JP-7856094-B2 - Phenylboronic acid compounds, modified polymers, polymer compositions, and tires

Inventors

• 姜 嵐

Assignees

• 住友ゴム工業株式会社

Dates

Publication Date

20260511

Application Date

20211025

Priority Date

20210419

Claims (6)

1. A tire having a tire component made of a polymer composition containing a modified polymer modified with a phenylboronic acid compound represented by the following formula (1). ( R11 is a monovalent hydrocarbon group having a nitrogen atom, either identical or different. n is an integer from 1 to 5.)
2. The tire according to claim 1, wherein the polymer constituting the backbone of the modified polymer is at least one selected from the group consisting of isoprene rubber, acrylonitrile butadiene rubber, butadiene rubber, and styrene butadiene rubber.
3. The tire according to claim 1 or 2, wherein the modified polymer is in a solid state at 25°C and has a weight-average molecular weight of 10,000 or more.
4. The tire according to claim 1, wherein the modified polymer is in a liquid state at 25°C.
5. The polymer composition contains a rubber component, The tire according to claim 1, wherein the rubber component comprises a modified polymer modified with a phenylboronic acid compound represented by formula (1), which is in a solid state at 25°C.
6. Certain polymer compositions include liquid polymers, The tire according to claim 1, wherein the liquid polymer comprises a modified polymer modified with a phenylboronic acid compound represented by formula (1), which is in a liquid state at 25°C.

Description

This disclosure relates to phenylboronic acid compounds, modified polymers, polymer compositions, and tires. Various polymers are used in products such as tires, and there is a demand for the imparting of various properties through polymers. This is an example of a synthesis of a phenylboronic acid compound represented by formula (1).This is an example of a 1H -NMR spectrum of a synthesized product.This is an example of a synthesis that shows a pathway in which a modified polymer is synthesized by the reaction of a phenylboronic acid compound with a polymer.These are examples of IR spectra and 1H -NMR spectra of synthetic compounds. <Modified polymers> This disclosure relates to a modified polymer modified with a phenylboronic acid compound represented by the following formula (1). The modified polymer can exhibit reversible changes in physical properties when exposed to water. The reason why the aforementioned effects are obtained is not entirely clear, but it is presumed to be due to the following mechanism. When a modified polymer, obtained by reacting a polymer with a phenylboronic acid compound represented by formula (1), is dried, it undergoes reversible dehydration condensation of three molecules to generate boroxine (boroxine crosslinks). Subsequently, upon contact with water, the generated boroxine crosslinks decompose. Therefore, during drying, a polymer with boroxine crosslinks is formed, while during water swelling, the boroxine crosslinks decompose, forming the modified polymer. Consequently, the modified polymer can exhibit reversible changes in physical properties due to water. Furthermore, for example, if the modified polymer is used in a tire, it is presumed that the elastic modulus decreases upon contact with water, increasing losses on wet surfaces and improving wet grip performance. The aforementioned modified polymer is a polymer modified with a phenylboronic acid compound represented by the following formula (1). (R 11 is a monovalent hydrocarbon group, which may have substituents, either identical or different, and may contain heteroatoms. n is an integer from 1 to 5.) In formula (1), the monovalent hydrocarbon group constituting the skeleton of R 11 can be a linear, cyclic, or branched alkyl group, alkenyl group, aryl group, aralkyl group, etc., with alkyl groups being particularly preferred. The number of carbon atoms in R 11 is preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, and also preferably 30 or less, more preferably 20 or less, even more preferably 10 or less, and particularly preferably 6 or less. Specifically, examples include a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, etc. In formula (1) above, the substituent in R 11 may be added to the monovalent hydrocarbon group that constitutes the R 11 skeleton, or introduced into the skeleton. The substituent is not particularly limited and known groups can be cited. For example, examples include alkoxy groups having 1 to 4 carbon atoms such as methoxy, ethoxy, and butoxy groups; halogen atoms such as chlorine, bromine, iodine, and fluorine; aryl groups having 6 to 12 carbon atoms such as phenyl, naphthyl, and biphenyl groups; polar groups such as oxo (=O), hydroxyl, carboxyl, carbonyl, amino, acetyl, amide, and imide groups. From the viewpoint of reactivity with polymers, carboxyl, amino, and thiol groups are preferred substituents. From the viewpoint of obtaining a more reversible property change function due to water, the substituent is preferably a group having a nitrogen atom, and more preferably an amino group. The reason why the aforementioned effects are obtained is not entirely clear, but it is presumed to be due to the following mechanism. As described above, when a modified polymer obtained by reacting with a phenylboronic acid compound represented by formula (1) is dried, it undergoes reversible dehydration condensation of three molecules to generate boroxine (boroxine crosslinks). Subsequently, when it comes into contact with water, the generated boroxine crosslinks decompose, thus providing the function of reversible property change due to water. Furthermore, while ordinary phenylboroxine requires heating for dehydration and recondensation of three molecules after hydrolysis, in the case of phenylboronic acid compounds containing nitrogen atoms, particularly phenylboronic acid compounds where the nitrogen atom is located near the phenylboroxine group, dehydration and recondensation of three molecules is possible even at room temperature. Therefore, it is presumed that by using the above-mentioned modified polymer, the function of reversible property change due to water can be better imparted. In formula (1) above, when R 11 has a nitrogen atom, it is preferable that the nitrogen atom and the boron atom