting defect or overburning of the edge sealing can be caused), performance degradation (the polymer degradation is easy to cause by high-temperature melt processing of the copolyester resin, the molecular weight and the final mechanical property are affected), complicated process (the synthesis and modification distribution are carried out, the production energy consumption cost is increased), high cost and the like. Patent document CN119931585A discloses a laser edge sealing collagen resin, which comprises the following reaction raw materials, by mass, 0.5% -3% of an antioxidant, 0.5% -2% of a light absorber, 0-1% of a heat conducting agent, 0-1% of a colorant, 0-1% of an adhesion promoter, 0.5% -2% of a nucleating agent, 0-2% of a hardener and the balance of a hot melt adhesive resin, wherein the light absorber is tin antimony oxide, hexaboride, copper pyrophosphate, and the like. However, the laser absorber is easy to agglomerate and disperse unevenly in the resin, so that the laser absorber is unstable in laser absorption efficiency and poor in product quality uniformity, and the problems of thermooxidative degradation, color yellowing, mechanical property degradation and the like of a polymer molecular chain are caused in the secondary heating and shearing process. Moreover, intensive studies have found that not all copolyester hot melt adhesives are suitable for this particular process. If the melting point of the copolyester is too high, the laser energy is insufficient to melt the copolyester rapidly, so that poor adhesion is caused, and if the melting point is too low, the heat resistance after edge sealing cannot be ensured. If the crystallization speed is too slow, the strength cannot be quickly established after lamination, and peeling easily occurs. The hardness is too low, and the conditions of cutter sticking, glue overflow, poor high temperature resistance and the like are easy to occur. Therefore, the novel laser edge-sealing copolyester hot melt adhesive with excellent comprehensive performance and moderate cost and the preparation method thereof are developed, the dispersion problem of a laser absorbent is fundamentally solved, the process flow is simplified, and the method has important significance for improving the performance of the laser edge-sealing hot melt adhesive and promoting the industrial progress. Disclosure of Invention The invention aims to provide a copolyester hot melt adhesive for laser edge sealing and a preparation method thereof, wherein a laser absorbent is introduced at one time through in-situ polymerization, molecular-level dispersion is realized, secondary processing is avoided, the process is simple and efficient, and the obtained copolyester hot melt adhesive has high laser absorption efficiency, uniform performance, proper melt viscosity and high bonding strength. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: The copolyester hot melt adhesive for laser edge sealing comprises, by mass, 51% -56% of dibasic acid, 40% -45% of dihydric alcohol, 0.1% -1.5% of laser absorbent, 0.025% -0.06% of catalyst, 0.01% -0.03% of heat stabilizer, 0.1% -1% of antioxidant, 0.2% -0.5% of trimethylolpropane and 0% -0.3% of inorganic hardening agent; The laser absorber is one or more of cesium tungsten bronze or lanthanide series hexaboride, the particle size is 30-80 nm, and the specific surface area is 20-50 m 2/g; The mol ratio of the dibasic acid to the dihydric alcohol is 1 (1.4-1.