Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J177/00—Adhesives based on polyamides obtained by reactions forming a carboxylic amide link in the main chain; Adhesives based on derivatives of such polymers
  • C09J177/06—Polyamides derived from polyamines and polycarboxylic acids
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G69/00—Macromolecular compounds obtained by reactions forming a carboxylic amide link in the main chain of the macromolecule
  • C08G69/40—Polyamides containing oxygen in the form of ether groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K2201/00—Specific properties of additives
  • C08K2201/001—Conductive additives
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K2201/00—Specific properties of additives
  • C08K2201/002—Physical properties
  • C08K2201/005—Additives being defined by their particle size in general

Definitions

• the present invention relates to a hot-melt adhesive composition for encapsulating electronic devices, a process for preparing such a composition and its use.
• polyamides as hot-melt adhesives to encapsulate electronic or mechanical devices used for example in the automotive fields or in the medical field.
• plastic materials are generally used to protect batteries, whether in an automobile or on a smaller scale, such as the shell of a mobile phone.
• the substrates to be encapsulated can be metals, such as copper or polymers such as, for example, materials making up printed circuits.
• these materials must be electrically insulating, in order to avoid possible short circuits. They must also be heat conductors in order to allow, for example, a battery, if this is the element to be encapsulated, to evacuate the heat it generates during its use.
• the encapsulation of the parts needs to be carried out at low pressure, so as not to damage the part to be molded.
• Encapsulation is a delicate process. The material used to encapsulate the part is melted. It is then delicately deposited hot on the element to be encapsulated. The pressure at the nozzle outlet of the molten material is qualified as low pressure. The term “wetting” is used to define this encapsulation. Indeed, if the pressure at the nozzle outlet is higher, the force applied to the part to be molded during the deposition of the ground material can damage the part, said Several low-pressure injection processes are known for encapsulating parts.
• epoxy potting has the disadvantage of being relatively long, leading to low productivity due to the relatively slow reaction time.
• the process by chemical vapor deposition is used in the field of encapsulation. However, this process is known to be dangerous. Thus, new materials are sought which must respond both to specific physico-chemical properties and must allow an easier low-pressure encapsulation process.
• the materials are in a molten state, generally in a melter, for a relatively long period of time.
• the known compositions have been observed to undergo phase segregation. This loss of homogeneity over time results in a difference in properties between the encapsulated product manufactured at the start of production, with the homogeneous material, and the encapsulated product manufactured at the end of production, with an inhomogeneous material.
• the sedimentation of the fillers, making the molten material too dense tends to clog the outlet nozzles. Then, over time, these relatively abrasive fillers deteriorate manufacturing facilities.
• the invention relates to a hot-melt adhesive composition
• a hot-melt adhesive composition comprising: i) at least one semi-crystalline aliphatic copolyamide comprising at least two units corresponding to the following formula (1): /Y (1)
• the X unit is a semi-crystalline unit obtained by the polycondensation of a unit chosen from an alpha, omega-aminocarboxylic acid in C6 to C18, a lactam in C6 to C18 and a unit (diamine in Ca).
• (Cb diacid) 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 linear or branched aliphatic, cycloaliphatic, saturated or unsaturated,
• the unit Y is a unit obtained by the polycondensation of a unit (Cd diamine). (Ce diacid), 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 linear or branched aliphatic, cycloaliphatic, saturated or unsaturated, the Cd diamine possibly being a polyether amine, the unit Y having a Tg of less than 30°C, advantageously less than 20°C, very advantageously less than 0°C, the copolyamide having a viscosity in the molten state measured according to standard ASTM D3236-88 (2009) between 0.5 and 300 Pa.s at 200° C., the copolyamide constituting the matrix of the composition, and ii) from 3 to 35% by weight relative to the total weight of the composition of at least one thermally conductive filler , the carbon atom content of which is between
• the invention also relates to a method for preparing the composition according to the invention.
• the invention finally relates to the use of the composition for encapsulating electronic devices.
• hot melt is meant within the meaning of the present invention the ability of the composition to melt under the effect of heat.
• copolyamide present in the composition according to the invention is semi-crystalline and aliphatic.
• polystyrene-crystalline copolyamide covers copolyamides which exhibit both a glass transition temperature Tg and a melting temperature Tm.
• Tg and Tf can be determined respectively according to ISO 11357-2:2013 and 11357-3:2013.
• polyamides The nomenclature used to define polyamides is described in standard ISO 1874-1:1992 "Plastics - Polyamide materials (PA) for molding and extrusion - Part 1: Designation", in particular on page 3 (tables 1 and 2) and is well known to those skilled in the art.
• PA denotes polyamide
• L denotes the number of carbon atoms of the amino acid or of the lactam.
• the polyamide is obtained by the polycondensation of the amino acid or the lactam comprising L carbon atoms.
• M designates the number of carbon atoms of the diamine
• N designates the number of carbon atoms of the diacid.
• the X unit is a semi-crystalline unit obtained by the polycondensation of a unit chosen from an alpha, omega-aminocarboxylic acid in C6 to C18, a lactam in C6 to C18 and a unit (diamine in Ca).
• (Cb diacid) 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 linear or branched aliphatic, cycloaliphatic, saturated or unsaturated,
• the unit Y is a unit obtained by the polycondensation of a unit (Cd diamine). (Ce diacid), 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 aliphatic linear or branched, cycloaliphatic, saturated or unsaturated, the Cd diamine possibly being a polyether amine, the unit Y having a Tg of less than 30°C, advantageously less than 20°C, very advantageously less than 0°C, the copolyamide having a viscosity in the molten state measured according to standard ASTM D3236-88 (2009) of between 0.5 and 300 Pa.s at 200° C. the copolyamide constituting the matrix of the composition.
• the polyamide of formula (1) has a ratio: number of carbon atoms to number of nitrogen atoms, denoted C/N greater than or equal to 8.
• semi-crystalline unit within the meaning of the present invention a polyamide, which has a melting temperature (Tm) in DSC according to the ISO 11357-3: 2013 standard, and an enthalpy of crystallization during the cooling step at a speed of 5 K/min in DSC measured according to standard ISO 11357-3 of 2013 greater than 15 J/g, preferably greater than 30 J/g.
• Tm melting temperature
• the X motif can result from the polycondensation of one or more C6 to C12 alpha, omega-aminocarboxylic acids.
• the alpha, omega-aminocarboxylic acid is chosen from amino-7-heptanoic acid, amino-11-undecanoic acid and amino-12-dodecanoic acid.
• the X motif can result from the polycondensation of one or more C6 to C12 lactams.
• the lactam is chosen from caprolactam, oenantholactam and lauryllactam.
• the X pattern can result from the polycondensation of a unit (diamine to Ca). (Cb diacid), with a representing the number of carbon atoms of the diamine and b representing the number of carbon atoms of the diacid, a being between 2 and 18 and b being between 4 and 18. More particularly, b is between 5 and 18.
• the Ca diamine can be chosen from aliphatic, linear or branched diamines, cycloaliphatic diamines.
• the Ca-diamine When the Ca-diamine is aliphatic and branched, it may have one or more methyl or ethyl substituents on the main chain.
• it can advantageously be chosen from 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2-methyl-1,5-pentanediamine, 2-methyl-1,8-octanediamine.
• the Ca diamine is chosen from ethylene diamine, hexamethylene diamine, decanediamine and piperazine.
• the Cb diacid can be chosen from aliphatic, linear or branched diacids, cycloaliphatic diacids.
• the diacid when it is cycloaliphatic, it may comprise the following carbon skeletons: norbornyl, cyclohexyl, dicyclohexyl, dicyclohexylpropane.
• the unit X is chosen from an amino acid and a lactam or PA 26, PA 29, PA 210, PA 212, PA 214, PA 218, PA59, PA510, PA 66, PA 69 PA610, PA 512, PA612, more particularly, the X unit is chosen from amino acids and the lactams have a number of carbon atoms greater than 6. More particularly, the X unit is a PA6, a PA11 a PA12, a PA 210, a PA 212, a PA 69, a PA610, or a PA612.
• these mixtures are present for example in tall oil.
• these mixtures mainly comprise the dimer, and in lesser quantities the monomer, the trimer and oligomers.
• the fatty acid dimers are mainly obtained from 75% to more than 98%, in a mixture with in particular the monomer, the “1 and 1/2 mer” and the corresponding trimer.
• the copolyamide according to the invention has a viscosity in the molten state measured according to standard ASTM D3236-88 (2009) of between 0.5 and 300 Pa.s at 200° C., preferably from 0.5 to 200 Pa. s, even more preferably from 1 to 100 Pa.s at 200°C, and more particularly from 2 to 30 Pa.s at 200°C. More particularly, the melt viscosity is measured using a Brookfield rheometer using the SC 4-27 module according to the ASTM D3236-88 (2009) standard at 200°C.
• the copolyamide consists of the two units X and Y defined above.
• the thermally conductive filler has a median average particle size D50 ranging from 0.5 to 500 micrometers. Within this range, filler particles having D50 sizes comprised from 1 to 200 ⁇ m, preferably from 20 to 150 ⁇ m can be advantageously used.
• Scanning electron microscopy allows observation and visual appreciation of the morphology of compounds.
• Morphometry based on video acquisition and image analysis, provides access to quantifiable parameters characteristic of particle morphology.
• Alpaga 500 Nano apparatus for each tested sample, acquisitions are made on 10,000 particles and the elongation and blunting parameters are calculated for each particle.
• composition defined above further comprises additives chosen from antioxidants, UV stabilizers, heat stabilizers, plasticizers, nucleating agents, sticking agents, modifiers shocks, flame retardants, antistatic agents, reinforcing agents, lubricants, organic and inorganic fillers, optical brighteners, mold release agents, pigments, dyes, catalysts and mixtures thereof.
• additives chosen from antioxidants, UV stabilizers, heat stabilizers, plasticizers, nucleating agents, sticking agents, modifiers shocks, flame retardants, antistatic agents, reinforcing agents, lubricants, organic and inorganic fillers, optical brighteners, mold release agents, pigments, dyes, catalysts and mixtures thereof.
• the composition may comprise between 0 and 10% by weight of additives relative to the total weight of the composition, preferably between 0.1 and 5% of additive.
• composition according to the invention is capable of being injected at low pressure, that is to say at a pressure of less than 100 bars, preferably less than 50 bars.
• Polyamide designates a hot-melt adhesive polyamide composed of 31 mol% of C10 diacid, 19% of pripol® 1013, 25 mol% of piperazine, 6.6 mol% of Jeffamine® D 2000 and 18.4 mol% of ethylene diamine.
• the Tg of the polyamide is -22°C measured by DSC, and a viscosity of 9 Pa.s at 200°C measured according to standard ASTM D3236-88 (2009).
• polyamide A is 210/pip10/pip36/POP36, pip being piperazine, POP being Jeffamine® D2000.
• the nomenclature used to define polyamides is described in standard ISO 1874-1:1992 "Plastics - Materials polyamides (PA) for molding and extrusion - Part 1: Designation", in particular on page 3 (tables 1 and 2).
• Graphite refers to graphite under the trade name Timrex® M100 with a density of less than 2.5 sold by Imerys
• Polyamide A designates a hot-melt adhesive polyamide composed of 31 mol% of C10 diacid, 19% of pripol® 1013, 25 mol% of piperazine, 6.6 mol% of Jeffamine® D 2000 and 18.4 mol% of ethylene diamine.
• Polyamide B denotes a PA 6 having a melting point of 220°C and a melt viscosity measured according to standard ASTM D3236-88 (2009) of 325 Pa.s at 280°C.
• Graphite refers to graphite with the trade name Timrex® M100 with a density of less than 2.5 sold by Imerys
• composition according to the invention makes it possible to encapsulate parts at low pressure using a melter.
• the composition according to the invention has good thermal conductivity making it possible to avoid overheating of electronic equipment while being electrically insulating, which makes it possible to avoid short circuits.
• Compositions 9 and 10 cannot be used in an overmolding process because of their excessive viscosities and melting points.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Chemistry (AREA)
• Polyamides (AREA)
• Adhesives Or Adhesive Processes (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)

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• 2021
  • 2021-10-14 FR FR2110897A patent/FR3128223B1/fr active Active
• 2022
  • 2022-10-13 WO PCT/FR2022/051931 patent/WO2023062325A1/fr not_active Ceased
  • 2022-10-13 CN CN202280069133.7A patent/CN118103474A/zh active Pending
  • 2022-10-13 JP JP2024522016A patent/JP2024536476A/ja active Pending
  • 2022-10-13 US US18/698,110 patent/US20240400872A1/en active Pending
  • 2022-10-13 EP EP22801511.1A patent/EP4416231A1/fr active Pending

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