JP2017071810A - Sintering material and sintered body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sintering material that can improve the conductivity of a sintered body.SOLUTION: A sintering material comprises (A) component: a metal resin composite material that is a complex of a metal particle (a1) and phenolic resin (a2) and has a metal atom-oxygen atom-carbon atom bond, and (B) component: organic solvent component. A sintered body has a bond of the metal particles (a1) included in the sintering material. A metal constituting the metal particle (a1) is preferably at least one selected from the group consisting of silver, copper, tin, nickel, iron, zinc, manganese and aluminum.SELECTED DRAWING: None

Description

  The present invention relates to a sintered material and a sintered body.

Along with miniaturization of electronic devices, miniaturization of wiring patterns formed on a circuit board is required. For the formation of such a wiring pattern, a conductive resin ink material (sintered material) that can draw a wiring pattern directly on a circuit board is used.
For example, metal fine particles having a coated molecular layer are used as a dispersoid, and a metal fine particle dispersion obtained by dispersing the dispersoid in a liquid phase dispersion medium containing an organic solvent is used as a resin ink material (sintering material). There has been proposed a method in which a conductive layer of a metal fine particle sintered body is formed on a wiring board by subjecting a coating layer of a metal fine particle dispersion to a heat treatment to sinter metal fine particles (Patent Document). 1).
According to the method described in Patent Document 1, sintering of metal fine particles can proceed even at a low temperature heat treatment of 200 ° C. or lower, and the conductivity of the sintered body is improved.

JP 2006-26602 A

By the way, in recent years, miniaturization of the line width, wiring interval, film thickness, etc. of the wiring pattern has been remarkably advanced. Under such circumstances, when forming a fine wiring pattern using a sintered material, it is required more than ever to achieve good electrical conductivity and to produce the wiring pattern with good reproducibility, and can cope with this. Technology is needed.
This invention is made | formed in view of the said situation, Comprising: It aims at providing the sintered material which can improve the electroconductivity of a sintered compact more.

As a result of intensive studies, the present inventors provide the following means in order to solve the above problems.
That is, the sintered material of the first aspect of the present invention is a composite of (A) component: metal particles (a1) and a phenol resin (a2), which has a metal atom-oxygen atom-carbon atom bond. A resin composite material and (B) component: an organic solvent component is contained.

The content of the component (A) is preferably 5 to 50% by mass.
The metal constituting the metal particles (a1) is preferably at least one selected from the group consisting of silver, copper, tin, nickel, iron, zinc, manganese and aluminum.
The proportion of the metal particles (a1) in the component (A) is preferably 1 to 85% by mass.

  The sintered body according to the second aspect of the present invention is characterized by having a joint between the metal particles (a1) contained in the sintered material according to the first aspect.

According to the sintered material of the present invention, the conductivity of the sintered body can be further increased.
The sintered body of the present invention has higher conductivity.

It is a figure which shows Ag3d narrow scan spectrum measured about the metal resin composite material (A-1). It is a figure which shows Ag3d narrow scan spectrum measured about the sample which cleaned Ag foil with Ar ion. It is a figure which shows the image which observed the surface of the metal resin composite material (A-1) with the transmission electron microscope (TEM).

(Sintered material)
The sintered material of this embodiment is a composite of (A) component: metal particles (a1) and a phenol resin (a2), and a metal resin composite material having a metal atom-oxygen atom-carbon atom bond, and Component (B): Contains an organic solvent component.
Examples of the dosage form of the sintered material include a liquid form and a paste form.

<(A) component>
The component (A) in the present embodiment is a composite of metal particles (a1) and a phenol resin (a2), which is a metal resin composite material having a metal atom-oxygen atom-carbon atom bond.
Hereinafter, the metal particles (a1) are also referred to as the (a1) component, and the phenol resin (a2) is also referred to as the (a2) component.

≪Metal particles (a1) ≫
The lower limit value of the average particle diameter for the particle group of the component (a1) is preferably 1 nm or more, more preferably 3 nm or more, and further preferably 5 nm or more because the mechanical strength of the sintered body can be more easily increased. .
The upper limit of the average particle diameter of the particle group of the component (a1) is preferably 1 μm or less, more preferably 600 nm or less, and even more preferably 300 nm or less because dispersibility in the component (a2) is easy to improve. .
The average particle size of the particle group of the component (a1) is obtained by observing the surface of the component (A) with a transmission electron microscope (TEM) and measuring the particle size of 100 arbitrarily selected metal particles. It is determined by calculating the value.

Examples of the metal constituting the component (a1) include gold (Au), platinum (Pt), palladium (Pd), silver (Ag), copper (Cu), tin (Sn), nickel (Ni), cobalt ( Co), iron (Fe), chromium (Cr), zinc (Zn), manganese (Mn), aluminum (Al), calcium (Ca), magnesium (Mg), titanium (Ti), scandium (Sc), vanadium ( V), gallium (Ga), strontium (Sr), yttrium (Y), niobium (Nb), molybdenum (Mo), ruthenium (Ru), cadmium (Cd), barium (Ba), lanthanum (La), cerium ( Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), tellurium Um (Tb), Dysprosium (Dy), Holmium (Ho), Erbium (Er), Thulium (Tm), Ytterbium (Yb), Lutetium (Lu), Hafnium (Hf), Tantalum (Ta), Tungsten (W), Examples include rhenium (Re), osmium (Os), and iridium (Ir).
Among these, gold, platinum, palladium, silver, copper, tin, nickel, cobalt, iron, chromium, zinc, manganese, and aluminum are preferable because the effects of the present invention are easily obtained.
(A1) The metal which comprises a component may be 1 type individual, and 2 or more types may be sufficient as it.
The metal constituting the component (a1) is more preferably at least one selected from the group consisting of silver, copper, tin, nickel, iron, zinc, manganese and aluminum.

  The metal constituting the component (a1) is usually mostly “zero-valent” metal atoms, but may contain metal ions having a cationic property. The mechanical strength is further increased by the interaction between the metal ion and the component (a2).

In the component (A), the component (a1) may be used alone or in combination of two or more.
The proportion of the component (a1) in the component (A) is preferably 1 to 85% by mass with respect to the total amount (100% by mass) of the entire component (A).
(A1) The lower limit of the ratio of the component is preferably 1% by mass or more with respect to the total amount (100% by mass) of the entire component (A) because the degree of expression of the mechanical strength derived from the metal particles is further increased. More preferably, it is 3% by mass or more, and further preferably 5% by mass or more.
The upper limit of the ratio of the component (a1) is preferably 85% by mass or less, more preferably based on the total amount of the component (A) (100% by mass) because the specific gravity of the component (A) as a whole is easily suppressed. Is 75% by mass or less, more preferably 65% by mass or less.

≪Phenolic resin (a2) ≫
Examples of the component (a2) include novolak-type phenol resins, resol-type phenol resins, and arylalkylene-type phenol resins.

-About novolak-type phenol resin As a novolak-type phenol resin, what is obtained by making phenols and aldehydes react under an acidic catalyst is used, for example.

Examples of phenols used in the production of novolac type phenol resins include phenol, cresol, xylenol, ethylphenol, p-phenylphenol, p-tert-butylphenol, p-tert-amylphenol, p-octylphenol, and p-nonylphenol. , P-cumylphenol, bisphenol A, bisphenol F, resorcinol, 2-hydroxybenzaldehyde, 3-hydroxybenzaldehyde, 4-hydroxybenzaldehyde or derivatives thereof.
Phenols may be used alone or in combination of two or more.

Examples of aldehydes used for the production of novolak type phenol resins include formaldehyde; alkyl aldehydes such as acetaldehyde, propyl aldehyde, butyraldehyde; benzaldehyde, 2-hydroxybenzaldehyde, 3-hydroxybenzaldehyde, 4- Aromatic aldehydes such as hydroxybenzaldehyde can be used.
Examples of the formaldehyde source include formalin (aqueous solution), paraformaldehyde, hemiformal with alcohols, trioxane and the like.
Aldehydes may be used alone or in combination of two or more.

Examples of the acidic catalyst include organic carboxylic acids such as oxalic acid and acetic acid; organic sulfonic acids such as benzenesulfonic acid, paratoluenesulfonic acid and methanesulfonic acid; 1-hydroxyethylidene-1,1′-diphosphonic acid, 2- Organic phosphonic acids such as phosphonobutane-1,2,4-tricarboxylic acid; inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid.
An acidic catalyst may be used individually by 1 type, and may use 2 or more types together.

  When synthesizing a novolac-type phenol resin, the reaction molar ratio of phenols and aldehydes is preferably 0.3 to 1.7 moles, more preferably 0.8 to aldehydes per mole of phenols. 5 to 1.5 mol.

-About a resole type phenol resin What is obtained by making phenols and aldehydes react under an alkali catalyst is used for a resole type phenol resin, for example.

Examples of the phenols used in the production of the resol type phenol resin include cresols such as phenol, o-cresol, m-cresol, and p-cresol; 2,3-xylenol, 2,4-xylenol, 2,5- Xylenols such as xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol; ethylphenols such as o-ethylphenol, m-ethylphenol, p-ethylphenol; isopropylphenol, butylphenol, p Butylphenols such as tert-butylphenol; alkylphenols such as p-tert-amylphenol, p-octylphenol, p-nonylphenol, p-cumylphenol; fluorophenol, chlorophenol, bromophenol, iodine Halogenated phenols such as phenol; monovalent phenol substitutes such as p-phenylphenol, aminophenol, nitrophenol, dinitrophenol, and trinitrophenol; monovalent phenols such as 1-naphthol and 2-naphthol; resorcin, Polyhydric phenols such as alkylresorcin, pyrogallol, catechol, alkylcatechol, hydroquinone, alkylhydroquinone, phloroglucin, bisphenol A, bisphenol F, bisphenol S, dihydroxynaphthalene; 2-hydroxybenzaldehyde, 3-hydroxybenzaldehyde, 4 -Phenols having an aldehyde group such as hydroxybenzaldehyde; or derivatives thereof.
Phenols may be used alone or in combination of two or more.

Examples of aldehydes used in the production of resol type phenol resins include formaldehyde, paraformaldehyde, trioxane, acetaldehyde, propionaldehyde, polyoxymethylene, chloral, furfural, glyoxal, n-butyraldehyde, caproaldehyde, allylaldehyde, Examples include benzaldehyde, crotonaldehyde, acrolein, phenylacetaldehyde, o-tolualdehyde, 2-hydroxybenzaldehyde, 3-hydroxybenzaldehyde, 4-hydroxybenzaldehyde and the like.
Among these aldehydes, formaldehyde and paraformaldehyde are preferable because they are excellent in reactivity and inexpensive.
Aldehydes may be used alone or in combination of two or more.

Examples of the alkali catalyst include alkali metal hydroxides such as sodium hydroxide, lithium hydroxide, and potassium hydroxide; alkaline earth metal oxides or hydroxides such as calcium, magnesium, and barium; sodium carbonate, ammonia Water; amines such as triethylamine and hexamethylenetetramine; and divalent metal salts such as magnesium acetate and zinc acetate.
An alkali catalyst may be used individually by 1 type, and may use 2 or more types together.

  When synthesizing a resol-type phenol resin, the reaction molar ratio of phenols to aldehydes is preferably 0.8 to 2.5 moles, more preferably 1. 0 to 2.3 moles.

-About aryl alkylene type phenol resin An aryl alkylene type phenol resin means the phenol resin which has a repeating unit containing one or more aryl alkylene groups.
Examples of such aryl alkylene type phenol resins include xylylene type phenol resins and biphenyl dimethylene type phenol resins.
The aryl alkylene type phenol resin is produced by a known production method.

The metal resin composite material (A) has a metal atom-oxygen atom-carbon atom bond.
The oxygen atom which forms this bond is not limited to the phenolic hydroxyl group which (a2) component (phenol resin) has, but may be an oxygen atom derived from a functional group other than this. Thus, the oxygen atom derived from various functional groups and the component (a1) (metal particle) interact with each other, so that a metal atom-oxygen atom-carbon atom bond is easily formed.

Among the components (a2), a phenol resin having an aliphatic alcohol group in the molecule, a phenol resin having an ether group in the molecule, a phenol resin having a ketone group in the molecule, and a formyl group (—CHO) in the molecule. A phenol resin, a phenol resin having a carboxy group in the molecule, a phenol resin having an ester group in the molecule, and a phenol resin having a urethane group in the molecule are preferable.
Among these, a phenol resin having a carbonyl moiety (carbonyl group) such as a ketone group, an aldehyde group, a carboxy group, an ester group, or a urethane group in the molecule is more preferable.
By using such a preferable phenol resin, the metal atom in the component (a1) can be bonded not only to the oxygen atom of the phenolic hydroxyl group in the component (a2) but also partially to the oxygen atom of the carbonyl group. Become. Thereby, a metal atom-oxygen atom-carbon atom bond is more easily formed.
In addition, the phenol resin which has a carbonyl group in a molecule | numerator as mentioned above is manufactured by using the phenols which have a corresponding functional group in a molecule | numerator as a raw material.

When a phenol resin having an aldehyde group in the molecule is used, the metal resin composite material as the component (A) can be easily produced.
As will be described later, when the component (A) is produced, a solution of a metal salt and a phenol resin are mixed to bond oxygen atoms and metal atoms in the phenol resin. When a phenol resin having an aldehyde group in the molecule is used as a raw material, the aldehyde group brings about a reducing action on the metal cation constituting the metal salt. In addition, in this case, the metal atom and the oxygen atom in the phenol resin are easily bonded.

  Such a phenol resin having an aldehyde group in the molecule is, for example, hydroxybensaldehyde such as 2-hydroxybenzaldehyde, 3-hydroxybenzaldehyde, 4-hydroxybenzaldehyde or the like as a raw material phenols. It is manufactured by using a derivative.

The lower limit of the number average molecular weight (Mn) of the component (a2) is preferably 150 or more, more preferably 200 or more, and still more preferably 250 or more.
The upper limit of the number average molecular weight (Mn) of the component (a2) is preferably 1500 or less, more preferably 1200 or less, and still more preferably 1000 or less.
By setting Mn of the component (a2) within the above preferable range, it becomes easy to express appropriate flexibility as the resin component.

The lower limit of the weight average molecular weight (Mw) of the component (a2) is preferably 200 or more, more preferably 300 or more, and still more preferably 400 or more.
The upper limit of the weight average molecular weight (Mw) of the component (a2) is preferably 2500 or less, more preferably 2000 or less, and even more preferably 1800 or less.
By setting the Mw of the component (a2) within the above preferable range, it becomes easy to express moderate flexibility as the resin component.

  In the present invention, the weight average molecular weight (Mw) and number average molecular weight (Mn) of the resin mean values in terms of polystyrene measured by gel permeation chromatography (GPC).

In the component (a2), the ratio of the weight average molecular weight to the number average molecular weight (Mw / Mn) is preferably 2.5 or less, more preferably 2.2 or less, and even more preferably 2.0 or less as the upper limit. .
The lower limit value of Mw / Mn is not particularly limited, and is 1.05 or more, for example.
The effect of the present invention is further enhanced by setting Mw / Mn of the component (a2) within the above preferred range.

In addition, since a chemical reaction is performed when the component (A) is produced, the phenol resin used as a raw material and the phenol resin after the reaction constituting the component (A) have a molecular weight (Mn , Mw, Mw / Mn) may not match.
In producing the component (A), considering the production conditions, the molecular weight of the component (a2) used as a raw material is adjusted so that the post-reaction phenol resin constituting the component (A) is in the range of the above molecular weight and the like. It is preferable to set.

In the component (A), the component (a2) may be used alone or in combination of two or more.
The proportion of the component (a2) in the component (A) is preferably 10 to 99% by mass with respect to the total amount (100% by mass) of the entire component (A).
The lower limit of the proportion of the component (a2) is easy to impart appropriate flexibility as a composite material, and it is easy to improve the applicability to the substrate. Therefore, the total amount of the component (A) (100% by mass) ) Is preferably 10% by mass or more, more preferably 15% by mass or more, and still more preferably 20% by mass or more.
The upper limit of the proportion of the component (a2) is preferably 99% by mass or less with respect to the total amount (100% by mass) of the entire component (A) because the degree of expression of mechanical strength derived from the metal particles is further increased. More preferably, it is 95 mass% or less, More preferably, it is 90 mass% or less.

In the component (A), the mixing ratio of the component (a1) and the component (a2) is expressed as a mass ratio represented by the component (a2) / component (a1) (hereinafter also simply referred to as “(a2) / (a1)”). 4 to 99 is preferable, 6 to 32 is more preferable, and 9 to 19 is more preferable.
If the mass ratio (a2) / (a1) is equal to or more than the above-mentioned preferable lower limit value, it is easy to impart moderate flexibility as a composite material, and it becomes easy to improve the coating property to the substrate, If it is below the said preferable upper limit, the degree of expression of mechanical strength will increase more.

≪Other ingredients (a3) ≫
The component (A) may contain components other than the components (a1) and (a2) (hereinafter also referred to as “component (a3)”) as necessary.
Examples of component (a3) include resins other than component (a2); mold release agents such as stearic acid, calcium stearate or polyethylene; flame retardants such as calcium hydroxide; colorants such as carbon black; coupling agents; Etc.

The specific gravity of the component (A) may be appropriately set, the lower limit of the specific gravity, for example 1.25 g / cm ³ or more, more preferably 1.27 g / cm ³ or more, more preferably 1.30g / Cm ³ or more.
The upper limit of the specific gravity of the component (A), for example, is preferably from 16.6 g / cm ^3, more preferably 16.0 g / cm ³ or less, more preferably 15.5 g / cm ³ or less.

The component (A) in the present embodiment has a metal atom-oxygen atom-carbon atom bond.
In the component (A), the metal atom (M) on the surface of the metal particles as the component (a1) and the oxygen atom (OC) in the phenol resin as the component (a2) form a bond, The component (a1) is dispersed in the matrix of component a2.
The metal atom (M) and O (oxygen atom) in O—C form a chemical bond (M—O). This is observed by X-ray photoelectron spectroscopy (ESCA) (FIGS. 1 and 2 described later).
Thus, in component (A), component (a1) forms bonds with oxygen atoms in component (a2), so component (a1) is stably dispersed in the matrix of component (a2). obtain. By using the component (A), better conductivity is exhibited in the sintered body of the sintered material of the present embodiment.

In the sintered material of the present embodiment, the component (A) may be used alone or in combination of two or more.
5-50 mass% is preferable with respect to the total mass (100 mass%) of a sintered material, and, as for the content rate of the (A) component in a sintered material, More preferably, it is 10-40 mass%.
(A) The intensity | strength of a sintered compact and electroconductivity increase more that the content rate of a component is more than a preferable lower limit. On the other hand, if the content ratio of the component (A) is less than or equal to the preferable upper limit value, the moldability is improved.

<< (A) Component Production Method >>
The metal resin composite material as component (A) can be produced, for example, by a production method having a step of mixing a metal salt solution and a phenol resin.
For this phenol resin, the component (a2) described above may be appropriately selected and used.

-Metal salt solution The metal salt solution is prepared by dissolving the metal salt constituting the component (a1) in a solvent.
As such a metal salt, one composed of a combination of a cation (cation) and an anion (anion) of the metal atom constituting the component (a1) described above is used.
This anion includes halogen ions such as chlorine ion, bromine ion and iodine ion; carboxylate ions such as acetate ion, oxalate ion and fumarate ion; p-toluenesulfonate ion, methanesulfonate ion, butanesulfonate ion, benzene Examples thereof include sulfonate ions such as sulfonate ions; sulfate ions; perchlorate ions; carbonate ions; nitrate ions.
For example, when silver is selected as the metal, it is preferable to use silver nitrate having nitrate ions as anions because of its high solubility in a solvent.
When selecting copper as a metal, it is preferable to use copper sulfate and copper nitrate.
When selecting zinc as a metal, it is preferable to use zinc chloride, zinc sulfate, and zinc nitrate.
When calcium is selected as the metal, calcium chloride or calcium nitrate is preferably used.
When iron is selected as the metal, it is preferable to use iron chloride, iron sulfate, or iron nitrate.
When selecting aluminum as a metal, it is preferable to use aluminum nitrate.
When selecting magnesium as a metal, it is preferable to use magnesium chloride, magnesium sulfate, and magnesium nitrate.
In addition, what is necessary is just to select the valence of the metal in a metal salt considering the solubility with respect to a solvent, the ease of a reduction | restoration, etc.

What is necessary is just to select suitably as a solvent at the time of preparing the solution of metal salt according to the characteristic of metal salt, for example, water.
In addition, water can be used other than water, for example, alcohol solvents such as methanol, ethanol, propanol, butanol, pentanol, hexanol, and ethylene glycol; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone. Ether solvents such as dimethyl ether, diethyl ether, methyl ethyl ether, dipropyl ether, tetrahydrofuran; cellosolves such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate; N-methyl-2-pyrrolidone, N An amide solvent such as N-dimethylformamide; dimethyl carbonate or the like can be used.
The solvent of the metal salt solution may be one kind alone, or two or more kinds of mixed solvents.
As a preferable mixed solvent, for example, a combination of water and a solvent other than this may be mentioned.

When preparing a solution of a metal salt, the pH of the solution may be adjusted for the purpose of improving the solubility of the metal salt in a solvent.
In the metal salt solution, the lower limit value of the content ratio of the metal salt is, for example, 1% by mass or more, preferably 3% by mass or more, more preferably 5% by mass or more, with respect to the total mass (100% by mass). The upper limit of the content ratio of the metal salt is, for example, 20% by mass or less, preferably 15% by mass or less, more preferably 12% by mass or less, with respect to the mass (100% by mass) of the entire solution. By setting the content ratio of the metal salt within the preferable range, desired metal particles are stably generated from the metal salt.

[Step of mixing metal salt solution and phenolic resin]
In this step, the metal resin composite material as the component (A) is obtained by mixing the metal salt solution and the phenol resin.
When the metal salt solution and the phenol resin are mixed, a reduction reaction is performed on the metal salt, whereby metal particles are generated from the metal salt (that is, precipitated as zero-valent metal particles).
In this reduction reaction, a known reducing agent may be used, or a reducing functional group resulting from the structure of the phenol resin may be utilized. In this embodiment, the phenol resin which is the component (a2) in the component (A) can function as a reducing agent.

As the reducing agent, known ones can be employed, for example, inorganic or organic reduction such as sodium hypophosphite, dimethylamine borane, sodium borohydride, potassium borohydride, formaldehyde, hydrazine, ascorbic acid and the like. Agents.
Examples of the reducing agent include resins having a polar group containing nitrogen or oxygen, such as an epoxy resin, a melamine resin, a urea resin, an aniline resin, and an isocyanate resin.

In the reduction reaction, when a reducing functional group resulting from the structure of the phenol resin is utilized, a phenol resin having an aldehyde group in the molecule can be employed as the phenol resin. In this case, the aldehyde group in the phenol resin molecule brings about a reducing action on the metal cation constituting the metal salt, thereby obtaining metal particles.
When using a phenol resin having an aldehyde group in the molecule, the phenol resin is preferably used in an amount of 0.1 times or more, more preferably 0.5 times or more of the phenol relative to the mass of the metal salt. A resin is used, and more preferably, the phenol resin is used in an amount twice or more. The upper limit of the amount of the phenol resin is not particularly limited, and for example, an amount of 100 times or less is used.

In this step, a reducing aid can be used as appropriate in order to promote the reduction reaction. For example, when a phenol resin having an aldehyde group in the molecule and silver nitrate are mixed, as a reducing auxiliary agent, dimethyl sulfide, diethyl sulfide, dipropyl sulfide, dibutyl sulfide, dipentyl sulfide, dihexyl sulfide, diphenyl sulfide, ethyl Phenyl sulfide, thiodiethanol, thiodipropanol, thiodibutanol, 1- (2-hydroxyethylthio) -2-propanol, 1- (2-hydroxyethylthio) -2-butanol, 1- (2-hydroxyethylthio) ) -3-butoxy-1-propanol and the like can be used.
In addition, amine compounds and alcohols can also be used as reducing aids.
Examples of the amine compound include ammonia, ethylamine, diethylamine, triethylamine, propylamine, dipropylamine, tripropylamine, isopropyldiethylamine, diethanolamine, triethanolamine, morpholine, ethylenediamine, and pyridine.
Examples of the alcohols include ethoxyethanol, ethylene glycol, diethylene glycol and the like.

In this step, the metal salt solution and the phenol resin may be mixed while ripening.
The temperature condition at the time of ripening is preferably 30 ° C. or more, more preferably 40 ° C. or more, further preferably 45 ° C. or more as its lower limit, and preferably 100 ° C. or less as its upper limit. Yes, more preferably 90 ° C. or lower, and still more preferably 80 ° C. or lower.

  The time (reaction time) for mixing the metal salt solution and the phenol resin is preferably 10 minutes or more, more preferably 30 minutes or more, still more preferably 1 hour or more as its lower limit, and its upper limit. Is preferably 24 hours or less, more preferably 12 hours or less, and even more preferably 8 hours or less.

<(B) component>
The component (B) in the present embodiment is an organic solvent component.
Examples of the component (B) include aromatic hydrocarbons such as xylene and toluene; ketone compounds such as acetone, methyl ethyl ketone and diisobutyl ketone; saturated hydrocarbons such as hexane, cyclohexane and heptane; ethyl acetate, propylene glycol monomethyl ether acetate, Ester compounds such as ethyl lactate; polar aprotic solvents such as N-methyl-2-pyrrolidone, γ-butyrolactone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide; ether compounds such as tetrahydrofuran and dioxane Alcohols and the like are included.

In the sintered material of the present embodiment, the component (B) may be used alone or in combination of two or more.
Among the components (B), an aromatic hydrocarbon is preferable from the viewpoint of compatibility with the component (A).
(B) The content rate of a component is not specifically limited, For example, it is a density | concentration which can apply | coat a sintered material to a board | substrate etc., and is suitably set according to a film thickness. Preferably, the solid content concentration of the sintered material is preferably 5 to 50% by mass, and more preferably 10 to 40% by mass with respect to the total mass (100% by mass) of the sintered material. Is used.

<Other ingredients>
The sintered material of this embodiment may contain components other than the component (A) and the component (B) as necessary.
Examples of components other than the component (A) and the component (B) include a curing agent, a surfactant, and a dispersant.

  What is necessary is just to select a hardening | curing agent suitably according to the kind etc. of (A) component, for example, hexamethylenetetramine, an isocyanate resin, hexamethoxymethylol melamine etc. can be used suitably.

  The sintered material of this embodiment can be prepared by, for example, dissolving or dispersing the component (A) and other components in the component (B) as necessary.

In the sintered material of the present embodiment described above, the metal resin composite material (component (A)) which is a composite of the component (a1) and the component (a2) and has a metal atom-oxygen atom-carbon atom bond. It is included. For this reason, the sintered material of this embodiment can improve the electroconductivity of a sintered compact more.
In addition, with the sintered material of this embodiment, it is possible to produce a wiring pattern made of a sintered body that is a thin film and has a higher conductivity than the conventional one.

(Sintered body)
The sintered body of the present embodiment has a joint between metal particles (a1) contained in the above-described sintered material.
The sintered body of the present embodiment is manufactured by heating and baking the above-described sintered material at about 150 to 300 ° C.
For example, when a sintered body is obtained on a substrate using the above-described sintered material, the thickness of the sintered body (wiring pattern) formed on the substrate can be set to, for example, 10 μm or less, preferably 5 μm or less, More preferably, it can be set to 1 μm or less, further 0.5 μm or less, particularly 0.1 μm or less. The lower limit of the film thickness of such a sintered body is substantially 0.01 μm or more.
A conventionally well-known thing can be used for a board | substrate, for example, the board | substrate for electronic components, specifically, a silicon wafer, a metal board | substrates, such as copper, chromium, iron, and aluminum, or a glass substrate etc. are mentioned. .
Since the sintered body mentioned above is used for the sintered body of this embodiment, electroconductivity (reduction of volume resistance value etc.) is improved more.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the scope of the present invention is not limited to these examples.

<Manufacture of resol type phenolic resin>
To a reactor equipped with a stirrer, a reflux condenser and a thermometer, 1000 g of phenol, 1294 g of formalin having a concentration of 37% by mass and 10 g of triethylamine were added and reacted for 1 hour. Then, while dehydrating under a reduced pressure of 650 mmHg, when the temperature in the system reached 70 ° C., 1100 g of methanol was added and dissolved, cooled, and resol type phenol resin (reaction liquid having a resin solid content of 50% by mass) 2400 g. Got.

<Manufacture of metal resin composite material (A-1)>
A four-necked 1 L flask equipped with a stirring blade, a thermometer, a dropping funnel and a condenser was prepared. In this flask, sodium hydroxide was added to 60.0 g of the resol-type phenolic resin obtained above and 300 g of water. A sodium hydroxide aqueous solution in which 4.6 g (0.11 mol) was dissolved, 6.0 g (0.05 mol) of thiodiethanol, and 1200 g (1.14 mol) of 1N silver nitrate were charged. Next, stirring was performed to dissolve them uniformly. Next, the temperature was raised until the internal temperature reached 50 ° C., and the reaction was carried out for 2 hours while maintaining the temperature from the time when the internal temperature reached 50 ° C.
After the reaction, it was confirmed that the internal temperature of the flask had dropped to 30 ° C. or lower, and 0.5 g of acetic acid was added dropwise from the dropping funnel to adjust the reaction system from neutral to weakly acidic with pH = 5 as the limit. As a result, the metal resin composite material (A-1) was deposited.
Finally, what was deposited in the flask was collected and dried to obtain 33 g of a metal resin composite material (A-1).

The obtained metal resin composite material (A-1) is added to tetrahydrofuran, and the molecular weight of the portion of the metal resin composite material (A-1) that is soluble in tetrahydrofuran is measured by GPC (gel permeation chromatography). , Number average molecular weight (Mn), weight average molecular weight (Mw), and Mw / Mn were determined. The results are shown below.
Number average molecular weight (Mn) 282, weight average molecular weight (Mw) 478, Mw / Mn 1.70

About metal resin composite material (A-1), the spectrum measurement was performed with the X-ray photoelectron spectroscopy analyzer (Escalab-220iXL, the product made by Thermo Fisher Scientific Co., Ltd.). The measurement conditions at this time were set as follows.
・ Irradiated X-ray: Monochrome AlKα
・ Detection depth: about 5nm
・ X-ray spot diameter: about 1mm

FIG. 1 is a diagram showing an Ag3d narrow scan spectrum measured for the metal resin composite material (A-1).
FIG. 2 is a diagram showing an Ag3d narrow scan spectrum measured for a sample obtained by cleaning an Ag foil with Ar ions.
In the spectrum shown in FIG. 1, the peak position of Ag3d5 was 368.9 eV. On the other hand, in the spectrum shown in FIG. 2, the peak position of Ag3d5 was 368.3 eV, and a difference of 0.6 eV was observed in the peak position between the two.
Usually, the peak of Ag alone appears at 368.1 to 368.3 eV, whereas in a compound in which an Ag atom and an O atom interact, such as silver acetate, this peak is 368.3. It is known to appear at 368.9 eV (Source: Handbook ofX-ray Photoelectron Spectroscopy (Physical Electronics)).
From this, it can be confirmed that the metal resin composite material (A-1) has an Ag—O—C bond in its structure.

FIG. 3 is a view showing an image obtained by observing the surface of the metal resin composite material (A-1) with a transmission electron microscope (TEM).
From the image shown in FIG. 3, in the metal resin composite material 10, it can be confirmed that the silver particles 1 of the order of several tens of nm are uniformly dispersed in the matrix 2 of the resol type phenol resin.

<Manufacture of resin ink material (sintered material)>
Example 1
100 g of the metal resin composite material (A-1) was dissolved in 300 g of xylene as a solvent to obtain a resin ink material (sintered material).

(Comparative Example 1)
The resol type phenol resin obtained above, silver powder having an average particle diameter of 1 μm (manufactured by DOWA), and xylene were mixed at room temperature for 10 minutes to obtain a resin ink material (sintered material).
The amount of each component was 300 g of xylene, 20 g of a resol type phenol resin, and 80 g of silver powder.

<Manufacture of sintered body>
(Example 2, comparative example 2)
A bar coater was applied to the portions where the resin ink materials (sintered materials) obtained in Example 1 and Comparative Example 1 were masked with a film of size 3 mm × 30 mm on the aluminum foil (thickness 80 μm) of the substrate. Was applied to form a coating film having a thickness of 100 μm.
Next, xylene contained in the coating film was dried to prepare an ink coating film on the aluminum foil.
Thereafter, the aluminum foil on which the ink coating film was produced was heat-treated in an oven at 200 ° C. for 60 minutes in a nitrogen atmosphere to obtain a sintered body.

<Evaluation of sintered body>
About the sintered compact of each example, the average film thickness (micrometer) and the specific resistance value (volume resistance value (ohm * cm)) were measured. The measurement results are shown in Table 1.
The average film thickness (μm) was measured with a micrometer.
The specific resistance value (volume resistance value (Ω · cm)) of the sintered body was measured by a four-terminal method.

  From the results shown in Table 1, it can be confirmed that the conductivity of the sintered body of Example 2 to which the present invention is applied is higher than that of the sintered body of Comparative Example 2.

1 silver particles,
2 matrix,
10 Metal resin composite material

Claims (5)

(A) component: a composite of metal particles (a1) and a phenol resin (a2), a metal resin composite material having a metal atom-oxygen atom-carbon atom bond, and
Component (B): A sintered material containing an organic solvent component.   Content of the said (A) component is a sintered material of Claim 1 which is 5-50 mass%.   The metal constituting the metal particles (a1) is at least one selected from the group consisting of silver, copper, tin, nickel, iron, zinc, manganese, and aluminum. Wood.   The ratio of the said metal particle (a1) to the said (A) component is 1-85 mass%, The sintered material as described in any one of Claims 1-3.   The sintered compact which has a coupling | bond part of the said metal particle (a1) contained in the sintered compact as described in any one of Claims 1-4.