Powder adhesive and bonded article
The powder adhesive comprises a thermoplastic resin and particles of an aromatic compound, wherein the particles of an aromatic compound are particles of a compound that has an aromatic ring and an azo bond bonded to the aromatic ring, or are particles of a compound comprising a heteroaromatic ring comprising nitrogen atom; the thermoplastic resin comprises an ester group; and, designating Es (mmol/g) as an ester group concentration in the thermoplastic resin, M (mass %) as a content of the aromatic compound particles in the powder adhesive, and N (mmol/g) as a nitrogen atom concentration in the aromatic compound particles, Es is from 1.0 mmol/g to 4.5 mmol/g, M is from 1.0×10 −4 mass % to 1.0×10 0 mass %, and N is from 5.0 mmol/g to 15.0 mmol/g.
1. A powder adhesive comprising:
a thermoplastic resin; and
a particle comprising an aromatic compound,
wherein the aromatic compound is a compound comprising an aromatic ring and an azo bond bonded to the aromatic ring, or a compound comprising a heteroaromatic ring comprising a nitrogen atom,
wherein the thermoplastic resin comprises an ester group, and
wherein, designating Es (mmol/g) as an ester group concentration in the thermoplastic resin, M (mass %) as a content of the aromatic compound particles in the powder adhesive, and N (mmol/g) as a nitrogen atom concentration in the aromatic compound particles,
Es is 1.0 to 4.5 mmol/g,
Mis 1.0×10 −4 to 5.0×10 −2 mass %, and
N is 5.0 to 15.0 mmol/g.
2. The powder adhesive according to claim 1 , wherein Es, M, and D satisfy formula (1), where D (nm) is a number-average particle diameter of the particle:
1.0×10 3 ≤Es ×( D/M )≤3.0×10 4 (1).
3. The powder adhesive according to claim 1 , wherein D is 30 to 200 nm where D (nm) is a number-average particle diameter of the particle.
4. The powder adhesive according to claim 1 , wherein the aromatic compound is the compound comprising the aromatic ring and the azo bond bonded to the aromatic ring.
5. The powder adhesive according to claim 4 , wherein the aromatic compound is a compound comprising a structure represented by following formula (4) below:
where, in the formula (4),
R 1 represents an alkyl group having 1 to 3 carbon atoms, and,
* and ** represent sites of bonding to aromatic rings present in the compound.
6. The powder adhesive according to claim 5 , wherein the compound comprising the structure represented by the formula (4) is a pigment.
7. The powder adhesive according to claim 1 , wherein the thermoplastic resin comprises a copolymer of monomers comprising:
a styrenic polymerizable monomer, and
at least one selected from the group consisting of acrylate esters and methacrylate esters.
8. The powder adhesive according to claim 7 , wherein a content of the copolymer in the thermoplastic resin is 70 to 100 mass %.
9. The powder adhesive according to claim 1 , wherein the aromatic compound is at least one selected from the group consisting of C. I. Pigment Yellow 74, C. I. Pigment Yellow 95, C. I. Pigment Yellow 155, and C. I. Pigment Yellow 180.
10. The powder adhesive according to claim 1 , wherein the powder adhesive comprises a hydrocarbon wax and an ester wax.
11. The powder adhesive according to claim 1 , wherein Mis 3.0−10 ×3 to 5.0×10 −2 mass %.
12. The powder adhesive according to claim 1 , wherein:
a content of the thermoplastic resin in the powder adhesive is 60.00 mass % to 99.99 mass %;
the aromatic compound is a compound selected from the group consisting of a compound comprising a structure represented by formula (4) and compounds 5 to 7:
where, in the formula (4):
R 1 represents an alkyl group having 1 to 3 carbon atoms; and
* and ** represent sites of bonding to aromatic rings present in the compound;
the thermoplastic resin comprises a copolymer of monomers comprising:
a styrenic polymerizable monomer; and
at least one selected from the group consisting of acrylate esters and methacrylate esters;
a content of the copolymer in the thermoplastic resin is 70 to 100 mass %; and
D is 30 to 200 nm, where D (nm) is a number-average particle diameter of the particle.
13. A bonded article comprising
an adhesive, and
at least one piece of paper bonded with the adhesive,
wherein the adhesive is a melt-hardened material from a powder adhesive,
the powder adhesive comprises
a thermoplastic resin, and
a particle comprising an aromatic compound,
wherein the aromatic compound is compound comprising an aromatic ring and an azo bond bonded to the aromatic ring, or a compound comprising a heteroaromatic ring comrpising a nitrogen atom,
wherein the thermoplastic resin comprises an ester group, and
wherein, designating Es (mmol/g) as an ester group concentration in the thermoplastic resin, M (mass %) as a content of the aromatic compound particles in the powder adhesive, and N (mmol/g) as a nitrogen atom concentration in the aromatic compound particles,
Es is 1.0 to 4.5 mmol/g,
M is 1.0×10 −4 to 5.0×10 31 2 mass %, and
N is 5.0 to 15.0 mmol/g.
14. The bonded article according to claim 13 , wherein:
a content of the thermoplastic resin in the powder adhesive is 60.00 mass % to 99.99 mass %;
the aromatic compound is a compound selected from the group consisting of a compound comprising a structure represented by formula (4) and compounds 5 to 7:
where, in the formula (4):
R 1 represents an alkyl group having 1 to 3 carbon atoms; and
* and ** represent sites of bonding to aromatic rings present in the compound;
the thermoplastic resin comprises a copolymer of monomers comprising:
a styrenic polymerizable monomer; and
at least one selected from the group consisting of acrylate esters and methacrylate esters;
a content of the copolymer in the thermoplastic resin is 70 to 100 mass %; and
D is 30 to 200 nm, where D (nm) is a number-average particle diameter of the particle.