JP7214215B2 - Composition - Google Patents

Description

The present invention relates to compositions containing fillers.

Various functional fillers may be dispersed to form various functional compositions such as thermally conductive pastes, conductive pastes, and paints. Preferably, the filler is uniformly dispersed in the composition.

Patent Document 1 describes a resin composition containing a pigment or filler, a resin, and a solvent as a resin composition for suppressing sedimentation of pigments and fillers, in which a specific urethane wax is dispersed and blended. A composition is disclosed.

Further, Patent Document 2 discloses a conductive paste containing a thermoplastic resin, a conductive filler, and a specific thixotropy-imparting agent as a conductive paste that suppresses sedimentation of the conductive filler.

JP-A-2004-059628 JP 2007-179772 A

In the compositions of Patent Documents 1 and 2, since the filler and the like are dispersed in the fluid, the filler may settle during storage of the composition, and there is a problem of storage stability.

The present invention solves such problems and provides a composition capable of dispersing fillers for a long period of time.

One embodiment of the composition according to the present invention contains a copolymer (A), a compatible compound (B) compatible with the copolymer (A), and a filler (C). In the composition, the gel composition obtained by dissolving the copolymer (A) and the compatible compound (B) has a liquid-gel transition temperature (Tc) in the range of 0 to 150 ° C. have.

One embodiment of the composition has a liquid-to-gel transition temperature (Tc) in the range of 0-150°C.

In one embodiment of the composition, the copolymer (A) is the following copolymer (A1), (A2) or (A3).
(A1): a block (a1) having a (meth)acrylate-based monomer (α1) as a main structural unit;
A block copolymer having a block (b1) having a (meth)acrylate monomer (β1) as a main structural unit,
The homopolymer of the monomer (α1) has a glass transition temperature of more than 50° C. and 180° C. or less,
A block copolymer (A1) in which a homopolymer of the monomer (β1) has a glass transition temperature of −100° C. or more and 50° C. or less.
(A2): a polymer chain (a2) having a (meth)acrylate-based monomer (α2) as a main structural unit;
A graft copolymer having a polymer chain (b2) having a (meth)acrylate monomer (β2) as a main structural unit,
The homopolymer of the monomer (α2) has a glass transition temperature of more than 30° C. and 180° C. or less,
A graft copolymer (A2) in which the homopolymer of the monomer (β2) has a glass transition temperature of −100° C. or more and 30° C. or less.
(A3): a block (a3) having a styrene-based monomer (α3) as a main structural unit;
A block (b3) whose main structural unit is one or more monomers (β3) selected from an alkene-based monomer, a diene-based monomer, and an alkyne-based monomer, or a (meth)acrylate-based monomer (β4) as a main A block copolymer having a block (b4) as a structural unit,
A block copolymer (A3) in which the homopolymer of the (meth)acrylate monomer (β4) has a glass transition temperature of −100° C. or more and 50° C. or less.

In one embodiment of the composition, the compatible compound (B) has a viscosity of 0.001 Pa·s or more and 10 Pa·s or less at 25°C.

In one embodiment of the composition, the filler (C) contains one or more selected from the group consisting of inorganic fillers, metal particles, and coated metal particles.

In one embodiment of the composition, the coated metal particles are coated with 2.5 to 5.2 particles/nm ² of one or more selected from aliphatic carboxylic acids and aliphatic aldehydes on the surfaces of the metal core particles. Density coated particles.

In one embodiment of the composition, the compatible compound (B) has a molecular weight of 500 or less.

ADVANTAGE OF THE INVENTION According to this invention, the composition which can disperse a filler for a long time can be provided.

Each embodiment of the composition according to the present invention will be described below.
In the present invention, the term "liquid-gel state transition temperature (Tc)" (hereinafter sometimes simply referred to as Tc) represents the temperature at which the storage modulus G' equals the loss modulus G''.
Moreover, in the present invention, (meth)acrylate represents each of acrylate and methacrylate, and (meth)acryl represents each of acrylic and methacrylic.

[Composition]
The composition of the present embodiment is a composition containing a copolymer (A), a compatible compound (B) compatible with the copolymer (A), and a filler (C). The gel composition obtained by dissolving the copolymer (A) and the compatible compound (B) has a liquid-gel transition temperature (Tc) in the range of 0 to 150 ° C. and

The gel composition, which is a combination of the copolymer (A) and the compatible compound (B), has the property of being gel when the temperature is lower than the Tc temperature and becoming liquid when heated to the Tc temperature or higher. Therefore, the filler (C) can be uniformly dispersed by heating to Tc or higher. Then, by cooling after dispersion, the gel composition is gelled while the filler (C) is uniformly dispersed. As a result, sedimentation of the filler is suppressed, and uniform dispersion of the filler (C) is maintained even after long-term storage.

In the present invention, the gel composition is a physical gel that undergoes a thermoreversible phase transition in the range of 0-150°C. When Tc is 0 to 150° C., it is easy to take advantage of the liquid-to-gel state transition property of the gel composition. Among them, Tc is preferably 10 to 100°C, more preferably 20 to 90°C, even more preferably 30 to 80°C.
The Tc of the gel composition and the Tc of the composition of the present invention in which the filler (C) is added to the gel composition are substantially the same. Therefore, the Tc of the entire composition of the present invention is also preferably within the above temperature range.

The composition of the present embodiment contains at least a copolymer (A), a compatible compound (B), and a filler (C), and may further contain other components within a range that does not impair the effects of the present invention. good. Each component that can be contained in the composition will be described in detail below.

<Copolymer (A)>
In the present embodiment, the copolymer (A) is compatible with a compatible compound (B) described later to form a physical gel with a Tc of 0 to 150°C.
Hereinafter, three examples of (A1), (A2) and (A3) will be given for such a copolymer (A) and will be specifically described, but the copolymer (A) in the present invention is limited to these. not to be For convenience, the gel composition containing copolymers (A1), (A2) or (A3) may be referred to in this order as gel composition (X1), (X2) or (X3).

1. Copolymer (A1)
The first copolymer (A1) constituting the gel composition (X1) is
a block (a1) having a (meth)acrylate-based monomer (α1) as a main structural unit;
A block copolymer having a block (b1) having a (meth)acrylate monomer (β1) as a main structural unit,
A block copolymer in which the homopolymer of the monomer (α1) has a glass transition temperature of more than 50° C. and is 180° C. or less, and the glass transition temperature of the homopolymer of the monomer (β1) is −100° C. or more and 50° C. or less. is.

A preferred embodiment of the copolymer (A1) is a “block copolymer compound” described in JP-A-2017-66368. Descriptions of portions that overlap with the description in JP-A-2017-66368 will be omitted as appropriate.
In addition, "polymer block a mainly composed of (meth)acrylate units" in JP-A-2017-66368 is changed to "block (a1) mainly composed of (meth)acrylate monomer (α1)". Correspondingly, "polymer block b mainly composed of (meth)acrylate units" corresponds to "block (b1) mainly composed of (meth)acrylate monomer (β1)".

The monomer (α1) and the monomer (β1) are, for example, alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, lauryl (meth)acrylate; Alkoxyalkyl (meth)acrylates such as acrylates; 2-hydroxyethyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, hydroxyalkyl (meth)acrylates; aromatics such as benzyl (meth)acrylate and phenyl (meth)acrylate (meth) acrylate; ethylene glycol di (meth) acrylate, di (meth) acrylate of diethylene glycol di (meth) acrylate; alicyclic structure-containing (meth) acrylate such as dicyclopentenyloxyethyl (meth) acrylate; acryloyl morpholine, Among (meth)acrylamides such as methacryloylmorpholine, dimethyl(meth)acrylamide, and diethyl(meth)acrylamide, a homocopolymer having a predetermined glass transition temperature can be selected and used. For the glass transition temperature of the homocopolymer, reference can be made to literature values.
As the monomer (α1), for example, methyl methacrylate whose homopolymer has a glass transition temperature of 140° C. can be used.
As the monomer (β1), for example, butyl acrylate whose homocopolymer has a glass transition temperature of −25° C. can be used.

The block (a1) is a block having the monomer (α1) as a main structural unit, and may contain a monomer that does not correspond to the monomer (α1) as long as the effect of the present invention is not impaired. Specifically, the proportion of the monomer (α1) constituting the block (a1) is preferably 90 mol% or more, more preferably 95 mol% or more, and further preferably 99 mol% or more. more preferred. When two or more monomers satisfying the glass transition temperature of a homopolymer of more than 50° C. and 180° C. or less are included as the monomers constituting the block (a1), any of the monomers shall be treated as the monomer (α1). . The weight average molecular weight of the block (a1) is preferably 1×10 ⁵ or more, more preferably 1×10 ⁵ or more and 1×10 ⁹ or less, and 1×10 ⁵ or more and 1×10 ⁷ or less. is even more preferred.

Further, the block (b1) is a block having the monomer (β1) as a main structural unit, and may contain a monomer that does not correspond to the monomer (β1) within a range that does not impair the effects of the present invention. Specifically, the proportion of the monomer (β1) constituting the block (b1) is preferably 90 mol% or more, more preferably 95 mol% or more, and further preferably 99 mol% or more. more preferred. When two or more monomers satisfying the glass transition temperature of a homopolymer of -100° C. or higher and 50° C. or lower are included as the monomers constituting the block (b1), any of the monomers shall be treated as the monomer (β1). do. The weight average molecular weight of the block (b1) is preferably 1×10 ⁵ or more, more preferably 1×10 ⁵ or more and 1×10 ⁹ or less, and 1×10 ⁵ or more and 1×10 ⁷ or less. is even more preferred.

The block configuration of the copolymer (A1) can be any configuration such as block (a1)-(b1) or block (b1)-(a1)-(b1). Among them, the copolymer (A1) is preferably a triblock copolymer of blocks (a1)-(b1)-(a1) in view of the liquid-gel transition of the gel composition (X1).

From the viewpoint of liquid-gel state transition property, the mass ratio (a1/b1) of block (a1) and block (b1) is preferably 5 to 95/95 to 5, more preferably 10 to 90/90 to 10, It is more preferably 15-85/85-15.

Further, from the viewpoint of liquid-gel state transition property, the weight average molecular weight of the copolymer (A1) is preferably 8,000 to 300,000, more preferably 15,000 to 280,000, still more preferably 30,000 to 250,000.

Further, the copolymer (A1) has a radical-reactive group, a cation-reactive group, an anion-reactive group, or a It may have at least one or more functional groups selected from the group consisting of groups and moisture-reactive groups.

As the copolymer (A1), for example, a commercially available product "KURARITY" (registered trademark, manufactured by Kuraray Co., Ltd.) may be used. Examples of the copolymer (A1) include LA2140, LA2250, LA4285, LA2330, LA3270, LA1114, LA1892 (manufactured by Kuraray Co., Ltd.).

2. Copolymer (A2)
The second copolymer (A2) constituting the gel composition (X2) is
a polymer chain (a2) having a (meth)acrylate-based monomer (α2) as a main structural unit;
A graft copolymer having a polymer chain (b2) having a (meth)acrylate monomer (β2) as a main structural unit,
The glass transition temperature of the homopolymer of the monomer (α2) is higher than 30° C. and 180° C. or lower, and the glass transition temperature of the homopolymer of the monomer (β2) is -100° C. or higher and 30° C. or lower. It is a coalescence.

A preferred embodiment of the copolymer (A2) is a “block copolymer compound” described in JP-A-2018-76496. Descriptions of portions that overlap with the description in JP-A-2018-76496 will be omitted as appropriate.
In JP-A-2018-76496, "polymer block a mainly composed of (meth)acrylate units" is "polymer chain (a2) mainly composed of (meth)acrylate monomer (α2)". and "polymer block b mainly composed of (meth)acrylate units" corresponds to "polymer chain (b2) composed mainly of (meth)acrylate monomer (β2)".

The monomer (α2) and the monomer (β2) can be appropriately selected and used from (meth)acrylate monomers satisfying the above conditions. Specific examples of the monomer include those exemplified for the copolymer (A1).
Examples of the monomer (α2) include methacrylate, methyl methacrylate and the like.
Examples of the monomer (β2) include butyl acrylate, ethyl acrylate, lauryl acrylate and the like.

The polymer chain (a2) is a polymer chain having the monomer (α2) as a main structural unit, and may contain a monomer that does not correspond to the monomer (α2) within a range that does not impair the effects of the present invention. Specifically, the proportion of the monomer (α2) constituting the polymer chain (a2) is preferably 90 mol% or more, more preferably 95 mol% or more, and preferably 99 mol% or more. Even more preferred. In addition, when two or more monomers satisfying the glass transition temperature of a homopolymer of more than 30° C. and 180° C. or less are included as the monomers constituting the polymer chain (a2), any of the monomers shall be treated as the monomer (α2). do. The weight average molecular weight of the polymer chain (a2) is preferably 1×10 ⁵ or more, more preferably 1×10 ⁵ or more and 1×10 ⁹ or less, and 1×10 ⁵ or more and 1×10 ⁷ or less. is even more preferred.

In addition, the polymer chain (b2) is a polymer chain having the monomer (β2) as a main constituent unit, and may contain a monomer that does not correspond to the monomer (β2) as long as the effect of the present invention is not impaired. . Specifically, the proportion of the monomer (β2) constituting the polymer chain (b2) is preferably 90 mol% or more, more preferably 95 mol% or more, and preferably 99 mol% or more. Even more preferred. In addition, when two or more monomers satisfying the glass transition temperature of the homopolymer of -100°C or higher and 30°C or lower are included as the monomers constituting the polymer chain (b2), any of the monomers are treated as the monomer (β2). and The weight average molecular weight of the polymer chain (b2) is preferably 1×10 ⁵ or more, more preferably 1×10 ⁵ or more and 1×10 ⁹ or less, and 1×10 ⁵ or more and 1×10 ⁷ or less. is even more preferred.

The copolymer (A2) may be a graft copolymer having the polymer chain (a2) as a main chain and the polymer chain (b2) as a side chain. It may be a graft copolymer having a chain (a2). Among them, it is preferable that the main chain is the polymer chain (b2) and the side chain is the polymer chain (a2).

The polymer chains constituting the side chains preferably have a number average molecular weight of 3,000 to 100,000, more preferably 5,000 to 50,000 by GPC, from the viewpoint of liquid-gel state transition.
Further, the polymer chain constituting the main chain preferably has a number average molecular weight of 5,000 to 200,000, preferably 10,000 to 150,000 by GPC method from the viewpoint of liquid-gel state transition.

From the viewpoint of liquid-gel transition property, the mass ratio (a2/b2) of the polymer chain (a2) and the polymer chain (b2) is preferably 5 to 95/95 to 5, more preferably 10 to 90/90 to 10, more preferably 15-85/85-15.

Further, from the viewpoint of liquid-gel state transition property, the weight average molecular weight of the copolymer (A2) is preferably 8,000 to 300,000, more preferably 15,000 to 280,000, still more preferably 30,000 to 250,000.

Further, the copolymer (A2) has a radical-reactive group, a cation-reactive group, an anion-reactive group, or a It may have at least one or more functional groups selected from the group consisting of groups and moisture-reactive groups.

The copolymer (A2) can be obtained, for example, by the production methods described in JP-A-5-170838 and JP-A-6-234822. NB5015, NB5065, NB5066, NB5073, and NB5088 manufactured by Mitsubishi Rayon Co., Ltd. (all of which are graft copolymers having butyl acrylate as the main chain and methyl methacrylate as the side chain) may also be used.

3. Copolymer (A3)
The first copolymer (A3) constituting the gel composition (X3) is
a block (a3) having a styrene-based monomer (α3) as a main structural unit;
A block (b3) whose main structural unit is one or more monomers (β3) selected from alkene-based monomers, diene-based monomers, and alkyne-based monomers, or
A block copolymer having a block (b4) having a (meth)acrylate monomer (β4) as a main structural unit,
A block copolymer (A3) in which the homopolymer of the (meth)acrylate monomer (β4) has a glass transition temperature of −100° C. or more and 50° C. or less.

A preferred embodiment of the copolymer (A3) is a “block copolymer compound” described in JP-A-2018-80330. Descriptions of portions that overlap with the description in JP-A-2018-80330 will be omitted as appropriate.
In addition, "polymer block a mainly composed of styrene-based compound units" in JP-A-2018-80330 corresponds to "block (a3) composed mainly of styrene-based monomer (α3)", and " Polymer block b ₁ mainly composed of units of at least one hydrocarbon-based compound selected from the group consisting of alkene-based compounds, diene-based compounds and alkyne-based compounds Corresponding to the block (b3) whose main structural unit is one or more monomers (β3) selected from the system monomers, the “polymer block b ₂ mainly composed of meth)acrylate units” corresponds to “(meth) ) corresponds to the block (b4) having the acrylate-based monomer (β4) as the main structural unit.

Monomers (α3) include styrene and styrene derivatives, specifically styrene; α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 1,3-dimethylstyrene, 4-tert -alkyl group-substituted styrenes such as butylstyrene and 4-hexylstyrene; hydroxyl group-substituted styrenes such as p-hydroxystyrene; alkoxy group-substituted styrenes such as p-methoxystyrene and 4-tert-butoxystyrene; amino group-substituted styrene; and halogen-substituted styrene such as 4-chlorostyrene and 4-bromostyrene.

Examples of alkene-based monomers in the monomer (β3) include ethylene and propylene. Examples of diene-based monomers include butadiene and isoprene. Moreover, acetylene etc. are mentioned as an alkyne-type monomer.

The monomer (β4) can be appropriately selected from among (meth)acrylate monomers and used. Specific examples of the monomer include those exemplified for the copolymer (A1).

The block (a3) is a block containing the monomer (α3) as a main structural unit, and may contain a monomer that does not correspond to the monomer (α3) within a range that does not impair the effects of the present invention. Specifically, the proportion of the monomer (α3) constituting the block (a3) is preferably 90 mol% or more, more preferably 95 mol% or more, and further preferably 99 mol% or more. more preferred. The weight average molecular weight of the block (a3) is preferably 1×10 ⁵ or more, more preferably 1×10 ⁵ or more and 1×10 ⁹ or less, and 1×10 ⁵ or more and 1×10 ⁷ or less. is even more preferred.

The block (b3) is a block having the monomer (β3) as a main constituent unit, and may contain a monomer other than the monomer (β3) as long as the effect of the present invention is not impaired. Specifically, the proportion of the monomer (β3) constituting the block (b3) is preferably 90 mol% or more, more preferably 95 mol% or more, and further preferably 99 mol% or more. more preferred. The weight average molecular weight of the block (b3) is preferably 1×10 ⁵ or more, more preferably 1×10 ⁵ or more and 1×10 ⁹ or less, and 1×10 ⁵ or more and 1×10 ⁷ or less. is even more preferred.

Further, the block (b4) is a block having the monomer (β4) as a main constituent unit, and may contain a monomer that does not correspond to the monomer (β4) within a range that does not impair the effects of the present invention. Specifically, the proportion of the monomer (β4) constituting the block (b4) is preferably 90 mol% or more, more preferably 95 mol% or more, and further preferably 99 mol% or more. more preferred. The weight average molecular weight of the block (b4) is preferably 1×10 ⁵ or more, more preferably 1×10 ⁵ or more and 1×10 ⁹ or less, and 1×10 ⁵ or more and 1×10 ⁷ or less. is even more preferred.

The block configuration of the copolymer (A3) is any configuration such as block (a3)-(b3) or (b4), block (b3)/(b4)-(a3)-(b3)/(b4), etc. be able to. Among them, the copolymer (A3) is preferably a triblock copolymer of blocks (a3)-(b3)-(a3) in view of the liquid-gel transition of the gel composition (X1).

From the viewpoint of liquid-gel state transition property, the mass ratio (a3/b3) of block (a3) and block (b3) is preferably 5 to 95/95 to 5, more preferably 10 to 90/90 to 10, It is more preferably 15-85/85-15.

Further, from the viewpoint of liquid-gel state transition property, the weight average molecular weight of the copolymer (A3) is preferably 8,000 to 300,000, more preferably 15,000 to 280,000, still more preferably 30,000 to 250,000.

Further, the copolymer (A3) has a radical-reactive group, a cation-reactive group, an anion-reactive group, or a It may have at least one or more functional groups selected from the group consisting of groups and moisture-reactive groups.

Examples of the copolymer (A3) having block (a3) and block (b3) include Hipler and Septon manufactured by Kuraray; Kraton, manufactured by Kraton Polymer; Quintac, manufactured by Nippon Zeon; mentioned.

<Compatible compound (B)>
In the present embodiment, the compatible compound (B) is compatible with the copolymer (A) to form a physical gel having a Tc of 0 to 150°C.

The composition ratio of the copolymer (A) and the compatible compound (B) in the gel composition is the same from the viewpoint of the coatability to members in the liquid state, the adhesiveness between the members in the gel state, and the phase transition property. The compatibilizing compound (B) is preferably 200 parts by mass or more and 1000 parts by mass or less, more preferably 250 parts by mass or more and 800 parts by mass or less with respect to 100 parts by mass of the polymer (A).

The compatible compound (B) is not particularly limited as long as it satisfies the conditions described above. agent or solvent.
When a monomer is used for the compatible compound (B), methyl (meth) acrylate, ethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t - alkyl (meth)acrylates such as butyl (meth)acrylate, lauryl (meth)acrylate; alkoxy-substituted alkyl (meth)acrylates such as methoxyethyl (meth)acrylate; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl ( hydroxy-substituted alkyl (meth)acrylates such as meth)acrylate and 2-hydroxybutyl (meth)acrylate; aromatic (meth)acrylates such as benzyl (meth)acrylate and phenyl (meth)acrylate; ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1 ,6-hexanediol di(meth)acrylate; 4-tert-butylcyclohexyl acrylate, dicyclopentenyloxyethyl (meth)acrylate, norbornene (meth)acrylate, dicyclopentanyl (meth)acrylate , alicyclic structure-containing (meth)acrylates such as isobornyl (meth)acrylate; (meth)acryloylmorpholine, (meth)acrylamides such as diethyl (meth)acrylamide; at least one or more monomers selected from the group consisting of Preferably, at least one or more monomers selected from isodecyl acrylate, 4-hydroxybutyl acrylate, and 4-tert-butylcyclohexyl acrylate are more preferably used.

From the viewpoint of improving the strength, elasticity and adhesiveness of the gel composition, the compatible compound (B) is selected from the group consisting of radical-reactive groups, cation-reactive groups, anion-reactive groups, and moisture-reactive groups. It is preferred to have one or more functional groups that are

The radical reactive group is selected from the group consisting of (meth)acrylate, (meth)acrylamide, (meth)acrylonitrile, urethane (meth)acrylate, vinyl group, vinyl ether, allyl ether, maleimide, and maleic anhydride. It is preferable to use one or more reactive groups, and it is more preferable to use one or more reactive groups selected from the group consisting of (meth)acrylates, (meth)acrylamides, urethane (meth)acrylates, and vinyl ethers. Even more preferably, one or more reactive groups selected from the group consisting of (meth)acrylates and urethane (meth)acrylates are used.
As the cationic reactive group, it is preferable to use one or more reactive groups selected from the group consisting of epoxy group, oxetane and vinyl ether.
As the anion reactive group, it is preferable to use one or more reactive groups selected from the group consisting of epoxy group, oxetane and vinyl ether.
As the moisture-reactive group, it is preferable to use one or more reactive groups selected from the group consisting of isocyanate groups and alkoxysilyl groups.
In addition, when the compatible compound (B) has the radical reactive group, it is preferable that the compatible compound (B) has two or more radical reactive groups from the viewpoint of rapid progress of the radical reaction.

From the viewpoint of improving the strength, elasticity, and adhesiveness of the gel composition, the copolymer (A) and the compatible compound (B) preferably have the same functional groups. That is, when the copolymer (A) has a radical reactive group, it is preferable that the compatible compound (B) also has a radical reactive group. Moreover, when the copolymer (A) has a cationic reactive group, it is preferable that the compatible compound (B) also has a cationic reactive group. Moreover, when the copolymer (A) has an anion-reactive group, it is preferable that the compatible compound (B) also has an anion-reactive group. Moreover, when the copolymer (A) has a moisture-reactive group, it is preferable that the compatible compound (B) also has a moisture-reactive group.

From the viewpoint of improving the strength, elasticity and adhesiveness of the gel composition, the compatible compound (B) preferably contains an appropriate type of polymerization initiator according to the type of functional group it has. .
For example, when the compatible compound (B) has a radical reactive group, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 1- Hydroxy-cyclohexyl-phenyl-ketone, benzophenone, 2,2-dimethoxy-1,2-diphenylethan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-methyl-1-[4- methylthio]phenyl]-2-morpholinopropan-1-one, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether, benzoin isopropyl ether, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2-hydroxy- 2-methyl-[4-(1-methylvinyl)phenyl]propanol oligomer, 2-hydroxy-2-methyl-[4-(1-methylvinyl)phenyl]propanol oligomer, 2-hydroxy-2-methyl-1- Phenyl-1-propanone, isopropylthioxanthone, methyl o-benzoylbenzoate, [4-(methylphenylthio)phenyl]phenylmethane, 2,4-diethylthioxanthone, 2-chlorothioxanthone, ethylanthraquinone, benzophenone ammonium salt, thioxanthone ammonium salt, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, 2,4, 6-trimethylbenzophenone, 4-methylbenzophenone, 4,4′-bisdiethylaminobenzophenone, 1,4 dibenzoylbenzene, 10-butyl-2-chloroacridone, 2,2′ bis(o-chlorophenyl)4,5, 4',5'-tetrakis(3,4,5-trimethoxyphenyl)1,2'-biimidazole, 2,2'bis(o-chlorophenyl)4,5,4',5'-tetraphenyl-1 , 2'-biimidazole, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoyldiphenyl ether, acrylated benzophenone, bis(η5- 2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium, o-methylbenzoylbenzoate, p-dimethylaminobenzoic acid ethyl ester , p-dimethylaminobenzoic acid isoamylethyl ester, active tertiary amine, carbazole-phenone photoinitiator compound, acridine photoinitiator compound, and triazine photoinitiator compound 1 It is preferable to use at least one polymerization initiator, and at least one polymerization initiator selected from the group consisting of 1-hydroxy-cyclohexyl-phenyl-ketone and 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide. It is more preferable to use

Further, when the compatible compound (B) has a cationic reactive group, it consists of an aryldiazonium salt, a diarylhalonium salt, a triarylsulfonium salt, a triphosphonium salt, an iron allene complex, a titanocene complex, and an arylsilanol aluminum complex. one or more ionic photoacid generator compounds selected from the group; and selected from the group consisting of nitrobenzyl esters, sulfonic acid derivatives, phosphate esters, phenol sulfonate esters, diazonaphthoquinones, and N-hydroxyimide sulfonates. It is preferable to use one or more polymerization initiators selected from the group consisting of one or more nonionic photoacid generator compounds.

Further, when the compatible compound (B) has an anion-reactive group, 1,10-diaminodecane, 4,4′-trimethylenedipiperazine, carbamate compounds and derivatives thereof, cobalt-amine complex compounds, amino It is preferable to use one or more polymerization initiators selected from the group consisting of oximino compounds and ammonium borate compounds.

Further, when the compatible compound (B) has a moisture-reactive group, one selected from the group consisting of tetrabutyl titanate, tetrapropyl titanate, titanium tetraacetylacetonate, and bisacetylacetonatodiisopropoxytitanium Dibutyltin dilaurate, dibutyltin maleate, dibutyltin phthalate, dibutyltin dioctate, dibutyltin diethylhexanolate, dibutyltin dimethyl maleate, dibutyltin diethyl maleate, dibutyltin dibutyl maleate, dibutyltin dioctyl maleate , dibutyltin ditridecyl maleate, dibutyltin dibenzyl maleate, dibutyltin diacetate, dioctyltin diethyl maleate, dioctyltin dioctyl maleate, dibutyltin dimethoxide, dibutyltin dinonylphenoxide, dibutenyltin oxide, dibutyltin diacetyl one or more organotin compounds selected from the group consisting of acetonate, dibutyltin diethylacetoacetonate, a reaction product of dibutyltin oxide and a silicate compound, and a reaction product of dibutyltin oxide and a phthalate ester; aluminum tris One or more organoaluminum compounds selected from the group consisting of acetylacetonate, aluminum trisethylacetoacetate, and diisopropoxyaluminum ethylacetoacetate; zirconium compounds such as zirconium tetraacetylacetonate; amine compounds; acidic phosphoric acid ester; reaction product of acidic phosphoric acid ester and amine compound; saturated or unsaturated polyvalent carboxylic acid or acid anhydride thereof; salt of carboxylic acid compound and amine compound; lead octylate; silanol condensation catalyst; It is preferable to use one or more polymerization initiators selected from the group consisting of isocyanate reaction catalysts.

As the isocyanate reaction catalyst, one or more amine compounds selected from the group consisting of triethylamine, benzylmethylamine, N,N',N'-trimethylaminoethylpiperazine, triethylenediamine and dimethylethanolamine; triethylphosphine, etc. trialkylphosphine compounds; one or more organotin compounds selected from the group consisting of dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin diacetate, tin octoate and dibutyltin diethylhexanolate; di(2-ethylhexanoic acid ) lead; lead naphthenate; copper naphthenate; and cobalt naphthenate.

When a plasticizer is used for the compatible compound (B), phthalates such as dibutyl phthalate, diisononyl phthalate, diheptyl phthalate, di(2-ethylhexyl) phthalate, diisodecyl phthalate, and butylbenzyl phthalate; dioctyl adipate, adipine polyvalent carboxylic acid esters such as diisononyl acid, dioctyl sebacate, diisononyl sebacate, and diisononyl 1,2-cyclohexanedicarboxylate; alkyl benzoates; phosphate esters such as tricresyl phosphate and tributyl phosphate; Rubber polymers such as (hydrogenated) polyisoprene, hydroxyl-containing (hydrogenated) polyisoprene, (hydrogenated) polybutadiene, hydroxyl-containing (hydrogenated) polybutadiene, polybutene; thermoplastic elastomers; petroleum resins; alicyclic saturated hydrocarbons Resins; terpene resins such as terpene resins, terpene phenol resins, modified terpene resins, and hydrogenated terpene resins; rosin resins such as rosin phenol; disproportionated rosin ester resins, polymerized rosin ester resins, and hydrogenated rosin Rosin ester resins such as ester resins; xylene resins; and acrylic resins such as acrylic polymers and acrylic copolymers; and rosin ester-based resins.

When using a solvent for the compatible compound (B), alcohols such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, benzyl alcohol; benzene, toluene, xylene, mineral spirits, cyclohexane, n-hexane , methylcyclohexane, hydrocarbons such as styrene; ethers such as diethyl ether; esters such as ethyl acetate, propyl acetate, butyl acetate, diethylene glycol monoethyl ether acetate, diethyl carbonate, dimethyl carbonate, propylene carbonate; acetone, methyl ethyl ketone, ketones such as methyl isobutyl ketone, diisobutyl ketone and diacetone alcohol; nitrogens such as N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone; butyl glycol, methyl diglycol, butyl diglycol, 3 Glycol ethers such as methyl-3-methoxybutanol and tetrahydrofuran; chlorines such as methylene chloride, chloroform, carbon tetrachloride and chlorobenzene; dimethylsulfoxide; acetonitrile; carboxylic acids such as formic acid and acetic acid; It is preferable to use one or more solvents selected from, more preferably one or more solvents selected from the group consisting of alcohols, hydrocarbons, esters, and ketones, acetone, hexane , isopropyl alcohol, and diethyl carbonate.

The compatible compound (B) is a compound in which the gel composition with the copolymer (A) has fluidity. ) to form a gel composition having a Tc between 0 and 150°C. In some cases, the copolymer (A) is dissolved in the compound B to form a solution. In such a case, the compatibilizing compound (B) is a medium of the gel composition when Tc is in the range of 0 to 150°C, and a solvent of the gel composition when Tc is less than 0°C. It will be.

The solvent in the present invention can be said to be a compound in which the Tc of the mixed composition of the solvent and the gel composition becomes less than 0° C. when the amount of the solvent exceeds a certain amount. Therefore, even if the radically polymerizable unsaturated bond-containing monomer or plasticizer is used, the Tc of the mixed composition becomes less than 0° C. when the amount of the radically polymerizable unsaturated bond-containing monomer or plasticizer exceeds a certain amount. If so, they can be considered solvents in the context of the present invention.

The viscosity of the compatible compound (B) is preferably 0.001 Pa s or more and 10 Pa s or less, and more preferably 0.001 Pa s or more and 1 Pa s or less, from the viewpoint that the gel composition can be easily produced. is more preferable, and 0.001 Pa·s or more and 0.5 Pa·s or less is even more preferable. In addition, if the compatible compound (B) has the above viscosity at the liquid-gel transition temperature (Tc) or higher of the gel composition, it has a high viscosity below the liquid-gel transition temperature (Tc). or solid. For example, when the compatibilizing compound (B) is an oligomer or the like, it may be highly viscous or solid in an environment at a temperature lower than the temperature Tc. Even in this case, the compatibilizing compound (B) becomes less viscous in an environment at a temperature higher than the temperature Tc, dissolves in other compatibilizing compounds (B) with low viscosity, or dissolves in solvents. Therefore, by combining these and kneading with the copolymer (A), a gel composition can be produced.

Moreover, the molecular weight of the compatible compound (B) is preferably 500 or less, more preferably 450 or less, from the viewpoint of excellent compatibility with the copolymer (A). When the molecular weight of the compatible compound (B) is 500 or less, the compatible compound (B) easily enters between the copolymers (A), and the copolymer (A) and the compatible compound (B) are compatible with each other.

When the gel composition is used as an adhesive composition to be described later, the viscosity of the liquid gel composition should be 0.1 Pa s or more and 100 Pa s or less from the viewpoint of applicability to members. , more preferably 0.3 Pa·s or more and 50 Pa·s or less, and even more preferably 0.5 Pa·s or more and 10 Pa·s or less. The viscosities of the compatible compound (B) and the gel composition can be measured under the measurement conditions described in Examples.

(Gel composition)
In the present embodiment, the gel composition can be obtained by mixing the copolymer (A) and the compatible compound (B).

The gel composition is a liquid that naturally flows when 0.01 g or more is dropped onto a horizontal glass plate under atmospheric pressure at a temperature Tc or higher, but at a temperature lower than the temperature Tc, it flows horizontally under atmospheric pressure. It is a gel-like material that does not flow even when 0.01 g or more is left still on a glass plate.

The gel composition reversibly changes into a gel state and a liquid state at temperatures around the temperature Tc.

The temperature Tc is preferably 10 to 100° C., more preferably 20 to 90° C., and even more preferably 30 to 80°C.

The temperature Tc can be set to a high temperature side by forming the blocks (a1), (a2), and (a3) from monomers having a high Tg, or by reducing the blending ratio of the compatible compound (B). On the other hand, the temperature Tc can be set to the low temperature side by configuring the blocks (a1), (a2), and (a3) with monomers having a low Tg or by increasing the blending ratio of the compatible compound (B).

For example, when the composition is used as an adhesive composition to be described later, a liquid composition at a temperature higher than the temperature Tc is applied on the member, the members are laminated via the composition, and the temperature is lower than the temperature Tc. Then, the members are stably adhered to each other through the gel-like composition, but when the temperature is again raised above the temperature Tc, the composition changes from the gel-like state to the liquid state, so that the members are easily separated from each other. can be

<Filler (C)>
Particles having any function can be used as the filler (C) used in the present embodiment. Examples of the particles include particles having electrical conductivity and thermal conductivity. The particles are dispersed in the gel composition described above. The filler (C) can contain, for example, one or more selected from the group consisting of inorganic fillers, metal particles, and coated metal particles. Above all, from the viewpoint of stability and dispersibility, the filler (C) is preferably coated metal particles.

The ratio of the filler (C) to the total of the copolymer (A) and the compatible compound (B) is determined from the viewpoint of the applicability to the member in the liquid state, the adhesiveness between the members in the gel state, and the phase transition property. , It is preferable that the filler (C) is 5 parts by mass or more and 60 parts by mass or less, and 10 parts by mass or more and 50 parts by mass with respect to a total of 100 parts by mass of the copolymer (A) and the compatible compound (B). It is more preferably 15 parts by mass or more and 40 parts by mass or less.

From the viewpoint of dispersibility, the average primary particle size of the filler (C) is preferably 100 µm or less, more preferably 50 µm or less, and even more preferably 20 µm or less. From the viewpoint of imparting physical properties, the average primary particle size of the filler (C) is preferably 1 nm or more, more preferably 5 nm or more, and even more preferably 20 nm or more.

When an inorganic filler is used as the filler (C), silica, fumed silica, precipitated silica, asbestos powder, copper oxide, copper hydroxide, iron oxide, alumina, zinc oxide, lead oxide, magnesia, tin oxide, etc. It is preferable to appropriately select and use one or more kinds from metal oxide particles and inorganic fine particles such as calcium carbonate, carbon, silica, mica, smectite, and carbon black.

When metal particles are used as the filler (C), their materials include gold, silver, copper, platinum, aluminum, iron, chromium, tin, nickel, zinc, lead, indium, bismuth, germanium, antimony, cobalt, and palladium. , rhodium, molybdenum, tungsten, titanium, zirconium, gallium, arsenic, boron, silicon, and alloys thereof. The material of the metal particles is preferably a metal that exhibits conductivity after sintering, more preferably gold, silver, or copper, and even more preferably silver or copper. By using these metals, the metal particle dispersion liquid of the present embodiment can be applied to, for example, printing of electronic circuits. Moreover, since the coated metal particles used in the present embodiment are excellent in oxidation resistance, copper can be suitably used as the metal particles. When there are a plurality of coated metal particles, each metal particle contained may be the same or different.

When coated metal particles are used as the filler (C), it is preferable to use organic-coated metal particles in which the surface of the metal core particles is coated with organic molecules, or oxide-coated metal particles in which the surface of the metal core particles is coated with an oxide film. . Materials for metal core particles include gold, silver, copper, platinum, aluminum, iron, chromium, tin, nickel, zinc, lead, indium, bismuth, germanium, antimony, cobalt, palladium, rhodium, molybdenum, tungsten, titanium, It is preferable to appropriately select and use one or more metals from among zirconium, gallium, arsenic, boron, silicon, and alloys thereof. The material of the metal core particles is preferably a metal that exhibits conductivity after sintering, more preferably gold, silver, or copper, and even more preferably silver or copper. By using these metals, the metal particle dispersion liquid of the present embodiment can be applied to, for example, printing of electronic circuits. Moreover, since the coated metal particles used in the present embodiment are excellent in oxidation resistance, copper can be suitably used as the metal core particles. When there are a plurality of coated metal particles, each contained metal core particle may be the same or different.

Among them, when coated metal particles are used as the filler (C), the surfaces of the metal core particles (C1) are coated with one or more coating molecules (C2) selected from aliphatic carboxylic acids and aliphatic aldehydes. (hereinafter sometimes referred to as coated metal particles (C0)). The coating molecule (C2) usually forms a monomolecular film by adsorbing the hydrophilic group side to the surface of the metal core particle (C1). Therefore, it is presumed that the surface of the metal core particles (C1) is protected by the coating molecules (C2) to suppress oxidation and have high oxidation resistance. For example, in the coated silver particles using silver core particles as the metal core particles (C1), the content ratio of silver oxide and silver hydroxide two months after production was determined to be 100% of the silver core particles in the coated silver particles. It is also possible to suppress it to 5 mass % or less with respect to mass %. The generation of metal oxide in the coated metal particles (C0) can be confirmed by X-ray diffraction (XRD) measurement of the coated metal particles (C0).

Moreover, since it is presumed that the coating molecules (C2) are bound to the metal core particles (C1) by physical adsorption or the like, they are thought to diffuse and desorb at a relatively low temperature. Therefore, the surface of each metal core particle (C1) is easily exposed by heating, and the surfaces of the metal core particles (C1) can be brought into contact with each other. Are better.

1. Metal core particles (C1)
From the viewpoint of low-temperature sinterability and dispersibility, the average primary particle size of the metal core particles (C1) used in the present embodiment is preferably less than 300 nm, more preferably 250 nm or less, and 200 nm or less. It is even more preferred to have The average primary particle size of the metal core particles (C1) is usually 1 nm or more, preferably 5 nm or more, and more preferably 20 nm or more. The average primary particle size of the metal core particles (C1) is the arithmetic mean value of the primary particle sizes of arbitrary 20 metal particles observed with a scanning electron microscope (SEM).

Materials of the metal core particles (C1) include, for example, gold, silver, copper, platinum, aluminum, iron, chromium, tin, nickel, zinc, lead, indium, bismuth, germanium, antimony, cobalt, palladium, rhodium, molybdenum, At least one of tungsten, titanium, zirconium, gallium, arsenic, boron, silicon, and alloys thereof can be appropriately selected and used. In addition, the material of the metal core particles (C1) is preferably a metal that exhibits conductivity after sintering, more preferably gold, silver, or copper, and more preferably silver or copper. more preferred. By using these metals, the metal particle dispersion liquid of the present embodiment can be applied to, for example, printing of electronic circuits. Moreover, since the coated metal particles (C0) used in the present embodiment are excellent in oxidation resistance, copper can be suitably used as the metal core particles (C1). When there are a plurality of coated metal particles (C0), each contained metal core particle (C1) may be the same or different.

The metal core particles (C1) may contain metal oxides, metal hydroxides, and other impurities within a range that does not impair the effects of the present invention. From the viewpoint of conductivity, the content of the metal oxide and metal hydroxide is preferably 5% by mass or less, more preferably 3% by mass or less, relative to the metal core particles (C1). % or less is even more preferable. From the viewpoint of conductivity, the metal content in the metal core particles (C1) is preferably 95% by mass or more, more preferably 97% by mass or more, and 99% by mass or more. is even more preferred.

The shape of the metal core particles (C1) can be appropriately selected depending on the application. The shape includes a substantially spherical shape including a true spherical shape, a plate-like shape, a rod-like shape, etc. Among them, a substantially spherical shape is preferable. According to the method for producing coated metal particles (C0) described later, substantially spherical metal core particles (C1) that can be approximated to a spherical shape can be obtained. The particle size of the coated metal particles (C0) can be determined by SEM observation.

2. Coating molecule (C2)
Aliphatic carboxylic acid In the present embodiment, the aliphatic carboxylic acid is used alone or in combination with an aliphatic aldehyde to be described later to coat the surface of the metal core particles (C1) to prevent oxidation of the metal core particles (C1). Suppress. Moreover, during sintering, the aliphatic carboxylic acid is easily removed from the surface of the metal core particles (C1), decomposed, or volatilized, so that it is suppressed from remaining in the sintered body. Thereby, a conductor having excellent electrical conductivity can be obtained.

Aliphatic carboxylic acid is a compound having a structure in which one or more carboxy groups are substituted on an aliphatic compound. The carboxy group of the acid is placed. In this embodiment, a structure in which one carboxy group is substituted on an aliphatic compound, that is, a compound having an aliphatic hydrocarbon group and one carboxy group is preferable.

The aliphatic hydrocarbon group that constitutes the aliphatic carboxylic acid is a hydrocarbon group having a linear, branched or cyclic structure, and may have an unsaturated bond. In the present embodiment, it is preferable to use a straight-chain aliphatic hydrocarbon group that does not have a branched or cyclic structure because it facilitates the formation of a monomolecular film with a predetermined density on the surface of the metal core particle (C1). The unsaturated bond may be a double bond or a triple bond, but is preferably a double bond. Further, when the aliphatic hydrocarbon group has an unsaturated bond, the number is preferably 1 to 3 in one molecule, more preferably 1 to 2, more preferably 1. preferable.

In the present embodiment, the aliphatic carboxylic acid preferably has a carboxy group at the terminal of the linear aliphatic hydrocarbon group. By making the aliphatic hydrocarbon group have a straight chain structure, the affinity between the coated metal particles (C0) and the gel composition can be enhanced, and the dispersibility of the coated metal particles (C0) can be improved. In the aliphatic carboxylic acid, the number of carbon atoms in the aliphatic group is preferably 3 or more, more preferably 5 or more, and even more preferably 7 or more. When the number of carbon atoms is 3 or more, the oxidation resistance of the coated metal particles (C0) and the affinity with the gel composition can be improved. On the other hand, the number of carbon atoms in the aliphatic group is preferably 17 or less, more preferably 16 or less, and even more preferably 11 or less. When the number of carbon atoms is 17 or less, it is easily removed during sintering of the coated metal particles (C0), and a conductor having excellent electrical conductivity can be obtained. In this embodiment, the number of carbon atoms in the aliphatic group does not include the carbon atoms forming the carboxy group.

Specific examples of preferred aliphatic carboxylic acids include butyric acid, caproic acid, caprylic acid, pelargonic acid, stearic acid, palmitoleic acid, oleic acid, vaccenic acid, linoleic acid and linolenic acid. An aliphatic carboxylic acid can be used individually by 1 type or in combination of 2 or more types.

- Aliphatic aldehyde In the present embodiment, an aliphatic aldehyde can be placed on the surface of the metal core particles (C1) in place of the aliphatic carboxylic acid or in combination with the aliphatic carboxylic acid. Even in this case, coated metal particles (C0) capable of forming a conductor with excellent electrical conductivity can be obtained, as with aliphatic carboxylic acids.

An aliphatic aldehyde is a compound having a structure in which one or more aldehyde groups are substituted on an aliphatic compound. The aliphatic aldehyde used in the present embodiment preferably has a structure in which an aliphatic compound is substituted with one aldehyde group, that is, a compound having an aliphatic hydrocarbon group and one aldehyde group. In this embodiment, aldehyde groups of an aliphatic aldehyde are usually arranged on the surface of the metal core particles (C1). Arrangement of the aldehyde groups on the surface of the metal core particles (C1) suppresses oxidation of the surfaces of the metal core particles (C1) and cleans contaminants due to the reducing action of the aliphatic aldehyde. In addition, it is presumed that the presence of aldehyde groups on the surface of the metal core particles (C1) has the effect of removing foreign substances and oxides from the substrate surface.

The aliphatic hydrocarbon group that constitutes the aliphatic aldehyde can be selected from those similar to those of the aliphatic carboxylic acid.
Specific examples of preferred aliphatic aldehydes include butyraldehyde, hexylaldehyde, octylaldehyde, nonylaldehyde, octadecylaldehyde, hexadecenylaldehyde and the like. An aliphatic aldehyde can be used individually by 1 type or in combination of 2 or more types.

The density of the coating molecules (C2) on the surface of the coated metal particles (C0) is not particularly limited, but from the viewpoint of interacting with the aliphatic group of the gel composition and having excellent compatibility, it is 2.5 to 2.5. It is preferably 5.2/nm ² , more preferably 3.0 to 5.2/nm ² , and even more preferably 3.5 to 5.2/nm ² . By setting the density of the coating molecules (C2) to 2.5/nm ² or more, the number of the coating molecules (C2) that can interact with the aliphatic groups of the gel composition increases, and the coated metal particles (C0) It is considered that the affinity between and the gel composition can be increased. In addition, by setting the density of the coating molecules (C2) to 5.2/nm ² or less, gaps for the aliphatic groups of the gel composition to enter between the coating molecules (C2) are generated, so that the coated metal particles It is believed that (C0) is efficiently dispersed in the gel composition.

The density of the coating molecules (C2) on the surface of the metal core particles (C1) can be calculated as follows. For the coated metal particles (C0), according to the method described in JP-A-2012-88242, organic components adhering to the surface are extracted using liquid chromatography (LC), and component analysis is performed. Also, TG-DTA measurement (thermogravimetric measurement/differential thermal analysis) is performed to measure the amount of organic component contained in the coated metal particles (C0). Next, the amount of the coating molecules (C2) contained in the coated metal particles (C0) is calculated together with the LC analysis results. Also, the average primary particle size of the metal core particles (C1) is measured by SEM image observation.
From the above analysis results, the number of coated molecules (C2) contained in 1 g of coated metal particles (C0) is represented by the following formula (a).
[Number of molecules of coating molecule (C2)]=M _A /(M _w /N _A ) (a)
Here, M _A is the mass [g] of the coating molecules (C2) contained in 1 g of the coated metal particles, _{M w} is the molecular weight of the coating molecules (C2), and NA is the Avogadro constant. When two or more types of coating molecules (C2) are included, the number of molecules is calculated for each component and totaled.
The shape of the metal core particles (C1) is approximated to a sphere, and the mass M _B [g] of the metal core particles (C1) is obtained by subtracting the amount of the organic component from the mass of the coated metal particles (C0). The number of metal core particles (C1) in 1 g of coated metal particles (C0) is represented by the following formula (b).
[Number of metal core particles (C1)]=M _B /[(4πr ³ /3)×d×10 ⁻²¹ ] (b)
Here, M _B is the mass [g] of the metal core particles (C1) contained in 1 g of the coated metal particles (C0), r is the radius [nm] of the primary particle diameter calculated by SEM image observation, and d is the density of the metal [g/cm ³ ] (d=8.94 for copper). The surface area of the metal core particles (C1) contained in 1 g of the coated metal particles (C0) is represented by the following formula (c) from the formula (b).
[Surface area (nm ² ) of metal core particles (C1)]=[Number of metal core particles (C1)]×4πr ² (c)
From the above, the coating density [number/nm ² ] of the metal core particles (C1) with the coating molecules (C2) is calculated by the following formula (d) using the formulas (a) and (c).
[Coating density]=[Number of coating molecules (C2)]/[Surface area of metal core particles (C1)] (d)

The bonding state between the coating molecules (C2) and the metal core particles (C1) in the coated metal particles (C0) may be ionic bonding or physical adsorption. From the viewpoint of the sinterability of the coated metal particles (C0), the coating molecules (C2) are preferably physically adsorbed on the surfaces of the metal core particles (C1), and the surfaces of the metal core particles (C1) have carboxyl groups. , or is preferably physically adsorbed by an aldehyde group.

Physical adsorption of the coating molecules (C2) to the metal core particles (C1) can be confirmed by analyzing the surface composition of the coating metal particles (C0). Specifically, the coated metal particles (C0) were subjected to time-of-flight secondary ion mass spectrometry (ToF-SIMS) surface analysis, and substantially only free coating molecules (C2) were detected and bound to metal atoms. It can be confirmed by substantially not detecting the covering molecule (C2) that is in contact. Here, the fact that the coating molecules (C2) bound to the metal atoms are not substantially detected means that the signal amount of the coating molecules (C2) attached to the metal core particles (C1) is equal to the free coating molecules ( It means that it is 5% or less, preferably 1% or less, of the signal amount of C2).

In addition, the fact that the coating molecules (C2) are physically adsorbed on the surface of the metal core particles (C1) with carboxy groups or aldehyde groups can be confirmed by measuring the infrared absorption spectrum of the coated metal particles (C0). It can be confirmed by the fact that only the stretching vibration peak derived from the CO-metal salt is actually observed and the stretching vibration peak derived from free carboxylic acid or the like is substantially not observed.

The particle size of the coated metal particles (C0) can be appropriately selected depending on the application. The average primary particle size of the coated metal particles (C0) is preferably 0.02 μm or more and 5 μm or less, more preferably 0.05 μm or more and 5 μm or less, from the viewpoint of dispersibility, conductivity, and crack suppression. , 0.07 μm or more and 2.5 μm or less.
The average primary particle size of the coated metal particles (C0) is calculated as the arithmetic mean value D _SEM of the primary particle sizes of arbitrary 20 coated metal particles observed by SEM.
In addition, the coefficient of variation of the particle size distribution (standard deviation SD/average primary particle diameter D _SEM ) of the coated metal particles (C0) is, for example, 0.01 to 0.5, preferably 0.05 to 0.3. . In particular, since the coated metal particles are produced by the method for producing coated metal particles described below, the coefficient of variation of the particle size distribution is small and the particle diameters can be made uniform. A small variation coefficient of the particle size distribution of the coated metal particles (C0) makes it possible to obtain a highly concentrated dispersion with excellent dispersibility.

The coated metal particles (C0) used in this embodiment are excellent in oxidation resistance and sinterability, and the resulting sintered body exhibits high bonding strength and electrical conductivity. Therefore, it can be suitably used for a metal particle dispersion for forming a wiring pattern or the like by printing on a base material.

The ratio of the coated metal particles (C0) contained in the metal particle dispersion liquid of the present embodiment can be appropriately changed within the range where the metal content is 40% by mass or less. For example, the metal content with respect to the total amount of the metal particle dispersion can be 5 to 40% by mass, preferably 10 to 35% by mass, more preferably 15 to 30% by mass. . By setting it as said content, the thin-film sintered compact can be obtained.

<Method for producing coated metal particles>
The coated metal particles (C0) used in the present embodiment are selected from metal carboxylates containing metals to be the specific metal core particles (C1), and the specific aliphatic carboxylic acids and aliphatic aldehydes. It is manufactured using more than one species of molecule. For example, it can be produced by referring to the descriptions of paragraphs 0052 to 0101 and paragraphs 0110 to 0114 of Patent Document 2. Alternatively, it can be manufactured with reference to paragraphs 0031 to 0066, paragraph 0085, etc. of JP-A-2016-069716.
In a preferred method for producing coated metal particles (C0), a reaction solution containing a metal carboxylate, a coating molecule (C2), and a medium is prepared, and a complex compound generated in the reaction solution is thermally decomposed. , a coated metal particle (C0) can be obtained. In this production method, the coated metal particles (C0) in which the surface of the metal core particles (C1) are coated with the coating molecules (C2) at a density of 2.5 to 5.2/nm ² can be obtained.

<Other ingredients>
The composition according to the present invention contains the copolymer (A), the compatible compound (B), and the filler (C) described above, and within a range that does not impair the effects of the present invention, It may contain other components as necessary. Examples of the other components include solvents, polymerization initiators, thickeners, etc. that are not contained in the copolymer (A), compatible compound (B), and filler (C). By combining these solvents, polymerization initiators, thickeners, etc., it is possible to adjust, for example, the rheological properties of the composition.

The viscosity of the mixture of the copolymer (A), the compatible compound (B), the filler (C), and the other components is, for example, 0.01 Pa s or more and 500 Pa s or less at 25°C and 10 rpm. can be adjusted as appropriate within the range of , and is preferably 0.01 Pa·s or more and 50 Pa·s or less. The amount of the above-mentioned other components to be blended is preferably 50% by mass or less, more preferably 30% by mass or less, based on the total mass of the composition.

(solvent)
Solvents that can be contained in the composition according to the present embodiment include solvents that are highly compatible with the copolymer (A) and the compatible compound (B). Examples of the solvent include nonpolar organic solvents such as hydrocarbon solvents, and aliphatic alcohols, aliphatic amino alcohols, aliphatic carboxylic acids, and aliphatic amines having a main chain skeleton having 2 or less carbon atoms. , aliphatic ethers, aliphatic acetates, aliphatic thiols, and aliphatic silanols. can.

(Additive)
The composition according to the present embodiment can contain additives other than the filler (C) within a range that does not impair the effects of the present invention. For example, additives such as antioxidants, wetting agents, surfactants, ionic liquids, antifoaming agents, UV absorbers, light stabilizers, various inorganic and organic fillers, and polymers can be included.

[Use of composition]
Since the composition of the present invention contains the filler (C) dispersed therein, it can be used as a functional paste such as a thermally conductive paste, an electrically conductive paste, or a paint. In particular, when coated metal particles are used as the filler (C), the coated metal particles are sintered by heating, so that the paste can be suitably used as a conductive paste for printing.

EXAMPLES The present invention will be specifically described below by way of examples, but the present invention is not limited to these examples.

(1) Production of coated metal particles (Production Example 1)
A 3000 mL glass four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet was placed in an oil bath at 150°C.
In the flask, 484 g (3.1 mol) of copper formate anhydride, 68 g (0.1 equivalent/copper formate anhydride) of lauric acid (manufactured by Kanto Chemical Co., Ltd.), and tripropylene glycol as a medium (auxiliary medium) 150 g of monomethyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.) (0.2 equivalent/anhydride of copper formate) and 562 g of petroleum-based hydrocarbon (C9 alkylcyclohexane mixture) ("Swaclean 150" manufactured by Gordo Co., Ltd.) as a medium (main medium) (1.4 equivalents/anhydrous copper formate) were charged. Under a nitrogen atmosphere, the contents in the flask were heated in an oil bath and mixed with stirring until the liquid temperature reached 50°C.
712 g (3.0 equivalents/anhydride of copper formate) of 3-amino-1-propanol (manufactured by Tokyo Chemical Industry Co., Ltd.) was slowly added dropwise to the above mixture as a complexing agent. After completion of dropping, the contents of the flask were heated in an oil bath and mixed with stirring until the liquid temperature reached around 120°C. As the liquid temperature increased, the color of the reaction liquid changed from dark blue to dark brown, and carbon dioxide gas was bubbled. When the bubbling of carbon dioxide stopped, the temperature control of the oil bath was stopped, and the mixture was naturally cooled to room temperature.
1200 g of methanol (manufactured by Kanto Kagaku Co., Ltd.) was added to the reaction solution cooled to room temperature and mixed. After allowing the resulting mixture to stand for 30 minutes or longer, the supernatant was decanted to obtain a precipitate. 1200 g of methanol (manufactured by Kanto Chemical Co., Ltd.) and 390 g of acetone (manufactured by Kanto Chemical Co., Ltd.) were added to the precipitate and mixed. After allowing the resulting mixture to stand for 30 minutes or longer, the supernatant was decanted to obtain a precipitate. These operations (addition and decantation of methanol and acetone) were repeated one more time.
The resulting precipitate was transferred to a 500 mL eggplant flask using 400 g of methanol (manufactured by Kanto Kagaku Co., Ltd.). After allowing this to stand for 30 minutes or longer, the supernatant was decanted.
18 g of α-terpineol (manufactured by Kanto Kagaku Co., Ltd.) was added to the resulting precipitate and mixed. After that, the eggplant flask was installed in a rotary evaporator, and the content was dried under reduced pressure (vacuum drying). After drying under reduced pressure (vacuum drying), it was naturally cooled to room temperature, and then the vacuum was released while replacing the inside of the eggplant flask with nitrogen. As described above, 200 g of brown viscous coated copper particles Cu1 were obtained.

(2) Evaluation of Coated Metal Particles Physical properties of coated metal particles were evaluated by the following TG-DTA measurement, XRD measurement, and SEM observation. The average primary particle diameter of the coated copper particles Cu1 was 86 nm, the coating amount of the coating molecules of the coated copper particles Cu1 was 0.68 wt %, and the coating density of the coating molecules of the coated copper particles Cu1 was 3.67 molecules/nm ² .

<Thermogravimetric/differential thermal (TG-DTA) analysis>
Measuring device: TG8120 manufactured by Rigaku
Heating rate: 10°C/min
Measurement temperature range: 25 to 500°C
Measurement atmosphere: Nitrogen (250 ml/min)
<Powder X-ray diffraction (XRD) analysis>
Measuring device: Smartlab manufactured by Rigaku
Tube voltage: 45kV
Tube current: 200mA
<SEM image observation>
Measuring device: FE-EPMA JXA-8500F manufactured by JEOL
Measurement conditions: acceleration voltage 15 to 20 kV
Observation magnification ×1,500 to ×30,000
<Calculation of average primary particle size and variation rate>
Measuring device: FE-EPMA JXA-8500F manufactured by JEOL
Average primary particle size: average value of 20 samples Variation rate: value calculated by standard deviation / average value of 20 samples

(2) Preparation of composition A composition was prepared using the following materials.
Copolymer (A-1): Polymethyl methacrylate/poly n-butyl acrylate/polymethyl methacrylate (PMMA/PnBA/PMMA) triblock polymer (manufactured by Kuraray Co., Ltd., KURARITY LA2330)
Copolymer (A-2): polystyrene/hydrogenated polybutadiene/polystyrene (PSt/hydrogenated PBD/PSt) triblock polymer (manufactured by Kuraray Co., Ltd., SEPTON J3341)
- Compatible compound (B-1): triethylene glycol bis(2-ethylhexanoate) (molecular weight 402.6, manufactured by Proviron, Proviplast 1783)
- Compatible compound (B-2): 1,2-cyclohexanedicarboxylic acid diisononyl ester (molecular weight 427.7 manufactured by BASF, Hexamoll DINCH)
- Compatible compound (B-3): 2-ethylhexyl palmitate (molecular weight 368.6, Nisshin OilliO Co., Ltd.)
Filler (C-1): coated copper particles Cu1 of Production Example 1
Filler (C-2): copper powder (average primary particle size 2.0 μm, manufactured by Mitsui Kinzoku Mining Co., Ltd., 1200N)
Filler (C-3): alumina particles (average primary particle size 0.10 μm, manufactured by Taimei Chemical Industry Co., Ltd., TM-DA)
Filler (C-4): silica particles (particle size 0.2 to 0.4 μm, manufactured by Admatechs, SO-C1)

(Example 1: Preparation of composition)
2.0 parts by mass of the copolymer (A-1), 6.4 parts by mass of the compatible compound (B-1), and 2.04 parts by mass of the filler (C-1) were mixed to obtain the 1 composition was obtained. The filler (C-1) contains 1.8 parts by mass of copper particles, 0.04 parts by mass of lauric acid, and 0.2 parts by mass of α-terpineol in 2.04 parts by mass. .

(Examples 2 to 10)
Compositions of Examples 2 to 10 were obtained in the same manner as in Example 1, except that each component and the blending ratio were changed as shown in Table 1.

(Comparative Examples 1 to 4)
Compositions of Comparative Examples 1 to 4 were obtained in the same manner as in Example 1, except that each component and the blending ratio in Example 1 were changed as shown in Table 1.

<condition evaluation>
The fluidity at 25° C. of the compositions obtained in Examples and Comparative Examples was visually evaluated. Table 1 shows the results.
"Gel" when the shape is maintained even when the composition enclosed in the sample bottle is tilted,
When the composition enclosed in the sample bottle was tilted, it was evaluated as "liquid" when it spontaneously flowed.

<Liquid-gel transition temperature (Tc) evaluation>
Storage modulus G′ and loss modulus G″ of the compositions obtained in Examples and Comparative Examples were measured using a rheometer (manufactured by Anton Paar) using a cone rotor (φ=25 mm, rotor angle 2°), At a frequency of 1 Hz and a strain of 1%, it is measured by cooling from 150 ° C. to 0 ° C. at 2 ° C./min. The temperature at which the temperature becomes equal is defined as Tc. Table 1 shows the results. In Table 1, those that do not have Tc in the range of 0°C to 150°C are indicated as "-".

Further, gel compositions 1 and 6 were prepared in the same manner as in Examples 1 and 6 except that no filler was added in Examples 1 and 6, and Tc evaluation was performed in the same manner as above. Gel composition 1 had a Tc of 41°C, and gel composition 6 had a Tc of 51°C.

<Dispersion stability evaluation>
Compositions of Examples and Comparative Examples were prepared and their dispersibility (dispersion stability) was visually evaluated after one week. Table 1 shows the results. When the filler (C) was dispersed, it was indicated as "O", and when the filler (C) was aggregated or precipitated, it was indicated as "X".

[Summary of results]
As shown in Table 1, the compositions of Examples 1 to 10 have a liquid-gel state transition temperature (Tc) in the range of 0 to 150°C, and the dispersion stability of the filler (C) at room temperature is It turned out to be excellent.

Claims (7)

a copolymer (A);
A compatible compound (B) having compatibility with the copolymer (A);
A composition containing a filler (C),
The copolymer (A) is the following copolymer (A1 ) or (A3),
The compatible compound (B) is an ester having a molecular weight of 500 or less,
The filler (C) is a coated metal particle (C0) in which the surface of the metal core particle (C1) is coated with one or more coating molecules (C2) selected from aliphatic carboxylic acids and aliphatic aldehydes,
The gel composition obtained by dissolving the copolymer (A) and the compatible compound (B) has a liquid-gel transition temperature (Tc) in the range of 0 to 150 ° C.
Composition.
(A1):
a block (a1) having a (meth)acrylate-based monomer (α1) as a main structural unit;
A block copolymer having a block (b1) having a (meth)acrylate monomer (β1) as a main structural unit,
Block copolymerization, wherein the homopolymer of the monomer (α1) has a glass transition temperature of more than 50° C. and 180° C. or less, and the homopolymer of the monomer (β1) has a glass transition temperature of −100° C. or more and 50° C. or less. Union (A1) .
( A3):
a block (a3) having a styrene-based monomer (α3) as a main structural unit;
A block (b3) whose main structural unit is one or more monomers (β3) selected from alkene-based monomers, diene-based monomers, and alkyne-based monomers, or
A block copolymer having a block (b4) having a (meth)acrylate monomer (β4) as a main structural unit,
A block copolymer (A3) in which the homopolymer of the (meth)acrylate monomer (β4) has a glass transition temperature of −100° C. or more and 50° C. or less. the composition has a liquid-to-gel transition temperature (Tc) in the range of 0 to 150°C;
A composition according to claim 1 . The compatible compound (B) has a viscosity of 0.001 Pa s or more and 10 Pa s or less at 25°C.
3. A composition according to claim 1 or 2. The coated metal particles (C0) have 2.5 to 5.2/nm of one or more coating molecules (C2) selected from aliphatic carboxylic acids and aliphatic aldehydes on the surfaces of the metal core particles (C1). Particles coated with a coating density of ² ,
A composition according to any one of claims 1-3. The composition according to any one of claims 1 to 4, wherein the metal core particles (C1) have an average primary particle size of 1 nm or more and less than 300 nm. The composition according to any one of claims 1 to 5, wherein the compatible compound (B) is 200 parts by mass or more and 1000 parts by mass or less with respect to 100 parts by mass of the copolymer (A). Any one of claims 1 to 6, wherein the filler (C) is 5 parts by mass or more and 60 parts by mass or less with respect to a total of 100 parts by mass of the copolymer (A) and the compatible compound (B). A composition according to claim 1.