Silicone foam composition

Abstract

The present invention relates to novel silicone foams obtainable from a foamable crosslinkable silicone composition comprising an organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule, an organosilicon compound having at least two, and preferably at least three, silicon-bonded hydrogen atoms per molecule, a hydrosilylation catalyst, at least one pore-forming agent which is water, a hydrogel, or an aqueous silicone emulsion, at least one chemical blowing agent, and a linear polydimethylsiloxane.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application No. 63 / 393,084, filed July 28, 2022, the contents of which are incorporated herein by reference in their entirety.

[0002] Technical Field The present invention relates to the technical field of silicone compositions, and more particularly to novel silicone foam compositions having reduced density. [Background technology]

[0003] Silicone elastomers have attracted considerable interest because the cured silicones have properties such as high elasticity, flexibility at low and high temperatures, high gas permeability, very low glass transition temperatures (Tg around -120°C), excellent dielectric properties, and fire resistance.

[0004] In electronic devices, silicone elastomers have a wide range of applications due to their diverse and excellent properties. Cured silicone elastomers are primarily used for electrical, thermal, and acoustic insulation, moisture-proofing, dust-proofing, and shock absorption, as well as for potting or sealing, sealing, bonding, and coating various types of components in harsh environments, as well as high-end, precision, and sensitive electronic devices such as light-emitting diodes (LEDs), displays, junction boxes for solar cell modules, diodes, semiconductor devices, relays, sensors, automotive stabilizers, and automotive electronic control units (ECUs).

[0005] Because silicone foams can offer significant weight savings when compared to non-foamed elastomers, much effort has been put into developing methods to introduce porosity without detrimentally affecting the mechanical properties of the silicone cured material in recent years.

[0006] Silicone foam articles are already known for a variety of applications, such as thermal and / or acoustic insulation, the manufacture of flexible joints, use as damping elements, shock absorption, etc. Markets are diverse, including construction, transportation, electronics, energy production, technical textiles, performance apparel, and consumer electronics.

[0007] For example, the transportation industry is interested in silicone foams that have low density while maintaining excellent mechanical properties and fire resistance. Silicone foam articles can be used as automotive parts such as hood shock absorbers, engine vibration insulators, seats, protective fabrics or seats, and vibration and noise damping materials. U.S. Patent Application Publication No. 2022 / 0275207 describes silicone foams with a density of 0.20 g / cm. 3 In the following, silicone foams are described that exhibit good physical, mechanical and fire resistance properties.

[0008] As another example, new energy storage means are exploring the use of silicone foam, which offers the advantage of being a lightweight alternative to traditional elastomeric encapsulants and sealants due to its excellent insulating properties and good moisture resistance. For example, U.S. Patent Application Publication No. 2018 / 223070, filed by Elkem Silicones USA Corp, describes the use of silicone syntactic foam to insulate secondary battery packs and further minimize the propagation of thermal runaway.

[0009] In addition to the transportation and energy storage industries, silicone foams can be used to manufacture articles in a variety of other markets. Examples include cosmetic puffs, medical absorbents, various filters, and various sealing components such as packings, gaskets, and O-rings. These may be foam articles themselves or composites or laminates with metals, organic resins, or elastic materials. Other well-known uses for foam articles include fuser rollers and fuser belts that fuse toner onto paper using heat and / or pressure in electrophotographic image forming devices such as copiers, printers, and facsimiles. Silicone foams can also be used in the textile and furniture fields: thermally-coated textiles, insulation for footwear and clothing, and padding. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] US Patent Application Publication No. 2022 / 0275207 [Patent Document 2] US Patent Application Publication No. 2018 / 223070 Summary of the Invention [Means for solving the problem]

[0011] The present invention provides a silicone foam obtained from a foamable crosslinkable silicone composition, comprising: at least one organopolysiloxane A having at least two silicon-bonded alkenyl groups per molecule; at least one organosilicon compound B having at least two, preferably at least three, silicon-bonded hydrogen atoms per molecule; at least one hydrosilylation catalyst C; at least one porosifying agent D which is water, a hydrogel, or an aqueous silicone emulsion; at least one chemical blowing agent E; and At least one linear polydimethylsiloxane F having a dynamic viscosity at 25°C between 50 mPa·s and 100,000 mPa·s The present invention relates to a silicone foam comprising:

[0012] The silicone foam defined above can be referred to as a "double foam" silicone foam in that: On the other hand, hydrogen bubbles are generated in a state where a pore-forming agent D, which is water, a hydrogel, or an aqueous silicone emulsion, is incorporated into a polyaddition-crosslinkable silicone composition containing an organopolysiloxane A having silicon-bonded alkenyl groups, an organosilicon compound B containing silicon-bonded hydrogen atoms, and a hydrosilylation catalyst C; On the other hand, chemical blowing agents E release a gas, typically carbon dioxide, upon decomposition.

[0013] The inventors have found that the resulting dual-cell silicone foam exhibits a lower density and the cell structure of the foam is significantly more uniform and stable than when using one or the other of the blowing agents, while retaining soft impact resistance. DETAILED DESCRIPTION OF THE INVENTION

[0014] Detailed Description of the Invention All viscosities discussed herein correspond to dynamic viscosity values measured at 25°C by well-known methods, such that viscosities measured in a Brookfield viscometer are independent of shear rate gradients.

[0015] Unless otherwise specified, all % or ppm contents are by weight.

[0016] The foamable crosslinkable silicone composition of the present invention comprises at least one organopolysiloxane A having at least two silicon-bonded alkenyl groups per molecule. Preferably, organopolysiloxane A has at least two C groups per molecule. 2~6 The alkenyl group is bonded to silicon and can consist of at least two siloxy units of the formula: Ya R 1 b SiO (4-a-b) / 2 (In the formula: Y is C 2~6 alkenyl, preferably vinyl; ·R 1 is a monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably selected from an alkyl group having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, or a propyl group, a cycloalkyl group having 3 to 8 carbon atoms, and an aryl group having 6 to 12 carbon atoms; a=1 or 2, b=0, 1 or 2, and the sum of a+b=2 or 3. ), and optionally a unit of the formula: R 1 c SiO (4-C) / 2 (In the formula, R 1 has the same meaning as above, and c=0, 1, 2 or 3.

[0017] Preferably, organopolysiloxane A has a dynamic viscosity at 25° C. of 100 mPa·s to 120,000 mPa·s, preferably 100 mPa·s to 80,000 mPa·s, more preferably 1,000 mPa·s to 50,000 mPa·s, and even more preferably 5,000 mPa·s to 20,000 mPa·s. The organopolysiloxane A can be preferably referred to as an organopolysiloxane oil.

[0018] The organopolysiloxane A can be a linear, cyclic or branched organopolysiloxane (resin). The foamable crosslinkable silicone composition according to the invention can contain a mixture of different organopolysiloxanes A.

[0019] According to one embodiment, organopolysiloxane A can be a linear organopolysiloxane. The linear organopolysiloxane is D or D Vi Siloxyl units and terminal M or M Vi It indicates a linear structure essentially formed from siloxyl units, and D, D Vi , M and MVi is defined as follows:D:R 1 2SiO 2 / 2 Siloxyl unit, D Vi :Y2SiO 2 / 2 or YR 1 SiO 2 / 2 siloxyl units selected from the group consisting of siloxyl units, M:R 1 3SiO 1 / 2 Siloxyl unit, M Vi :YR 1 2SiO 1 / 2 and Y2R 1 SiO 1 / 2 siloxyl units selected from the group consisting of: 1 is as above.

[0020] End "M or M Vi Examples of the "unit" include a trimethylsiloxy group, a dimethylphenylsiloxy group, a dimethylvinylsiloxy group, and a dimethylhexenylsiloxy group.

[0021] "D or D Vi Examples of the "" unit include a dimethylsiloxy group, a methylphenylsiloxy group, a methylvinylsiloxy group, a methylbutenylsiloxy group, a methylhexenylsiloxy group, a methyldecenylsiloxy group, and a methyldecadienylsiloxy group.

[0022] Examples of linear or cyclic organopolysiloxanes that can be organopolysiloxane A according to the invention are: · Poly(dimethylsiloxane) containing dimethylvinylsilyl termini; · Poly(dimethylsiloxane-co-methylphenylsiloxane) containing dimethylvinylsilyl termini; · Poly(dimethylsiloxane-co-methylvinylsiloxane) containing dimethylvinylsilyl termini; · Trimethylsilyl-terminated poly(dimethylsiloxane-co-methylvinylsiloxane); and · Cyclic poly(methylvinylsiloxane).

[0023] Preferably, organopolysiloxane A has a content by weight of alkenyl units of 0.001% to 30%, preferably 0.01% to 10%, more preferably 0.02% to 5%.

[0024] According to a preferred embodiment, organopolysiloxane A contains terminal dimethylvinylsilyl units, and more preferably, organopolysiloxane A is a poly(dimethylsiloxane) containing dimethylvinylsilyl terminal groups. The number of dimethylsiloxane units can be between 5 and 1000, preferably between 100 and 600.

[0025] According to another embodiment, the organopolysiloxane A is 2~6 A branched organopolysiloxane (i.e., resin) containing alkenyl units is preferably selected from the group consisting of silicone resins of the formula: M Vi Q (wherein the alkenyl group bonded to the silicon atom is held by the M group); ·MM Vi Q (wherein the alkenyl group bonded to the silicon atom is carried by part of the M unit); ·MD Vi Q (wherein the alkenyl group bonded to the silicon atom is held by the D group); MDD Vi Q (wherein the alkenyl group bonded to the silicon atom is held by part of the D group); ·MM Vi TQ (wherein the alkenyl group bonded to the silicon atom is carried by part of the M unit); ·MM Vi DD Vi Q (wherein the hydrogen atoms bonded to the silicon atoms are held by part of the M and D units); and mixtures thereof (wherein M, M Vi , D and D Vi is as defined above, and T: formula R 1 SiO 3 / 2 and Q: a siloxyl unit of the formula SiO 4 / 2where R is a siloxyl unit of 1 have the same meaning as above).

[0026] According to a preferred embodiment, the foamable crosslinkable silicone composition of the present invention comprises a mixture of at least one linear organopolysiloxane as defined above and at least one branched organopolysiloxane (i.e., resin) as defined above. For example, the foamable crosslinkable silicone composition of the present invention may comprise a mixture of a linear poly(dimethylsiloxane) containing dimethylvinylsilyl termini and a branched organopolysiloxane of formula M Vi Q.M.M. Vi Q, M.D. Vi Q, MDD Vi Q.M.M. Vi TQ or MM Vi DD Vi Q, preferably M Vi Q.M.M. Vi Q, M.D. Vi Q or MDD Vi The foamable cross-linkable silicone composition of the present invention may contain a mixture of the linear poly(dimethylsiloxane) and the silicone resin Q. The amount of linear poly(dimethylsiloxane) in the foamable cross-linkable silicone composition of the present invention may be in the range of 0.8 to 94% by weight, preferably 2.5 to 45% by weight, and more preferably 3.5 to 25% by weight of the total composition. The amount of silicone resin in the foamable cross-linkable silicone composition of the present invention may be in the range of 0 to 10% by weight, preferably 0.01 to 5% by weight, and more preferably 0.05 to 2% by weight of the total composition.

[0027] The foamable crosslinkable silicone composition of the present invention further comprises at least one organosilicon compound B having at least two, and preferably at least three, silicon-bonded hydrogen atoms per molecule. Organosilicon compound B is preferably an organohydrogenpolysiloxane compound containing at least two, and preferably at least three, hydrosilyl functional groups (or Si—H units) per molecule.

[0028] The organosilicon compound B may advantageously be a polyorganosiloxane containing at least two, preferably at least three, siloxyl units of the formula: H d R 2 e SiO (4-d-e) / 2 (In the formula: ·R 2 groups are the same or different and represent monovalent groups having 1 to 12 carbon atoms, d=1 or 2, e=0, 1 or 2, and d+e=1, 2 or 3; and optionally other units of the formula: R 2 f SiO (4-f) / 2 (In the formula, R 2 has the same meaning as above, and f=0, 1, 2 or 3.

[0029] In the above formula, multiple R 2 It is understood that when groups are present, they may be the same or different from one another. 2 R may represent a monovalent group selected from the group consisting of an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, and an aryl group having 6 to 12 carbon atoms, which may be substituted with at least one halogen atom such as chlorine or fluorine. 2 may advantageously be selected from the group consisting of methyl, ethyl, propyl, 3,3,3-trifluoropropyl, xylyl, tolyl and phenyl, and most preferably R 2 is methyl.

[0030] The symbol d is preferentially equal to 1.

[0031] The organosilicon compound B may have a linear, branched or cyclic structure. The degree of polymerization is preferably 2 or more. Generally, the degree of polymerization is less than 5,000.

[0032] In the case of linear polymers, the latter has the formula D:R 2 2SiO 2 / 2 or D':R 2 HSiO 2 / 2and a siloxyl unit selected from units of the formula M:R 2 3SiO 1 / 2 or M':R 2 2HSiO 1 / 2 (In the formula, R 2 and a terminal siloxyl unit selected from the group consisting of the following units: (wherein R, R, and R have the same meaning as above): Preferably, the viscosity of organosilicon compound B is 1 mPa·s to 5000 mPa·s, more preferably 1 mPa·s to 2000 mPa·s, and even more preferably 5 mPa·s to 1000 mPa·s.

[0033] Examples of organohydrogenpolysiloxanes which can be organosilicon compounds B according to the invention containing at least two hydrogen atoms bonded to the silicon atom are: · Poly(dimethylsiloxane) containing hydrodimethylsilyl termini; · Poly(dimethylsiloxane-co-methylhydrosiloxane) containing trimethylsilyl termini; · Poly(dimethylsiloxane-co-methylhydrosiloxane) containing hydrodimethylsilyl termini; · trimethylsilyl-terminated poly(methylhydrosiloxane); and · Cyclic poly(methylhydrosiloxane).

[0034] If the organosilicon compound B has a branched structure, it is preferably selected from the group consisting of silicone resins of the following formula: M'Q (where the hydrogen atoms bonded to the silicon atoms are held by M units), MM'Q (wherein the hydrogen atom bonded to the silicon atom is held by part of the M unit), MD'Q (wherein the hydrogen atom bonded to the silicon atom is held by a D group), MDD'Q (wherein the hydrogen atom bonded to the silicon atom is held by part of the D group), MM'TQ (wherein the hydrogen atom bonded to the silicon atom is held by part of the M unit), MM'DD'Q (wherein the hydrogen atoms bonded to the silicon atoms are carried by part of the M and D units), and mixtures thereof (M, M', D and D' are as defined above, T: a compound of formula R 2 SiO 3 / 2 and Q: a siloxyl unit of the formula SiO 4 / 2 where R is a siloxyl unit of 2 has the same meaning as above.

[0035] Preferably, organosilicon compound B has a content of hydrosilyl Si—H functional groups of 0.2 to 91% by weight, more preferably 3 to 80% by weight, and even more preferably 15 to 70% by weight.

[0036] Advantageously, the molar ratio of hydrosilyl SiH functional groups of organosilicon compound B to alkene functional groups of compound A is between 1 and 50, preferably between 2 and 30, more preferably between 3 and 20.

[0037] According to a preferred embodiment, the foamable crosslinkable silicone composition of the present invention comprises a mixture of at least one organosilicon compound B1 having at least three silicon-bonded hydrogen atoms per molecule and at least one organosilicon compound B2 having two silicon-bonded hydrogen atoms per molecule. The organosilicon compound B2 preferably contains terminal dimethylhydrogensilyl units, and more preferably is a poly(dimethylsiloxane) containing terminal dimethylhydrogensilyl groups. The number of dimethylsiloxane units in organosilicon compound B2 can be 1 to 200, preferably 1 to 150, and more preferably 3 to 120. Such organosilicon compound B2 can be described as a "chain extender" because it is believed to increase the mesh size of the network when crosslinked. Furthermore, organosilicon compound B1 having three or more silicon-bonded hydrogen atoms per molecule can be described as a "crosslinker." Preferably, organosilicon compound B1 is a poly(dimethylsiloxane-co-methylhydrosiloxane) containing trimethylsilyl and / or hydrodimethylsilyl termini.

[0038] The hydrosilylation catalyst C can be selected, in particular, from platinum and rhodium compounds, but also from silicon compounds, such as those described in WO 2015 / 004396 and WO 2015 / 004397, germanium compounds, such as those described in WO 2016 / 075414, or nickel, cobalt, or iron complexes, such as those described in WO 2016 / 071651, WO 2016 / 071652, and WO 2016 / 071654. Catalyst C is preferably a compound derived from at least one metal belonging to the platinum group. These catalysts are well known. In particular, the complexes of platinum with organic products described in U.S. Pat. Nos. 3,159,601, 3,159,602, 3,220,972 and EP 0 057 459, 0 188 978 and 0 190 530, and the complexes of platinum with vinylated organosiloxanes described in U.S. Pat. Nos. 3,419,593, 3,715,334, 3,377,432 and 3,814,730 may be used.

[0039] Preferably, catalyst C is a compound derived from platinum. Preferably, catalyst C is a Karstedt platinum catalyst.

[0040] The foamable crosslinkable silicone composition according to the present invention comprises water, a hydrogel or an aqueous silicone emulsion as pore-forming agent D. Water can be added directly to the foamable crosslinkable silicone composition. Advantageously, water can be introduced in the form of an aqueous silicone emulsion, such as a direct oil-in-water silicone emulsion or an inverse water-in-oil silicone emulsion, comprising a continuous silicone oil phase, an aqueous phase and a stabilizer.

[0041] According to one embodiment, water is introduced via a silicone oil-in-water emulsion having a water content of about 60% by weight. Introducing water into the foamable cross-linkable silicone composition via an emulsion improves the dispersibility of water in the foamable cross-linkable silicone composition and its stability during storage.

[0042] According to one embodiment, an emulsifier can be added together with the water or aqueous silicone emulsion. Those skilled in the art can select the emulsifier from among typical emulsifiers. Examples include anionic emulsifiers, cationic emulsifiers, amphoteric emulsifiers, and nonionic emulsifiers. Among these, nonionic surfactants, which are believed to have minimal effect on the hydrosilylation reaction, are most preferred. The emulsifier can be added in an amount such that the weight ratio of emulsifier to water is 1:5 to 5:1, preferably 2:1 or 1:2.

[0043] Some of the hydrosilyl functional groups of organosilicon compound B react with the water provided by porosifying agent D to form gaseous hydrogen, allowing good foaming of the composition.

[0044] The foamable crosslinkable silicone composition according to the present invention comprises at least one chemical foaming agent E. Preferably, the chemical foaming agent E is at least one hydrogen carbonate (also commonly referred to as "bicarbonate"). More preferably, the chemical foaming agent E is selected from the group consisting of ammonium hydrogen carbonate (NH4)HCO3, sodium hydrogen carbonate NaHCO3, calcium hydrogen carbonate Ca(HCO3)2, and mixtures thereof. Even more preferably, the chemical foaming agent E is ammonium hydrogen carbonate.

[0045] The chemical blowing agent E may have particles with a median particle size (D50) of ≦50 μm, more preferably ≦10 μm. According to a preferred embodiment, the particles of chemical blowing agent E may be crushed and sieved before use.

[0046] For ease of application and manufacturing, the chemical blowing agent E can be pre-dispersed in the organopolysiloxane A, for example at a level of 30% to 60% by weight, and finally, any additives that help stabilize the shelf life of the resulting composition can be incorporated.

[0047] The foamable cross-linkable silicone composition according to the present invention comprises at least one linear polydimethylsiloxane F having a dynamic viscosity at 25°C of 50 mPa·s to 100,000 mPa·s, preferably 50 mPa·s to 70,000 mPa·s, more preferably 100 mPa·s to 20,000 mPa·s, even more preferably 200 mPa·s to 5,000 mPa·s, and even more preferably 1,000 mPa·s to 2,000 mPa·s.

[0048] According to a first embodiment of the invention, the linear polydimethylsiloxane F has the formula: (CH3)3SiO(SiO(CH3)2) n Si(CH3)3(I) In the formula, n is an integer of 50 to 900, preferably 50 to 700.

[0049] According to a second embodiment of the invention, the linear polydimethylsiloxane F has the following formula: (CH3)3SiO(SiO(CH3)2) n Si(CH3)2(Y) (II) In the formula, Y is C 2~6 It is alkenyl, preferably vinyl, and n is an integer of 50 to 900, preferably 50 to 700. The compound has exactly one silicon-bonded alkenyl group per molecule.

[0050] Preferably, the linear polydimethylsiloxane F according to the present invention consists of a mixture of linear polydimethylsiloxanes (I) and (II) as defined above. The weight ratio (I):(II) can be 100:0 to 0:100, or 90:10 to 10:90, or 80:20 to 20:80, or 70:30 to 30:70. The foamable crosslinkable silicone composition according to the present invention can be free of, or substantially free of, linear polydimethylsiloxane (II). The linear polydimethylsiloxane F according to the present invention consists of one or several linear polydimethylsiloxanes (I) as defined above.

[0051] The foamable crosslinkable silicone composition of the present invention may optionally contain additives. Examples of suitable additives include elasticity additives, reinforcing fillers, thermally or electrically conductive fillers, nanoparticles, silicone resins, pigments, antibacterial agents, UV stabilizers, dyes, pigments, fragrances, flavors, essential oils, flame retardant additives, heat stabilizers, rheology modifiers, viscosity modifiers, thickeners, adhesion promoters, biocides, preservatives, enzymes, peptides, surfactants, reactive diluents, active pharmaceutical ingredients, excipients, or cosmetic ingredients. The content of additives is typically less than 5 wt %, preferably less than 2.5 wt %, and more preferably less than 1 wt %, based on the total weight of the foamable crosslinkable silicone composition. Those skilled in the art can select suitable additives according to the intended application and general knowledge in the technical field.

[0052] According to one embodiment, the foamable crosslinkable silicone composition of the present invention can optionally contain at least one filler, preferably a reinforcing filler, which can typically improve the mechanical strength of the cured silicone elastomer article. The filler can be precipitated silica, fumed (or pyrogen) silica, colloidal silica, and mixtures thereof. These active reinforcing fillers have a specific surface area of at least 10 m2 as determined by the BET method. 2 / g, preferably 50m 2 / g~400m 2 In a preferred embodiment, the silica reinforcing filler has a molecular weight of at least 10 m / g as determined by the BET method. 2 / g, preferably 50m 2 / g~400m 2 The fumed silica has a specific surface area in the range of 0.01 to 10% by weight, preferably 0.01 to 5% by weight, and more preferably 0.05 to 2% by weight of the total composition.

[0053] According to one embodiment, the foamable crosslinkable silicone composition of the present invention may optionally contain hollow microspheres. Suitable hollow microspheres include hollow glass microspheres or hollow ceramic microspheres.

[0054] Hollow glass microspheres are sometimes called "hollow glass beads" or "hollow glass bubbles." They are small, hollow spheres of hardened silica (glass) that vary in size and density depending on the grade. They have a thick enough shell to maintain structural rigidity. Their hollow nature makes them very lightweight, and their density varies with size and wall thickness. They appear as a white powder in bulk. The primary differences between grades are their size, strength, and density, with the strength of the microspheres being expressed in terms of average isotropic crush strength.

[0055] According to one embodiment, the hollow glass beads are hollow borosilicate glass microspheres.

[0056] According to one embodiment, the hollow glass microspheres have a density of 0.10 grams per cubic centimeter (g / cm 3 )~0.75g / cm 3 It has a true density in the range of

[0057] The term "true density" refers to the quotient obtained by dividing the mass of a sample of hollow glass microspheres by the true volume of the mass of the glass bubbles measured with a gas pycnometer. "True volume" refers to the total volume of the glass bubbles, not the bulk volume.

[0058] According to a preferred embodiment, the hollow glass microspheres are selected from: Sold by 3M 1.3M™ Glass Bubble Floated Series (A16 / 500, G18, A20 / 1000, H20 / 1000, D32 / 4500, H50 / 10000 EPX glass bubble products) and 3M™ Glass Bubble Series K, S, iM and XLD Series (K1, K11, K15, S15, S22, K20, K20HS, K25, S32, S32LD, S35, XLD3000, S28HS, S35, K37, S38, S38HS, S38XHS, S32HS, K46, K42HS, S42XHS, S60, S60HS, iM16K, iM30K glass bubble products, etc.; not limited to). The glass bubbles exhibit various crush strengths ranging from 250 psi to 27,000 psi, at which 10% by volume of the first plurality of glass bubbles collapse. Other glass bubbles sold by 3M, such as 3M™ Glass Bubbles - HGS Series and surface-treated 3M™ Glass Bubbles, may also be used in accordance with the present invention. 2. Hollow glass microspheres sold by Potters Industries under the SPHERICEL® trademark (e.g., the following products: 110P8, 60P18, 34P30, 25P45) or those sold under the Q-Cel® Lightweight trademark (e.g., the following products: 6014, 6019, 7019, 6019S, 5020, 5020FPS, 7023, 7028, 2058, 6036, 7037, 7040S, 6042S, 6048, 5070S).

[0059] Suitable hollow glass microspheres may be surface-treated or untreated. Surface-treated hollow glass microspheres may typically be hydrophobic. Examples of surface treatment agents include silane coupling agents such as aminopropyltriethoxysilane, y-glycidoxypropyltrimethoxysilane, y-(methacryloyloxy)propyltrimethoxysilane (also known as silane coupling agent KH-570), and sodium methylsiliconate.

[0060] Hollow ceramic microspheres, also known as cenospheres, are lightweight, inert hollow spheres filled with inert air or gas and are typically produced as a by-product of coal combustion in thermal power plants. Silica and alumina are the primary components. Cenospheres vary in color from gray to almost white and have a density of approximately 0.4 g / cm. 3 ~0.8g / cm 3 It flows like a liquid and looks like a powder. Suitable cenospheres are either untreated or surface treated with a silane coupling agent such as one or more of 3-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 4-aminopropylmethyldimethoxysilane, or 3-aminopropylmethyldiethoxysilane.

[0061] Commercially available examples of hollow ceramic microspheres include Z-Light™ Spheres Microspheres available from 3M™ Company (e.g., the following products: 3M™ Z-Light™ Spheres G-3125, G-3150, G-3500).

[0062] According to one embodiment, the foamable crosslinkable silicone composition according to the present invention comprises (by weight, relative to the total weight of the composition): 1.99% to 98.99% of a partial mixture of at least one organopolysiloxane A having at least two silicon-bonded alkenyl groups per molecule, at least one organosilicon compound B having at least two, preferably at least three, silicon-bonded hydrogen atoms per molecule, at least one hydrosilylation catalyst C, and at least one pore-forming agent D, which is water, a hydrogel, or an aqueous silicone emulsion; At least one chemical blowing agent E, 0.01% to 2%; and 1% to 98% of at least one linear polydimethylsiloxane F having a dynamic viscosity at 25°C of 50 mPa·s to 100,000 mPa·s.

[0063] According to another embodiment, the foamable crosslinkable silicone composition according to the present invention comprises (by weight, based on the total weight of the composition): 4.95% to 49.95% of a partial mixture of at least one organopolysiloxane A having at least two silicon-bonded alkenyl groups per molecule, at least one organosilicon compound B having at least two, preferably at least three, silicon-bonded hydrogen atoms per molecule, at least one hydrosilylation catalyst C, and at least one pore-forming agent D, which is water, a hydrogel, or an aqueous silicone emulsion; At least one chemical blowing agent E, 0.05% to 1.5%; and 50% to 95% of at least one linear polydimethylsiloxane F having a dynamic viscosity at 25°C of 50 mPa·s to 100,000 mPa·s.

[0064] According to another embodiment, the foamable crosslinkable silicone composition according to the present invention comprises (by weight, based on the total weight of the composition): 6.9% to 24.9% of a partial mixture of at least one organopolysiloxane A having at least two alkenyl groups bonded to silicon per molecule, at least one organosilicon compound B having at least two, preferably at least three, hydrogen atoms bonded to silicon per molecule, at least one hydrosilylation catalyst C, and at least one pore-forming agent D, which is water, a hydrogel, or an aqueous silicone emulsion; 0.1% to 1.0% of at least one chemical blowing agent E; and 75% to 93% of at least one linear polydimethylsiloxane F having a dynamic viscosity at 25°C of 50 mPa·s to 100,000 mPa·s.

[0065] Within the above embodiment, the submixture of at least one organopolysiloxane A having at least two silicon-bonded alkenyl groups per molecule, at least one organosilicon compound B having at least two, and preferably at least three, silicon-bonded hydrogen atoms per molecule, at least one hydrosilylation catalyst C, and at least one pore-forming agent D that is water, a hydrogel, or an aqueous silicone emulsion can have the following composition (by weight, based on the total weight of the submixture): 40% to 95% of at least one organopolysiloxane A having at least two alkenyl groups bonded to silicon per molecule; 1% to 20% of at least one organosilicon compound B having at least two, preferably at least three, hydrogen atoms bonded to silicon per molecule; 2 to 400 ppm (calculated by weight of platinum metal) of at least one platinum hydrosilylation catalyst C; 0.3% to 2.5% of at least one porosifying agent D, which is water, a hydrogel, or an aqueous silicone emulsion. More preferentially, the partial mixture may have the following composition (by weight relative to the total weight of the partial mixture): 50% to 90% of at least one organopolysiloxane A having at least two alkenyl groups bonded to silicon per molecule; 3% to 15% of at least one organosilicon compound B having at least two, preferably at least three, hydrogen atoms bonded to silicon per molecule; 5 ppm to 200 ppm of at least one platinum hydrosilylation catalyst C; 0.5% to 1.5% of at least one porosifying agent D, which is water, a hydrogel, or an aqueous silicone emulsion.

[0066] The foamable crosslinkable silicone composition of the present invention can be a two-component system, provided in two separate parts P1 and P2 that are intended to be mixed to form the foamable crosslinkable silicone composition, wherein one of parts P1 or P2 contains at least one hydrosilylation catalyst C and does not contain at least one organosilicon compound B.

[0067] Another object of the present invention relates to a method for producing an article made from said silicone foam.

[0068] According to a first embodiment, the object of the present invention is a method for manufacturing an article made of silicone foam, comprising the following steps: (1a) mixing the components of the foamable crosslinkable silicone composition according to the present invention as defined above to obtain a silicone foam precursor; (lb) filling the silicone foam precursor into a mold; and (lc) foaming and crosslinking the silicone foam precursor.

[0069] According to said embodiment, step (lb) can preferably be carried out in a mold so that the silicone foam can have a particular desired shape.

[0070] According to a second embodiment, the object of the present invention is a method for the manufacture of an article comprising a substrate coated with silicone foam, said method comprising the following steps: (2a) mixing the components of the foamable crosslinkable silicone composition of the present invention as defined above to obtain a silicone foam precursor; (2b) coating said silicone foam precursor onto a substrate, preferably a woven, nonwoven or composite textile; (2c) The silicone foam precursor is foamed and crosslinked.

[0071] Steps (1c) and (2c) of the method of the present invention (i.e., foaming and crosslinking the precursor to form a silicone foam) can be carried out by heating at a temperature ranging from 50°C to 200°C, preferably from 100°C to 170°C. The temperature in step (c) can be adjusted depending on the decomposition temperature of the chemical foaming agent E. For example, the decomposition temperature of ammonium bicarbonate is approximately 60°C. The temperatures in steps (1c) and (2c) can be set to preferably 60°C or higher so that both foaming and crosslinking proceed substantially simultaneously. Alternatively, steps (1c) and (2c) can be initiated at room temperature, and the temperature can then be increased to separately control foaming and crosslinking by chemical foaming agent E.

[0072] Another object of the present invention is to provide a novel method for additive manufacturing of 3D shaped articles composed of said silicone foams, which also allows for the production of complex shaped objects made of such materials.

[0073] One object of the present invention relates to a method for additive manufacturing of 3D shaped articles made from silicone foam, the method comprising the following steps: (3a) printing a portion of said foamable crosslinkable silicone composition as defined above in a 3D printer to form a deposit on a support material SM, which is a gel or microgel suitable for 3D gel printing of a silicone foam, said deposit being achieved by an apparatus having at least one delivery unit positionable in the x-, y- and z-directions; (3b) partially or fully foaming and crosslinking the printed foamable crosslinkable silicone composition to obtain a silicone foam deposit within said support material SM; (3c) optionally repeating steps (a) and (b) several times until the desired 3D shape is obtained; (3d) removing the support material SM mechanically or via dissolution in a solvent, and (3e) recovering a 3D shaped article comprised of silicone foam.

[0074] According to a specific embodiment, step (3b) can be carried out by heating at a temperature ranging from 50°C to 200°C, preferably from 100°C to 170°C. The temperature in step (3b) can be adapted depending on the decomposition temperature of the chemical blowing agent E. For example, the decomposition temperature of ammonium bicarbonate is approximately 60°C. The temperature in step (3b) can be set to preferably 60°C or higher so that both foaming and crosslinking proceed substantially simultaneously. Alternatively, step (3b) can be initiated at room temperature, and the temperature can then be increased to separately control foaming and crosslinking by the chemical blowing agent E. This specific embodiment can advantageously provide a desiliconized foam with anisotropic properties.

[0075] Printing is preferably performed layer-by-layer with a 3D printer, which may be selected from an extrusion 3D printer or a material jetting 3D printer. 3D printing generally relates to a host of related technologies used to manufacture physical objects from computer-generated, e.g., computer-aided design (CAD), data sources. A "3D printer" is defined as a machine used for 3D printing, and "3D printing" is defined as the manufacture of an object by the deposition of material using printheads, nozzles, and other printer technology.

[0076] In a preferred embodiment, a method for producing an article composed of a silicone foam according to the present invention uses an extrusion 3D printer. The foamable cross-linkable silicone composition is extruded through a nozzle. The nozzle may be heated to aid in the extrusion of the addition-cross-linkable silicone composition. The foamable cross-linkable silicone composition extruded through the nozzle may be supplied from a cartridge-like system. A coaxial cartridge system with a static mixer and only one nozzle may also be used. The pressure is adapted to the extruded fluid, the average diameter of the associated nozzle, and the printing speed. Due to the high shear rate generated during nozzle extrusion, the viscosity of the foamable cross-linkable silicone composition is significantly reduced, allowing for the printing of fine layers. The cartridge pressure is between 1 bar (i.e., atmospheric pressure) and 28 bar, preferably between 1 bar and 10 bar, and most preferably between 2 bar and 8 bar. To withstand such pressures, a suitable device using an aluminum cartridge can be used. The nozzle and / or build platform move in the xy (horizontal) plane to complete a cross-section of the object, and then move in the z-axis (vertical) plane once a layer is completed. The nozzle has a high xyz movement accuracy of about 10 pm. After printing each layer in the x- and y-work plane, the nozzle is displaced in the z-direction a distance sufficient for the next layer to be applied to the x- and y-work location. In this way, 3D articles are produced one layer at a time, from bottom to top. The average diameter of the nozzle is related to the layer thickness. In one embodiment, the layer diameter is comprised between 50 pm and 2000 pm, preferably between 100 pm and 800 pm, and most preferably between 100 pm and 500 pm. Advantageously, the printing speed is comprised between 1 mm / s and 50 mm / s, preferably between 5 mm / s and 30 mm / s, to obtain the best compromise between good accuracy and production speed.

[0077] The support material SM is a gel or microgel suitable for 3D gel printing of silicone foam. The gel or microgel provides constant support for the liquid material during 3D printing. This allows for more complex objects to be printed at a faster pace without the need for additional supports. The support material SM can be selected by one of skill in the art from among the materials disclosed in, for example, WO 2019 / 215190 and WO 2020 / 127882, or U.S. Patent Application Publication Nos. 2015 / 0028523, 2018 / 0036953, and 2018 / 0057682. Further details can be found in the scientific publication by Arthur Colly, Christophe Marquette and Edwin-Joffrey Courtia: "Poloxamer / Poly(ethylene glycol) Self-Healing Hydrogel for High-Precision Freeform Reversible Embedding of Suspended Hydrogel" (Langmuir 2021,37,14,4154-4162).

[0078] According to one embodiment of the claimed method, the support material SM can be provided as a matrix, for example in a container, and allowed to set at the required temperature. According to another embodiment, the support material SM can be delivered simultaneously or at staggered intervals with the foamable cross-linkable silicone composition at specific locations using an apparatus having at least one delivery unit positionable in the x, y, and z directions.

[0079] Furthermore, the present invention relates to the use of the silicone foams defined according to the invention in the fields of electronics, transport, aerospace, energy production and storage, textiles and furniture, and construction. In the electronics market, we provide potting or encapsulation, sealing, bonding or coating for various types of components, as well as high-end precision / sensitive electronic devices such as light-emitting diodes (LEDs), displays, solar power generation junction boxes for solar cell modules, diodes, semiconductor devices, relays, sensors, automotive stabilizers, automotive electronic control units (ECUs), etc. In the transportation sector, automotive, marine or aerospace parts such as hood buffer pads, motor vibration insulators, seats, vibration and noise damping parts, In the aerospace field, aerospace insulation materials, In the energy production and storage sectors, high voltage electrical insulation, insulation of secondary battery packs, insulation of stationary energy storage devices, insulation of charging stations, solar cells and assemblies, wind turbines, hydroelectric power assemblies, In the textile and furniture sector, thermal insulation coatings and composite textiles, artificial leather, footwear and clothing insulation, padding, In the construction field, construction electrical protection, In other fields, cosmetic puffs, medical absorbent materials, various filters, various sealing members such as packings, gaskets, O-rings, flexible joints, damping elements, fixed rollers, fixed belts, etc., which fix toner to paper by heat and / or pressure in electrophotographic image forming devices such as copiers, printers, and facsimiles.

[0080] According to the present application, the silicone foam can be used to manufacture foamed articles by itself, or can be used to manufacture composites or laminates with metals, organic resins, or elastomeric materials. For example, a composite article can comprise a shell and a filler, the filler consisting of or including the silicone foam according to the present invention.

[0081] Various embodiments of the present invention may be better understood by reference to the following examples, which are provided for illustrative purposes, but the present invention is not limited to the examples set forth herein. [Example]

[0082] Raw materials: Organopolysiloxane A1 = A mixture of multiple polydimethylsiloxane oils having dimethylvinylsilyl terminal units, with a viscosity at 25°C ranging from about 4,000 mPa to about 100,000 mPa·s, and an average viscosity at 25°C of about 10,000 mPa·s. Organopolysiloxane A2=MD Vi Q Branched organopolysiloxanes in which vinyl groups bonded to silicon atoms are held by D groups Organopolysiloxane B1 = Poly(methylhydrogen)siloxane with trimethylsilyl terminal units, having a viscosity of about 20 mPa·s at 25°C Organopolysiloxane B2 = Polydimethylsiloxane with dimethylhydrogensilyl terminal units, having a viscosity of approximately 7 mPa·s at 25°C Catalyst C = 10 wt% platinum metal, known as Karstedt's catalyst Emulsion D = Silicone emulsion containing approximately 59.5% water by weight Foaming agent E1 = ammonium bicarbonate Foaming agent E2 = Finely ground ammonium bicarbonate mixed with silica and polydimethylsiloxane oil (NH4HCO3 content = 50% by weight) Polydimethylsiloxane F1 = PDMS with a viscosity of approximately 1000 mPa·s at 25°C Polydimethylsiloxane F2 = PDMS with a viscosity of approximately 5000 mPa·s at 25°C Polydimethylsiloxane F3 = A mixture of several polydimethylsiloxane oils (PDMS and polydimethylsiloxane with one dimethylvinylsilyl end unit and one trimethylsilyl end unit) with an average viscosity of approximately 300 mPa·s at 25°C. Polydimethylsiloxane F4 = A mixture of several polydimethylsiloxane oils (PDMS and polydimethylsiloxane with one dimethylvinylsilyl end unit and one trimethylsilyl end unit) with an average viscosity of approximately 1000 mPa·s at 25°C. Polydimethylsiloxane F5 = A mixture of several polydimethylsiloxane oils (PDMS and polydimethylsiloxane with one dimethylvinylsilyl end unit and one trimethylsilyl end unit) with an average viscosity of approximately 2000 mPa·s at 25°C. Polydimethylsiloxane F6 = A mixture of several polydimethylsiloxane oils (PDMS and polydimethylsiloxane with one dimethylvinylsilyl end unit and one trimethylsilyl end unit) with an average viscosity of approximately 20,000 mPa·s at 25°C.

[0083] Comparative Example 1: A foamable crosslinkable silicone composition was prepared by mixing the ingredients set forth in Table 1 below:

[0084] [Table 1]

[0085] The resulting hydrogen-blown silicone foam exhibited high rigidity.

[0086] Comparative Example 2: The silicone foam described in WO 2020 / 072374, a prior art document listed in Table 14, was reproduced. The raw materials (linear PDMS, dimethylvinylsilyl-terminated polydimethylsiloxane, platinum catalyst, crosslinker, and ammonium bicarbonate) were mixed and maintained at 150°C for 30 minutes to allow crosslinking and foaming to occur. The silicone foam was exclusively chemically foamed.

[0087] The feel of this material was significantly improved compared to Comparative Example 1, however, this material was found to have a very irregular cell structure.

[0088] Examples 1-6: A foamable crosslinkable silicone composition was prepared by mixing the ingredients listed below in Table 2. After mixing, the temperature was maintained at 150° C. for 60 minutes.

[0089] [Table 2]

[0090] The silicone foam obtained by the present invention is a simultaneous hydrogen- and chemically foamed product, exhibiting low density, low weight, and good cell structure, and has a soft, impact-resistant feel.

[0091] Examples 7-9: A foamable crosslinkable silicone composition was prepared by mixing the ingredients listed below in Table 3. After mixing, the temperature was maintained at 150° C. for 60 minutes.

[0092] [Table 3]

[0093] Examples 10-15: Typical composition of hydrogen-blown silicone foam "H2B Foam": 67.10% by weight of a mixture of several polydimethylsiloxane oils containing dimethylvinylsilyl terminal units and having an average viscosity of approximately 1,000 mPa·s at 25°C; · 11.2 wt% treated fumed silica; · 0.64 wt% water; · 0.64% by weight of emulsifier; · 0.03 wt% of Karstedt catalyst (containing 10 wt% platinum metal); · 20.00 wt. % of poly(methylhydrogensiloxane) having trimethylsilyl terminal units and a viscosity of about 20 mPa·s at 25°C; · 0.39% by weight of ethynylcyclohexanol.

[0094] A foamable crosslinkable silicone composition was prepared by mixing the ingredients listed below in Table 4. After mixing, the temperature was maintained at 150°C for 60 minutes.

[0095] [Table 4]

[0096] PVP10 = Polyvinylpyrrolidone; average molecular weight 10,000 PVP40 = Polyvinylpyrrolidone; average molecular weight 40,000

[0097] Example 16: Example 10 was reproduced except that the composition of the hydrogen-blown silicone foam "H2B Foam" contained 14.6 wt% (instead of 11.2 wt%) treated fumed silica and 63.7 wt% (instead of 67.1 wt%) of the same mixture of polydimethylsiloxane oils.

[0098] The silicone foams obtained with the compositions of Examples 7 to 16 exhibit low density, low weight, and good cell structure.

[0099] [Table 5]

Claims

1. A silicone foam obtained from a foamable cross-linkable silicone composition, the foamable cross-linkable silicone composition comprising: at least one organopolysiloxane A having at least two silicon-bonded alkenyl groups per molecule; at least one organosilicon compound B having at least two, preferably at least three, silicon-bonded hydrogen atoms per molecule; at least one hydrosilylation catalyst C; at least one porosifying agent D which is water, a hydrogel, or an aqueous silicone emulsion; at least one chemical blowing agent E; and At least one linear polydimethylsiloxane F having a dynamic viscosity at 25°C between 50 mPa·s and 100,000 mPa·s Silicone foam containing.

2. 2. The silicone foam of claim 1, wherein the organopolysiloxane A comprises a linear organopolysiloxane; preferably, the organopolysiloxane A comprises terminal dimethylvinylsilyl units, and more preferably, the organopolysiloxane A is a poly(dimethylsiloxane) comprising terminal dimethylvinylsilyl groups.

3. The organopolysiloxane A is C 2～6 It comprises a branched organopolysiloxane containing alkenyl units, preferably having the following formula: ・M Vi Q (wherein the alkenyl group bonded to the silicon atom is held by the M group); ・MM Vi Q (wherein the alkenyl group bonded to the silicon atom is carried by part of the M unit); ・MD Vi Q (wherein the alkenyl group bonded to the silicon atom is held by a D group); MDD Vi Q (wherein the alkenyl group bonded to the silicon atom is held by part of the D group); ・MM Vi TQ (wherein the alkenyl group bonded to the silicon atom is carried by part of the M unit); ・MM Vi D.D. Vi Q (wherein the hydrogen atoms bonded to the silicon atoms are held by part of the M and D units); and mixtures thereof, wherein M:R 1 3 SiO 1 / 2 Siloxyl unit, M Vi : YR 1 2 SiO 1 / 2 , and Y 2 R 1 SiO 1 / siloxyl units selected from the group consisting of D:R 1 SiO 2 / 2 Siloxyl units, D Vi :Y 2 SiO 2 / 2 or YR 1 SiO 2 / 2 a siloxyl unit selected from the group consisting of siloxyl units, T: a siloxyl unit of formula R 1 SiO 3 / 2 Siloxyl units of the formula: and Q: SiO 4 / 2 The symbol Y represents a siloxyl unit of C 2～6 alkenyl, preferably vinyl; 1 is a monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably selected from alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, or propyl groups, cycloalkyl groups having 3 to 8 carbon atoms, and aryl groups having 6 to 12 carbon atoms.

4. 4. The silicone foam according to claim 1, wherein the foamable crosslinkable silicone composition comprises a mixture of at least one linear organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule, and at least one branched organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule.

5. 5. The silicone foam according to claim 1, wherein the foamable crosslinkable silicone composition comprises a mixture of at least one organosilicon compound B1 having at least three silicon-bonded hydrogen atoms per molecule and at least one organosilicon compound B2 having two silicon-bonded hydrogen atoms per molecule.

6. The silicone foam according to any one of claims 1 to 5, wherein the pore-forming agent D is an aqueous silicone emulsion.

7. 6. The silicone foam according to claim 1, wherein the pore-forming agent D is a mixture of water and at least one emulsifier.

8. The chemical foaming agent E is preferably ammonium bicarbonate (NH 4 ) HCO 3 , sodium bicarbonate NaHCO 3 , calcium bicarbonate Ca(HCO 3 ) 2 and mixtures thereof, and more preferably, said chemical blowing agent E is ammonium bicarbonate.

9. The linear polydimethylsiloxane F comprises a mixture of linear polydimethylsiloxanes (I) and (II), with a weight ratio of (I):(II) of 100:0 to 0:100, wherein the linear polydimethylsiloxane (I) is a compound represented by the following formula: (CH 3 , 3 t0.834597575 Subscribe Us 3 , 2 , n Si(CH 3 , 3 (I) wherein n is an integer of 50 to 900, preferably 50 to 700; and the linear polydimethylsiloxane (II) has the following formula: (CH 3 , 3 t0.834597575 Subscribe Us 3 , 2 , n Si(CH 3 , 2 (Y) (II) (Wherein, Y is C 2～6 The silicone foam according to any one of claims 1 to 8, wherein n is an integer from 50 to 900, preferably from 50 to 700.

10. The silicone foam according to any one of claims 1 to 9, wherein the foamable crosslinkable silicone composition further comprises hollow microspheres, preferably hollow glass microspheres.

11. The silicone foam of any one of claims 1 to 10, wherein the foamable crosslinkable silicone composition comprises (by weight, based on the total weight of the composition): 1.99% to 98.99% of a partial mixture of at least one organopolysiloxane A having at least two silicon-bonded alkenyl groups per molecule, at least one organosilicon compound B having at least two, and preferably at least three, silicon-bonded hydrogen atoms per molecule, at least one hydrosilylation catalyst C, and at least one porosifying agent D which is water, a hydrogel, or an aqueous silicone emulsion; 0.01% to 2% of at least one chemical blowing agent E; and 1 to 98% of at least one linear polydimethylsiloxane F having a dynamic viscosity at 25°C of from 50 mPa·s to 100,000 mPa·s.

12. 12. The silicone foam of claim 11, wherein the submixture of at least one organopolysiloxane A having at least two silicon-bonded alkenyl groups per molecule, at least one organosilicon compound B having at least two, and preferably at least three, silicon-bonded hydrogen atoms per molecule, at least one hydrosilylation catalyst C, and at least one pore-forming agent D which is water, a hydrogel, or an aqueous silicone emulsion has the following composition (by weight, based on the total weight of the submixture): 40% to 95% of at least one organopolysiloxane A having at least two silicon-bonded alkenyl groups per molecule; 1% to 20% of at least one organosilicon compound B having at least two, preferably at least three, hydrogen atoms bonded to silicon per molecule; from 2 to 400 ppm (calculated as the weight of platinum metal) of at least one platinum hydrosilylation catalyst C; 0.3% to 2.5% of at least one porosifying agent D which is water, a hydrogel, or an aqueous silicone emulsion.

13. 1. A method of manufacturing an article comprised of silicone foam, comprising the steps of: (1a) mixing the components of the foamable cross-linkable silicone composition according to any one of claims 1 to 12 to obtain a silicone foam precursor; (lb) filling the silicone foam precursor into a mold; and (lc) foaming and crosslinking the silicone foam precursor. A method comprising:

14. 1. A method of manufacturing an article comprising a substrate coated with a silicone foam, comprising the steps of: (2a) mixing the components of the foamable cross-linkable silicone composition according to any one of claims 1 to 12 to obtain a silicone foam precursor; (2b) coating said precursor of silicone foam onto a substrate, preferably a woven, nonwoven or composite textile; (2c) foaming and crosslinking the silicone foam precursor. A method comprising:

15. 1. A method for additive manufacturing of 3D shaped articles composed of silicone foam, comprising the steps of: (3a) printing a portion of the foamable crosslinkable silicone composition according to any one of claims 1 to 12 with a 3D printer to form a deposit on a support material SM, which is a gel or microgel suitable for 3D gel printing of a silicone foam, said depositing being achieved using an apparatus having at least one delivery unit positionable in the x-, y- and z-directions; (3b) partially or fully foaming and crosslinking the printed foamable crosslinkable silicone composition to obtain a silicone foam deposit within said support material SM; (3c) optionally repeating steps (a) and (b) several times until the desired 3D shape is obtained; (3d) removing the support material SM mechanically or via dissolution in a solvent; and (3e) Recovering the 3D shaped article composed of silicone foam. A method comprising:

16. Use of the silicone foam according to any one of claims 1 to 12, wherein the silicone foam is used as such for the production of foamed articles, or for the production of composites or laminates with metals, organic resins or elastic materials in the fields of electronics, transportation, aerospace, energy production, energy storage, textiles and furniture, and construction.

17. The use, - In the electronics market, we provide potting or encapsulation, sealing, bonding or coating for various types of components, as well as high-end precision / sensitive electronic devices such as light-emitting diodes (LEDs), displays, photovoltaic junction boxes for solar cell modules, diodes, semiconductor devices, relays, sensors, automotive stabilizers, automotive electronic control units (ECUs), etc. - In the transportation sector, automotive, marine or aerospace parts such as hood buffer pads, motor vibration insulators, seats, vibration and noise damping parts, - In the aerospace field, aerospace insulation materials, In the energy production and energy storage sectors, high voltage electrical insulation, insulation of secondary battery packs, insulation of stationary energy storage devices, insulation of charging stations, solar cells and assemblies, wind turbines, hydroelectric power assemblies, - In the textile and furniture sector, thermal insulation coatings and composite textiles, artificial leather, footwear and clothing insulation, padding, - In the construction field, construction electrical protection 17. The use according to claim 16, comprising:

Images