Additive, surface treatment agent, surface-modified latex particles, method for producing surface-modified latex particles, reagent for latex agglutination reaction, kit, and method for detecting target substance
Provided are an additive and a surface treatment agent capable of suppressing agglutination of latex particles contained in a reagent for a latex agglutination reaction during storage of the reagent although a synthetic polymer is contained as an active component. An additive is to be added to latex particles used in a reagent for a latex agglutination reaction. The latex particles have not been subjected to blocking treatment. The additive includes a polymer containing more than 60% by mass and 99% by mass or less of hydrophilic repeating units (A) relative to all repeating units and 1% by mass or more and less than 40% by mass of hydrophobic repeating units (B) relative to all repeating units, and having a weight average molecular weight of 3,000 or more.
1. Surface-modified latex particles comprising:
latex particles, and
a polymer on surfaces of the latex particles,
wherein
the polymer comprises:
from more than 60% by mass to 99% by mass of hydrophilic repeating units relative to all repeating units, and
from 1% by mass to less than 40% by mass of hydrophobic repeating units relative to all repeating units, and
the polymer has a weight average molecular weight of 3,000 or more, and
wherein the hydrophilic repeating units comprise:
a hydrophilic repeating unit of the formula (6):
wherein R 21 represents a hydrogen atom or a methyl group, and
R 22 and R 23 each independently represent an alkanediyl group having 1 to 3 carbon atoms, and
a hydrophilic repeating unit of the formula (2):
wherein
R1 represents an alkanediyl group having 2 to 4 carbon atoms, and n represents 2 to 100 as an average value,
R2 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms,
R3 represents a hydrogen atom or a methyl group,
R4 represents —O—, *—(C═O)—O—, *-NR5-(C═O), wherein R5 represents a hydrogen atom or an organic group having 1 to 10 carbon atoms, and * represents a position bonded to a carbon atom to which R3 in the formula (2) is bonded, or a phenylene group.
2. A method for producing the surface-modified latex particles of claim 1 , the method comprising:
bringing the polymer into contact with the latex particles.
3. A reagent, comprising:
the surface-modified latex particles according to claim 1 .
4. A kit, comprising:
the reagent according to claim 3 .
5. The surface-modified latex particles according to claim 1 , wherein the hydrophilic repeating units further comprise a repeating unit of the formula (5):
wherein R 18 represents a hydrogen atom or a methyl group, and
R 19 and R 20 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a hydroxyalkyl group.
6. The surface-modified latex particles according to claim 1 , wherein the hydrophobic repeating units comprise at least one selected from the group consisting of a hydrophobic repeating unit of the formula (7) and a hydrophobic repeating unit of the formula (8):
wherein
R 31 represents a hydrogen atom or a methyl group,
R 32 represents —O—, *—(C═O)—O—, *—(C═O)—NR 34 —, *-NR 34 —(C═O)— wherein R 34 represents a hydrogen atom or an organic group having 1 to 10 carbon atoms, and * represents a position bonded to a carbon atom to which R 31 in formula (7) is bonded, or a phenylene group, and
R 33 represents a hydrocarbon group and
wherein
R 35 represents a hydrogen atom or a methyl group, and
Z represents an organic group having a formyl group or a keto group.
7. The surface-modified latex particles according to claim 6 , wherein the hydrophobic repeating units comprise the hydrophobic repeating unit of the formula (7) and the hydrophobic repeating unit of the formula (8).
8. The surface-modified latex particles of claim 1 , wherein n is from 4 to 90 as an average value.