JP2019196446A - Polymer and paste composition - Google Patents

Abstract

To provide a polymer excellent in thixotropic properties and also excellent in thermal decomposability.SOLUTION: The polymer has a molar ratio of a monomer (A) represented by formula (1) of 10-100 mol% and has a weight average molecular weight of 10,000-1,000,000. (Rrepresents a hydrogen atom or a methyl group; Rrepresents a C1-18 alkyl group or a C1-18 hydroxyalkyl group; A represents a C1-10 alkylene group; X represents 0 or 1; and Yis one or more structures selected from the group consisting of hydroxyurethane structures.)SELECTED DRAWING: None

Description

  The present invention relates to a polymer particularly excellent as a binder resin for paste, which is excellent in thixotropic property and thermal decomposability.

  The metal paste used for the formation of internal electrode layers of multilayer electronic components such as multilayer ceramic capacitors and the formation of conductive layers of solar cells consists mainly of metal powders such as nickel and copper, a solvent, and a binder resin. It is printed on the sheet by a method such as printing.

  As shown in Patent Document 1, an ethyl cellulose resin that has high thixotropy and does not have stringing or bleeding at the time of printing and is suitable for printing is used as the binder resin. However, since ethylcellulose has low thermal decomposability and a carbon component remains at the time of firing, there is a problem that there is a large amount of heating residue and leads to electrode defects.

  Acrylic resin, on the other hand, has excellent thermal decomposability, but has low thixotropy, high stringiness increases stringing, and lowering viscosity to reduce stringing causes bleeding during printing. There was a problem that it was not suitable for printing. Here, the thixotropic property of the metal paste means a property in which the apparent viscosity is low when the shear rate is high and the apparent viscosity is high when the shear rate is low and when the shear rate is not sheared.

JP2012-181988

  2. Description of the Related Art In recent years, multilayer devices such as multilayer ceramic capacitors have been made thinner and multilayered green sheets for the purpose of downsizing. However, as thinning progresses, the problem that the effect of defects due to residual carbon content in the electrode layer becomes large at the time of firing becomes obvious, excellent thixotropy, no stringing or bleeding at the time of printing, printing Therefore, there is a demand for a polymer that is suitable as a binder resin that has excellent properties for thermal decomposition but is more excellent in thermal decomposability and has less residual carbon content.

  In order to solve such problems, there is a demand for a polymer that is excellent in thixotropy and has high printability without stringing or bleeding at the time of printing, but also has excellent thermal decomposability and little heating residue.

  An object of the present invention is to provide a polymer having excellent thixotropy, no stringing or bleeding at the time of printing, and excellent thermal decomposition.

  As a result of studies to solve the above problems, the present inventors have found that the above problems can be solved by a polymer having a specific structure having a hydroxyurethane structure.

（式（１）中、
Ｒ_１は、水素原子またはメチル基を示し、
Ｒ_２は、炭素数１〜１８のアルキル基または炭素数１〜１８のヒドロキシアルキル基を示し、
Ａは、炭素数１以上、１０以下のアルキレン基を示し、
Ｘは０または１を示し、
Ｙ_１は、下記式（２）および下記式（３）のヒドロキシウレタン構造からなる群より選ばれた一種以上の構造である。）

That is, the present invention is as follows.
[1] The molar ratio of the monomer (A) represented by the following formula (1) is 10 mol% to 100 mol%, and the molar ratio of the other monomer (B) copolymerizable with the monomer (A) is 0. A polymer having a weight average molecular weight of 10,000 to 1,000,000 and a molecular weight of ˜90 mol%.

(In the formula (1),
R ₁ represents a hydrogen atom or a methyl group,
R ₂ represents an alkyl group having 1 to 18 carbon atoms or a hydroxyalkyl group having 1 to 18 carbon atoms,
A represents an alkylene group having 1 to 10 carbon atoms,
X represents 0 or 1,
Y ₁ is one or more structures selected from the group consisting of hydroxyurethane structures of the following formula (2) and the following formula (3). )

[2] A conductive paste composition comprising the polymer according to [1], an organic solvent, and metal particles.

[3] When the ratio of the metal particles is 100 parts by weight, the ratio of the polymer is 0.5 to 30 parts by weight, and the ratio of the organic solvent is 10 to 200 parts by weight. [2] The conductive paste composition.

  The polymer of the present invention is excellent in solubility in a paste solvent, excellent in thixotropy, free from stringing or bleeding during printing, and excellent in thermal decomposability. As a result, a paste using the polymer of the present invention as a binder resin, particularly a metal paste, has high printability and can reduce the residual carbon content during firing.

Embodiments of the present invention will be described below.
[Monomer (A)]
The monomer (A) used in the present invention is represented by the following general formula (1).

In Formula (1), R ₁ is a hydrogen atom or a methyl group, and a methyl group is particularly preferable from the viewpoint of ease of polymerization.

R ₂ is an alkyl group having 1 to 18 carbon atoms or a hydroxyalkyl group having 1 to 18 carbon atoms. Examples of the alkyl group having 1 to 18 carbon atoms include a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, iso-butyl group, tert-butyl group, n-hexyl group, n-octyl group, Examples include 2-ethylhexyl group, decyl group, dodecyl group, stearyl group and the like. In view of ease of synthesis and thixotropy, the alkyl group constituting R ₂ preferably has 2 to 12 carbon atoms, and more preferably 3 to 6 carbon atoms.

Examples of the hydroxyalkyl group having 1 to 18 carbon atoms include a hydroxymethyl group, a 2-hydroxyethyl group, a 3-hydroxypropyl group, a 2-hydroxypropyl group, a 4-hydroxybutyl group, a 5-hydroxybutyl group, and 8 -Hydroxyoctyl group, 12-hydroxydodecyl group and the like are mentioned, and from the viewpoint of ease of synthesis and thixotropy, the number of carbon atoms of the hydroxyalkyl group constituting R ₂ is preferably 2-12, more preferably 2-6. .

From the viewpoint of solubility in the paste solvent, R ₂ is more preferably an alkyl group.

  A is an alkylene group having 1 to 10 carbon atoms, and preferably 6 or less carbon atoms, more preferably 4 or less carbon atoms from the viewpoint of thixotropic properties.

  X is 0 or 1, and 0 is preferable from the viewpoint of thixotropy.

Y ₁ is one or more hydroxyurethane structures selected from the group consisting of the hydroxyurethane structures of formula (2) and formula (3). From the viewpoint of thixotropy, the structure of the formula (2) is particularly preferable.
A monomer (A) may be used individually by 1 type, and may use 2 or more types together.

  Of the monomers constituting the polymer, the molar ratio of the monomer (A) is 10 mol% or more. If the molar ratio of the monomer (A) is too low, the thixotropic property may be lowered. Therefore, the molar ratio is set to 10 mol% or more, preferably 15 mol% or more, and more preferably 20 mol% or more.

  Moreover, the monomer (A) molar ratio among the monomers constituting the polymer is 100 mol% or less. When the molar ratio of the monomer (A) is 100 mol%, the polymer of the present invention becomes a homopolymer, and when the molar ratio of the monomer (A) is less than 100 mol%, the polymer of the present invention. Becomes a copolymer. By making the molar ratio of the monomer (A) 50 mol% or less, the thermal decomposability of the polymer is further improved, but from this viewpoint, it is more preferably 40 mol% or less.

As the monomer (A), a monomer obtained by mixing the isomer of the monomer (A) represented by the formula (4) or the formula (5) with the hydroxy urethane structure of Y _{1 in} the formula (1) may be used. .

[Monomer (B)]
The monomer (B) is a vinyl monomer copolymerizable with the monomer (A), and examples thereof include (meth) acrylic acid ester compounds, aromatic alkenyl compounds, vinyl cyanide compounds, and acrylamide compounds.

  Examples of the (meth) acrylic acid ester compound include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, tert-butyl (meth) acrylate, n- Examples include hexyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, and the like.

  Examples of the aromatic alkenyl compound include styrene, α-methyl styrene, p-methyl styrene, p-methoxy styrene and the like.

  Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile.

  Examples of acrylamide compounds include acrylamide and methacrylamide.

  A monomer (B) may be used individually by 1 type, and may use 2 or more types together. Among these, (meth) acrylic acid ester compounds are preferable from the viewpoint of solvent solubility and thermal decomposability, and (meth) acrylic acid alkyl ester compounds are particularly preferable. The alkyl group preferably has 1 to 24 carbon atoms, more preferably 1 to 12 carbon atoms, still more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 4 carbon atoms. Most preferred are methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, and iso-butyl (meth) acrylate.

  In the monomer mixture, the total amount of the monomer (A) and the monomer (B) is 100 mol%. Therefore, the molar ratio of the monomer (B) is 0 to 90 mol%.

(Polymer)
The weight average molecular weight of the polymer of the present invention can be determined in terms of polystyrene using gel permeation chromatography (GPC), and is 10,000 to 1,000,000, preferably 10,000 to 800,000. 000, more preferably 30,000 to 300,000. If the weight average molecular weight of the polymer is too low, the strength and viscosity of the polymer will be insufficient, and if the weight average molecular weight is too high, solvent solubility and printability may be reduced.

[Method for Producing Monomer (A)]
The monomer (A) of the present invention is a monomer having a hydroxyurethane bond.
The monomer (A) can be obtained, for example, by an addition reaction between a compound having both a (meth) acryloyl group and a 5-membered cyclic carbonate group and an amine compound.

  The compounds having both a (meth) acryloyl group and a 5-membered cyclic carbonate group used in the present invention are represented by general formulas (6) and (7).

However, in the general formula (6) and (7), _{R 1} is a hydrogen atom or a methyl group, _{R 2} represents an alkyl or hydroxyalkyl group having 1 to 19 carbon atoms having 1 to 18 carbon atoms, A is An alkylene group having 1 to 10 carbon atoms is shown, and X represents 0 or 1. )

  Specific examples of the compounds represented by the general formulas (6) and (7) include the following compounds (6-1) to (6-3) and (7-1).

  The amine compound is preferably a primary amine compound or a secondary amine compound, and more preferably a primary amine compound.

  The reaction between the five-membered ring carbonate compound and the amine compound can be carried out by a known method by mixing the two and raising the temperature as desired. Moreover, you may add a well-known polymerization inhibitor as needed. This reaction is desirably performed at a temperature of 0 to 100 ° C, preferably 5 to 50 ° C. The above reaction may use a solvent, and can be performed in the presence of acetone, methyl isobutyl ketone, ethyl acetate, butyl acetate, toluene, xylene, tetrahydrofuran, or the like.

[Production method of polymer]
Next, a method for producing the polymer of the present invention will be described.
The polymer in the present invention can be obtained by radical polymerization of a monomer mixture containing at least the monomer (A). The polymerization can be performed by a known method. For example, solution polymerization, suspension polymerization, emulsion polymerization and the like can be mentioned, but solution polymerization and suspension polymerization are preferable in terms of easy adjustment of the weight average molecular weight of the copolymer within the above range.

A well-known thing can be used for a polymerization initiator. For example, di (4-t-butylcyclohexyl) peroxydicarbonate, organic peroxides such as 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,2′-azobis Examples thereof include azo polymerization initiators such as isobutyronitrile. These polymerization initiators may be used alone or in combination of two or more.
The usage-amount of a polymerization initiator can be suitably set according to the combination of the monomer to be used, reaction conditions, etc.

  In addition, when charging the polymerization initiator, for example, the whole amount may be charged all at once, a part may be charged all at once and the rest may be dropped, or the whole amount may be dropped. Moreover, it is preferable to add a polymerization initiator together with the monomer because the control of the reaction is easy, and it is preferable to add a polymerization initiator even after the monomer is added because the residual monomer can be reduced.

  As a polymerization solvent used in the solution polymerization, a solvent in which a monomer and a polymerization initiator are dissolved can be used. Specifically, methanol, ethanol, 1-propanol, acetone, methyl ethyl ketone, propylene glycol monomethyl ether, etc. Can be mentioned.

  The concentration of the monomer (total amount) with respect to the polymerization solvent is preferably 10 to 60% by mass, particularly preferably 20 to 50% by mass. If the concentration of the monomer mixture is too low, the monomers are likely to remain, and the molecular weight of the resulting copolymer may be reduced. If the concentration of the monomer is too high, it may be difficult to control heat generation.

  When the monomer is added, for example, the whole amount may be charged all at once, a part may be charged all at once and the rest may be dropped, or the whole amount may be dropped. From the viewpoint of easy control of heat generation, it is preferable to prepare a part of the solution and add the rest, or add the entire amount.

  The polymerization temperature depends on the type of the polymerization solvent, and is, for example, 50 ° C to 110 ° C. The polymerization time depends on the type of polymerization initiator and the polymerization temperature. For example, when di (4-t-butylcyclohexyl) peroxydicarbonate is used as the polymerization initiator, the polymerization temperature is set to 70 ° C. A suitable time is about 6 hours.

  By performing the above polymerization reaction, a copolymer according to the resin composition of the present invention is obtained. The obtained copolymer may be used as it is, or may be isolated by filtering or purifying the reaction solution after the polymerization reaction.

[Metal paste]
The polymer of the present invention is particularly suitable as a binder resin for metal paste. The metal paste contains a metal powder and a solvent in addition to the polymer of the present invention.

Examples of such metal powders include platinum, gold, silver, copper, nickel, tin, palladium, aluminum, and alloys of these metals. Among these, silver, copper, nickel, and aluminum are preferable, and nickel is more preferable. The central particle size (D ₅₀ ) of the metal powder, that is, the volume cumulative particle size D50 measured by a laser diffraction / scattering particle size distribution measuring device is preferably 0.05 μm to 50.0 μm. Among these, 0.06 μm to 10.0 μm is more preferable, 0.07 μm to 1.00 μm is further preferable, and 0.10 μm to 0.30 μm is particularly preferable. The particle size can be determined by a dynamic light scattering method or a laser diffraction particle size distribution measuring device.

  Examples of the solvent include hydrocarbon solvents such as toluene and xylene, ester solvents such as ethyl acetate and butyl acetate, alcohol solvents such as methanol, ethanol, isopropyl alcohol, isobutyl alcohol, 1-butanol and diacetone alcohol, Glycol ether solvents such as ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, glycol ether acetate solvents such as diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, terpineol, dihydroterpineol Terpineols such as dihydroterpineol acetate Medium, acetone, methyl ethyl ketone, and the like ketone solvents such as methyl isobutyl ketone. Among these, glycol ether acetate solvents and terpineol solvents are preferable, terpineol solvents are more preferable, terpineol or dihydroterpineol is more preferable, and dihydroterpineol is particularly preferable. These can be used alone or in admixture of two or more.

  The content of the binder resin in the metal paste is preferably 0.5 to 30 parts by weight, more preferably 1 to 15 parts by weight, and further more preferably 1 to 10 parts by weight when the weight of the metal powder is 100 parts by weight. 1 to 5 parts by weight is preferable. Further, the content of the solvent in the metal paste is preferably 10 to 200 parts by weight, more preferably 50 to 150 parts by weight, and further preferably 75 to 125 parts by weight, when the weight of the metal powder is 100 parts by weight. . In addition, other components such as a surfactant and an antioxidant can be blended as necessary.

  These mixtures are stirred and dispersed to obtain a metal paste. For the stirring, a known means can be used without particular limitation, and for example, a PD mixer or a planetary kneader can be preferably used, and a planetary kneader is particularly preferably used. For the dispersion, known means can be used without particular limitation, and for example, a kneader, a bead mill, or a three-roll can be used, and a three-roll is particularly preferably used.

  The metal paste is printed on the sheet by a method such as screen printing.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples.
Table 1 below shows the structure and abbreviation of the monomer (A).

(Synthesis Example 1: Monomer A1)
A reactor equipped with a stirrer, a thermometer, a cooler, a dropping funnel and a gas introduction tube, 100 parts of glycidyl methacrylate (manufactured by NOF Corporation, trade name: Bremmer G), and lithium bromide (manufactured by Wako Pure Chemical) as a catalyst ) 5 parts and N-methyl-2-pyrrolidone 100 parts were added, carbon dioxide was continuously blown in with stirring, and the reaction was carried out at 100 ° C. for 12 hours. The progress of the reaction was confirmed by the disappearance of the peak of glycidyl methacrylate as a raw material by gas chromatography (manufactured by Shimadzu Corporation, trade name: GC-2014, column DB-1). After completion of the reaction, 200 parts of toluene and 200 parts of water were added, mixed, and allowed to stand to separate the aqueous layer. After removing the aqueous layer, it was washed 3 times with 100 parts of water. The washed organic layer was concentrated under reduced pressure to synthesize a 5-membered ring carbonate compound.

  After adding 100 parts of dihydroterpineol to 100 parts of this 5-membered ring carbonate compound, cooling and adding dropwise the 5-membered ring carbonate compound and an equimolar amount of butylamine while controlling the internal temperature to 10 ° C. or less while stirring, The mixture was then stirred for 2 hours. The progress of the reaction was confirmed by disappearance of the peak of the 5-membered cyclic carbonate compound by gas chromatography (manufactured by Shimadzu Corporation, trade name: GC-2014, column DB-1).

Monomer A1 is, Y ₁ of the formula (1) is obtained as equation (2) and (3) structural isomer mixture is, after adjusting the monomer concentration in the 50 wt%, it was used as it is polymerized as monomer solution.

(Synthesis Example 2: Monomer A2)
A 50 wt% solution of monomer A2 (isomer mixture) was obtained in the same manner as in Synthesis Example 1, except that the amine compound was changed from butylamine to 3-amino-1-propanol.

(Synthesis Example 3: Monomer A3)
A 50 wt% solution of monomer A3 (mixed isomers) was obtained in the same manner as in Synthesis Example 1 except that the amine compound was changed from butylamine to nonylamine.

(Synthesis Example 4: Monomer A4)
A 50 wt% solution of monomer A4 (mixed with isomers) was obtained in the same manner as in Synthesis Example 1 except that glycidyl methacrylate was changed to 4-hydroxybutyl acrylate glycidyl ether (trade name: 4HBAGE, manufactured by Nippon Kasei Co., Ltd.). It was.

(Synthesis Example 5: Monomer A5)
Except for changing glycidyl methacrylate to 3,4-epoxycyclohexylmethyl methacrylate (manufactured by Daicel Corporation, trade name: Cyclomer M-100), monomer A5 (mixed isomers) was prepared in the same manner as in Synthesis Example 1. A 50 wt% solution was obtained.

(Polymerization Example 1: Copolymer A)
350 g of dihydroterpineol was charged into a 1 L separable flask equipped with a stirrer, a thermometer, a cooler, a dropping funnel, and a nitrogen introducing tube, and the atmosphere in the flask was replaced with nitrogen to create a nitrogen atmosphere. A monomer solution obtained by mixing 151.3 g of isobutyl methacrylate (product name: acrylate ester IB (manufactured by Mitsubishi Rayon Co., Ltd.)) and 97.4 g of a 50% solution of monomer A1, and 50 g of dihydroterpineol and 2,2′-azobis (2 , 4-Dimethylvaleronitrile) (Product name: V-65 (manufactured by Wako Pure Chemical Industries, Ltd.)) 0.4 g mixed with a polymerization initiator solution was prepared.

  The temperature in the reaction vessel was raised to 75 ° C., and the monomer solution and the polymerization initiator solution were simultaneously added dropwise over 3 hours. Then, it was made to react at 75 degreeC for 3 hours, and the dihydro terpineol solution of the copolymer A was obtained.

(Polymerization Example 2: Copolymer B)
Copolymer B was obtained in the same manner as in Polymerization Example 1 except that the amount of isobutyl methacrylate used was changed to 112.3 g and the amount of the 50% monomer A1 solution used was changed to 175.5 g.

(Polymerization Example 3: Copolymer C)
The amount of isobutyl methacrylate used was changed to 70.8 g, the amount of 50% monomer A1 solution used was 258.3 g, and the amount of 2,2′-azobis (2,4-dimethylvaleronitrile) used was changed to 0.9 g. Except for this, copolymer C was obtained in the same manner as in Polymerization Example 1.

(Polymerization Example 4: Copolymer D)
The amount of isobutyl methacrylate used was 111.9 g, the monomer A1 solution was changed to the monomer A2 solution, 176.2 g was used, and the amount of 2,2′-azobis (2,4-dimethylvaleronitrile) used was 0.2 g. A copolymer D was obtained in the same manner as in Polymerization Example 1 except that the copolymer D was changed.

(Polymerization Example 5: Copolymer E)
Copolymer E was obtained in the same manner as in Polymerization Example 1 except that the amount of isobutyl methacrylate used was 100.4 g, the monomer A1 solution was changed to the monomer A3 solution, and 199.3 g was used.

(Polymerization Example 6: Copolymer F)
A copolymer F was obtained in the same manner as in Polymerization Example 1, except that the amount of isobutyl methacrylate used was 102.2 g, the monomer A1 solution was changed to the monomer A4 solution, and 195.6 g was used.

(Polymerization Example 7: Copolymer G)
A copolymer G was obtained in the same manner as in Polymerization Example 1, except that the amount of isobutyl methacrylate used was 102.9 g, the monomer A1 solution was changed to the monomer A5 solution, and 194.3 g was used.

(Polymerization Example 8: Copolymer H)
The copolymer H was prepared in the same manner as in Polymerization Example 1 except that the amount of isobutyl methacrylate used was changed to 84.2 g, the amount of the monomer A1 solution used was changed to 184.2 g, and 23.7 g of methyl methacrylate was used. Obtained.

(Polymerization Example 9: Copolymer I)
A copolymer I was obtained in the same manner as in Polymerization Example 1 except that the amount of isobutyl methacrylate used was changed to 83.8 g, the amount of the monomer A1 solution used was changed to 183.3 g, and 24.5 g of styrene was used. It was.

(Polymerization Example 10: Copolymer J)
A copolymer J was obtained in the same manner as in Polymerization Example 1 except that the amount of isobutyl methacrylate used was changed to 101.3 g, the amount of the monomer A1 solution used was changed to 184.8 g, and 6.3 g of acrylonitrile was used. It was.

(Polymerization Example 11: Copolymer K)
A copolymer K was obtained in the same manner as in Polymerization Example 1 except that the amount of isobutyl methacrylate used was changed to 100.2 g, the amount of the monomer A1 solution used was changed to 182.8 g, and 8.4 g of acrylamide was used. It was.

(Polymerization Example 12: Copolymer L)
A copolymer L was obtained in the same manner as in Polymerization Example 1, except that the amount of isobutyl methacrylate used was changed to 182.5 g and the amount of the monomer A1 solution used was changed to 35.0 g.

(Polymerization Example 13: Copolymer M)
Copolymer M was obtained in the same manner as in Polymerization Example 1 except that 143.7 g of isobutyl methacrylate was used and 56.3 g of 2-hydroxyethyl methacrylate was used instead of monomer A1.

(Measurement of weight average molecular weight)
The weight average molecular weights of the copolymers A to M were determined under the following conditions using gel permeation chromatography (GPC).
Apparatus: manufactured by Tosoh Corporation, HLC-8220
Column: manufactured by shodex, LF-804
Standard substance: Polystyrene Eluent: THF (tetrahydrofuran)
Flow rate: 1.0 ml / min
Column temperature: 40 ° C
Detector: RI (differential refractive index detector)

[Evaluation of thixotropic properties]
A 20 wt% copolymer solution (solvent dihydroterpineol) was prepared, and the shear rate dependence of the viscosity was measured in the range of 1 s-1 to 1,000 s-1 with a rheometer. The ratio of viscosity at 1 s-1 and 1,000 s-1 was calculated as the TI value.

[Evaluation of thermal decomposability]
5 mg of the copolymer was placed in an aluminum pan, heated in a TG / DTA to 500 ° C. in an air atmosphere at a heating rate of 10 ° C./min, and the remaining amount of the sample was measured.

[Evaluation of printability]
1 part by weight of oleoyl sarcosine (manufactured by NOF: Esliem 221P), 3 parts by weight of binder resin, and 90 parts by weight of dihydroterpineol are added to 100 parts by weight of Ni powder (manufactured by JFE Mineral: NFP201S). These mixtures were stirred using a planetary kneader and then kneaded with three rolls to obtain a Ni paste.

  The obtained Ni paste was screen-printed, and the obtained printed body was confirmed with an optical microscope, and it was visually confirmed whether there was any blur or stringing mark. If no bleeding or stringing was observed, “◯” (good), and if bleeding or stringing was observed, “×” (bad).

  In Examples 1 to 11, the thixotropy value was high, the heating residue was small, and the printability was high.

  In Comparative Example 1, the ratio of the monomer A1 was less than 10 mol%, but the heating residue was reduced, but the thixotropy value was low and the printability was also low.

  In Comparative Example 2, the copolymer containing no monomer of the present invention was used, but the heating residue was reduced, but the thixotropy value was low and the printability was also low.

In Comparative Example 3, ethyl cellulose was used, but the thixotropy value was large and the printability was high, but the heating residue increased.

Claims (3)

The molar ratio of the monomer (A) represented by the following formula (1) is 10 to 100 mol%, and the molar ratio of the other monomer (B) copolymerizable with the monomer (A) is 0 to 90 mol. %, And a weight average molecular weight of 10,000 to 1,000,000.

(In the formula (1),
R ₁ represents a hydrogen atom or a methyl group,
R ₂ represents an alkyl group having 1 to 18 carbon atoms or a hydroxyalkyl group having 1 to 18 carbon atoms,
A represents an alkylene group having 1 to 10 carbon atoms,
X represents 0 or 1,
Y ₁ is one or more structures selected from the group consisting of hydroxyurethane structures of the following formula (2) and the following formula (3). )

A conductive paste composition comprising the polymer according to claim 1, an organic solvent, and metal particles.
The ratio of the polymer is 0.5 to 30 parts by weight when the ratio of the metal particles is 100 parts by weight, and the ratio of the organic solvent is 10 to 200 parts by weight. 2. The conductive paste composition according to 2.