Adhesive composition, and method for preparing same
Provided is an adhesive composition including ornithine, citric acid, and water, wherein the ornithine and the citric acid are present in the form of an aqueous salt solution and do not form precipitates in the aqueous solution. Also provided a method of preparing an adhesive composition including: mixing ornithine, citric acid, and water to form a mixture of the ornithine, the citric acid, and the water; and stirring the mixture at a temperature of less than 80° C., wherein respective contents of the ornithine, the citric acid, and the water are adjusted such that precipitates of the ornithine and the citric acid do not form in the adhesive composition.
1. An adhesive composition in combination with substrates, the adhesive composition comprising:
ornithine, citric acid, and water,
wherein the ornithine and the citric acid are present in the form of an aqueous salt solution, wherein the aqueous salt solution does not form a precipitate when stored for 14 days or more at a temperature of −18° C. to 80° C.,
wherein the mixing molar ratio of the ornithine to the citric acid is in the range of 1.8:1 to 1:3, and the solid content in the adhesive composition is 10 parts by weight to 70 parts by weight based on 100 parts by weight of the adhesive composition, and
wherein the adhesive composition is present between a first substrate and a second substrate.
2. The adhesive composition in combination with the substrates of claim 1 , wherein
the mixing molar ratio of the ornithine to the citric acid is in the range of 1.5:1 to 1:3.
3. The adhesive composition in combination with the substrates of claim 1 , wherein
the sum of the contents of ornithine and citric acid is in the range of 60 parts by weight to 100 parts by weight based on 100 parts by weight of the solid content in the adhesive composition.
4. The adhesive composition in combination with the substrates of claim 1 , wherein the adhesive composition further comprises
at least one alcohol selected from a primary alcohol, a polyhydric alcohol, an unsaturated aliphatic alcohol, or an alicyclic alcohol.
5. The adhesive composition of in combination with the substrates claim 4 , wherein
the alcohol comprises at least one of:
a monohydric alcohol selected from methanol, ethanol, propane-2-ol, butane-1-ol, pentane-1-ol, and hexadecane-1-ol;
a polyhydric alcohol selected from ethane-1,2-diol, propane-1,2-diol, propane-1,2,3-triol, butane-1,3-diol, butane-1,2,3,4-tetraol, pentane-1,2,3,4,5-pentol, hexane-1,2,3,4,5,6-hexol, and heptane-1,2,3,4,5,6,7-heptol;
an unsaturated aliphatic alcohol selected from prop-2-en-1-ol, 3,7-dimethylocta-2,6-dien-1-ol, and prop-2-yn-1-ol; or
an alicyclic alcohol selected from cyclohexane-1,2,3,4,5,6-hexol and 2-(2-propyl)-5-methylcyclohexane-1-ol.
6. The adhesive composition in combination with the substrates of claim 1 , wherein the precipitate of ornithine and citric acid does not form when stored for 12 months at a temperature of −18° C. to 80° C.
7. The adhesive composition in combination with the substrates of claim 1 , wherein the adhesive composition further comprises at least one of itaconic acid, oxaloacetic acid, alpha-ketoglutaric acid, or malic acid, in an amount of 0.1 parts by weight to 10 parts by weight, based on 100 parts by weight of citric acid.
8. The adhesive composition in combination with the substrates of claim 1 , wherein the adhesive composition further comprises at least one alcohol selected from a primary alcohol, a polyhydric alcohol, an unsaturated aliphatic alcohol, or an alicyclic alcohol, and a weight ratio of the water to the alcohol is in a range from 1:1 to 3:2.
9. The adhesive composition in combination with the substrates of claim 1 , wherein the first substrate and the second substrate are independently selected from the group consisting of glass, a polymer film, a metal, plastic, paper, and fiber.
10. The adhesive composition in combination with the substrates of claim 1 , wherein at least one of the first or the second substrate includes an uneven surface.
11. The adhesive composition in combination with the substrates of claim 1 , wherein at least one of the first or the second substrate includes a surface that is hydrophilically treated.
12. The adhesive composition in combination with the substrates of claim 4 , wherein the mixing weight ratio of the water to the alcohol in the adhesive composition is in a range of 1:1 to 5:1.