WO-2026093677-A1 - THERMALLY CONDUCTIVE COMPOSITION BASED ON (METH)ACRYLATE COMPOUNDS

Abstract

The present invention relates to a crosslinkable two-component composition comprising: a component A, comprising: an oxidant; at least one (meth)acrylate monomer; a component B comprising: a reducing agent; said composition comprising at least one thermally conductive filler in component A and/or B; the composition having, after crosslinking, a density at 23°C of 1.6 to 2.2; the composition having, after crosslinking, a ratio of density at 23° C/thermal conductivity of 0.80 to 1.30; and the composition being free of compounds comprising a peroxide group.

Inventors

• MAZAJCZYK, Jérôme
• FLAT, Karl
• Simon, Frédéric

Assignees

• BOSTIK SA

Dates

Publication Date

20260507

Application Date

20251027

Priority Date

20241028

Claims (20)

1. DEMANDS
2. 1. Two-component, crosslinkable composition comprising:
3. - a component A comprising:
4. • an oxidant;
5. • at least one (meth)acrylate monomer;
6. - a component B comprising:
7. • a reducer;
8. said composition comprising at least one thermally conductive filler in component A and/or B;
9. said composition having, after crosslinking, a density at 23°C ranging from 1.6 to 2.2; said composition having, after crosslinking, a density at 23°C / thermal conductivity ratio ranging from 0.80 to 1.30;
10. said composition being devoid of compounds comprising a peroxide group.
11. 2. Composition according to claim 1, wherein the oxidant is selected from the group consisting of: organic copper derivatives, iodoniums, thiopheniums, sulfoniums, thianthreniums, their derivatives, and mixtures thereof.
12. 3. Composition according to any one of claims 1 or 2, wherein the oxidant is selected from the group consisting of:
13. compounds with the following formulas (la) or (Ib):
14. (the (Ib)
15. in which:
16. Each of R1 , R2 , R3 , R4 , R5 , R6 , R7 , R8 , Ra , and Rb represents, independently of each other, a radical chosen from the group consisting of a hydrogen atom, a halogen, an alkyl, a cycloalkyl, or an aryl;
17. R f represents a perhaloalkyl or halogenoalkyl; X' represents an anion;
18. - compounds with the following formulas: (Ha) or (llb) or (Ile):
19. in which:
20. R 9 and R 10 each represent, independently of each other, a hydrogen atom, an alkyl radical, an alkenyl radical, a cycloalkyl radical, a cycloalkenyl radical, an aryl radical, a chlorine atom, a bromine atom, an iodine atom, a carboxylic radical, or a -NO2 radical;

Description

Thermoconductive composition based on (meth)acrylate compounds FIELD OF INVENTION The present invention relates to a thermally conductive composition based on a (meth)acrylate compound. The invention also relates to the use of said composition for bonding, in particular in electric vehicle batteries. TECHNOLOGICAL BACKGROUND As technology evolves towards sustainable energy and transportation, electric mobility is becoming increasingly important. Temperature management plays a key role in electric vehicle batteries. Battery cells can only deliver maximum performance within a specific temperature range and must not overheat. Furthermore, heating modern lithium-ion batteries can trigger a thermal reaction, which can escalate and cause a fire or even an explosion within the battery. The need to quickly dissipate the heat generated during battery cell operation is increasingly crucial for batteries that are expected to achieve ever-greater performance. While silylated polymer-based thermally conductive compositions are available on the market, these compositions function more like conductive sealants and lack the mechanical properties suitable for structural or semi-structural bonding. In fact, they are not designed to withstand stresses exceeding 7 MPa at 23°C (70 kg/ cm² ). They also cannot be reliably subjected to a high percentage of their maximum resistance for a long period of time under hostile conditions (low temperatures, heat, chemical agents, etc.). Acrylic compositions are known reactive systems that crosslink by radical polymerization. Radical polymerization is typically initiated by a redox system which, through a redox reaction, leads to the production of radicals. The majority of acrylic systems are two-component systems. The first component traditionally contains the reducing agent and reactive monomers, and the second component contains the oxidizing agent. Once the two components are mixed, the reducing agent induces the cleavage of the O-O bond of the organic peroxide, for example, and initiates polymerization. Most current acrylic systems use peroxide/amine pairs to initiate the redox reaction and are most often offered as 10:1 two-component formulations without methacrylate in the hardener portion to ensure good long-term stability. Currently, there are few thermally conductive acrylic compositions suitable for the electric vehicle market. Existing solutions generally result in rather brittle and rigid bonds/seals, which fail to withstand the vibrations experienced by electric vehicles in motion, and/or poor adhesion to specific substrates such as aluminum. Furthermore, the thermally conductive filler content is often high to achieve good thermal conductivity, which can lead to stability issues during storage (filler settling). Storage instability also negatively impacts production rates. The electric vehicle market is also increasingly seeking solutions to reduce battery weight. Therefore, there is a need to find a composition that can at least partially remedy one or more of the aforementioned disadvantages. In particular, there is a need for compositions exhibiting good thermal conductivity (after crosslinking), good storage stability, and good adhesion to aluminum-type substrates. More specifically, there is a need for compositions that offer a good compromise between sufficient thermal conductivity (after crosslinking), low density, storage stability, good reactivity, and mechanical performance (especially a good compromise between hardness and flexibility). DESCRIPTION OF THE INVENTION A. Composition The present invention relates to a two-component crosslinkable composition comprising: - a component A comprising: • an oxidant; • at least one (meth)acrylate monomer; - a component B comprising: • a reducer; said composition comprising at least one thermally conductive filler in component A and/or B; said composition having, after crosslinking, a density at 23°C ranging from 1.6 to 2.2; said composition having, after crosslinking, a density at 23°C / thermal conductivity ratio ranging from 0.80 to 1.30; said composition being devoid of compounds comprising a peroxide group. Preferably, crosslinking is carried out at 23°C and even more preferably at 50% relative humidity, for 24 hours. Compounds including a peroxide group -OO- include compounds of the type R'-OOR i , R k -OOH (hydroperoxides), R l C(=O)-OOH, and peroxides including the peroxide anion [OO] 2- . The composition according to the invention advantageously offers at least one of the following advantages: good adhesion to aluminium-type substrates; good stability to sedimentation over time; good responsiveness, even after the composition has aged over time; good thermal conductivity after crosslinking, while having a low density in order to meet the weight reduction requirements of electric batteries in the automotive field in particular; a good compromise between hardness and flexibility with an elongation at break preferably