Polysiloxane dispersant

Abstract

To provide a use of a polysiloxane having a plurality of siloxane groups as a dispersant for solid particles in a non-aqueous composition, and to provide a non-aqueous composition containing the polysiloxane having the plurality of siloxane groups, a dispersion medium, and the solid particles.SOLUTION: Use of a polysiloxane having a plurality of siloxane groups and at least one cyclic carboxylic anhydride group covalently bonded to the polysiloxane or a hydrolysis product thereof as a dispersant for solid filler particles in a non-aqueous composition having a dispersion medium, wherein the content of filler particles is in the range of 500 to 2,500 parts by weight per 100 parts by weight of the dispersion medium.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to the use of a polysiloxane having multiple siloxane groups as a dispersant for solid particles in a non-aqueous composition, and to a non-aqueous composition having a polysiloxane having multiple siloxane groups, a dispersion medium, and solid particles. The present invention further relates to a method for dispersing solid particles in a non-aqueous composition. [Background technology]

[0002] A large number of different substances can be used as dispersants for pigments and fillers, including simple compounds with low molecular weight, such as fatty acids and their salts, or various silanes, such as alkyl or vinyl silanes, as well as more complex structures.

[0003] EP 0 931 537 B1 describes the dispersion of organic and inorganic powders in oil-containing compositions using polysiloxane-containing compounds: Polymers are prepared by radical copolymerization of vinyl polysiloxane macromonomers with other vinyl monomers, the latter bearing nitrogen-containing, polyoxyalkylene, anionic, or polylactone groups.

[0004] US9217083B2 describes copolymers having a backbone structure of at least one polysiloxane group and an adduct of at least one amine and at least one epoxide. The invention further relates to the use of said products as dispersants for organic and inorganic pigments and fillers in oil-based compositions, especially silicone-containing compositions.

[0005] US Pat. No. 7,329,706 B2 describes a thermally conductive silicone composition, which contains an organopolysiloxane, a thermally conductive filler, and a specific polysiloxane macromonomer having an alkoxysilane group as a dispersing agent.

[0006] EP 2107078 A1 describes the reaction of a Si-H functional polysiloxane with allyl succinic anhydride to prepare an anhydride functional polysiloxane. The anhydride functional polysiloxane is then hydrolyzed to form a dicarboxylic acid functional polysiloxane. Titanium dioxide powder and zinc oxide are treated with this material.

[0007] JP2020 / 059771A describes a dispersant having a silicone structure and a dicarboxylic acid anhydride structure at one end of the silicone structure. The dispersant is used to treat zirconia, which is then dispersed in silicone oil.

[0008] While prior art dispersants provide acceptable stability of dispersed pigments and / or fillers, there remains a need for improved systems, a need to reduce pigment settling, a need to improve the color fidelity of pigment dispersions, a need to reduce viscosity, and a need to ensure relatively broad compatibility of dispersants with different compositions, such as compatibility with highly apolar compositions (e.g., oil-based compositions and silicone-based compositions).

[0009] The silicone-containing composition may be a non-curable or curable composition, and the curing may be, for example, condensation curing or addition curing. In the case of addition curing, the composition consists of two components, an SiH- and vinyl-functional organopolysiloxane component, and typically a platinum-based catalyst. If the composition further contains one or more functional fillers or one or more pigments, a dispersant is generally used to compatibilize the filler(s) or pigment(s) with the silicone. It has been found that known dispersants are insufficient to completely disperse the filler(s) or pigment(s). In particular, it has not been possible to achieve sufficient viscosity of the composition without adversely affecting the curing process.

[0010] In the field of modern electronics, thermal management plays an increasingly important role. Without thermally conductive materials, advances in microelectronics technology would not have resulted in electronic devices that process signals and data at ever-increasing speeds. As electronic and / or integrated circuit (IC) devices, such as microprocessors, memory devices, printed circuits, etc., become smaller, the heat dissipation requirements become greater.

[0011] High thermally conductive particle loadings are required to achieve high thermal conductivity in potting materials, gaskets, solder pastes, underfills, thermal interface materials (e.g., thermal gap fillers, gap pads, sil-pads, phase change materials, thermally conductive greases, thermal gels, thermal clads, thermal encapsulants), adhesives, sealants, and coatings. A major disadvantage of these highly filled systems is that high filler loadings increase the conductive material viscosity to an undesirably high degree, significantly compromising application properties. Summary of the Invention [Problem to be solved by the invention]

[0012] The present invention aims to overcome or mitigate the above disadvantages by combining effective dispersion and cure speed. [Means for solving the problem]

[0013] The present invention relates to the use of a polysiloxane having a plurality of siloxane groups and at least one cyclic carboxylic acid anhydride group or a hydrolysis product thereof covalently bonded to the polysiloxane as a dispersant for solid filler particles in a non-aqueous composition containing a dispersion medium, the content of the filler particles being in the range of 500 to 2500 parts by weight per 100 parts by weight of the dispersion medium.

[0014] The above use can also be described as a method for dispersing pigments / fillers in a non-aqueous composition, which method includes adding a polysiloxane having a plurality of siloxane groups and at least one cyclic carboxylic acid anhydride group or its hydrolysis product covalently bonded to the polysiloxane to a non-aqueous composition containing solid particles, and then dispersing the solid particles in the non-aqueous composition. This liquid composition can be used as is, or can be further reacted with a crosslinker to obtain a cured composition. In such cases, there is no limitation regarding the curing mechanism of the liquid composition, which can be based on, for example, a hydrosilylation reaction, a condensation reaction, an addition reaction, or an organic peroxide-induced free radical reaction.

[0015] A non-aqueous composition is one that contains less than 10% by weight, preferably less than 5% by weight, of water, calculated based on the weight of the composition. In some embodiments, a non-aqueous composition is free of water or substantially free of water.

[0016] It has been discovered that the use of a polysiloxane having a plurality of siloxane groups and at least one cyclic carboxylic acid anhydride group or its hydrolysis product covalently bonded to the polysiloxane as a dispersion in a composition containing solid particles provides improved dispersion properties and can reduce viscosity when used in potting materials, gaskets, solder pastes, underfills, thermal interface materials (thermal interface materials), such as thermal gap fillers, gap pads, sil pads, phase change materials, thermally conductive greases, thermal gels, thermal cladding materials, thermal encapsulants, adhesives, sealants, and coating compositions.

[0017] The non-aqueous compositions are preferably used as thermal interface materials, particularly in electronic components.

[0018] As described above, the polysiloxane has at least one cyclic carboxylic acid anhydride group or its hydrolysis product covalently bonded to the polysiloxane. The hydrolysis product of the cyclic carboxylic acid anhydride is the corresponding dicarboxylic acid or its salt. Suitable examples of the cyclic carboxylic acid anhydride group are those derived from bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride, 5-norbornene-2,3-carboxylic anhydride, 1-cyclopentene-1,2-dicarboxylic anhydride, maleic anhydride, tetrahydrophthalic anhydride, citraconic anhydride, itaconic anhydride, and allyl succinic anhydride. In some embodiments, the cyclic carboxylic acid anhydride group is present in the form of a five-membered ring. In further embodiments, the at least one cyclic carboxylic acid anhydride group is derived from allyl succinic anhydride. In other embodiments, the cyclic carboxylic acid anhydride group is present as a six-membered ring. When a polysiloxane has two or more cyclic carboxylic acid anhydride groups covalently bonded to the polysiloxane, the individual anhydride groups may be the same or different types. In some embodiments, a polysiloxane has more than two cyclic carboxylic acid anhydride groups or hydrolysis products thereof covalently bonded thereto. In another further embodiment, a polysiloxane has two cyclic carboxylic acid anhydride groups bonded thereto. In yet a further embodiment, a polysiloxane has one cyclic carboxylic acid anhydride group or hydrolysis product thereof bonded thereto. However, mixtures of polysiloxanes can also be used, such as a mixture of a first polysiloxane having one or more cyclic carboxylic acid anhydride groups or hydrolysis products thereof bonded thereto and a second, different polysiloxane having one or more cyclic carboxylic acid anhydride groups or hydrolysis products thereof bonded thereto. The cyclic carboxylic acid anhydride groups or hydrolysis products thereof may be located at various positions along the polysiloxane chain. In some embodiments, at least one anhydride group is covalently bonded to the polysiloxane as a terminal group at the two ends of the polysiloxane chain. Polymers in which two anhydride groups are located at the two ends of the polysiloxane chain may also be referred to as ABA polymers.In further embodiments, at least one anhydride group is covalently bonded to the polysiloxane as a terminal group at only one end of the polysiloxane chain. Polymers in which only anhydride groups are located at only one end of the polysiloxane chain may also be referred to as macromonomers. Alternatively, or in addition, at least one anhydride group is covalently bonded to the polysiloxane at a non-terminal position. Polymers in which multiple anhydride groups are pendant from the polysiloxane chain at different positions may also be referred to as comb polymers.

[0019] Polysiloxanes having multiple siloxane groups generally have 1 to 15 cyclic carboxylic acid anhydride groups or hydrolysis products thereof covalently bonded thereto. In preferred embodiments, 1 to 10, more preferably 1 to 2, cyclic carboxylic acid anhydride groups or hydrolysis products thereof are covalently bonded to the polysiloxane. In some embodiments, a mixture of multiple polysiloxanes having different numbers of cyclic carboxylic acid anhydride groups or hydrolysis products thereof may be used. When such a mixture is used, the number of cyclic carboxylic acid anhydride groups or hydrolysis products thereof relates to the average number of cyclic carboxylic acid anhydride groups or hydrolysis products thereof. In preferred embodiments, an average of 0.7 to 3.0 cyclic carboxylic acid anhydride groups or hydrolysis products thereof are covalently bonded to the polysiloxane molecule.

[0020] Polysiloxanes having multiple siloxane groups and at least one cyclic carboxylic acid anhydride group or its hydrolysis product covalently bonded to the polysiloxane can be prepared according to known methods. In a preferred embodiment, the cyclic carboxylic acid anhydride group or its hydrolysis product is bonded to the polysiloxane via an Si-C bond.

[0021] In one embodiment, the compounds of interest are prepared by a hydrosilylation reaction, in which a polysiloxane having multiple siloxane groups and at least one Si-H group is reacted with an anhydride compound having an ethylenically unsaturated group. Such reactions are generally catalyzed by a metal-based catalyst. The details and suitable conditions for such hydrosilylation reactions are generally known.

[0022] The hydrosilylation catalyst used is preferably a noble metal or a compound thereof, such as platinum, rhodium, or palladium, or a compound thereof, more preferably a platinum compound. Particularly preferred platinum compounds are hexachloroplatinic acid, an alcohol solution of hexachloroplatinic acid, a complex of platinum with an aliphatic unsaturated hydrocarbon compound, and a platinum-vinylsiloxane complex. However, platinum black and platinum on activated carbon can also be used. For example, when a platinum compound is used, 1 to 50 ppm of platinum metal is preferably used.

[0023] The progress of the hydrosilylation reaction was monitored by gas volume determination of the remaining SiH groups or by infrared spectrometry (at 2150 cm -1 The polysiloxanes of the present invention preferably have no residual Si-H groups.

[0024] When a polysiloxane having a plurality of siloxane groups and having at least one cyclic carboxylic acid anhydride group or its hydrolysis product covalently bonded to the polysiloxane is prepared by the hydrosilylation reaction of an ethylenically unsaturated anhydride, a covalent bond is formed between the polysiloxane and at least one anhydride group.One specific example of an ethylenically unsaturated anhydride suitable for preparing the polysiloxane used in accordance with the present invention is allyl succinic anhydride.

[0025] The above synthetic route requires a polysiloxane having multiple siloxane groups and at least one Si—H group as a starting material. Suitable polysiloxanes having at least one Si—H group can be represented by the following general formula (I): M a M´ b D c D´ d T e Q f (I) where: M is [R3SiO 1 / 2 ], M' is [R2SiHO 1 / 2 ], ·D represents [R2SiO2 / 2], ·D´ is [RSiHO 2 / 2 ], ·T is [RSiO 3 / 2 ], Q is SiO 4 / 2 ], a is an integer from 0 to 10, preferably an integer from 0 to 1, more preferably 1, b is an integer of 0 to 10, preferably an integer of 1 to 2, and more preferably 1; c is an integer from 0 to 500, preferably an integer from 2 to 300, more particularly an integer from 5 to 250, d is an integer from 0 to 100, preferably an integer from 0 to 50, more particularly an integer from 0 to 30, e is an integer from 0 to 10, preferably an integer from 0 to 5, more particularly 0, f is an integer from 0 to 10, preferably an integer from 0 to 5, more particularly 0, The conditions a+b≧2 and b+d≧1 are met, R is independently C1 to C 30 and preferably represents methyl, octyl, or phenyl, (α-methyl)styryl, more preferably methyl.

[0026] The description of polysiloxanes using M, D, T and Q is generally known in the art.

[0027] Generally, polysiloxanes having SiH groups are synthesized using classical equilibrium reactions known in the art.

[0028] Generally, the polysiloxane has 1 to 15 SiH groups, preferably 1 to 10, and more preferably 1 to 2. Generally, the polysiloxane has 4 to 70 silicon atoms, and preferably 10 to 50 silicon atoms.

[0029] If desired, polysiloxanes having a plurality of siloxane groups and two anhydride groups covalently bonded thereto can be prepared by other suitable synthetic routes, for example, by the equilibration reaction of anhydride-functional polysiloxanes of ABA structure, such as those described in EP 0 112 845 B1, particularly in Example 4 of this document.

[0030] The number average molecular weight of the polysiloxane having a plurality of siloxane groups and at least one anhydride group covalently bonded to the polysiloxane is generally in the range of 300 to 15,000 g / mol, preferably in the range of 500 to 10,000 g / mol, and even more preferably in the range of 800 to 8,000 g / mol.

[0031] The number average molecular weight can be determined by gel permeation chromatography performed at 22° C. using a Waters 2695 separation module and a Waters 2414 refractive index detector. Toluene is a suitable eluent, and polydimethylsiloxane standards are used for calibration.

[0032] Optionally, the polysiloxane having a plurality of siloxane groups and at least one anhydride group covalently bonded thereto may have additional structural moieties. Such optional moieties may be added to adjust and fine-tune the compatibility with the system in which it is used and other properties of the polysiloxane. Examples of such optional moieties are polyether moieties, such as those based on polyethylene oxide and / or polypropylene oxide, polyester moieties, hydrocarbon moieties, fluorinated hydrocarbon moieties, and polyurethane moieties. These optional moieties may be attached to the polysiloxane backbone by hydrosilylation or dehydrocondensation. Such dehydrocondensation reactions are suitably catalyzed by metal complexes. This type of reaction is described in German Patent Application DE102005051939A. These optional moieties are preferably attached to the polysiloxane backbone by hydrosilylation.

[0033] In many embodiments, the polysiloxane, which has a plurality of siloxane groups and at least one anhydride group covalently bonded to the polysiloxane, is liquid at room temperature.It can be used according to the present invention and can be added directly to the liquid composition as 100% active material.If desired, the polysiloxane can be diluted with an organic solvent or oil or silicone before being added to the liquid composition.In yet another embodiment, the polysiloxane can be contained in the liquid composition as an emulsion or dispersion.The liquid composition preferably contains the polysiloxane in an amount that achieves effective dispersion properties.This specific amount depends on the content of solid particles, such as the content of pigments and / or fillers in the composition, and on the required degree of dispersion. Generally, the liquid composition contains 0.001% to 10,000% by weight of polysiloxane, preferably 0.010% to 8,000% by weight, more preferably 0.050% to 7,000% by weight, or 0.060% to 6,000% by weight, or 0.080% to 5,000% by weight, and especially 0.100 to 2,000% by weight, each based on the total weight of the composition.

[0034] The pigment and / or filler dispersions according to the present invention can be used in a wide range of formulations, such as resins, oils, greases, lubricants, rubber materials, potting materials, gaskets, solder pastes, underfills, thermal interface materials (e.g., thermal gap fillers, gap pads, sil pads, phase change materials, thermally conductive greases, thermal gels, thermal cladding materials, thermal encapsulants), adhesives, sealants, coatings, waxes, or material compositions. The dispersions may be used in formulations made in the body care industry, or for electronic applications in the electronics industry, in the marine industry, for medical applications, in the construction industry, or in the electronic, battery, and automotive industries.

[0035] Examples include beauty products, electronic paper, eg displays in e-books, encapsulation of microelectronic chips, submersible skin coatings, eg anti-fouling coatings, silicone tubing, or lubricity additives for brake parts.

[0036] The dispersions are particularly suitable for use in thermal interface material (TIM) products. These materials are used as interfaces between devices or their components to dissipate heat from these devices (e.g., microprocessors). A typical TIM typically has a polymer matrix and one or more thermally conductive fillers. This TIM technology used for electronic devices encompasses several types of materials, including epoxies, greases, sheets, pads, phase change materials, filled polymer matrices such as elastomers, gels, carbon-based materials, and adhesives. U.S. Patent No. 6,469,379 describes a silicone-based TIM having a vinyl-terminated silicon polymer; a silicone crosslinker with terminal silicon hydride units, a chain extender, and a thermally conductive filler, such as a metal (e.g., aluminum, silver, etc.) and / or a ceramic (e.g., aluminum nitride, aluminum oxide, zinc oxide, etc.).

[0037] The use of non-aqueous compositions as thermal interface materials is preferred, and their use as thermal interface materials in electronic components is especially preferred.

[0038] One embodiment of the present invention relates to a method for preparing a dispersion, which method comprises mixing at least one pigment and / or filler in a medium selected from the group consisting of at least one silicone oil and silicone rubber material, under the presence of at least one anhydride-modified polysiloxane according to the present invention. These dispersions are preferably pigment and / or filler preparations, and are preferably used for various compositions.

[0039] In a further embodiment, the dry filler is treated with a polysiloxane having a plurality of siloxane groups and at least one cyclic carboxylic acid anhydride group, or a hydrolysis product thereof, covalently bonded to the polysiloxane to modify the surface of the dry filler, and then the treated filler is mixed with the dispersing medium.

[0040] In a preferred embodiment, the non-aqueous composition contains a dispersion medium other than a polysiloxane having a plurality of siloxane groups and at least one cyclic carboxylic acid anhydride group or a hydrolysis product thereof.

[0041] In further preferred embodiments, the dispersion medium comprises a silicone, hi some embodiments, the silicone is a silicone oil or a silicone gum.

[0042] Examples of silicone oils include those having the following structure: [ka] [ka] [ka]

[0043] where R 2 is a group selected from hydrogen, a hydroxyl group, an alkyl or fluorinated alkyl group having 2 to 20 carbon atoms, an aryl group, an aminoalkyl group, a C6 to 22 alkoxy group, and a group of the formula (CH3)3SiO[(CH3)2SiO] y Si(CH3)2CH2CH2-, where y is an integer from 0 to 500. 3 is C 1-20 In formula (II), h is an integer of 0 to 1000, i is an integer of 0 to 1000, provided that h+i is 1 to 2000, and j and k are each, independently of each other, 0, 1, 2, or 3. In formula (III), l and m are integers of 0 to 8, and l+m is in the range of 3 to 8, and in formula (IV), z is an integer of 1 to 4. Radical R 2Examples of the alkyl groups include methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, trifluoropropyl, nonafluorohexyl, heptadecylfluorodecyl, phenyl, aminopropyl, dimethylaminopropyl, aminoethylaminopropyl, stearoxy, butoxy, ethoxy, propoxy, cetyloxy, myristyloxy, styryl, and alpha-methylstyryl, of which preferred are hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, trifluoropropyl, phenyl, aminopropyl, and aminoethylaminopropyl. Examples of silicone oils include organopolysiloxanes having low or high viscosity, such as dimethylpolysiloxane, methylphenylpolysiloxane, methyl-hydrogenpolysiloxane, and dimethylsiloxane-methyl-phenylsiloxane copolymers, and cyclosiloxanes such as octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), tetramethyltetrahydrogencyclotetrasiloxane (H4), and tetramethylcyclotetrasiloxane (H5). tris-trimethylsiloxysilane (M3T), tetrakis-trimethylsiloxysilane (M4Q); branched siloxanes such as tris-trimethylsiloxypropylsilane, tris-trimethylsiloxybutylsilane, tris-trimethylsiloxyhexylsilane, and trimethylsiloxyphenylsilane; higher alcohol-modified silicones such as steroxysilicones; alkyl-modified silicones, amino-modified silicones, and fluorine-modified silicones.

[0044] In some embodiments, the silicone dispersion medium is a crosslinkable silicone.Crosslinkable silicones can exist in multiple forms and compounds, such as silicone oil, high-solids silicone, waterborne silicone, silicone alkyd, siliconized polyester, or siliconized acrylic resin.Crosslinking can occur by moisture curing, hydrosilylation curing, radiation curing, free-radical induced curing, or a combination of radiation and heat curing (dual curing).Crosslinkable silicones are also referred to as silicone rubber or liquid silicone rubber.

[0045] Methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, and other straight-chain alkyl groups; isopropyl, tertiary butyl, isobutyl, 2-methylundecyl, 1-hexylheptyl, and other branched alkyl groups; cyclopentyl, cyclohexyl, cyclododecyl, and other cyclic alkyl groups; vinyl, allyl, butenyl, pentenyl, hexenyl, and other alkenyl groups; phenyl, tolyl, xylyl, and other aryl groups; benzyl, phenethyl, 2-(2,4,6-trimethylphenyl)propyl, and other aralkyl groups; and 3,3,3-trifluoropropyl, 3-chloropropyl, and other halogenated alkyl groups have been proposed as silicon-bonded groups for organopolysiloxanes.

[0046] Preferably, such groups are alkyl, alkenyl, or aryl groups, with methyl, vinyl, or phenyl being particularly preferred. Furthermore, there is no limitation regarding the viscosity of the organopolysiloxane at 25°C. However, this viscosity is preferably within the range of 20 to 100,000 mPa·s, more preferably 50 to 100,000 mPa·s, even more preferably 50 to 50,000 mPa·s, and particularly preferably 100 to 50,000 mPa·s. This is due to the fact that if the viscosity at 25°C is lower than the lower limit of the above range, the physical properties of the resulting silicone composition tend to deteriorate, while, on the other hand, if the viscosity exceeds the upper limit of the above range, the handleability of the resulting silicone composition tends to deteriorate. There is no limitation regarding the molecular structure of such organopolysiloxane. This may be, for example, linear, branched, partially branched linear, or dendritic (dendrimeric), and is preferably linear or partially branched linear. Examples of such organopolysiloxanes are, for example, homopolymers having the above molecular structures, copolymers having the above molecular structures, or mixtures of the above polymers.

[0047] Dimethylpolysiloxanes in which both molecular chain terminals are blocked with dimethylvinylsiloxy groups, dimethylpolysiloxanes in which both molecular chain terminals are blocked with methylphenylvinylsiloxy groups, dimethylsiloxane-methylphenylsiloxane copolymers in which both molecular chain terminals are blocked with dimethylvinylsiloxy groups, dimethylsiloxane-methylvinylsiloxane copolymers in which both molecular chain terminals are blocked with dimethylvinylsiloxy groups, and dimethylsiloxane-methylvinylsiloxane copolymers in which both molecular chain terminals are blocked with trimethylsiloxy groups. Blocked dimethylsiloxane-methylvinylsiloxane copolymer, methyl(3,3,3-trifluoropropyl)-polysiloxane with both molecular chain terminals blocked with dimethyl-vinylsiloxy groups, dimethylsiloxane-methylvinylsiloxane copolymer with both molecular chain terminals blocked with silanol groups, dimethylsiloxane-methylvinyl-siloxane-methylphenylsiloxane copolymer with both molecular chain terminals blocked with silanol groups, formula (CH3)3SiO 1 / 2 Siloxane units represented by the formula (CH3)2(CH2=CH)SiO 1 / 2 The oxane unit, represented by the formula CH3SiO 3 / 2 and siloxane units represented by the formula (CH3)2SiO 2 / 2 Examples of the organopolysiloxane include organosiloxane copolymers consisting of siloxane units represented by the formula: dimethylpolysiloxanes in which both molecular chain terminals are blocked with silanol groups, dimethylsiloxane-methylphenylsiloxane copolymers in which both molecular chain terminals are blocked with silanol groups, dimethylpolysiloxanes in which both molecular chain terminals are blocked with trimethoxysiloxy groups, dimethylsiloxane-methylphenylsiloxane copolymers in which both molecular chain terminals are blocked with trimethoxysilyl groups, dimethylpolysiloxanes in which both molecular chain terminals are blocked with methyldimethoxysiloxy groups, dimethylpolysiloxanes in which both molecular chain terminals are blocked with triethoxysiloxy groups, dimethylpolysiloxanes in which both molecular chain terminals are blocked with trimethoxysilylethyl groups, and mixtures of two or more of the above compounds.

[0048] When the composition is cured by a hydrosilylation reaction, the dispersion medium is preferably an organopolysiloxane having an average of 0.1 or more silicon-bonded alkenyl groups per molecule. More preferably, it is an organopolysiloxane having an average of 0.5 or more silicon-bonded alkenyl groups per molecule, and particularly preferably an organopolysiloxane having an average of 0.8 or more silicon-bonded alkenyl groups per molecule. This is due to the fact that if the average number of silicon-bonded alkenyl groups per molecule is below the lower limit of the above range, the resulting composition tends not to be cured to a sufficient degree. The silicon-bonded alkenyl groups of the organopolysiloxane are exemplified by the same alkenyl groups as described above, preferably vinyl. Furthermore, the silicon-bonded groups other than alkenyl groups in the organopolysiloxane are exemplified by the same linear alkyl, branched alkyl, cyclic alkyl, aryl, aralkyl, and halogenated alkyl groups as described above. These are preferably alkyl and aryl groups, and particularly preferably methyl and phenyl. There are no limitations on the molecular structure of such organopolysiloxanes, and they are exemplified by the same structures as those described above, preferably linear or partially branched linear. Such organopolysiloxanes are exemplified, for example, by homopolymers having the above molecular structures, copolymers having the above molecular structures, or mixtures of these polymers. Such organopolysiloxanes are exemplified by organopolysiloxanes having the same alkenyl groups as those described above.

[0049] When the composition is cured by condensation reaction, the dispersion medium is an organopolysiloxane having at least two silanol groups or silicon-bonded hydrolyzable groups per molecule.Examples of silicon-bonded hydrolyzable groups in organopolysiloxane include, for example, methoxy, ethoxy, propoxy, and other alkoxy groups; vinyloxy, propenoxy, isopropenoxy, 1-ethyl-2-methylvinyloxy, and other alkenoxy groups; methoxyethoxy, ethoxyethoxy, methoxypropoxy, and other alkoxyalkoxy groups; acetoxy, octanoyloxy, and other acryloxy groups; dimethylketoxime, methylethylketoxime, and other ketoxime groups; dimethylamino, diethylamino, butylamino, and other amino groups; dimethylaminooxy, diethylaminooxy, and other aminoxy groups; N-methylacetamide group, N-ethylacetamide, and other amide groups. Furthermore, the silanol groups and silicon-bonded hydrolyzable groups of the organopolysiloxane are exemplified by the same linear alkyl, branched alkyl, cyclic alkyl, alkenyl, aryl, aralkyl, and halogenated alkyl groups as described above. There are no limitations on the molecular structure of such organopolysiloxanes, and they are exemplified by the same structures as described above, preferably linear or partially branched linear. Such organopolysiloxanes are exemplified by organopolysiloxanes having at least two silanol groups or silicon-bonded hydrolyzable groups per molecule, and these groups are the same as described above.

[0050] When the composition is cured by an organic peroxide-induced free radical reaction, there are no limitations regarding the organopolysiloxane of the dispersion medium. However, organopolysiloxanes having at least one silicon-bonded alkenyl group are preferred. The silicon-bonded group in such organopolysiloxanes is exemplified by the same linear alkyl, branched alkyl, cyclic alkyl, alkenyl, aryl, aralkyl, and halogenated alkyl groups as described above, preferably alkyl, alkenyl, or aryl groups, with methyl, vinyl, and phenyl being particularly preferred. There are no limitations regarding the molecular structure of such organopolysiloxanes, and they are exemplified by the same structures as described above, preferably linear or partially branched linear. Such organopolysiloxanes are exemplified, for example, by homopolymers having the above-described molecular structures, copolymers having the above-described molecular structures, or mixtures of the above-described polymers. Such organopolysiloxanes are exemplified by the same organopolysiloxanes as described above.

[0051] Silicone rubbers can be classified as room temperature vulcanizing (RTV) or high temperature vulcanizing (HTV) silicone rubbers, which are commonly known and described, for example, in US6172150B1, WO2018051158A1, WO2003078527A1, US6194508B1, and WO2003057782A1.

[0052] Liquid silicone rubbers are further described in WO2015003978A1, WO2018051158A1, and WO2020223864A1.

[0053] Suitable crosslinkable silicones are commercially available, for example under the ELSATOSIL™ and SEMICOSIL™ trademarks from Wacker Chemie AG.

[0054] As mentioned above, polysiloxanes having a plurality of siloxane groups and at least one cyclic carboxylic acid anhydride group or its hydrolysis product covalently bonded to the polysiloxane are used as dispersants for solid particles in non-aqueous compositions, such as pigments and fillers.

[0055] The solid particles may be surface-modified, the surface may be, for example, hydrophilic, amphiphilic or hydrophobic compounds or groups. The surface treatment may consist of providing the pigment with a thin hydrophilic and / or hydrophobic inorganic or organic layer by methods known to those skilled in the art.

[0056] In a preferred embodiment, the solid particles have an average particle size in the range of 0.1 to 500.0 μm, and preferably in the range of 0.1 to 100 μm.

[0057] The average particle size relates to the D50 mass average particle size determined by laser diffraction analysis according to ISO 13320:2009-10.

[0058] In a further preferred embodiment, the solid particles include aluminum oxide particles, preferably at least one of spherical aluminum oxide particles having an average particle size in the range of 1.0 to 50.0 μm and irregular aluminum oxide particles having an average particle size in the range of 0.1 to 50.0 μm.

[0059] Pigments include inorganic and organic pigments, pigment blacks, effect pigments such as pearlescent and / or metallic effect pigments, glitter pigments, and mixtures thereof.

[0060] Suitable organic pigments include, for example, nitroso, nitro, azo, xanthene, quinoline, anthraquinone, phthalocyanine, metal complex, isoindolinone, isoindoline, quinacridone, perinone, perylene, diketopyrrolopyrrole, thioindigo, dioxazine, triphenylmethane, and quinophthalone compounds. Further, the organic pigment can be selected from, for example, carmine, carbon black, aniline black, azo yellow b, quinacridone, and phthalocyanine blue. Examples of these are: D&C Red (CI 45), D&C Orange (CI 45), D&C Red 3 (CI 45530), D&C Red 7 (CI 15850), D&C Red 4 (CI 15510), D&C Red 33 (CI 17200), D&C Red 34 (CI 15880), D&C Yellow 5 (CI 19140), D&C Yellow 6 (CI 15985), D&C Green (CI 61570), D&C Yellow 10 (CI 77002), D&C Green 3 (CI 42053), and / or D&C Blue 1 (CI 42090).

[0061] Suitable inorganic pigments include, for example, metal oxides or other metal compounds that are sparingly soluble or at least substantially insoluble in water, in particular oxides of titanium, such as titanium dioxide (CI 77891), zinc, iron, such as red and black iron oxides (CI 77491 (red), 77499 (black)) or iron oxide hydroxide (CI 77492, yellow), zirconium, silicon, manganese, aluminum, cerium, chromium, and mixed oxides of the aforementioned elements, as well as mixtures thereof. Further suitable pigments are barium sulfide, zinc sulfide, manganese violet, ultramarine blue, and Berlin blue pigments.

[0062] With regard to pearlescent pigments, for example, one or more of the following types of pearlescent pigments can be used: Natural pearlescent pigments, such as "fish silver" (mixed guanine / hypoxanthine crystals from fish scales) and "mother of pearl" (crushed mussel shells) monocrystalline pearlescent pigments, such as bismuth oxychloride (BiOCl) or platelet-shaped titanium dioxide, and Layer substrate pearlescent pigment.

[0063] Suitable platelet-shaped (platelet-shaped) transparent substrates to be coated for the pearlescent pigment are non-metallic, natural, or synthetic platelet-shaped substrates. The substrate is preferably substantially transparent, preferably transparent, i.e., at least partially transparent to visible light. The platelet-shaped transparent substrate can be selected from the group consisting of natural mica, synthetic mica, glass flakes, SiO2 platelets, Al2O3, kaolin, graphite, talc, polymer platelets, platelet-shaped bismuth oxychloride, platelet-shaped substrates with inorganic-organic mixed layers, and mixtures thereof.

[0064] In addition to pearlescent pigments, metallic effect pigments may also be used in accordance with the present invention.

[0065] The platelet-shaped metal substrates may in this case in particular consist of pure metals and / or metal alloys, which may preferably be selected from the group consisting of silver, aluminum, iron, chromium, nickel, molybdenum, gold, copper, zinc, tin, stainless steel, magnesium, steel, bronze, brass, titanium, and alloys thereof.

[0066] In a further embodiment, the solid particles comprise a filler. All types of fillers known in the art can be used. In particular, functional fillers are used in the composition. Thermally conductive materials aid in removing heat from components and include one or more thermally conductive fillers as one or more functional fillers. The filler material comprises a solid material having a thermal conductivity greater than that of the matrix material. Suitable filler materials for use in embodiments of the present invention include, for example, aluminum powder, copper powder, nickel powder, or other metal powder; alumina powder, magnesia powder, beryllium powder, chromia powder, precipitated silica, fumed silica, titania powder, or other metal oxide powder; boron nitride powder, aluminum nitride powder, or other metal nitride powder; boron carbide powder, titanium carbide powder, silicon carbide powder, or other metal carbide powder; Fe—Si alloy, Fe—A Powders of Fe-Al alloys, Fe-Si-Al alloys, Fe-Si-Cr alloys, Fe-Ni alloys, Fe-Ni-Co alloys, Fe-Ni-Mo alloys, Fe-Co alloys, Fe-Si-Al-Cr alloys, Fe-Si-B alloys, and Fe-Si-Co-B alloys; other soft magnetic alloy powders; Mn-Zn ferrite, Mn-Mg-Zn ferrite, Mg-Cu-Zn ferrite, Ni-Zn ferrite, Ni-Cu-Zn ferrite, Cu-Zn ferrite, or other ferrites, and mixtures of two or more of the above-mentioned materials. Furthermore, the shape of the filler may be, for example, spherical, acicular, disc-like, rod-like, flat, or irregular. When electrical insulation properties are required for the composition or the cured silicone product obtained by curing the composition, the filler is preferably a metal oxide powder, metal nitride powder, or metal carbide powder, and particularly preferably alumina powder. Although there are no limitations on the average particle size of the filler, it is preferably in the range of 0.1 to 500 μm, and particularly preferably in the range of 0.1 to 100 μm. When aluminum oxide particles are used as the thermally conductive filler, they are preferably a mixture of (B1) spherical aluminum oxide particles having an average particle size in the range of 1 to 50 μm and (B2) spherical or irregular aluminum oxide particles having an average particle size of 0.1 to 50 μm.Furthermore, in such a mixture, the content of the above-mentioned component (B1) is preferably in the range of 30 to 90% by weight, and the content of the above-mentioned component (B2) is preferably in the range of 10 to 70% by weight, calculated based on the total of components (B1) and (B2). There are no limitations on the content of the filler in the present composition. However, to form a silicone composition with excellent thermal conductivity, its content in volume % in the composition is preferably at least 30% by weight, more preferably in the range of 30 to 90% by volume, even more preferably in the range of 60 to 90% by volume, and particularly preferably in the range of 80 to 90% by volume. To form a silicone composition with excellent thermal conductivity, the content of the filler in volume % in the composition is preferably at least 50% by weight, more preferably in the range of 70 to 98% by weight, and particularly preferably in the range of 90 to 97% by weight. The fillers may have different particle sizes and may exist not only individually but also in mixtures, or even coated on each other.

[0067] In particular, the filler content is in the range of 500 to 2500 parts by weight, more preferably 500 to 2000 parts by weight, and particularly preferably 800 to 2000 parts by weight, per 100 parts by weight of the dispersion medium. This is due to the fact that if the filler content is below the lower limit of the above range, the thermal conductivity of the resulting silicone composition tends to decrease, and on the other hand, if it exceeds the upper limit of the above range, the viscosity of the resulting silicone composition increases, making it difficult to handle.

[0068] The composition may further contain a curing agent, which allows for the production of a curable composition. When the composition is cured by a hydrosilylation reaction, the curing agent is formed from a platinum catalyst and an organopolysiloxane having an average of at least two silicon-bonded hydrogen atoms per molecule. The groups bonded to silicon atoms in the organopolysiloxane are exemplified by the same linear alkyl, branched alkyl, cyclic alkyl, aryl, aralkyl, and halogenated alkyl groups as described above, and are preferably alkyl or aryl groups, particularly preferably methyl or phenyl. Examples of suggested organopolysiloxanes include dimethylpolysiloxanes in which both molecular chain ends are blocked with dimethylhydrogensiloxy groups, dimethylsiloxane-methylhydrogensiloxane copolymers in which both molecular chain ends are blocked with trimethylsiloxy groups, dimethylsiloxane-methylhydrogensiloxane copolymers in which both molecular chain ends are blocked with dimethylhydrogensiloxy groups, and organopolysiloxanes of the formula (CH3)3SiO 1 / 2 Siloxane units of the formula (CH3)2HSiO 1 / 2 and a siloxane unit of the formula SiO 4 / 2 and organosiloxane copolymers consisting of siloxane units of the formula: as well as mixtures of two or more of the above compounds.

[0069] The content of the organopolysiloxane having an average of at least two silicon-bonded hydrogen atoms per molecule in the composition is the content required to cure the composition. In particular, it is preferable to provide 0.1 to 10.0 mol, more preferably 0.1 to 5.0 mol, and particularly preferably 0.1 to 3.0 mol of silicon-bonded hydrogen atoms from the component per mol of silicon-bonded alkenyl groups in the dispersion medium. This is due to the fact that if the content of this component is below the lower limit of the above range, the resulting silicone composition tends to not cure completely, while if it exceeds the upper limit of the above range, the resulting cured silicone product tends to be extremely rigid and develop numerous cracks on the surface. Furthermore, a platinum catalyst is used to accelerate the curing of the composition. Suggested examples of such catalysts include chloroplatinic acid, alcohol solutions of chloroplatinic acid, platinum olefin complexes, platinum alkenylsiloxane complexes, and platinum carbonyl complexes. The content of the platinum catalyst in the composition is the content required to cure the composition. In particular, it is sufficient to provide, by weight, from the component, preferably 0.01 ppm to 1,000 ppm, particularly preferably 0.1 ppm to 500 ppm of platinum metal relative to the amount of dispersion medium. This is due to the fact that when the content of the component is below the lower limit of the above range, the resulting silicone composition tends not to cure completely, while, on the other hand, adding an amount exceeding the upper limit of the above range does not significantly improve the cure rate of the resulting silicone composition.

[0070] When the composition is cured by a condensation reaction, the curing agent is characterized by being composed of a silane or a partial hydrolyzate thereof having at least two silicon-bonded hydrolyzable groups per molecule, and optionally a condensation reaction catalyst. Silicon-bonded hydrolyzable groups in the silane are exemplified by the same alkoxy, alkoxyalkoxy, acryloxy, ketoxime, alkenyl, amino, aminoxy, and amide groups as described above. In addition to the above hydrolyzable groups, examples of groups that can be bonded to the silicon atom of the silane include, for example, the same linear alkyl, branched alkyl, cyclic alkyl, alkenyl, aryl, aralkyl, and halogenated alkyl groups as described above. Suggested silanes or partial hydrolyzates thereof include, for example, methyltriethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, and ethyl orthosilicate (ethyl orthosilicate).

[0071] The content of the silane or its partial hydrolysis product in the composition is the content necessary for curing the composition. In particular, it is preferably in the range of 0.01 to 20 parts by weight, and particularly preferably 0.1 to 10 parts by weight, per 100 parts by weight of the dispersion medium. This is due to the fact that when the content of the silane or its partial hydrolysis product is below the lower limit of the above range, the storage stability of the resulting composition tends to decrease, and furthermore, its adhesive properties tend to decrease. On the other hand, when the content exceeds the upper limit of the above range, the curing rate of the resulting composition tends to be slow. Furthermore, a condensation reaction catalyst is an optional component; it is not essential, for example, when silanes having aminoxy, amino, ketoxime, and other hydrolyzable groups are used as curing agents. Condensation reaction catalysts that have been proposed include, for example, tetrabutyl titanate, tetraisopropyl titanate, and other organic titanates; diisopropoxybis(acetylacetate)titanium, diisopropoxybis(ethylacetoacetate)titanium, and other chelating organic titanium compounds; aluminum tris(acetylacetonate), aluminum tris(ethylacetoacetate), and other organic aluminum compounds; zirconium tetra(acetylacetonate), zirconium tetrabutylate, and other organic zirconium compounds; dibutyltin dioctoate, dibutyltin dilaurate. Examples of suitable condensation reaction catalysts include butyltin 2-ethylhexanoate, butyltin 2-ethylhexanoate, and other organotin compounds; tin naphthenate, tin oleate, tin butyrate, cobalt naphthenate, zinc stearate, and other metal salts of organic carboxylic acids; hexylamine, dodecylamine phosphate, and other amine compounds or their salts; benzyltriethylammonium acetate and other quaternary ammonium salts; potassium acetate, lithium nitrate, and other alkali metal salts of lower fatty acids; dimethylhydroxylamine, diethylhydroxylamine, and other dialkylhydroxylamines; and guanidyl-containing organosilicon compounds. The amount of condensation reaction catalyst in the composition varies and must be sufficient to cure the composition. It is preferably in the range of 0.01 to 20.00 parts by weight, more preferably 0.1 to 10.0 parts by weight, per 100 parts by weight of the dispersion medium.This is due to the fact that, when a catalyst is essential, a catalyst content lower than the lower limit of the above range tends to make it difficult for the resulting composition to fully cure, while a content higher than the upper limit of the above range tends to reduce the storage stability of the resulting composition.

[0072] When the composition is cured by an organic peroxide-induced free radical reaction, the curing agent is suitably an organic peroxide. Suggested organic peroxides include, for example, benzoyl peroxide, dicumyl peroxide, 2,5-dimethyl-bis(2,5-t-butylperoxyl)hexane, di-t-butyl peroxide, and t-butyl perbenzoate. The content of the organic peroxide is the content required to cure the composition, and is preferably in the range of 0.1 to 5.0 parts by weight per 100 parts by weight of the organopolysiloxane in the dispersion medium.

[0073] In particular, when the present composition is cured by a hydrosilylation reaction, in order to adjust the curing rate of the composition and improve its handleability, it is preferably combined with 2-methyl-3-butyn-2-ol, 2-phenyl-3-butyn-2-ol, 1-ethynyl-1-cyclohexanol, and other acetylene compounds; 3-methyl-3-penten-1-yne, 3,5-dimethyl-3-hexen-1-yne, and other ene-yne ​​compounds; and further, hydrazine compounds, phosphine compounds, mercaptan compounds, and other curing reaction inhibitors. The content of the curing reaction inhibitor is not limited, but is preferably in the range of 0.0001 to 1.0 wt.% based on the amount of the present composition. When the present composition is curable, the curing method is not limited. This method may include, for example, molding the composition and leaving it at room temperature, or molding the composition and heating it to 50 to 200°C. Furthermore, there is no limitation as to the physical characteristics of the silicone thus obtained, but suggested forms include, for example, a gel, a low stiffness rubber, or a high stiffness rubber.

[0074] The present invention further relates to a non-aqueous composition comprising: (a) a polysiloxane having a plurality of siloxane groups and at least one cyclic carboxylic acid anhydride group or hydrolysis product thereof covalently bonded to the polysiloxane; (b) a dispersion medium, and (c) solid filler particles; Including, The content of the filler particles is in the range of 500 to 2500 parts by weight per 100 parts by weight of the dispersion medium.

[0075] In a preferred embodiment, the dispersion medium (b) comprises a silicone different from the polysiloxane (a).

[0076] It is particularly preferred that the dispersion medium (b) is a crosslinkable silicone.

[0077] The solid particles in the composition preferably comprise at least one of a filler and a pigment, as described above.

[0078] In a preferred embodiment of the composition, component (a) is present in an amount of 0.010 to 10.000 weight percent, calculated based on the total weight of the composition.

[0079] There are no limitations on the content of polysiloxane (a) in the composition. The content must be sufficient to treat the surface of the filler with polysiloxane (a), thereby improving its dispersibility in the resulting thermally conductive silicone composition. In particular, the content is preferably 0.001 to 10,000 parts by weight per 100 parts by weight of filler, and particularly preferably 0.001 to 5 parts by weight per 100 parts by weight of filler. This is due to the fact that if the content of polysiloxane (a) is below the lower limit of the above range, the addition of a large amount of filler will result in a decrease in the moldability of the resulting silicone composition, and will also cause precipitation and separation of the filler during storage of the resulting silicone composition, resulting in a significant decrease in its uniformity. On the other hand, if the content exceeds the upper limit of the above range, the physical properties of the resulting silicone composition will tend to deteriorate.

[0080] In some embodiments, the composition is embodied as a paint or coating composition, as a molding composition, or as a paste or potting material, a gasket, a solder paste, an underfill, a thermal interface material, such as a thermal gap filler, a gap pad, a sil pad, a phase change material, a thermally conductive grease, a thermal gel, a thermal cladding material, a thermal encapsulant, an adhesive, or a sealant.

[0081] If desired, the composition may contain other components, such as binders or polymer resins, reactive or non-reactive diluents, solvents, and conventional auxiliary additives, such as adhesion promoters, e.g., 3-glycidyloxypropyltrimethoxysilane or 3-methacryloxypropyltrimethoxysilane, stain repellents, heat or UV stabilizers, rheology-related additives, flow and leveling additives, crosslinkers, chain extenders, reinforcing fillers, non-reinforcing fillers, plasticizers, flame retardants, and heat resistance additives, e.g., triazole compounds, water scavengers, biocides, cure accelerators, (fluorescent) dyes, inhibitors, antistatic agents, wax catalysts, and other additives well known to those skilled in the art.

[0082] The present invention further relates to a method for dispersing solid particles in a non-aqueous composition, comprising: (a) providing a polysiloxane having a plurality of siloxane groups and at least one cyclic carboxylic acid anhydride group or hydrolysis product thereof covalently bonded to the polysiloxane; (b) providing solid filler particles; (c) incorporating the ingredients provided in steps (a) and (b) into a non-aqueous composition containing a dispersion medium to form a dispersion base; and (d) subjecting the dispersion base to shear forces; Including, The content of the filler particles is in the range of 500 to 2500 parts by weight per 100 parts by weight of the dispersion medium. [Example]

[0083] Comparative dispersant Synthesis of epoxy / amine addition copolymers with polysiloxane groups: A four-neck flask equipped with a stirrer, thermometer, dropping funnel, reflux condenser, and nitrogen inlet tube was charged with the monoamino-functional polysiloxane described in Example 1 of US9217083B2 (376.3 g) and 1,6-hexanediol diglycidyl ether (22.8 g) and heated to 140°C under nitrogen. Epoxide conversion was monitored by 1H NMR. After complete conversion of the epoxide groups, the reaction mixture was cooled to room temperature. GPC data: Mn=5500 g / mol and PDI=2.0.

[0084] Preparation of Si-H functional intermediates Butyl-D 25 M H The synthesis of SiH-functional silicone macromer of Mw 2000 was carried out as described in Example 1 of US8304077B2. The butyl-D by adapting the ratio of butyllithium to hexamethylcyclotrisiloxane monomer was 38.5 M H and butyl-D 65.5 M H Synthesis of.

[0085] Dispersant 1 Butyl-D 25 M H Reaction of 1,2-dichloro-2,2-dichloro- ... In a flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet tube, 181.15 g of butyl-D 25 M H The mixture was placed in a jar and heated to 75°C. 0.60 g of a 0.6% xylene solution of HPtCl was then added. 18.85 g of allyl succinic anhydride was then added via a dropping funnel. The reaction mixture was held at 100°C for 3 hours. After this time, the conversion of the SiH groups was found to be greater than 98%. Volatiles were removed by rotary evaporation at 130°C and 15 mbar.

[0086] GPC data of the obtained product: Mn 1759 g / mol, Mw 2232 g / mol, DPI 1.27

[0087] Dispersant 2 Butyl-D 65.5 M H Reaction of 1,2-dichloro-2,2-dichloro- ... In a flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet tube, 143.91 g of butyl-D 65.5 M H The mixture was placed in a flask and heated to 75°C. 0.53 g of a 0.6% xylene solution of HPtCl was then added. 6.09 g of allyl succinic anhydride was then added via a dropping funnel. The reaction mixture was held at 100°C for 3 hours. After this time, the conversion of the SiH groups was found to be greater than 98%. Volatiles were removed by rotary evaporation at 130°C and 15 mbar.

[0088] GPC data of the obtained product: Mn 5630 g / mol, Mw 9153 g / mol, DPI 1.62

[0089] Dispersant 3 Butyl-D 38.5 M H Reaction of 1,2-dichloro-2,2-dichloro- ... In a flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet tube, 140.98 g of butyl-D 38.5 M H The mixture was placed in a flask and heated to 75°C. 0.53 g of a 0.6% xylene solution of HPtCl was then added. 9.02 g of allyl succinic anhydride was then added via a dropping funnel. The reaction mixture was held at 100°C for 3 hours. After this time, the conversion of the SiH groups was found to be greater than 98%. Volatiles were removed by rotary evaporation at 130°C and 15 mbar.

[0090] GPC data of the obtained product: Mn 2745 g / mol, Mw 3399 g / mol, DPI 1.21

[0091] Dispersant 4 Process 1 formula md 38.5 M H Preparation of siloxanes with an average of one SiH group In a flask equipped with a stirrer, thermometer, and reflux condenser, 9.46 g of HMDSO (hexamethyldisiloxane), 302.93 g of D5, and 37.61 g of M H 2D6 was placed. The mixture was heated to 75°C. At this temperature, 3.5 g of catalyst K20 ex Clariant (calcium montmorillonite treated with hydrochloric acid) was added to the mixture. The mixture was stirred at 80°C for 3 hours, then cooled to 50°C and stirred at this temperature for another 3 hours. 1.75 g of Harbolite 900 (amorphous alumina silicate) filter aid was added, and the mixture was stirred and filtered through a pressure filter. The content of SiH groups was determined by iodine value determination, which was 8.14.

[0092] Process 2 Step 1: Reaction of siloxane with allyl succinic anhydride In a flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet, 141.72 g of the siloxane from step 1 was placed and heated to 75°C. 0.53 g of a 0.6% xylene solution of HPtCl was then added. 8.28 g of allyl succinic anhydride was then added via a dropping funnel. The reaction mixture was held at 100°C for 3 hours. After this time, the conversion of the SiH groups was found to be greater than 98%. Volatiles were removed by rotary evaporation at 130°C and 15 mbar.

[0093] GPC data of the obtained product: Mn 1813 g / mol, Mw 5272 g / mol, DPI 2.91

[0094] Dispersant 5 Process 1 formula md 65.6 M H Preparation of siloxanes with an average of one SiH group In a flask equipped with a stirrer, thermometer, and reflux condenser, 5.68 g of HMDSO, 321.76 g of D5, and 22.57 g of M H 2D6 was placed. The mixture was heated to 75°C. At this temperature, 3.5 g of catalyst K20 was added to the mixture. The mixture was stirred at 80°C for 3 hours, then cooled to 50°C and stirred at this temperature for another 3 hours. 1.75 g of Harbolite 900 filter aid was added, and the mixture was stirred and filtered through a pressure filter. The content of SiH groups was determined by iodine value determination, which was 4.81.

[0095] Process 2 Step 1: Reaction of siloxane with allyl succinic anhydride 144.99 g of the siloxane from step 1 was placed in a flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet tube and heated to 75°C. 0.53 g of a 0.6% xylene solution of HPtCl was then added. 5.01 g of allyl succinic anhydride was then added via a dropping funnel. The reaction mixture was held at 100°C for 3 hours. After this time, the conversion of the SiH groups was found to be greater than 98%. Volatiles were removed by rotary evaporation at 130°C and 15 mbar.

[0096] GPC data of the obtained product: Mn 2094 g / mol, Mw 8247 g / mol, DPI 3.94

[0097] Dispersant 6 Process 1 formula md 86 M H Preparation of siloxanes with an average of one SiH group In a flask equipped with a stirrer, thermometer, and reflux condenser, 4.35 g of HMDSO, 328.31 g of D5, and 17.33 g of M H2D6 was placed. The mixture was heated to 75°C. At this temperature, 3.5 g of catalyst K20 was added to the mixture. The mixture was stirred at 80°C for 3 hours, then cooled to 50°C and stirred at this temperature for another 3 hours. 1.75 g of Harbolite 900 filter aid was added, and the mixture was stirred and filtered through a pressure filter. The content of SiH groups was determined by iodine value determination, which was 3.48.

[0098] Process 2 Step 1: Reaction of siloxane with allyl succinic anhydride In a flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet, 146.34 g of the siloxane from step 1 was placed and heated to 75°C. 0.53 g of a 0.6% xylene solution of HPtCl was then added. 3.66 g of allyl succinic anhydride was then added via a dropping funnel. The reaction mixture was held at 100°C for 3 hours. After this time, the conversion of the SiH groups was found to be greater than 98%. Volatiles were removed by rotary evaporation at 130°C and 15 mbar.

[0099] GPC data of the obtained product: Mn 2240 g / mol, Mw 11034 g / mol, DPI 4.93

[0100] Dispersant 7 Process 1 formula md 106 M H Preparation of siloxanes with an average of one SiH group In a flask equipped with a stirrer, thermometer, and reflux condenser, 3.55 g of HMDSO, 332.33 g of D5, and 14.12 g of M H2D6 was placed. The mixture was heated to 75°C. At this temperature, 3.15 g of catalyst K20 was added to the mixture. The mixture was stirred at 80°C for 3 hours, then cooled to 50°C and stirred at this temperature for another 3 hours. 1.75 g of Harbolite 900 filter aid was added, and the mixture was stirred and filtered through a pressure filter. The content of SiH groups was determined by iodine value determination, which was 2.95.

[0101] Process 2 Step 1: Reaction of siloxane with allyl succinic anhydride 146.89 g of the siloxane from step 1 was placed in a flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet tube and heated to 75°C. 0.53 g of a 0.6% xylene solution of HPtCl was then added. 3.11 g of allyl succinic anhydride was then added via a dropping funnel. The reaction mixture was held at 100°C for 3 hours. After this time, the conversion of the SiH groups was found to be greater than 98%. Volatiles were removed by rotary evaporation at 130°C and 15 mbar.

[0102] GPC data of the obtained product: Mn 2255 g / mol, Mw 13177 g / mol, DPI 5.37

[0103] Dispersant 8 Process 1 formula md 133 M H Preparation of siloxanes with an average of one SiH group In a flask equipped with a stirrer, thermometer, and reflux condenser, 2.84 g of HMDSO, 335.86 g of D5, and 11.30 g of M H2D6 was placed. The mixture was heated to 75°C. At this temperature, 3.15 g of catalyst K20 was added to the mixture. The mixture was stirred at 80°C for 3 hours, then cooled to 50°C and stirred at this temperature for another 3 hours. 1.75 g of Harbolite 900 filter aid was added, and the mixture was stirred and filtered through a pressure filter. The content of SiH groups was determined by iodine value determination, which was 2.54.

[0104] Process 2 Step 1: Reaction of siloxane with allyl succinic anhydride 147.31 g of the siloxane from step 1 was placed in a flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet tube and heated to 75°C. 0.53 g of a 0.6% xylene solution of HPtCl was then added. 2.69 g of allyl succinic anhydride was then added via a dropping funnel. The reaction mixture was held at 100°C for 3 hours. After this time, the conversion of the SiH groups was found to be greater than 98%. Volatiles were removed by rotary evaporation at 130°C and 15 mbar.

[0105] GPC data of the obtained product: Mn 2717 g / mol, Mw 16878 g / mol, DPI 6.21

[0106] Dispersant 9 Hydrolysis of Dispersant 5 with Deionized Water 248.29 g of Dispersant 5 and 1.7 g of deionized water were placed in a flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet. The mixture was stirred and heated at 70° C. for 10 hours. After this time, 89 mole percent of the cyclic carboxylic acid anhydride groups were found to have hydrolyzed to dicarboxylic acid groups. Volatiles were removed by rotary evaporation at 130° C. and 15 mbar.

[0107] Dispersant 10 Salt formation of dispersant 9 In a glass beaker, 116.19 g of Dispersant 9 was mixed with 3.81 g of N,N-dibutylethanolamine.

[0108] Below we describe the application of dispersants in addition-cure RTV silicone formulations.

[0109] For the preparation of the addition-curing RTV silicone compositions, a double asymmetric centrifugal mixer, Speedmixer DAC 400.1 FVZ, Hauschild GmbH & Co. KG, was used.

[0110] raw materials Addition-cure, RTV-2 silicone rubber part A (SilGel 612A, Wacker) - vinyl polydimethylsiloxane and additives Addition-cure, RTV-2 silicone rubber part B (SilGel 612B, Wacker) - SiH-functional polydimethylsiloxane and polydimethylsiloxane with functional groups, plus additives containing a platinum catalyst. Adhesion promoter - methacryloxypropyltrimethoxysilane Filler 1 - Aluminum oxide - average particle size 1.4 μm Filler 2 - Aluminum oxide - average particle size 45.0 μm Filler 3 - Aluminum oxide - average particle size 0.2mm

[0111] To determine the effect of dispersants on the curing behavior and application properties of silicone compositions, formulations were evaluated in unfilled systems. Parts A and B were prepared separately in a PE Speedmixer cup by adding all the raw materials for each of Part A and Part B and homogenizing at 2500 rpm for 30 seconds. Parts A and B were then mixed at 2000 rpm for 30 seconds using a Speedmixer at an A:B ratio of 1.5:1, and the formulation was placed in an oven at 100°C until cured. The formulation was observed at 60-second intervals to evaluate the curing stage. The time when the first skin formed on the surface of the formulation was defined as the skin formation time. The time for the formulation to fully cure without further changes in stiffness and viscosity was defined as the cure time.

[0112] [Table 1]

[0113] [Table 2]

[0114] From the above table it can be concluded that the comparative dispersants completely prevent the curing of silicone rubber. The dispersants according to the invention have only a slight effect on the curing properties, which can be adjusted by the amount of curing catalyst.

[0115] Aluminum oxide filled addition cure RTV-2 compositions were formulated to evaluate the effect of dispersants on the viscosity of highly filled silicone compositions.

[0116] Part A of the RTV2 composition was compounded by adding the silicone gel, adhesion promoter, and dispersant to a PE Speedmixer cup and homogenizing them with the Speedmixer at 2500 rpm for 30 seconds. The Al2O3 filler was then added in one portion and homogenized at 2500 rpm for 30 seconds. The viscosity of the compounded Part A was determined using an AntonPaar MCR201 rheometer under the following conditions: PP25, shear rate 0.1-100 s-1, 1.0 mm gap, 23 °C, sample trimming. In particular, 1 s -1 Viscosity at 10s -1 The viscosity at 100°C was observed and represented the viscosity of the filled and modified composition.

[0117] Part B of the RTV2 composition was compounded by dosing the silicone gel and dispersant into a PE Speedmixer cup and homogenizing them in the Speedmixer for 30 seconds at 2500 rpm, followed by adding the Al2O3 filler all at once and homogenizing for 30 seconds at 2500 rpm.

[0118] Parts A and B were mixed using a Speedmixer at 2000 rpm for 30 seconds and kept in an oven at 100° C. until the formulation cured. As with the unfilled system, the formulation was observed at 60 second intervals to assess the cure stage.

[0119] [Table 3]

[0120] [Table 4]

[0121] From the above table it can be concluded that the effect of the dispersants according to the invention on viscosity reduction in highly filled silicone compositions is significantly greater than that of the comparative dispersants. In contrast to the comparative dispersants, the dispersants according to the invention do not interfere with cure.

[0122] One of the major applications of thermally conductive, filled silicone compositions is the application of these materials to copper substrates as thermal interface materials (TIMs). For this application, the corrosion properties of the dispersions were evaluated on each substrate. A drop of pure dispersion was placed on copper, covered with a cotton pad, and placed in an environmental chamber at 55°C and 80% relative humidity for 14 days. In a second test, an unfilled silicone composition containing the dispersion was applied to copper using a spatula, covered with a cotton pad, and placed in an environmental chamber at 55°C and 80% relative humidity for 14 days. Corrosion of the copper substrate was visually evaluated and ranked on a scale of 1 to 6. [Table 5]

[0123] From the above table it can be concluded that the dispersants according to the invention are relatively less corrosive than the comparative dispersants on copper substrates.

[0124] The effect of dispersants on viscosity reduction with different filler types was evaluated by amending Part A of the above formulation with calcium carbonate, boron nitride, and aluminum hydroxide and dispersing additives.

[0125] The viscosity of the compounded Part A was determined using an AntonPaar MCR201 rheometer under the following conditions: PP25, shear rate 0.1-100 s, 1.0 mm gap, 23 °C, sample trimming. -1 The viscosity at this point was recorded.

[0126] Filler Calcium Carbonate - CaCO3 - Average particle size 5μm Aluminum hydroxide - Al(OH)3 - average particle size 12μm Boron nitride BN - average particle size 16μm

[0127] [Table 6]

[0128] [Table 7]

[0129] [Table 8]

[0130] The effect of the comparative dispersant additives and the dispersant additives of the present invention on viscosity reduction of the compositions is shown in the table below.

[0131] [Table 9]

[0132] From the above table it can be concluded that Dispersant 5 significantly reduces the viscosity of addition-cured RTV-2 compositions with various fillers.

Claims

1. 1. Use of a polysiloxane having a plurality of siloxane groups and at least one cyclic carboxylic acid anhydride group, or a hydrolysis product thereof, covalently bonded to said polysiloxane as a dispersant for solid filler particles in a non-aqueous composition having a dispersion medium, comprising: The content of the filler particles is in the range of 500 to 2500 parts by weight per 100 parts by weight of the dispersion medium. use.

2. The use according to claim 1 , wherein the cyclic carboxylic acid anhydride group forms a five-membered ring.

3. 3. The use according to claim 1, wherein the cyclic carboxylic acid anhydride group or its hydrolysis product is bonded to the polysiloxane via an Si-C bond.

4. 4. The use according to claim 1, wherein an average of 0.7 to 3.0 cyclic carboxylic acid anhydride groups or hydrolysis products thereof are covalently bonded to one polysiloxane molecule.

5. The use according to any one of claims 1 to 4, wherein the non-aqueous composition comprises a dispersion medium different from the polysiloxane having a plurality of siloxane groups and at least one cyclic carboxylic acid anhydride group or a hydrolysis product thereof.

6. The use according to claim 5, wherein the dispersion medium contains a silicone.

7. The use according to any one of claims 1 to 6, wherein the non-aqueous composition is used as a thermal interface material.

8. The use according to claim 7, wherein the non-aqueous composition is used as a thermal interface material in electronic components.

9. 1. A non-aqueous composition comprising: (a) a polysiloxane having a plurality of siloxane groups and at least one cyclic carboxylic acid anhydride group or hydrolysis product thereof covalently bonded to said polysiloxane; (b) a dispersion medium; and (c) solid filler particles; Including, The content of the filler particles is in the range of 500 to 2500 parts by weight per 100 parts by weight of the dispersion medium. Non-aqueous composition.

10. The composition according to claim 9, wherein the dispersion medium (b) contains a silicone different from the polysiloxane (a).

11. The composition of claim 10, wherein the silicone is a crosslinkable silicone.

12. The composition according to any one of claims 9 to 11, wherein the solid filler particles have an average particle size in the range of 0.1 to 500.0 µm.

13. The composition of any one of claims 9 to 12, wherein the solid filler particles comprise aluminum oxide particles.

14. 14. The composition of claim 13, wherein the aluminum oxide particles comprise at least one of spherical aluminum oxide particles having an average particle size in the range of 1.0 to 50.0 μm and irregularly shaped aluminum oxide particles having an average particle size in the range of 0.1 to 50.0 μm.

15. 15. The composition according to any one of claims 7 to 14, wherein component (a) has a number average molecular weight Mn in the range of 500 to 10,000 g / mol.

16. The composition of any one of claims 7 to 15, wherein component (a) is present in an amount of 0.010 to 10.000 weight percent, calculated based on the total weight of the composition.

17. 1. A method for dispersing solid filler particles in a non-aqueous composition, comprising: (a) providing a polysiloxane having a plurality of siloxane groups and at least one cyclic carboxylic acid anhydride group or hydrolysis product thereof covalently bonded to said polysiloxane; (b) providing solid filler particles; (c) incorporating the ingredients provided in step (a) and step (b) into a non-aqueous composition with a dispersion medium to form a dispersion base; and (d) subjecting the dispersion base to a shear force; Including, The content of the filler particles is in the range of 500 to 2500 parts by weight per 100 parts by weight of the dispersion medium. method.

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