Polymeric additive

Abstract

A polymeric additive according to the present invention has an aromatic ring in a side chain or at an end of a polymer main chain, has at least one reactive functional group in the molecular structure, has a maximum fluorescence peak within the range of 370-410 nm, and has a total Hansen solubility parameter δtot, shown by the following expression, of 17-24. (In the expression, δd, δp, and δh respectively indicate the dispersion term, polarity term, and hydrogen-bonding term of Hansen solubility parameter.) This polymeric additive has high solubility in moderately to highly polar solvents and in resins such as epoxy resins, acrylic resins, and urethane resins, and can improve the dispersibility of π-conjugated fillers in these solvents and resins.

Description

Polymer Additives

[0001] The present invention relates to polymeric additives.

[0002] In recent years, the amount of heat generated by electronic devices has increased with the increasing integration of circuits, making heat management important, and there has been a growing demand for heat dissipation materials. Heat dissipation materials are generally made from resin compositions containing a resin and a filler.

[0003] Boron nitride, graphite, carbon black, and the like are known as fillers with six-membered ring structures and π-electron conjugated systems (hereinafter sometimes referred to as π-conjugated fillers), and are used in a variety of applications, such as inks and resin composites. However, because π-conjugated fillers have low affinity for solvents and resins, additives are generally used to improve affinity. Polymer additives are often used, particularly to improve the dispersibility of fillers.

[0004] Polymer additives generally consist of a functional group (hereinafter sometimes referred to as a filler linker) that interacts with the filler and a polymer backbone. Patent Document 1 describes an invention related to a filler dispersant using an acrylic polymer. The dispersant described in Patent Document 1 has an ionic functional group as a filler linker. Dispersants with ionic functional groups (amine, carboxylic acid, phosphoric acid, etc.) exhibit a dispersing effect by bonding with functional groups present on the side, edge, or other surfaces of the filler. However, they have low reactivity and poor filler dispersing effect with π-conjugated fillers that have a surface without functional groups, such as the (001) surface of boron nitride.

[0005] Meanwhile, studies have also been conducted to enhance the dispersibility of π-conjugated fillers by utilizing π-π interactions using polymer additives having aromatic rings. Patent Document 2 describes an invention related to a nanocarbon dispersant having a specific repeating unit, and discloses a nanocarbon dispersant having, in its structure, an atomic group containing a functional group that interacts with nanocarbon and can adsorb to its surface. Examples of the functional group include a 1-pyrenyl group. Patent Document 3 discloses norbornene-based ring-opening (co)polymers having a maximum absorption wavelength in the range of 300 nm to 400 nm, specifically citing polymers containing anthracene, pyrene, etc. Patent Document 4 discloses an invention related to a method for dispersing graphite-like nanoparticles using a block copolymer-based dispersing aid, and cites a compound containing pyrene as a dispersing aid. Patent Document 5 discloses an invention relating to a conjugated polymer consisting of specific repeating units, having a weight average molecular weight of 20,000 or more and a polydispersity (Mw / Mn) of 2.40 or less, and describes that the conjugated polymer may have a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, etc. as a substituent. Patent Document 6 discloses an invention relating to a nanofiller dispersant composition containing (a) a reaction product of at least one halogenated copolymer containing units derived from an isoolefin having 4 to 7 carbon atoms and a para-alkylstyrene and at least one polycyclic aromatic hydrocarbon, and (b) at least one nanofiller, and describes anthracene, pyrene, benzopyrene, etc. as polycyclic aromatic hydrocarbons.

[0006] Japanese Patent No. 6965703 JP 2012-82120 A JP 2009-46615 A ​​JP 2012-520224 A JP 2014-218669 A JP 2018-537548 A

[0007] However, conventionally used polymer additives have low solubility in medium to high polarity solvents (e.g., toluene, 2-propanol, methyl ethyl ketone, etc.) and resins (e.g., various monomers for forming epoxy resins, acrylic resins, urethane resins, etc.), and have sometimes resulted in precipitation, etc. Furthermore, it is difficult for conventional additives to improve the dispersibility of π-conjugated fillers in the above-mentioned solvents and resins, and there is room for improvement.

[0008] Therefore, an object of the present invention is to provide a polymer additive that has high solubility in medium to high polarity solvents and resins such as epoxy resins, and that can improve the dispersibility of π-conjugated fillers in these solvents.

[0009] As a result of extensive investigation, the present inventors have found that a compound having an aromatic ring and at least one reactive functional group, a maximum fluorescence peak within the range of 370 nm to 410 nm, and a total Hansen solubility parameter δ ｔｏｔ The present inventors have found that the above problems can be solved by using a polymer additive having a molecular weight of 17 or more and 24 or less, and have completed the present invention.

[0010] That is, the present invention relates to the following [1] to

[12] : [1] A polymer having an aromatic ring in a side chain or at a terminal of the polymer main chain, and having at least one reactive functional group in its molecular structure, with a maximum fluorescence peak in the range of 370 nm to 410 nm, and a total Hansen solubility parameter δ represented by the following formula: ｔｏｔ A polymer additive having a molecular weight of 17 or more and 24 or less. (δ in the above formula ｄ , δ ｐ , δ ｈ(where δp and δp represent the dispersion term, polar term, and hydrogen bond term of the Hansen solubility parameter, respectively.) [2] The polymeric additive according to the above [1], wherein the polar term δp of the Hansen solubility parameter is 0.5 or more and 19 or less. [3] The polymeric additive according to the above [1] or [2], wherein the aromatic ring contains a fused ring compound in which four or more six-membered rings are fused. [4] The polymeric additive according to the above [3], wherein the number of the fused ring compounds is 1 or more and 5 or less per polymer chain. [5] The polymeric additive according to any of the above [1] to [4], wherein the reactive functional group contains any one selected from the group consisting of a hydroxy group, an acid anhydride group, and a trialkoxysilyl group. [6] The polymeric additive according to any of the above [1] to [5], wherein the number average molecular weight (Mn) measured by GPC is 4,000 or more and 100,000 or less. [7] The polymer additive according to any one of [1] to [6] above, which has two maximum UV absorption peaks in the range of 320 nm to 350 nm. [8] The polymer additive according to any one of [1] to [7] above, wherein the polymer main chain comprises a (meth)acrylate. [9] The polymer additive according to any one of [1] to [8] above, which has an alkyl group having 1 to 22 carbon atoms in its molecular structure.

[10] A filler-containing composition comprising the polymer additive according to any one of [1] to [9] above, a filler, and a matrix which is at least one of a resin and a solvent.

[11] The filler-containing composition according to

[10] above, wherein the filler is a thermally conductive filler.

[12] The filler-containing composition according to

[10] or

[11] above, wherein the resin comprises a curable resin, and the curable resin comprises an epoxy compound.

[0011] It is possible to provide a polymer additive that has high solubility in medium to high polarity solvents and resins such as epoxy resins, and that can improve the dispersibility of π-conjugated fillers in these solvents.

[0012] [Polymer Additive] The polymer additive of the present invention has an aromatic ring in a side chain or at an end of the polymer main chain, and has at least one reactive functional group in its molecular structure, and has a maximum fluorescence peak in the range of 370 nm to 410 nm, and has a total Hansen solubility parameter δ represented by the following formula: ｔｏｔ is between 17 and 24. (δ ｄ , δ ｐ , δ ｈ represent the dispersion term, polar term, and hydrogen bonding term of the Hansen solubility parameters, respectively)

[0013] The polymer additive of the present invention has the above-described configuration, which improves its solubility in medium- to high-polarity solvents and resins. In this specification, "solubility in resin" refers to the compatibility of the polymer additive with the resin after curing. A polymer additive with good compatibility with the resin after curing is considered to have good solubility in the resin. Furthermore, in the present invention, the polymer additive must have excellent solubility in both medium- to high-polarity solvents and resins. By dissolving in both medium- to high-polarity solvents and resins, it becomes easy to prepare a slurry of a composite material of resin and filler without impairing various physical properties after curing of the resin.

[0014] <Aromatic Ring> The polymer additive of the present invention has an aromatic ring in a side chain or at the end of the polymer main chain. The polymer additive having an aromatic ring facilitates the generation of π-π interaction with the π-conjugated filler. Such π-π interaction between the polymer additive and the filler improves the dispersibility of the filler. Here, the π-conjugated filler is a filler having a six-membered ring atomic structure as a constituent unit, such as boron nitride, graphite, or carbon black.

[0015] The aromatic ring of the polymer additive preferably includes a fused ring compound in which multiple aromatic rings (6-membered rings) are fused. By including a fused ring compound, the polymer additive is more likely to undergo π-π interaction with the π-conjugated filler, which makes it easier to improve the dispersibility of the filler. Examples of the fused ring compound include naphthalene, anthracene, phenanthrene, triphenylene, pyrene, tetracene, picene, perylene, pentaphene, pentacene, and hexaphene. In addition, in the fused ring compound, at least one or more hydrogen atoms constituting the fused ring compound may be substituted with a substituent. Examples of the substituent include organic groups having 1 to 10 carbon atoms.

[0016] Among these, from the viewpoint of improving the dispersibility of the π-conjugated filler, the fused ring compound contained in the polymer additive is preferably a fused ring compound having four or more fused six-membered rings. Furthermore, among the fused ring compounds having four or more fused six-membered rings, pyrene is particularly preferable from the viewpoint of improving the solubility of the polymer additive in medium to high polarity solvents.

[0017] Furthermore, the number of fused ring compounds is preferably 1 to 5 per polymer chain of the polymer additive. When the number of fused ring compounds is 1 or more, they tend to interact with the π-conjugated filler, improving dispersibility. When the number of fused ring compounds is 5 or less, the polymer additive is less likely to self-aggregate, improving solubility in solvents and resins. The number of fused ring compounds is more preferably 1 to 3 per polymer chain of the polymer additive, and even more preferably 1.

[0018] <Reactive Functional Group> The polymer additive of the present invention has at least one reactive functional group in its molecular structure. The polymer additive having a reactive functional group facilitates reaction or interaction with a resin, thereby improving solubility in the resin. The type of reactive functional group possessed by the polymer additive is not particularly limited, and it is advisable to select a reactive functional group that readily reacts or interacts with a resin. The reactive functional group is preferably one or more selected from the group consisting of a trialkoxysilyl group, a vinyl group, an acid anhydride group, a carboxyl group, an amino group, a hydroxyl group, an isocyanate group, a urethane group, an oxazoline group, an oxetane group, a cyanate group, a phenol group, a hydrazide group, and an amide group. Among these, any one selected from the group consisting of a hydroxyl group, an acid anhydride group, and a trialkoxysilyl group is preferred, with a hydroxyl group being more preferred. The trialkoxysilyl group is preferably a trimethoxysilyl group.

[0019] <Alkyl Group> The polymer additive of the present invention preferably has an alkyl group having from 1 to 22 carbon atoms in its molecular structure. From the viewpoint of adjusting the total Hansen solubility parameter (described later) to a desired range, the alkyl group is preferably an alkyl group having from 6 to 18 carbon atoms, more preferably an alkyl group having from 8 to 18 carbon atoms. Specific examples of the alkyl group include a hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, pentadecyl group, and octadecyl group (stearyl group). Of these, a dodecyl group and an octadecyl group (stearyl group) are preferred, and an octadecyl group (stearyl group) is more preferred.

[0020] <Structure of polymer additive> The polymer main chain of the polymer additive of the present invention is not particularly limited, but preferably contains (meth)acrylate. More specifically, the polymer additive of the present invention is preferably a polymer containing a structural unit derived from (meth)acrylate. In this specification, (meth)acrylate represents acrylate or methacrylate, and the same applies to other similar terms.

[0021] The polymer additive of the present invention is preferably a polymer containing a structural unit derived from (meth)acrylate, which is represented by the following general formula (1). In formula (1), R １ is an alkyl group having 1 to 22 carbon atoms, R ２ is a group containing a reactive functional group, R ３ is a group containing an aromatic ring. ４ ~R ６ are each independently a hydrogen atom or a methyl group. １ represents the number of units having R (hereinafter, also referred to as alkyl group-containing units), and is 10 or more and 200 or less. ２ z represents the number of units having R (hereinafter, also referred to as reactive group-containing units), and is 5 to 50. ３(hereinafter, also referred to as aromatic ring-containing units) and is 1 to 5. The * symbols at both ends represent bonds. The * symbols are usually bonded to a group (generally an organic group having 1 to 20 carbon atoms) derived from a reagent such as a polymerization initiator used in producing the polymer represented by formula (1).

[0022] The polymer additive represented by formula (1) is composed of an alkyl group-containing unit, a reactive group-containing unit, and an aromatic ring-containing unit, and each unit may be bonded in a block or random manner. In addition, the Hansen solubility parameter δ ｔｏｔ For example, by decreasing the number of alkyl group-containing units or increasing the number of reactive group-containing units, the total Hansen solubility parameter δ ｔｏｔ , the value of the polar term δp of the Hansen solubility parameter can be adjusted to a high value.

[0023] R １ From the viewpoint of adjusting the total Hansen solubility parameter (described later) to a desired range, the alkyl group is preferably an alkyl group having 6 to 18 carbon atoms, more preferably an alkyl group having 8 to 18 carbon atoms. Specific examples of the alkyl group include a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a pentadecyl group, and an octadecyl group (stearyl group). Of these, a dodecyl group and an octadecyl group (stearyl group) are preferred, and an octadecyl group (stearyl group) is more preferred.

[0024] R ２is a group containing a reactive functional group, and the reactive functional group is as described above. That is, the reactive functional group is preferably one or more selected from the group consisting of a trialkoxysilyl group, a vinyl group, an acid anhydride group, a carboxyl group, an amino group, a hydroxyl group, an isocyanate group, a urethane group, an oxazoline group, an oxetane group, a cyanate group, a phenol group, a hydrazide group, and an amide group. Among these, any one selected from the group consisting of a hydroxyl group, an acid anhydride group, and a trialkoxysilyl group is preferred, and a hydroxyl group is more preferred. Note that the trialkoxysilyl group is preferably a trimethoxysilyl group.

[0025] R ３ is a group containing an aromatic ring. The aromatic ring is preferably a fused ring compound, and examples of the fused ring compound include naphthalene, anthracene, phenanthrene, triphenylene, pyrene, tetracene, picene, perylene, pentaphene, pentacene, and hexaphene, with pyrene being particularly preferred.

[0026] In formula (1), x is 10 or more and 200 or less, preferably 20 or more and 100 or less, and more preferably 30 or more and 60 or less. In formula (1), y is 5 or more and 50 or less, preferably 6 or more and 30 or less, and more preferably 8 or more and 15 or less. In formula (1), z is 1 or more and 5 or less, preferably 1 or more and 3 or less, and more preferably 1. By setting x, y, and z within the above ranges, the total Hansen solubility parameter δ, which will be described later, can be reduced. ｔｏｔ , it becomes easier to adjust the polarity term δp of the Hansen solubility parameter to a desired range.

[0027] The polymer additive of the present invention is more preferably a polymer represented by formula (2), from the viewpoint of improving the solubility in medium to high polarity solvents and resins and further improving the dispersibility of the π-conjugated filler in these solvents and resins. The polymer additive represented by formula (2) is a compound represented by formula (1) ２ is "-(R ７ -O) ｎ -H" and R in formula (1) ３ is "-CH２ -R ８ " is the same as formula (1). That is, R １ , R ４ ~R ６ , x, y, and z have the same meanings as in formula (1). ７ is an alkylene group having 2 to 4 carbon atoms, preferably an ethylene group. Also, n is an oxyalkylene group (R ７ R represents the number of repeating groups (—O) and is 1 to 50, preferably 3 to 20, and more preferably 6 to 12. ８ is a condensed ring compound, and examples thereof include naphthalene, anthracene, phenanthrene, triphenylene, pyrene, tetracene, picene, perylene, pentaphene, pentacene, and hexaphene, with pyrene being preferred.

[0028] The polymer additive of the present invention is more preferably a polymer represented by formula (3), from the viewpoint of improving the solubility in medium to high polarity solvents and resins and further improving the dispersibility of the π-conjugated filler in these solvents and resins. The polymer additive represented by formula (3) is a compound represented by formula (2) ４ ~R ６ is a methyl group, and R ７ is an ethylene group, and R ８ is a polymer additive in which R is pyrene. １ , x, y, and z have the same meanings as in formula (1).

[0029] The polymer additives represented by the above formulas (1) to (4) can be obtained by polymerizing the following monomers (a) to (c) for forming the alkyl group-containing unit, the reactive group-containing unit, and the aromatic ring-containing unit: R in the above monomers (a) to (c) １ ~R ６ has the same meaning as that explained in the above formula (1).

[0030] As the polymerization method, a method of polymerizing a general acrylic monomer can be used, but from the viewpoint of appropriately adjusting the molecular weight of the polymer additive and improving the solubility in a solvent and the dispersibility of the filler, it is preferable to apply RAFT polymerization (Reversible Addition-Fragmentation Chain Transfer Polymerization). When RAFT polymerization is applied, a structure derived from the polymerization initiator and RAFT reagent (chain transfer agent) used in RAFT polymerization becomes the terminal of the polymer additive. That is, * in formula (1) is preferably bonded to the structure derived from the polymerization initiator and RAFT reagent (chain transfer agent) used in RAFT polymerization. In this case, an example of a specific structure of the polymer additive is shown below. R in formula (4) １ is as explained in equation (1), and n is as explained in equation (3).

[0031] <Maximum Fluorescence Peak> The polymer additive of the present invention has a maximum fluorescence peak in the range of 370 nm or more and 410 nm or less. Having a maximum fluorescence peak within this range facilitates interaction with the π-conjugated filler and facilitates suppression of stacking of aromatic rings such as fused ring compounds. As a result, the solubility and dispersibility of the polymer additive in solvents and resins are improved. The maximum fluorescence peak is preferably in the range of 380 nm or more and 410 nm or less, more preferably 390 nm or more and 410 nm or less, and even more preferably 395 nm or more and 405 nm or less. The maximum fluorescence peak can be adjusted by the type of aromatic ring contained in the polymer additive. The maximum fluorescence peak can also be measured by the method described in the Examples.

[0032] <Hansen Solubility Parameter> The polymer additive of the present invention has a total Hansen solubility parameter δ represented by the following formula: ｔｏｔ is between 17 and 24. (δ ｄ , δ ｐ , δ ｈ represent the dispersion term, polar term, and hydrogen bond term of the Hansen solubility parameter, respectively) Total Hansen solubility parameter δ ｔｏｔis the square root of the sum of the squares of the three parameters of the Hansen solubility parameter (HSP): the dispersion term, the polarity term, and the hydrogen bonding term.

[0033] Total Hansen solubility parameter δ of polymer additives ｔｏｔ When the Hansen solubility parameter δ is 17 or more and 24 or less, the solubility in solvents of medium to high polarity is improved. The Hansen solubility parameter δ is preferably 17 or more and 22 or less, and more preferably 18 or more and 20 or less. In addition, the polarity term δp of the Hansen solubility parameter is preferably 0.5 or more and 19 or less, more preferably 1 or more and 10 or less, and even more preferably 2 or more and 6 or less, from the viewpoint of improving the solubility of the polymer additive in solvents of medium to high polarity.

[0034] The Hildebrand solubility parameter, commonly known as the SP value (δ), assumes that the only forces acting between the solvent and solute are intermolecular forces. Meanwhile, the Hansen solubility parameter (HSP) represents solubility in a three-dimensional space consisting of the dispersion term δd, the polar term δp, and the hydrogen bonding term δh. The dispersion term δd represents the effect of dispersion forces, the polar term δp represents the effect of dipole-dipole forces, and the hydrogen bonding term δh represents the effect of hydrogen bonding forces. The definition and calculation of the Hansen solubility parameter are described in "Hansen Solubility Parameters: A Users Handbook" by Charles M. Hansen (CRC Press, 2007). The Hansen solubility parameter can also be easily estimated using the computer software Hansen Solubility Parameters in Practice (HSPiP).

[0035] Total Hansen solubility parameter δ of polymer additives ｔｏｔ is expressed by the above formula and can be determined by conducting a test to measure solubility using a solvent with a known Hansen Solubility Parameter (HSP). Details are as described in the Examples.

[0036] <Molecular Weight> The number average molecular weight of the polymer additive of the present invention is not particularly limited, but is preferably 4,000 or more and 100,000 or less. When the number average molecular weight of the polymer additive is 4,000 or more, the dispersibility of the filler is easily improved. Furthermore, when the number average molecular weight of the polymer additive is 100,000 or less, the solubility in medium to high polarity solvents and resins such as epoxy resins is improved. The number average molecular weight of the polymer additive is more preferably 6,000 or more and 30,000 or less, and even more preferably 8,000 or more and 15,000 or less. The number average molecular weight of the polymer additive can be measured by gel permeation chromatography (GPC) and is a value converted into standard polystyrene.

[0037] <Ultraviolet Absorption (UV)> When the ultraviolet absorption (UV) spectrum of the polymer additive of the present invention is measured, it is preferable that the polymer additive has two maximum UV absorption peaks in the range of 320 nm to 350 nm. A polymer additive having two maximum UV absorption peaks in such a specific wavelength range is likely to improve the dispersibility of a π-conjugated filler and also likely to increase the solubility in medium to high polarity solvents. The ultraviolet absorption spectrum of the polymer additive can be adjusted by the type of aromatic ring, such as a fused aromatic ring, that the polymer additive has.

[0038] <Applications> The polymer additive of the present invention can be suitably used as a dispersant for various fillers. The filler is not particularly limited, but from the perspective of use as a heat dissipation material, a thermally conductive filler is preferred, and examples thereof include aluminum, copper, nickel, aluminum oxide (alumina), magnesium oxide, zinc oxide, aluminum hydroxide, aluminum nitride, diamond, boron nitride, and carbon-based materials. Here, the thermally conductive filler is a filler having thermal conductivity, preferably a filler having a thermal conductivity of 10 W / m·K or more. As described above, the polymer additive of the present invention can effectively disperse π-conjugated fillers. Therefore, the polymer additive of the present invention can be suitably used as a dispersant for π-conjugated fillers such as boron nitride and carbon-based materials. Examples of boron nitride include boron nitride nanotubes, boron nitride nanosheets, and hexagonal boron nitride particles. Examples of carbon-based materials include graphite, carbon black, carbon fiber, and carbon nanotubes.

[0039] The average particle size of the filler is not particularly limited, but is, for example, 1 to 100 μm, preferably 1 to 50 μm, and more preferably 1 to 10 μm. The average particle size refers to the particle size at 50% volume (D50) in the particle size distribution of the insulating fine particles determined by a laser diffraction / scattering method.

[0040] When the polymer additive of the present invention is used as a dispersant for fillers, the amount of the polymer additive is, for example, 0.5 to 10 parts by mass, more preferably 1 to 5 parts by mass, per 100 parts by mass of filler.

[0041] The polymer additive of the present invention has good solubility in medium to high polarity solvents. Therefore, it can be suitably used in applications where a filler is dispersed in a medium to high polarity solvent. Examples of medium to high polarity solvents include toluene, ethyl acetate, methyl ethyl ketone, tetrahydrofuran, acetone, cyclohexanone, n-propanol, 2-propanol, ethanol, and methanol.

[0042] The polymer additive of the present invention can also be used to disperse a filler in a resin (matrix). Examples of resins include curable resins, thermoplastic resins, and elastomer resins. Examples of curable resins include epoxy resins, silicone resins, urethane resins, phenolic resins, unsaturated polyester resins, polyimide resins, and oxetane resins. Examples of thermoplastic resins include polyolefin resins such as polypropylene resins, polyethylene resins, poly(1-)butene resins, and polypentene resins; polyester resins such as polyethylene terephthalate; polystyrene resins; acrylonitrile-butadiene-styrene (ABS) resins; ethylene-vinyl acetate copolymers (EVA); (meth)acrylic resins; polyamide resins; and polyvinyl chloride resins (PVC).

[0043] Among the above-mentioned resins, those containing a curable resin are preferred. The curable resin preferably contains an epoxy resin. The epoxy resin preferably contains an epoxy compound and a curing agent. Examples of the epoxy compound include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol S type epoxy compounds, phenol novolac type epoxy compounds, biphenyl type epoxy compounds, biphenyl novolac type epoxy compounds, biphenol type epoxy compounds, naphthalene type epoxy compounds, fluorene type epoxy compounds, phenol aralkyl type epoxy compounds, naphthol aralkyl type epoxy compounds, dicyclopentadiene type epoxy compounds, anthracene type epoxy compounds, epoxy compounds having an adamantane skeleton, epoxy compounds having a tricyclodecane skeleton, naphthylene ether type epoxy compounds, and epoxy compounds having a triazine nucleus in the skeleton.

[0044] Examples of curing agents include phenol compounds (phenol curing agents), amine compounds (amine curing agents), imidazole compounds, acid anhydrides, cyanate ester compounds, carbodiimide compounds, and imide oligomers. The imide oligomer is a compound having an imide skeleton in its main chain, preferably a compound having an aromatic ring in its skeleton. The imide oligomer has reactive functional groups at both ends or one end of the molecule that can react with the curable resin, and the reactive functional groups are preferably acid anhydride groups, amino groups, or hydroxyl groups. The amino group is not particularly limited and may be any of primary amino groups, secondary amino groups, and tertiary amino groups. The hydroxyl group may be a phenolic hydroxyl group or a hydroxyl group other than a phenolic hydroxyl group.

[0045] Examples of elastomer resins include acrylonitrile butadiene rubber, ethylene-propylene-diene rubber, ethylene-propylene rubber, natural rubber, polybutadiene rubber, and polyisoprene rubber. These elastomer resins may be liquid elastomers that are liquid at room temperature (23°C) and normal pressure (1 atmosphere), solid elastomers, or mixtures thereof. Thermoplastic elastomers such as polyester-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, and styrene-based thermoplastic elastomers may also be used as elastomer resins.

[0046] The polymer additive of the present invention has high solubility in monomers for forming resins such as epoxy resins. Furthermore, the polymer additive of the present invention has a reactive functional group, which makes it easy to react with resins such as epoxy resins, and allows fillers to be dispersed in resins with good dispersibility.

[0047] For example, when a monomer for forming a resin such as an epoxy resin, a filler, and the polymer additive of the present invention are mixed in a medium- to high-polarity solvent, the solubility of the polymer additive in the monomer is good, and further, the dispersibility of the filler in the solvent is good. Therefore, when the monomer in the solvent is polymerized to form a polymer, a filler / polymer composite with good filler dispersibility is obtained. In particular, even when a π-conjugated filler is used as the filler, the polymer additive of the present invention can be used to prepare a π-conjugated filler / polymer composite with good π-conjugated filler dispersibility. These filler / polymer composites have excellent filler dispersibility, resulting in uniform physical properties such as thermal conductivity and excellent interfacial elastic modulus relaxation.

[0048] <Resin Composition> In the present invention, a resin composition can be provided that contains the above-mentioned polymer additive, a filler, and a matrix that is at least one of a resin and a solvent. Specific examples of the resin, solvent, and filler are as described above.

[0049] The present invention will be clarified below by showing specific examples and comparative examples of the present invention, but the present invention is not limited to the following examples.

[0050] [Molecular Weight] The number average molecular weight of each polymer additive was measured under the following conditions: A Waters "ACQUITY APC System" was used as the GPC apparatus, an LF-604 6.0 x 150 mm column was used, and THF was used as the solvent, at a flow rate of 0.3 mL / min and a temperature of 40°C. A polystyrene standard was used as the standard sample.

[0051] [Maximum Fluorescence Peak] The fluorescence spectrum of each polymer additive was measured. Specifically, a fluorescence spectrum was obtained by measuring each polymer additive sandwiched between glass slides to a thickness of 40 μm under conditions of an excitation wavelength of 339 nm using a Hitachi High-Tech Science F-2700 spectrofluorometer. The wavelength at which the intensity in the fluorescence spectrum was maximum was taken as the maximum fluorescence peak.

[0052] [Maximum Ultraviolet (UV) Absorption Peak] The UV absorption peak of each polymer additive was measured using a spectrophotometer U-3900 manufactured by Hitachi High-Tech Science Corporation.

[0053] [Total Hansen solubility parameter δ ｔｏｔ Each polymer additive was dissolved in 25 solvents selected from the Master Database, whose Hansen Solubility Parameters (HSP) were confirmed, to evaluate its solubility and dispersibility. The 25 solvents used and their Hansen Solubility Parameters (HSP) are shown in Table 1. The dispersion term δ ｄ , polar term δ ｐ , and the hydrogen bond term δ ｈ The unit is "MPa １／２ "

[0054]

[0055] (Evaluation of Solubility and Dispersibility) The solubility and dispersibility of each polymer additive were determined as follows. Each polymer additive was added to each of the solvents shown in Table 1 so that the concentration was 5% by mass, and the mixture was stirred at room temperature (25°C) for 30 minutes at 50 rpm using a mix rotor, model VMR-5R, manufactured by AS ONE Corporation. After stirring, the mixture was allowed to stand at room temperature (25°C) for 1 hour, and the solubility and dispersibility were evaluated according to the following criteria: Score 1: Dissolved, no precipitation Score 2: Dissolved, slight precipitation Score 3: Dissolved, more than half precipitated Score 4: Dissolved, almost precipitated Score 5: Insoluble, complete precipitation For each solvent shown in Table 1, a score was determined, and then the HSP was estimated using the computer software Hansen Solubility Parameters in Practice (HSPiP). Specifically, the Sphere program of HSPiP was started, and each solvent used in the evaluation of solubility and dispersibility was selected on the program. Next, the score of each solvent identified by the above method was input into the program, and calculations were performed to obtain δ ｔｏｔ , δp were calculated automatically.

[0056] <Dispersibility Evaluation> A polymer additive solution was prepared by adding 0.2 g of the polymer additive of each Example and Comparative Example to 20 g of methyl ethyl ketone and stirring. 0.2 g of boron nitride (UHP-1K manufactured by Showa Denko K.K., scale-like, average particle size 8 μm) was added as a filler to the polymer additive solution, and the mixture was stirred for 5 minutes at a stirring speed of 100 rpm using a rotating ultrasonic nano-disperser "PR-1" (Thinky Corporation). The mixture was then left to stand for 5 minutes and then shaken by hand to obtain a dispersion. The resulting dispersion was transferred to a centrifuge tube (Violamo, model number VIO-50BN), and the thickness of the precipitate was measured 10 minutes after leaving the mixture to stand, and evaluated according to the following criteria. (Evaluation Criteria) A: The precipitate thickness was 8 mm or less. B: The precipitate thickness was greater than 8 mm and less than 9.5 mm. C: The precipitate thickness was greater than 9.5 mm.

[0057] <Solubility Evaluation> Evaluation of Solubility in 2-Propanol 0.4 g of the polymer additive of each Example and Comparative Example was added to 8 g of 2-propanol and stirred to confirm the solubility of the polymer additive. Specifically, the transmission spectrum of the polymer additive solution was obtained using a "Spectrophotometer U-3900" manufactured by Hitachi High-Tech Science Corporation, and the transmittance at a wavelength of 600 nm was measured. The solubility evaluation was carried out at 25°C and evaluated according to the following criteria. (Evaluation Criteria) A: Transmittance of 90% or more B: Transmittance of 50% or more but less than 90% C: Transmittance of less than 50%

[0058] Evaluation of Solubility in Epoxy Resin: 0.2 g of the polymer additive of each Example and Comparative Example, 1.0 g of bisphenol A-type epoxy resin (YD-127, manufactured by Nippon Steel Chemical & Material Co., Ltd.), 0.010 g of imidazole-type curing accelerator (manufactured by Shikoku Kasei Co., Ltd.), and 1.2 g of methyl ethyl ketone were mixed and stirred to obtain a reaction solution. Then, 0.3 g of the solution was dropped onto a glass slide, formed into a 140 μm-thick sheet, and dried at 100°C for 10 minutes. After drying, the sheet was sandwiched between glass slides and cured at 150°C for 30 minutes and 200°C for 90 minutes to evaluate the solubility of the polymer additive in the epoxy resin. Specifically, the total light transmittance of the polymer additive solution was measured using a "Spectrocolorimetric Haze Meter COH 7700" manufactured by Nippon Denshoku Industries Co., Ltd., and evaluated according to the following criteria. (Evaluation criteria) A: Total light transmittance of 80% or more B: Total light transmittance of 70% or more but less than 80% C: Total light transmittance of less than 70%

[0059] Example 1: A reaction vessel equipped with a condenser was charged with 0.3158 g of 1-pyrenylmethyl methacrylate, 11.5324 g of dodecyl methacrylate, 3.6446 g of polyethylene glycol methacrylate (Mn=360), 0.1717 g of 2-cyanopropan-2-yl benzodithioate, 0.0317 g of 2,2'-azobis(isobutyronitrile), and 19.70 g of toluene, and the contents were stirred and mixed. After replacing the atmosphere inside the reaction vessel with nitrogen, the reaction vessel was heated with stirring until the temperature reached 80°C, and the reaction was carried out for 17 hours. The reaction vessel was then ice-cooled to terminate the reaction, yielding a copolymer solution. The resulting reaction solution was added dropwise to methanol and purified to obtain a polymer additive represented by formula (5). The number-average molecular weight of the resulting polymer additive was 15,360. The structure of the resulting polymer additive is shown in Table 3. １ The progress of the above reaction was confirmed by H NMR measurement. The NMR measurement device used was a JEOL "ECX-400," and the measurement was carried out under the conditions of a sample concentration of 1% by weight using deuterated chloroform as the solvent, 25°C, a measurement frequency of 400 MHz, and 8 accumulations. The progress of the reaction was also confirmed in the other examples and comparative examples. １ This was confirmed by H NMR measurement.

[0060]

[0061] Example 2 A polymer additive of formula (7) was obtained in the same manner as in Example 1, except that the compound of formula (6) below was used instead of 1-pyrenylmethyl methacrylate, 2-cyanopropan-2-yl benzodithioate was not used, and the blending amounts of each component were adjusted as shown in Table 2. Details of the obtained polymer additive are as shown in Table 3.

[0062]

[0063]

[0064] Example 3 A polymer additive of formula (8) was obtained in the same manner as in Example 1, except that the blending amounts of each component were adjusted as shown in Table 2. Details of the obtained polymer additive are as shown in Table 3.

[0065]

[0066] Example 4 A polymer additive of formula (9) was obtained in the same manner as in Example 1, except that propyl methacrylate was used instead of dodecyl methacrylate, and the amounts of each component were adjusted as shown in Table 2. Details of the obtained polymer additive are as shown in Table 3.

[0067]

[0068] Example 5 A polymer additive of formula (10) was obtained in the same manner as in Example 1, except that the blending amounts of each component were adjusted as shown in Table 2. Details of the obtained polymer additive are as shown in Table 3.

[0069]

[0070] Example 6 A polymer additive of formula (11) was obtained in the same manner as in Example 1, except that the blending amounts of each component were adjusted as shown in Table 2. Details of the obtained polymer additive are as shown in Table 3.

[0071]

[0072] Example 7 A polymer additive of formula (12) was obtained in the same manner as in Example 1, except that the blending amounts of each component were adjusted as shown in Table 2. Details of the obtained polymer additive are as shown in Table 3.

[0073]

[0074] Example 8 A polymer additive of formula (20) was obtained in the same manner as in Example 1, except that stearyl acrylate was used instead of dodecyl methacrylate, 2-(methacryloyloxy)ethyl 1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylate was used instead of polyethylene glycol methacrylate, and the amounts of each component were adjusted as shown in Table 2. Details of the obtained polymer additive are as shown in Table 3.

[0075] Example 9 A polymer additive of formula (21) was obtained in the same manner as in Example 8, except that 3-(trimethoxysilyl)propyl methacrylate was used instead of 2-(methacryloyloxy)ethyl-1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylate, and further polyethylene glycol methacrylate was used, and the amounts of each component were adjusted as shown in Table 2. Details of the obtained polymer additive are as shown in Table 3. In formula (21), y1 = 5 and y2 = 8. That is, the total number of reactive group-containing units is 13.

[0076] Example 10 A polymer additive of formula (22) was obtained in the same manner as in Example 9, except that 3-(trimethoxysilyl)propyl methacrylate was not used and the amounts of each component were adjusted as shown in Table 2. Details of the obtained polymer additive are as shown in Table 3.

[0077] Comparative Example 1 A polymer additive of formula (13) was obtained in the same manner as in Example 1, except that 1-pyrenylmethyl methacrylate was not used and the blending amounts of each component were adjusted as shown in Table 2. Details of the obtained polymer additive are as shown in Table 3.

[0078]

[0079] Comparative Example 2 A polymer additive of formula (14) was obtained in the same manner as in Example 1, except that 9-anthrylmethyl methacrylate was used instead of 1-pyrenylmethyl methacrylate, and the amounts of each component were adjusted as shown in Table 2. Details of the obtained polymer additive are as shown in Table 3.

[0080]

[0081] Comparative Example 3 A polymer additive of formula (15) was obtained in the same manner as in Example 1, except that benzyl methacrylate was used instead of 1-pyrenylmethyl methacrylate, and the amounts of each component were adjusted as shown in Table 2. Details of the obtained polymer additive are as shown in Table 3.

[0082]

[0083] Comparative Example 4 A polymer additive of formula (16) was obtained in the same manner as in Example 1, except that the blending amounts of each component were adjusted as shown in Table 2. Details of the obtained polymer additive are as shown in Table 3.

[0084]

[0085] Comparative Example 5 A polymer additive of formula (17) was obtained in the same manner as in Example 1, except that ethyl methacrylate was used instead of dodecyl methacrylate, and the amounts of each component were adjusted as shown in Table 2. Details of the obtained polymer additive are as shown in Table 3.

[0086]

[0087] Comparative Example 6 A polymer additive of formula (18) was obtained in the same manner as in Example 1, except that the blending amounts of each component were adjusted as shown in Table 2. Details of the obtained polymer additive are as shown in Table 3.

[0088]

[0089] Comparative Example 7 A polymer additive of formula (19) was obtained in the same manner as in Example 1, except that polyethylene glycol methyl ether methacrylate (Mn=500) was used instead of polyethylene glycol methacrylate (Mn=360) and the amounts of each component were adjusted as shown in Table 2. Details of the obtained polymer additive are as shown in Table 3.

[0090]

[0091] <Reference Example 1> The above-mentioned dispersibility evaluation was carried out without using any polymer additive. That is, the dispersibility evaluation was carried out using only methyl ethyl ketone. The results are shown in Table 3.

[0092]

[0093]

[0094] From the results of each example, it can be seen that the polymer additives satisfying the requirements of the present invention have excellent solubility in solvents and resins of medium to high polarity. Furthermore, the use of the polymer additives of the present invention can improve the dispersibility of π-conjugated fillers in solvents of medium to high polarity. In contrast, the polymer additives of Comparative Examples 1 to 3 and 6 did not show a maximum fluorescence peak in the range of 370 nm to 410 nm, and the polymer additives of Comparative Examples 4 and 5 showed a total Hansen solubility parameter δ ｔｏｔ is outside the range of 17 or more and 24 or less, and the polymer additive of Comparative Example 7 does not have a reactive functional group and is a polymer additive that does not satisfy the requirements of the present invention. The polymer additives of these Comparative Examples were poor in at least one of solubility in medium to high polarity solvents, solubility in resins, and dispersibility of the π-conjugated filler in medium to high polarity solvents, and were inferior in performance to the Examples.

Claims

1. It has an aromatic ring in the side chain or at the end of the polymer main chain, and at least one reactive functional group in the molecular structure, and the maximum fluorescence peak is in the range of 370 nm to 410 nm, and the total Hansen solubility parameter δ is expressed by the following formula. ｔｏｔ A polymer additive, wherein the molecular weight is 17 or more and 24 or less. (δ in the above formula ｄ , δ ｐ , δ ｈ represent the dispersion term, polarity term, and hydrogen bonding term of the Hansen solubility parameters, respectively.) 2. The polymer additive according to claim 1, wherein the polar term δp of the Hansen solubility parameter is 0.5 or more and 19 or less.

3. The polymer additive according to claim 1 or 2, wherein the aromatic ring comprises a fused ring compound having four or more fused six-membered rings.

4. The polymer additive according to claim 3, wherein the number of said condensed ring compounds is 1 or more and 5 or less per polymer chain.

5. The polymer additive according to claim 1 or 2, wherein the reactive functional group comprises any one selected from the group consisting of a hydroxy group, an acid anhydride group, and a trialkoxysilyl group.

6. The polymer additive according to claim 1 or 2, having a number average molecular weight (Mn) measured by GPC of 4,000 or more and 100,000 or less.

7. The polymer additive according to claim 1 or 2, which has two maximum UV absorption peaks within the range of 320 nm or more and 350 nm or less.

8. The polymeric additive of claim 1 or 2, wherein the polymeric backbone comprises a (meth)acrylate.

9. The polymer additive according to claim 1 or 2, which has an alkyl group having 1 to 22 carbon atoms in its molecular structure.

10. A filler-containing composition comprising the polymeric additive according to claim 1 or 2, a filler, and a matrix which is at least one of a resin and a solvent.

11. The filled composition of claim 10, wherein the filler is a thermally conductive filler.

12. The filler-containing composition of claim 10, wherein the resin comprises a hardenable resin, the hardenable resin comprising an epoxy compound.

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