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US-12624153-B2 - Modified polyurethane prepolymer, two-component polyurethane adhesive and preparation method thereof

US12624153B2US 12624153 B2US12624153 B2US 12624153B2US-12624153-B2

Abstract

The present invention relates to a modified polyurethane prepolymer, a two-component polyurethane adhesive and the preparation method thereof. The modified polyurethane prepolymer is prepared from the raw materials comprising the following components: polyurethane prepolymer and graphene oxide; wherein, the polyurethane prepolymer is prepared from the raw materials comprising the following components: copolymer containing ureidopyrimidinone groups and aliphatic isocyanate; wherein, the copolymer containing ureidopyrimidinone groups is formed by copolymerization of the raw materials comprising the following components: alkyl acrylate ureidopyrimidinone, and hydroxyethyl alkyl acrylate; wherein, the alkyl acrylate ureidopyrimidinone has the structure shown in Formula (I); and the hydroxyethyl alkyl acrylate has the structure shown in Formula (II). The two-component polyurethane adhesive containing the modified polyurethane prepolymer has excellent mechanical properties and aging resistance simultaneously.

Inventors

  • Jun Song
  • Long TANG
  • Jianjun Chen
  • Hengchao HUANG
  • Mingsong Miao

Assignees

  • GUANGZHOU BAIYUN TECHNOLOGY CO., LTD.

Dates

Publication Date
20260512
Application Date
20221013
Priority Date
20200416

Claims (19)

  1. 1 . A modified polyurethane prepolymer, is prepared from raw materials comprising the following components: polyurethane prepolymer and graphene oxide; wherein, the polyurethane prepolymer is prepared from raw materials including the following components: copolymer containing ureidopyrimidinone groups, and aliphatic isocyanate; wherein the copolymer containing ureidopyrimidinone groups is formed by copolymerization of raw materials including the following components: alkyl acrylate ureidopyrimidinone, and hydroxyethyl alkyl acrylate; wherein, the alkyl acrylate ureidopyrimidinone has a structure shown in Formula (I): the hydroxyethyl alkyl acrylate has a structure shown in Formula (II): wherein, R 1 is C 1 -C 6 alkyl; R 2 is H, or C 1 -C 6 alkyl.
  2. 2 . The modified polyurethane prepolymer according to claim 1 , wherein, the copolymer containing ureidopyrimidinone groups has a structure shown in Formula (III): wherein, n is 1-100, m is 1-10; R 1 is C 1 -C 6 alkyl; R 2 is H or C 1 -C 6 alkyl.
  3. 3 . The modified polyurethane prepolymer according to claim 1 , wherein the aliphatic isocyanate is at least one of the following: hexamethylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, isophorone diisocyanate, 1,4-cyclohexyl diisocyanate and methylcyclohexyl diisocyanate.
  4. 4 . The modified polyurethane prepolymer according to claim 1 , having a structure shown in Formula (IV): wherein, n is 1-100, m is 1-10; R 1 is C 1 -C 6 alkyl; R 2 is H or C 1 -C 6 alkyl; and R is —(CH 2 ) 6 —,
  5. 5 . The modified polyurethane prepolymer according to a claim 1 , wherein R 1 is methyl; and/or R 2 is H or methyl.
  6. 6 . The modified polyurethane prepolymer according to claim 2 , wherein R 1 is methyl; and/or R 2 is H or methyl.
  7. 7 . The modified polyurethane prepolymer according to claim 4 , wherein R 1 is methyl; and/or R 2 is H or methyl.
  8. 8 . The modified polyurethane prepolymer according to claim 1 , wherein a mass ratio of the alkyl acrylate ureidopyrimidinone, the hydroxyethyl alkyl acrylate, the aliphatic isocyanate and the graphene oxide is 100:(5-20):(60-90):(1-30).
  9. 9 . The modified polyurethane prepolymer according to claim 8 , wherein the mass ratio of the alkyl acrylate ureidopyrimidinone, the hydroxyethyl alkyl acrylate, the aliphatic isocyanate and the graphene oxide is 100:(8-12):(75-85):(15-25).
  10. 10 . The modified polyurethane prepolymer according to claim 1 , wherein NCO content of the modified polyurethane prepolymer is 11% to 14%, and its viscosity at 25° C. is 30000 mPa·s to 70000 mPa·s.
  11. 11 . The modified polyurethane prepolymer according to claim 4 , wherein NCO content of the modified polyurethane prepolymer is 11% to 14%, and its viscosity at 25° C. is 30000 mPa·s to 70000 mPa·s.
  12. 12 . A preparation method of the modified polyurethane prepolymer according to claim 1 , comprising the following steps: step 1: dissolving a chain transfer agent, together with the alkyl acrylate ureidopyrimidinone, hydroxyethyl alky acrylate and an initiator in an organic solvent to carry out copolymerization reaction to obtain a copolymer containing the ureidopyrimidinone groups, thereby forming a first solution; step 2: adding the aliphatic isocyanate to the first solution after the reaction in step 1, to react, and obtaining the polyurethane prepolymer, thereby forming a second solution; and step 3: adding the graphene oxide to the second solution after the reaction in step 2 to react, and obtaining the modified polyurethane prepolymer.
  13. 13 . The preparation method of the modified polyurethane prepolymer according to claim 12 , wherein the chain transfer agent is at least one of the following: cumyl dithiobenzoate, tert-buty benzodithioate, bis(benzylsulfanyl)methanethione and 2-phenyl-2-propylbenzodithioate; and/or, the initiator is azobisisobutyronitrile and/or benzoyl peroxide.
  14. 14 . The preparation method of the modified polyurethane prepolymer according to claim 13 , wherein an amount of the chain transfer agent is 0.1 wt % to 2 wt % of the alkyl acrylate ureidopyrimidinone; and an amount of the initiator is 0.1 wt % to 2 wt % of the alkyl acrylate ureidopyrimidinone.
  15. 15 . The preparation method of the modified polyurethane prepolymer according to claim 12 , wherein a temperature of the copolymerization reaction in step 1 is 50° C. to 70° C., and a time of the copolymerization reaction is 6 hours to 18 hours; and/or, a temperature of the reaction in step 2 is 20° C. to 30° C., and a reaction time is 18 hours to 28 hours; and/or, a temperature of the reaction in step 3 is 20° C. to 30° C., and a reaction time is 1 hour to 3 hours.
  16. 16 . A two-component polyurethane adhesive, comprising component A and component B; in parts by weight, the component A is prepared from raw materials comprising the following components: 100 parts of polyol; 0.01 parts˜5 parts of catalyst; and 50 parts˜100 parts of inorganic filler, and the component B is the modified polyurethane prepolymer according to claim 1 .
  17. 17 . The two-component polyurethane adhesive according to claim 16 , wherein a mass ratio of the component A and the component B is (1-3):1; and/or, the polyol is one or more of the following: phenyl-modified polyether polyol, polyether polyol, polyester polyol and short-chain polyol; and/or, the catalyst is an organotin catalyst and/or a tertiary amine catalyst; and/or, the inorganic filler is at least one of the following: ultrafine calcium carbonate, nano-calcium carbonate and aluminum hydroxide.
  18. 18 . The two-component polyurethane adhesive according to claim 17 , wherein a viscosity of the polyol at 25° C. is 1000 cps to 5000 cps; the organotin catalyst is dibutyltin dilaurate and/or stannous octoate, and the tertiary amine catalyst is triethylenediamine, triethanolamine and/or triethylamine; a particle size of the aluminum hydroxide is 1000 mesh to 2000 mesh.
  19. 19 . A preparation method of the two-component polyurethane adhesive according to claim 16 , comprising the following steps: preparation of the component A: mixing the polyol with the inorganic filler, then adding the catalyst, stirring and dispersing, and vacuum defoaming to obtain the component A; preparation of the component B: step 1: dissolving a chain transfer agent, together with the alkyl acrylate ureidopyrimidinone, hydroxyethyl alky acrylate and an initiator in an organic solvent to carry out copolymerization reaction to obtain a copolymer containing the ureidopyrimidinone groups, thereby forming a first solution; step 2: adding the aliphatic isocyanate to the first solution after the reaction in step 1 to react, and obtaining the polyurethane prepolymer, thereby forming a second solution; step 3: adding the graphene oxide to the second solution after the reaction in step 2 to react, and obtaining the modified polyurethane prepolymer.

Description

CROSS-REFERENCE TO RELATED APPLICATION The present application is a continuation of PCT application No. PCT/CN2020/139812, filed on Dec. 28, 2020, which claims the priority of China Patent Application No. 202010300025.9, filed on Apr. 16, 2020. The entirety of each of the above mentioned patent applications is incorporated by reference herein and made a part of this specification. TECHNICAL FIELD The present disclosure relates to the technical field of adhesives, in particular to a modified polyurethane prepolymer, a two-component polyurethane adhesive and the preparation method thereof. DESCRIPTION OF RELATED ART Two-component polyurethane adhesive is widely used in automobile, woodworking, food packaging, civil construction and other fields because of its advantages of strong adhesion, adjustable curing rate, and strong performance designability. It has become the PU adhesive product with the largest variety and output. However, although aromatic polyurethane adhesive has strong mechanical properties, it has the defect of easy yellowing and aging, which restricts the high-end development of two-component polyurethane adhesives. There are roughly two methods to solve the above-mentioned problems. One method is to add anti-aging agents or inorganic fillers that can absorb ultraviolet radiation. This method can only delay aging to a certain extent, but yellowing and aging will still occur when the exposure to natural light becomes longer. Therefore, this method cannot fundamentally eliminate the yellowing and aging of the polyurethane adhesive, and moreover, adding too much anti-yellowing agent or filler will affect the overall mechanical properties of the polyurethane adhesive. Another method is to solve the yellowing problem from the design of molecular structure, such as changing the raw material of aromatic isocyanate to aliphatic isocyanate. This method can effectively avoid yellowing. However, it also significantly reduces the mechanical strength of the polyurethane colloid, which consequently cannot be used as structural bonding for metals or other materials. Therefore, the development of polyurethane adhesives with excellent mechanical properties and resistance to yellowing and aging is of great significance for the high-end expansion of the polyurethane adhesive industry. SUMMARY Based on the above, one of the objects of the present disclosure is to provide a new type of two-component polyurethane adhesive with excellent mechanical properties and aging resistance simultaneously. In order to achieve the purpose above, the present disclosure firstly provides a modified polyurethane prepolymer, and the two-component polyurethane adhesive comprising said modified polyurethane prepolymer, which has excellent mechanical properties and aging resistance simultaneously. The specific technical solutions are as follows. A modified polyurethane prepolymer, is prepared from the raw materials comprising the following components: polyurethane prepolymer and graphene oxide; wherein said polyurethane prepolymer is prepared from the raw materials including the following components: copolymer containing ureidopyrimidinone groups, and aliphatic isocyanate; whereinsaid copolymer containing ureidopyrimidinone groups is formed by copolymerization of the raw materials including the following components: alkyl acrylate ureidopyrimidinone, and hydroxyethyl alkyl acrylate; wherein, said alkyl acrylate ureidopyrimidinone has the structure shown in Formula (I): said hydroxyethyl alkyl acrylate has the structure shown in Formula (II): wherein, R1 is C1-C6 alkyl; R2 is H, or C1-C6 alkyl. In some embodiments, the copolymer containing ureidopyrimidinone groups has the structure shown in Formula (III): wherein, n is 1-100, m is 1-10; R1 is C1-C6 alkyl; R2 is H or C1-C6 alkyl. In some embodiments, the aliphatic isocyanate is at least one of the following: hexamethylene diisocyanate (HDI), 4,4′-dicyclohexylmethane diisocyanate (HMDI), isophorone diisocyanate (IPDI), 1,4-cyclohexyl diisocyanate and methylcyclohexyl diisocyanate (HTDI). In some embodiments, the modified polyurethane prepolymer has the structure shown in Formula (IV): wherein, n is 1-100, m is 1-10; R1 is C1-C6 alkyl; R2 is H or C1-C6 alkyl; andR is —(CH2)6—, In some embodiments, R1 is methyl. In some embodiments, R2 is H or methyl. In some embodiments, a mass ratio of the alkyl acrylate ureidopyrimidinone, the hydroxyethyl alkyl acrylate, the aliphatic isocyanate and the graphene oxide is 100:(5-20):(60-90):(1-30). In some embodiments, the mass ratio of the alkyl acrylate ureidopyrimidinone, the hydroxyethyl alkyl acrylate, the aliphatic isocyanate and the graphene oxide is 100:(8-12):(75-85):(15-25). In some embodiments, the NCO content of the modified polyurethane prepolymer is 11%-14%, and its viscosity at 25° C. is 30000 mPa·s-70000 mPa·s. The present disclosure also provides a method for preparing the above-mentioned modified polyurethane prepolymer. The specific t