Invented by Hiroshi Yabu, Matsuhiko Nishizawa, Kuniaki Nagamine, Yuta Saito, Jun Kamei, Tatsuaki SHIMAZAKI, Shun CHIHARA, Japan Science and Technology Agency

Catechol is a chemical compound that has been gaining a lot of attention in the field of adhesive hydrogels. Adhesive hydrogels are materials that have the ability to stick to surfaces and are commonly used in medical and industrial applications. The market for catechol-containing adhesive hydrogels, compositions for preparing adhesive hydrogels, and compositions containing catechol is growing rapidly due to the unique properties of catechol. Catechol-containing adhesive hydrogels have been found to have superior adhesive properties compared to traditional hydrogels. The catechol group in the adhesive hydrogel allows for strong adhesion to a variety of surfaces, including wet surfaces. This makes them ideal for use in medical applications such as wound dressings and tissue engineering. Additionally, catechol-containing adhesive hydrogels have been found to have excellent biocompatibility, making them safe for use in the human body. Compositions for preparing adhesive hydrogels containing catechol are also in high demand. These compositions typically include a polymer matrix and catechol-containing molecules. The polymer matrix provides the structure for the hydrogel, while the catechol-containing molecules provide the adhesive properties. These compositions can be tailored to meet specific application requirements, such as strength, flexibility, and biocompatibility. Compositions containing catechol are also being used in a variety of applications outside of adhesive hydrogels. Catechol has been found to have antioxidant properties, making it useful in the development of anti-aging and skin care products. Additionally, catechol has been used in the development of coatings for metal surfaces, providing corrosion resistance and improved adhesion. The market for catechol-containing adhesive hydrogels, compositions for preparing adhesive hydrogels, and compositions containing catechol is expected to continue to grow in the coming years. The unique properties of catechol make it an attractive material for a variety of applications, from medical to industrial. As research continues to uncover new uses for catechol, the market for these materials is expected to expand even further.

The Japan Science and Technology Agency invention works as follows

The hydrogel adheres to surfaces of materials by using a water-soluble monomer main chain, a crosslinking agent and a polymerization initiator.

Background for Catechol containing adhesive hydrogels, compositions for preparing adhesive Hydrogels, and compositions containing said adhesive hydrogels

1. “1.

The present invention is a new adhesive hydrogel that contains a catechol group. It also relates to a composition of an adhesive hydrogel.

2. “2.

A hydrogel consists of a three-dimensional structure created by crosslinking polymers. Hydrogels have a hydrous nature, are flexible, absorbent, and exhibit volume phase transition. They are used in a variety of fields, including medical materials and industrial products. Medical materials include, for example, wound healing materials that adhere tissue, adhesives in implants, and matrices used to deliver drugs.

In recent years, the study of imparting different functions to hydrogels according to their purpose and using them for the desired purposes has been carried out. ?Smart gels? The development of gels that can function autonomously when they detect an external stimulus, such as light, heat, electricity or pH, is also underway. Hydrogels with various functions are currently being developed. However, they are limited in their applications because the hydrogels have virtually no adhesion to other materials like metals.

The main reason why hydrogels do not adhere to other surfaces is that there is a high water content in the three-dimensional polymer network and hydrogels can be easily deformed structurally. Hydrogels have been given adhesive properties through various methods. “Non-patent documents 1 and 2” have disclosed methods of immobilizing hydrogels by introducing photoinitiating groupings such as phenylazide into a substrate, or attaching the hydrogel after it has been decomposed with an excimer.

A method for chemically altering the polymer main chains and adding an adhesive group was also disclosed. Patent Document 1 discloses a bioinjectable tissue-adhesive hydrogel having tissue adhesive force through bonding with DOPA (3,4-dihydroxyphenylalanine) or a DOPA derivative. DOPA derivatives have been found to adhere to surfaces such as metals, concrete, rocks, trees and other materials. This is even true in environments with high tides and moist environments. DOPA, which is secreted by the byssus of mussels, can stick to many materials even when they are submerged in water. Patent Document 1 prepares an adhesive hydrogel by linking a DOPA derivative compound to the main chain in a hydrogel.

Patent Document 2 describes a method of producing a gel polymer endowed with adhesiveness, by impregnating an amorphous base material with a polymer with a structure similar to polyacrylate in the main chain. The side chain has a structure like a chain-like polyalkylene oxide.

PRIOR ART DOCUMENTS

Patent Documents

Non-Patent Documents

The method disclosed by Non-patent Document 1 involves chemical modification of substrate surface, and requires complex procedures. The Non-patent Document 2 method requires a powerful light source. “A hydrogel can’t be immobilized by simply placing it on the surface of a substrate, even if you use either method.

The Patent Document 1 describes a method for imparting adhesiveness to a polymer by adding a catechol group that is highly adhesive into the main chain of the polymer. All catechols introduced, however, cannot be used for adhesion as the catechols introduced in the main chain also serve to link polymers. A strong adhesive force could not be obtained. There is also a risk that the hydrogel may not hold its shape when free catechol is present, which raises doubts about the practical application. The peeling adhesive strength of the examples also showed that the Patent Document 2 method was not intended to provide a firm adhesive. The adhesiveness of the example was insufficient. “The purpose of this invention is to create a hydrogel with a firm enough adhesive force that it can function as an adhesive.

All catechol groups introduced work effectively as adhesible group by causing the catachol groups, adhesive molecules, be contained in the side chain instead of the main chain. Since the amount of catechols in the side chains can be freely adjusted, the adhesive force can be altered. There are some problems, such as selecting the main chain monomer which polymerizes the monomer with a catechol group on a side-chain and functions as a Hydrogel. Also, the polymerization stops due to a decrease in polarity in the monomer of the catechol monomer because it imparts polymerizables groups. It was also difficult to create a hydrogel causing catechol groups to remain in the side-chain.

The purpose of this invention is to create a hydrogel which bonds strongly to the surface or various materials, or to create a variety applications using an adhesive hydrogel. By containing catechol groups in the side chain of a hydrogel, it is possible to produce a hydrogel with a stronger adhesive force than conventional adhesive hydrogels, as well as a hydrogel with a range of applications.

The present invention is a catechol-containing adhesion hydrogel. It also relates to adhesives, bioadhesives, antifouling paint for ship bottoms, water-based lubricants, and coating materials for antifouling.

(1) A water-soluble monomer main chain, a crosslinking agents, a polymerization initiater, and an adhesive monomer with a catechol group on a side chain are constituent elements of the adhesive hydrogel.

(2) The adhesion hydrogel of (1), wherein the catechol is derived either from DOPA or its derivative.

(3) The water-soluble monomer main chain of the adhesive hydrogel as per (1) or (2), wherein it is a monomer containing a vinyl group.

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