Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F2/00—Processes of polymerisation
  • C08F2/44—Polymerisation in the presence of compounding ingredients, e.g. plasticisers, dyestuffs, fillers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F299/00—Macromolecular compounds obtained by interreacting polymers involving only carbon-to-carbon unsaturated bond reactions, in the absence of non-macromolecular monomers
  • C08F299/02—Macromolecular compounds obtained by interreacting polymers involving only carbon-to-carbon unsaturated bond reactions, in the absence of non-macromolecular monomers from unsaturated polycondensates
  • C08F299/08—Macromolecular compounds obtained by interreacting polymers involving only carbon-to-carbon unsaturated bond reactions, in the absence of non-macromolecular monomers from unsaturated polycondensates from polysiloxanes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/38—Polysiloxanes modified by chemical after-treatment
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/01—Use of inorganic substances as compounding ingredients characterized by their specific function
  • C08K3/013—Fillers, pigments or reinforcing additives
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/02—Elements
  • C08K3/04—Carbon
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K9/00—Use of pretreated ingredients
  • C08K9/04—Ingredients treated with organic substances
  • C08K9/06—Ingredients treated with organic substances with silicon-containing compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L83/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
  • C08L83/04—Polysiloxanes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L83/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
  • C08L83/10—Block- or graft-copolymers containing polysiloxane sequences

Definitions

• the present invention relates to polysiloxane particles.
• Liquid crystal technology has made great advances, and is now used not only in conventional display devices but also in light-control materials such as light-control films for the purpose of blocking light.
• Light-control materials are generally sandwiched between two glass plates or films, with spacer particles arranged to maintain a consistent thickness of the light-control layer.
• Typical properties required of spacer particles include particle size uniformity, insulation, appropriate particle strength, and light-blocking properties.
• Particle size uniformity is a factor that affects device precision
• insulation is a factor that affects device reliability
• particle strength is a factor that affects defects due to particle breakage or intrusion into other components
• light-blocking properties are a factor that affects display quality.
• Various classification techniques have been developed to achieve particle size uniformity after synthesis.
• insulation, particle strength, and light-blocking properties are properties that are greatly influenced by the material and synthesis method.
• insulation is known to be due to the polymerized monomer structure and the conductivity and loading amount of the pigment or dye, and can be adjusted by selecting the polymerized monomer structure and pigment or dye.
• Particle strength can be adjusted by changing the polymerized monomer structure.
• Light-blocking properties can be adjusted by carbonizing the particles or by encapsulating or surface-adsorbing pigments and dyes.
• Carbon black is a typical pigment that contributes to the light-blocking properties of spacer particles. Carbon black is frequently used because it can produce a natural black color and is easily available. However, because carbon black itself is conductive, it can potentially impair the reliability of liquid crystal devices. However, reducing the amount of carbon black filled to improve insulation results in insufficient light-blocking properties. Furthermore, from the perspective of insulating reliability, it is necessary for the particles to maintain their insulating properties even when compressed. For example, Patent Documents 1 and 2 propose polysiloxane particles with high electrical resistance that can be used as spacer particles.
• an object of the present invention is to provide polysiloxane particles that contain a pigment within the particles and that have high insulating properties even when the particles are compressed.
• the present invention has been made to solve the above problems, and the gist of the present invention is as follows.
• Polysiloxane particles comprising a polysiloxane and a pigment, the pigment being coated with a surface treatment agent.
• the polysiloxane particles according to [1] having a 20% K value of 100 N/mm2 or less .
• the present invention makes it possible to provide polysiloxane particles that contain pigments and have high insulating properties even when compressed.
• the polysiloxane particles contain polyorganosiloxane.
• polyorganosiloxane may be the main component, and its content is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more.
• the content of polyorganosiloxane is equal to or more than the above lower limit, the polysiloxane particles can be imparted with appropriate particle strength and insulating properties.
• the polysiloxane particles can be obtained by, without particular limitation, uniformly mixing and dispersing the pigment in a monomer component, followed by polymerization. Here, it is preferable to further add a surface treatment agent to the monomer component.
• the polymerization method is not particularly limited, and polymerization can be carried out by known methods such as radical polymerization, ionic polymerization, polycondensation (condensation polymerization, polycondensation), addition condensation, living polymerization, and living radical polymerization.
• suspension polymerization in the presence of a radical polymerization initiator
• seed polymerization and dispersion polymerization which are methods in which non-crosslinked seed particles are used to swell and polymerize a monomer together with a radical polymerization initiator.
• suspension polymerization is preferred.
• the monomer components, pigment, and optionally a surface treatment agent are dispersed in an aqueous solvent such as water, and the polymerization reaction is carried out in the presence of a radical polymerization initiator.
• a dispersion aid such as gelatin, starch, polyvinyl alcohol, or carboxymethyl cellulose to the aqueous solvent.
• the use of the dispersion aid stabilizes the monomer droplets, allowing polysiloxane particles of an appropriate particle size to be obtained.
• Polyvinyl alcohol is a preferred dispersion aid.
• the number of ethylenically unsaturated groups in one molecule is preferably two or more, about 2 to 6, more preferably 2 to 4, and even more preferably 2, and it is even more preferable that the ethylenically unsaturated groups be located at both terminals.
• the silicone macromonomer may be a linear or branched organopolysiloxane, or a mixture of linear and branched organopolysiloxanes, but is preferably a linear organopolysiloxane.
• examples of the residual groups bonded to the silicon atom other than the ethylenically unsaturated group include hydrocarbon groups such as alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, and dodecyl, aryl groups such as phenyl, and aralkyl groups such as 2-phenylethyl and 2-phenylpropyl.
• the silicone macromonomer is preferably an organopolysiloxane containing vinyl groups at both ends, or an organopolysiloxane containing (meth)acryloyl groups at both ends, with organopolysiloxanes containing (meth)acryloyl groups at both ends being more preferred.
• the number average molecular weight of the silicone macromonomer is preferably 200 to 5,000, more preferably 300 to 4,500, and even more preferably 400 to 4,000. In this specification, the number average molecular weight is a value determined by gel permeation chromatography (GPC) measurement and converted into polystyrene equivalent.
• a silicone-based surface treatment agent As the surface treatment agent used in the polysiloxane particles, a silicone-based surface treatment agent is preferably used.
• the silicone-based surface treatment agent include polyglycerin-modified silicone, polysiloxane having a conjugated ring structure, amine-modified silicone, carboxyl-modified silicone, carbinol-modified silicone, and carboxylic anhydride-modified silicone.
• polysiloxane having a conjugated ring structure is preferred from the viewpoint of increasing the dispersibility of the pigment and improving the light-shielding property.
• the polyglycerin-modified silicone may be, for example, a branched polyglycerin-modified silicone in which the silicone chain is branched.
• the polysiloxane having a conjugated ring structure may be a polysiloxane having three or more conjugated ring structures that form a common conjugated system, and preferably a polysiloxane having three to six conjugated aromatic six-membered rings.
• the amount of surface treatment agent added is, for example, 10% by mass to 200% by mass, preferably 50% by mass to 95% by mass, and more preferably 60% by mass to 90% by mass, relative to 100% by mass of pigment.
• the polysiloxane having a conjugated ring structure specifically has a structure represented by the following formula (1).
• each R is independently a group represented by A-B or a monovalent hydrocarbon group having 1 to 4 carbon atoms, at least one R among the plurality of R is a group represented by A-B, A is a divalent organic group bonded to a silicon atom, and B is three or more conjugated ring structures that form a common conjugated system; n is an integer of 1 or more.
• the silicone surface treatment agent having the structure represented by formula (1) preferably has a number average molecular weight of 1,000 or more and 40,000 or less, more preferably 2,000 or more and 30,000 or less, even more preferably 3,000 or more and 25,000 or less, even more preferably 5,000 or more and 20,000 or less, and most preferably 7,000 or more and 18,000 or less. Having a number average molecular weight within the above range makes it easier to properly disperse the pigment.
• each R is independently a group represented by AB or a monovalent hydrocarbon group having 1 to 4 carbon atoms. At least one of the multiple R's is a group represented by A-B, where A is a divalent organic group and is bonded to the silicon atom of formula (1).
• A is a divalent organic group bonded to the silicon atom of formula (1), preferably a divalent organic group having 11 or fewer carbon atoms, and more preferably a divalent organic group having 10 or fewer carbon atoms.
• polyorganosiloxanes in which A has a certain number of carbon atoms or less are preferred as they tend to improve the dispersibility of the pigment.
• A be a divalent organic group having 4 or more carbon atoms.
• A may be a hydrocarbon group, but may also have a heteroatom.
• a has a heteroatom it is preferable that any of the ⁇ -position atom, ⁇ -position atom, and ⁇ -position atom among the atoms constituting A is a heteroatom. Due to the above structure, the structure of the silicone surface treatment agent is thought to have an increased degree of freedom of rotation due to the presence of a heteroatom near the aromatic ring, allowing the vicinity of the aromatic ring to adopt various conformations, thereby reducing self-aggregation force. As a result, the silicone surface treatment agent increases its affinity to the pigment while reducing the self-aggregation force of the silicone surface treatment agent itself, thereby improving the flexibility of the polysiloxane particles.
• the ⁇ -position atom or ⁇ -position atom is a heteroatom, and it is even more preferable that the ⁇ -position atom is a heteroatom.
• the ⁇ -atom is an atom constituting A that is bonded to a conjugated ring possessed by B (i.e., one of the three or more conjugated rings possessed by B, preferably one of the three to six conjugated aromatic six-membered rings).
• the ⁇ -atom is an atom constituting A that is bonded to the ⁇ -atom.
• the ⁇ -atom is an atom conjugated to the ⁇ -atom but is other than the ⁇ -atom.
• A may also have heteroatoms in positions other than the ⁇ -, ⁇ -, and ⁇ -atoms.
• Heteroatoms are not particularly limited and include, for example, oxygen atoms, nitrogen atoms, sulfur atoms, and boron atoms, with oxygen atoms being preferred from the standpoint of effectively improving compatibility with resins.
• A has a structural unit having a heteroatom.
• structural units include ethers, esters, amides, urethanes, thioethers, and thioesters.
• ethers or esters are preferred, ethers are more preferred, and cyclic ethers are particularly preferred.
• a cyclic ether is an ether having a structure in which a carbon atom in a cyclic hydrocarbon is substituted with oxygen.
• A preferably has a skeleton represented by the following formula (5-1) or formula (5-2).
• formula (5-1) *1 and *2 are bonds
• R4 is a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, preferably a hydrogen atom.
• Two R4s may be the same or different.
• R3 is a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, preferably a hydrocarbon group having 1 to 4 carbon atoms, more preferably a hydrocarbon group having 1 to 3 carbon atoms, and even more preferably an ethyl group.
• R5 is a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, preferably a hydrogen atom.
• the oxygen atom in formula (5-1) is the ⁇ -position atom or ⁇ -position atom described above, preferably a ⁇ -position atom.
• *3 and *4 are bonds.
• the oxygen atom having the bond *3 is the above-mentioned ⁇ -atom, ⁇ -atom, or ⁇ -atom.
• A preferably has a skeleton represented by formula (5-1).
• A preferably has any of the structures represented by the following formulas (6) to (11).
• *5 is a bond bonded to the conjugated ring that B has
• *6 is a bond bonded to the silicon atom of formula (1).
• A may be a group other than those in which any of the ⁇ -, ⁇ -, and ⁇ -position atoms is a heteroatom.
• A may be a hydrocarbon group such as an alkylene group such as a methylene group or an ethylene group, or an arylene group such as a phenylene group.
• A may be a group in which an atom other than the ⁇ -, ⁇ -, and ⁇ -position atoms is a heteroatom, or may be an oxygen-containing hydrocarbon group composed of an alkylene group and an ester group.
• B represents three or more conjugated ring structures that form a common conjugated system. Conjugation refers to a molecular structure in which unsaturated bonds and single bonds are alternately connected, resulting in stabilization due to the interaction of p orbitals and delocalization of electrons (spread throughout the conjugated system).
• B preferably has three or more aromatic ring structures, and more preferably has three to six conjugated aromatic six-membered rings.
• the number of aromatic six-membered rings is three or more, the adsorption to the pigment is improved, making it easier to disperse the pigment in the resin.
• the compatibility of the polyorganosiloxane with the resin is easily improved. From the viewpoint of improving the adsorption to the pigment and the compatibility with the resin, the number of aromatic six-membered rings is preferably 4 or more and 5 or less.
• the conjugated ring may be a fused ring compound or a non-fused ring compound, but is preferably a fused ring compound.
• B contains a fused ring compound or when B is a fused ring compound, adsorption to the pigment is improved, making it easier to disperse the pigment in the resin.
• the fused ring is preferably an aromatic ring, and the fused ring compound is preferably a fused aromatic ring compound.
• fused ring compound examples include anthracene-substituted compounds, phenanthrene-substituted compounds, triphenylene-substituted compounds, pyrene-substituted compounds, tetracene-substituted compounds, picene-substituted compounds, perylene-substituted compounds, pentaphene-substituted compounds, pentacene-substituted compounds, and hexaphene-substituted compounds, among which anthracene-substituted compounds, pyrene-substituted compounds, and perylene-substituted compounds are preferred, and pyrene-substituted compounds and perylene-substituted compounds are more preferred.
• substituted compounds means that they may have a substituent
• anthracene-substituted compounds means that they include both anthracene and anthracene having a substituent, and the same applies to other substituents.
• the fused ring compound has a substituent
• at least one of the hydrogen atoms constituting the fused ring compound is substituted with the substituent.
• the substituent include an organic group having 1 to 10 carbon atoms.
• the fused ring compound has no substituent.
• B is more preferably anthracene, pyrene, or perylene, and particularly preferably pyrene or perylene.
• the fused ring compound may be any compound as long as any carbon atom constituting the fused ring is bonded to the above A.
• the non-fused ring compound is preferably a non-fused aromatic ring compound, for example, a terphenyl-substituted compound, which has a structure in which a plurality of aromatic rings are linked by single bonds.
• the non-fused ring compound may also be a compound in which a carbon atom constituting an aromatic ring is bonded to the above-mentioned A.
• B can be any of the above-mentioned compounds without any particular limitation, but the preferred structure of B is shown below.
• * represents a bond to A.
• the fused ring compounds represented by formulas (12) to (14) are preferred, with pyrene represented by formula (12) or perylene represented by formula (13) being more preferred, and perylene represented by formula (13) being even more preferred.
• At least one R is the group represented by A-B above, and the remaining R are hydrocarbon groups having 1 to 4 carbon atoms.
• the number of groups represented by A-B among the multiple R is, for example, 1 to 8, preferably 1 to 5, more preferably 1 to 4, and even more preferably 1 or 2, and the remainder are preferably monovalent hydrocarbon groups having 1 to 4 carbon atoms.
• the multiple groups represented by A-B may be the same or different.
• the monovalent hydrocarbon group having 1 to 4 carbon atoms include a methyl group, an ethyl group, a propyl group, and a butyl group, and among these, a methyl group is preferable.
• the multiple monovalent hydrocarbon groups having 1 to 4 carbon atoms may be the same or different.
• n represents the number of repetitions and is an integer of 1 or greater. There are no particular restrictions on n as long as it is an integer of 1 or greater, but from the perspective of keeping the number average molecular weight of the polyorganosiloxane within a certain range, it is, for example, 530 or less, preferably 500 or less, more preferably 300 or less, even more preferably 250 or less, and for example, 20 or more, preferably 50 or more, more preferably 100 or more, even more preferably 200 or more.
• a silicone surface treatment agent according to one embodiment of the present invention has a structure represented by the following formula (3):
• the silicone surface treatment agent has groups represented by AB at both ends.
• each R is independently a monovalent hydrocarbon group having 1 to 4 carbon atoms, and A, B, and n are defined as in formula (1).
• R in formula (3) has the same meaning as R in formula (2), and A, B, and n have the same meanings as those in formula (1).
• m is an integer of 1 or more and 8 or less, preferably an integer of 1 or more and 6 or less, more preferably an integer of 1 or more and 5 or less, and even more preferably 1 or 2.
• the polyorganosiloxane represented by formula (4) may be a random polymer or a block polymer. More specifically, the unit shown in parentheses m and the unit shown in parentheses n may exist in the molecule in a block form or random form.
• silicone surface treatment agents described above those having a structure represented by formula (2) or (3) above are preferred for use in the present invention, with those having a structure represented by formula (2) above being more preferred.
• the method for producing the silicone surface treatment agent of the present invention is not particularly limited, and can be obtained by reacting a commonly available polyorganosiloxane having a functional group with a compound having three or more conjugated rings that form a common conjugated system and having a functional group that can react with the functional group of the polyorganosiloxane.
• the silicone surface treatment agent of the present invention can be produced by utilizing the acetalization reaction between an aldehyde and a diol, or the hydrosilylation reaction between a hydrosilyl group and a carbon-carbon unsaturated bond.
• the silicone surface treatment agent of the present invention can be produced by reacting a polyorganosiloxane having a diol structure with a compound having an aldehyde group and three or more conjugated rings that form a common conjugated system.
• the silicone surface treatment agent of the present invention can be produced by reacting a polyorganosiloxane having a hydrosilyl group at the end and/or side chain with a compound having a group with a carbon-carbon unsaturated bond, such as an acrylate group or a methacrylate group, and three or more conjugated rings that form a common conjugated system.
• the silicone surface treatment agent of the present invention may also be one obtained by further chain-extending a compound having a structure shown in formulas (1) to (4) with a chain extender.
• Chain extension makes it easier to increase the number average molecular weight of the silicone surface treatment agent of the present invention.
• the chain extender may be a linear polyorganosiloxane or a cyclic polyorganosiloxane such as octamethylcyclotetrasiloxane or decamethylcyclopentasiloxane.
• the polysiloxane particles of the present invention may contain additives other than the above-mentioned polysiloxane, pigment, and surface treatment agent, as needed, as long as the effects of the present invention are not impaired.
• additives such as curing catalysts, alkoxysilane compounds, antioxidants, heat stabilizers, colorants, flame retardants, and antistatic agents may be blended.
• the other components may be used alone or in combination of two or more.
• the polysiloxane particles of the present invention may be used in any application requiring light-shielding properties, and may be used, for example, as spacer particles in liquid crystal display devices or light-adjusting materials.
• the number average molecular weight of the polyorganosiloxane was measured under the following conditions. The measurement was carried out using a Waters "APC System” as the measuring device, an HSPgel HR MB-M 6.0 x 150 mm column, and THF as the solvent at a flow rate of 0.5 mL/min and a temperature of 40°C.
• resistivity at 50% compression The resistivity of the polysiloxane particles when compressed to 50% was measured according to the measurement method described in the specification. Furthermore, the electrical reliability when used in an environment where a load is applied was evaluated based on the measured resistivity when compressed by 50%.
• the evaluation criteria were as follows: A: 500 ⁇ / ⁇ m or more B: 200 ⁇ / ⁇ m or more and less than 500 ⁇ / ⁇ m C: 50 ⁇ / ⁇ m or more and less than 200 ⁇ / ⁇ m D: Less than 50 ⁇ / ⁇ m
• the polysiloxane particles produced in each example had high insulating properties even when the particles were compressed, because the pigment was coated with a surface treatment agent.
• the polysiloxane particles produced in Comparative Examples 1 to 3 did not exhibit high insulating properties when the particles were compressed, because the pigment was not coated with a surface treatment agent.

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  • 2025-03-27 WO PCT/JP2025/012397 patent/WO2025206145A1/ja active Pending
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