HOT-MELT ADHESIVE COMPOSITION
The invention relates to a hot-melt adhesive composition comprising: i) at least one specific semicrystalline aliphatic copolyamide, ii) at least one filler, the content of carbon atoms of which is between 60% and 100% relative to the number of atoms constituting the filler, the carbon-based filler having a D90 median average particle size ranging from 1 to 400 micrometers, iii) at least one electrically insulating filler chosen from oxides of metals and nitrides, the sum of the contents of carbon-based filler and of electrically insulating filler is between 30% and 75% by weight relative to the total weight of the composition, said fillers having a D90 median average particle size ranging from 1 to 400 micrometers. The invention also relates to a process for the preparation thereof and to the use thereof.
1 - 16 . (canceled)
17 . A hot-melt adhesive composition comprising:
i) at least one semicrystalline aliphatic copolyamide comprising at least two units corresponding to the following formula (1):
X/Y (1)
in which:
the unit X is a semicrystalline unit obtained by the polycondensation of a unit chosen from a C6 to C18 α,ω-aminocarboxylic acid, a C6 to C18 lactam and a (Ca diamine). (Cb diacid) unit, with a representing the number of carbon atoms of the diamine and b representing the carbon number of the diacid, a being between 2 and 18 and b being between 4 and 18, the Ca diamine and the Cb diacid being saturated or unsaturated, linear or branched aliphatic or cycloaliphatic,
the unit Y is a unit obtained by the polycondensation of a (Cd diamine). (Ce diacid) unit, with d representing the number of carbon atoms of the diamine and e representing the carbon number of the diacid, d and e being between 2 and 48, the Cd diamine and the Ce diacid being saturated or unsaturated, linear or branched aliphatic or cycloaliphatic, it being possible for the Cd diamine to be a polyetheramine,
the unit Y having a Tg of less than 30° C.,
the copolyamide having a melt viscosity, measured according to the standard ASTM D3236-88 (2009), of between 0.5 and 300 Pa·s at 200° C.,
the copolyamide constituting the matrix of the composition,
ii) at least one filler, the content of carbon atoms of which is between 60% and 100% relative to the number of atoms constituting the filler, and
iii) at least one electrically insulating filler chosen from oxides of metals and nitrides,
the sum of the contents of carbon-based filler and of electrically insulating filler is between 30% and 75% by weight relative to the total weight of the composition, said fillers having a D90 median average particle size ranging from 1 to 400 micrometers.
18 . The composition as claimed in claim 17 , characterized in that the carbon-based filler has a D50 median average particle size ranging from 0.5 to 500 micrometers.
19 . The composition as claimed in claim 17 , characterized in that the carbon-based filler has a BET specific surface area measured according to ISO 9277:2010 of between 1 and 300 m 2 /g.
20 . The composition as claimed in claim 17 , characterized in that the electrically insulating filler has a BET specific surface area measured according to ISO 9277:2010 of between 0.1 and 80 m 2 /g.
21 . The composition as claimed in claim 17 , characterized in that it has a melt viscosity of between 0.5 and 400 Pa·s.
22 . The composition as claimed in claim 17 , characterized in that it has a surface resistivity measured according to the standard IEC 62631 Mar. 2 (2015) of greater than 1010 Ω.m.
23 . The composition as claimed in claim 17 , characterized in that it has a melting point of less than 220° C.
24 . The composition as claimed in claim 17 , characterized in that the copolyamide comprises at least one of the units selected from the group consisting of PA 26, PA 29, PA 210, PA 212, PA 214, PA 218, PA 56, PA 59, PA 510, PA 512, PA 66, PA 69, PA 610, PA 612, PA 6, PA 11, PA 12, PA 1010, PA 1012, PA 1212, PA pip10, PA pip36, PA pip44, PA POP40036, PA POP40044, PA POP40010, PA POP4006, PA POP200036, PA POP200044, PA POP200010, PA POP20006, PA3636, PA3644, PA 4436, PA 4444 and a mixture thereof.
25 . The composition as claimed in claim 17 , characterized in that the copolyamide comprises a polyetheramine as Cd diamine or else an acid dimer as Ce diacid.
26 . The composition as claimed in claim 17 , characterized in that the copolyamide is a terpolyamide or a tetrapolyamide.
27 . The composition as claimed in claim 17 , characterized in that the composition comprises additives chosen from antioxidants, UV stabilizers, heat stabilizers, plasticizers, nucleating agents, tackifying agents, impact modifiers, flame retardants, antistatic agents, reinforcing agents, lubricants, organic and inorganic fillers, optical brighteners, mold-release agents, pigments, dyes, catalysts, and mixtures thereof.
28 . The composition as claimed in claim 17 , characterized in that it is capable of being injected at a pressure of less than 100 bar.
29 . The composition as claimed in claim 17 , characterized in that:
when the carbon-based filler is expanded graphite, then it is present in the composition in a content of between 5% and 17% by weight relative to the total weight of the composition;
when the carbon-based filler is not expanded graphite, then it is present in the composition in a content of between 5% and 35% by weight, relative to the total weight of the composition.
30 . The composition as claimed in claim 17 , characterized in that the electrically insulating filler is chosen from metal oxides.
31 . The composition as claimed in claim 17 , characterized in that it comprises from 17% to 60% by weight, of electrically insulating filler relative to the weight of the composition.
32 . An electronic device assembly comprising an electronic device and the composition as defined in claim 17 , wherein the electronic device is encapsulated in the composition.