TW202336122A - Paste for electronic components - Google Patents

Abstract

The present invention provides a paste for electronic components, the paste containing a binder that has the characteristics of a cellulose resin and the characteristics of a terminal functional group derived from a resin of another kind or a low-molecular weight material of another kind at the same time with good compatibility, and the paste enabling the achievement of a smooth coating film. The present invention relates to a paste for electronic components, the paste containing inorganic particles, a dispersant, a binder and an organic solvent. With respect to this paste for electronic components, the binder contains, for example, at least a copolymer which is represented by general formula 1, wherein a first binding site at one end of the molecular chain of a cellulose resin is bonded to a resin of another kind or a low-molecular weight material of another kind by an ester bond or an amide bond.

Description

Paste for electronic parts

The invention relates to a paste for electronic parts that contains inorganic particles, dispersants, adhesives and organic solvents used in the manufacture of electronic parts, especially the improvement of adhesives.

For example, as laminated ceramic capacitors become higher in capacity and smaller in size, there is a demand for multilayering and thinning of dielectric sheets and internal electrode layers. In addition, good adhesion between the dielectric layer and the internal electrode layer, good printability of the internal electrode layer, and high strength of the internal electrode layer are required.

Previously, the conductive paste used to form the internal electrode layer used cellulose-based resin as a binder. However, there was insufficient adhesion between the cellulose-based resin and the acetal-based resin commonly used as a binder in dielectric sheets. Sometimes the problem of delamination between layers occurs.

Therefore, a technique has been proposed, for example, as described in Japanese Patent No. 5299904 (Patent Document 1), in which a cellulose-based resin and an acetal-based resin are blended as a binder used in a conductive paste. Improve the adhesion between the dielectric layer and the internal electrode layer; or, for example, as described in Japanese Patent No. 5224722 (Patent Document 2), maintain the dielectric by blending a cellulose-based resin and an acetal-based resin It has the effect of improving the adhesion between the body layer and the internal electrode layer, and further improves the compatibility between the cellulose resin and the acetal resin, and improves the storage stability.

However, in the blending of resins as described in Japanese Patent Documents 1 and 2, the compatibility is relatively low. Therefore, for example, in the technology described in International Publication No. 2015/107811 (Patent Document 3), cross-linking is performed using a binding agent containing a dicarboxylic acid using the hydroxyl groups of cellulose-based resins and acetal-based resins. Made of adhesive to improve adhesion and compatibility. Prior art documents Patent documents

Patent Document 1: Japanese Patent No. 5299904 Patent Document 2: Japanese Patent No. 5224722 Patent Document 3: International Publication No. 2015/107811

[Problem to be solved by the invention]

Generally, a polysaccharide solution with a large number of hydroxyl groups increases in viscosity and gels as the concentration of the polysaccharide increases. It is said that when the concentration of polysaccharides in a liquid is high, the polysaccharide molecules entangle with each other and partially combine, thereby building a network network based on this part as a base point, and the entire solution becomes a gel.

In Patent Document 3, the following method is designed to combine the cellulose resin and the acetal resin. That is, for the less reactive site as the hydroxyl group remaining in the cellulose resin, a lower reactivity than the acetal resin is used. The molecular weight of the binder makes it easy to react with acetal resin.

However, as a result, cross-linked products of cellulose-based resins or cross-linked products of acetal-based resins are also easily produced. At this time, a cross-linked product with a network structure is formed, and sometimes a cross-linked product with a huge cyclic structure may be formed. In particular, cross-linked products composed only of cellulose-based resins cause gelation as in the above-mentioned examples, and if they are locally present in the paste for electronic components, the smoothness of coating films such as internal electrode layers may be impaired.

In the adhesion phenomenon of polymers, the molecular structure of the polymer main chain and side chains has a greater influence. As the second largest influencing factor, it is speculated that the molecular structure of the polymer terminals is there. The reason is: it is believed that because the molecular size of polymers is very large and the polymers are entangled with each other, it is difficult for the polymer as a whole to move during the bonding process. Especially in the initial process of bonding where there are time or temperature constraints, the degree of freedom of movement is limited. The relatively high molecular structure of the polymer terminal facilitates adhesion. Therefore, it is considered that in order to improve the adhesion to the dielectric sheet, in addition to the method of combining different types of resins with the cellulose-based resin, it is considered that low-molecular hydrogen bonds that contribute to improving the adhesion are introduced into the terminals of the cellulose-based resin. Methods of coordination bonds and terminal functional groups capable of realizing dipolar interactions, acid-base interactions, etc. are also effective.

Therefore, the object of this invention is to provide a paste for electronic parts, in which the adhesive has both the characteristics of cellulose-based resins and the characteristics of terminal functional groups derived from different types of resins or different types of low molecules, and is compatible with both. With good properties, the above-mentioned paste for electronic parts can obtain a smooth coating film. [Technical means to solve problems]

The invention is characterized in that it relates to a paste for electronic parts containing inorganic particles, a dispersant, a binder and an organic solvent. The above-mentioned binder at least contains: (A) The first of the single ends of the molecular chain of the cellulose resin. A copolymer represented by the general formula of Formula 1 below or the general formula of Formula 2 below, or (B) fiber in which the bonding part is an ester bond or an amide bond and is connected to a different kind of resin or a different kind of low molecule The following formula in which the first bonding part at one end of the molecular chain of the base resin is an ester bond or an amide bond and is connected to the second bonding part (X) and a different type of resin through a binding agent (R ₃ ) A copolymer represented by the general formula 3 or the general formula 4 below.

[Chemical 1]

[Chemicalization 2]

In the formula, R ₁ represents hydrogen, alkyl, hydroxyalkyl or hydroxyl group, R ₂ represents different types of resin or alkyl group.

[Chemical 3]

[Chemical 4]

In the formula, R ₁ represents hydrogen, alkyl, hydroxyalkyl or amide group, R ₄ represents different types of resins, R ₃ represents a binding agent containing an alkyl or sulfide group, and X represents an ester bond or amide bond. [Effects of the invention]

According to the paste for electronic parts of the invention, the binder contained therein has both the characteristics of cellulose-based resins and the characteristics of terminal functional groups derived from different types of resins or different types of low molecules, and can realize the combination of cellulose-based resins and Good compatibility between different types of resins or different types of low molecules. In addition, in the adhesive, resin that causes gelation is less likely to form, so it is possible to obtain a paste for electronic parts that does not impair the smoothness of the coating film.

The paste for electronic parts of the invention contains inorganic particles, dispersant, adhesive and organic solvent. The binder at least contains: (A) One of the following compounds in which the first bonding part at one end of the molecular chain of the cellulose resin is an ester bond or an amide bond and is connected to different types of resins or different types of low molecules. A copolymer represented by the general formula or the general formula of Formula 6 below, or (B) a cellulose resin in which the first bonding portion at one end of the molecular chain is an ester bond or an amide bond via a binding agent (R ₃ ) is a copolymer represented by the general formula of Formula 7 below or the general formula of Formula 8 below that is connected to the second bonding part (X) and a different type of resin.

[Chemistry 5]

[Chemical 6]

In the formula, R ₁ represents hydrogen, alkyl, hydroxyalkyl or hydroxyl group, R ₂ represents different types of resin or alkyl group. The alkyl group as R ₂ preferably has 1 to 4 carbon atoms.

[Chemical 7]

[Chemical 8]

In the formula, R ₁ represents hydrogen, alkyl, hydroxyalkyl or amide group, R ₄ represents different types of resins, R ₃ represents a binding agent containing an alkyl or sulfide group, and X represents an ester bond or amide bond.

The method of combining the cellulose resin contained in the above-mentioned adhesive with different types of resins or different types of low molecules can be based on commonly used ester bonding or amide bonding reactions. Therefore, as long as different types of resins or different types of low molecules are used, The low molecules only need to have hydroxyl or amine groups, and the selection of materials is wide.

Therefore, in addition to the characteristics such as viscosity expression, elasticity, and printability of cellulose-based resins, it is also necessary to impart characteristics of terminal functional groups derived from different types of resins or different types of low molecules (for example, adhesive properties). properties, adhesion to sheet adhesives containing different types of resins, etc.), it can be obtained by combining cellulose-based resin with different types of resins or different types of low molecules through the above synthesis method. A binder that has the characteristics of cellulose-based resins and the characteristics of terminal functional groups derived from different types of resins or different types of low molecules.

Furthermore, in this invention, when different types of resins are combined, the compatibility between the cellulose-based resin and the different types of resins can be improved. Furthermore, since one single terminal carboxyl group of the cellulose-based resin is used for bonding with different types of resins, only a graft structure is formed instead of a network structure as a combination of cellulose-based resins. As a result, it is difficult to Since a resin is formed that causes gelation, the smoothness of the coating film obtained by using the paste for electronic parts of the present invention is less likely to be impaired.

In this invention, when an ester group or a amide group is introduced as a terminal functional group derived from a different type of low molecule, the hydrogen of an acetal resin commonly used as a binder in a cellulose resin and a dielectric sheet is Bonding can improve adhesion. In addition, it does not exhibit abnormal behavior such as adsorption of powder, so the smoothness of the paste film is also excellent.

In the above aspect (B), the binding agent (R ₃ ) is a binding agent containing an alkyl group or a sulfide group. However, except for the case where a vinyl group or an allyl group is introduced to perform a binding reaction based on free radicals, no binding reaction will occur. A combination of different types of resins. Therefore, it is preferable not to use a binder introducing a vinyl group or an allyl group.

When combining different types of resins in this invention, by selecting optimal conditions shown in the following experimental examples, even cellulose-based resins that are prone to gelation with each other can be combined with different types of resins. The blending ratio or the reaction conditions using the binder (R ₃ ) in (B) above only form a graft structure and do not easily form a resin that causes gelation, thereby preventing the smoothness of the coating film from being damaged.

The cellulose-based resin is preferably a cellulose ether having a carboxyl group at one end of the molecular chain. The reason is that if the following synthesis reaction scheme is considered, it is more practical to obtain a cellulose ether having a carboxyl group at one end of the molecular chain as a cellulose-based resin.

The above-mentioned cellulose ether is preferably alkyl cellulose.

Terminal functional groups derived from different types of resins and different types of low molecules are used, for example, to supplement the characteristics that cellulose-based resins do not have or to enhance the characteristics of cellulose-based resins.

The different types of resins are not particularly limited. For example, the resins that can be used include polyvinyl acetal resins, acrylic resins, polycarbonate resins, polyurethane resins, and polyether resins having hydroxyl or amine groups. At least one of the group consisting of resin and polyester resin.

As terminal functional groups derived from different types of low molecules, ester groups or amide groups that are relatively conducive to hydrogen bonding and can improve adhesion can be used.

The content ratio of cellulose-based resin and different types of resins is preferably in the range of 80:20 to 20:80 in terms of mass, more preferably in the range of 60:40 to 40:60 in terms of mass. By selecting such a ratio, the performance of both the cellulose-based resin and the resin of different types can be reliably exhibited.

The dispersant is usually a low-molecular single-terminal adsorption dispersant or a comb-type polymer dispersant, and is not particularly limited. A polycarboxylic acid-based dispersant is particularly preferred.

The inorganic particles contained in the paste for electronic components of the present invention preferably include at least one of ceramic particles and metal particles. For example, a paste used to form a dielectric layer in a multilayer ceramic capacitor contains at least ceramic particles, and a paste used to form an internal electrode layer contains at least metal particles. The ceramic particles include, for example, at least one element selected from the group consisting of Ba, Ti, Ca, Zr, and Sr. The metal particles include, for example, at least one metal selected from Cu, Ni, Au, and Ag.

"Experimental Example" In this experimental example, as a paste for electronic parts, 26 types of conductive pastes containing various binders were produced, targeting conductive pastes used to obtain internal electrode layers of multilayer ceramic capacitors.

Details of the 26 types of samples produced in this experimental example are shown in Table 3 below. Among these samples, "Examples" include adhesives composed of cellulose-based resins and different types of resins, and "Comparative Examples" "Contains binders that are simple blends of cellulosic resins and different types of resins.

Cellulose derivatives having a single terminal carboxyl group were synthesized as described below. Here, as a synthesis method of a cellulose derivative having a single terminal carboxyl group, a synthesis method using ethylcellulose, which is a type of cellulose derivative and is widely used in pastes for electronic parts and the like, is adopted. In addition, the synthesis method is not particularly limited to the method shown below.

(1) Single-terminal carboxylated cellulose is generated through the oxidation reaction of the reducing terminal of cellulose. 50% sodium hydroxide aqueous solution (1680 g) was added to the water-dispersed cellulose slurry (solid content: 1440 g). Thereafter, sodium anthraquinone-2-sulfonate (24 g) dissolved in 30% hydrogen peroxide was added and stirred to oxidize the reducing end of the cellulose, followed by filtration and water washing to obtain the single-terminal carboxyl group. Chemical cellulose. This reaction is a reaction in which the formyl group in the form of a formyl group is oxidized into a carboxyl group by ring opening in the tautomerization of the reducing terminal of cellulose.

Furthermore, various methods are known for the oxidation reaction of the reducing end of cellulose or the carboxyl group of the ring-opened sugar.

(2) Deprotonation reaction using sodium hydroxide Add 50% sodium hydroxide aqueous solution to the aqueous solution of carboxylated cellulose at one end, and stir at 60°C for 20 minutes to obtain alkali cellulose with a hydroxyl group of -ONa and a single end of -COONa.

(3) Ethoxylation (etherification) reaction and ethyl esterification reaction using ethyl chloride In a 0.5 MPa pressure kettle, alkali cellulose and ethyl chloride were stirred at 110°C for 12 hours to obtain ethyl cellulose with a hydroxyl group of -OEt and a single end of -COONa or -COOH or -COOEt. Furthermore, the degree of substitution (DS) of the ethoxylation of the three OH groups of the monomer units of the cellulose thus obtained is in the range of 2.46 to 2.58 (the degree of ethoxylation is 48.0 to 49.5% by mass). Method to adjust the amount of sodium hydroxide and ethyl chloride added.

Furthermore, in this synthesis, more etherification reactions are carried out than esterification reactions, so there are fewer esterification reactions into -COOEt.

(4) Hydrolysis reaction of ester Carry out a reaction to convert -COOEt of ethyl cellulose with -COOEt at one end to -COOH by hydrolysis, and obtain a hydroxyl group of -OEt (degree of substitution 2.5) and a single end of -COONa (carboxylate) or -COOH (carboxyl group) ) of ethylcellulose.

There are various hydrolysis reaction conditions, and the reaction can proceed by adding water to the alcohol solvent and heating. In order to carry out the reaction efficiently, a catalyst can also be added. Furthermore, when using ethyl chloride in the etherification reaction, esterification is not easy to proceed. Therefore, even if this step is not performed, most of the ethyl esters with single terminal -COONa (carboxylate) or -COOH (carboxyl group) can be obtained. base cellulose.

(5) Wash and dry After washing with hot water to remove salts or by-products, dry under reduced pressure to obtain an ethoxy group with -COONa (carboxylate) or -COOH (carboxyl group) at one end and -OEt (ether) at the other end. The solid of single-terminal carboxylated ethyl cellulose with a degree of substitution of 2.5. By adjusting the number average molecular weight of the initially used cellulose within the range of 10,000 to 100,000, it is possible to produce the first single-terminal carboxylated ethyl cellulose with a number average molecular weight Mn of 13,000 (expressed as " in Table 3 CC1"), the 2nd single-terminal carboxylated ethyl cellulose with a number average molecular weight Mn of 20,000, the 3rd single-terminal carboxylated ethyl cellulose with a number average molecular weight Mn of 54,000, and the 4th single-terminal carboxylated ethyl cellulose with a number average molecular weight Mn of 88,000 Four types of single-terminal carboxylated ethyl cellulose (shown as "CC4" in Table 3).

In addition, the number average molecular weight was determined by carrying out gel permeation chromatography (GPC) measurement using polystyrene as a standard polymer and tetrahydrofuran (THF) as an eluent.

(6) Quantification of carboxyl groups in single-terminal carboxylated ethyl cellulose The amount of carboxyl groups in single-terminal carboxylated ethyl cellulose synthesized in the above manner was quantified by ¹ H-NMR measurement. It is expected that the conventional NMR measurement will not be quantitatively sensitive enough for trace amounts of terminal carboxyl groups, so the trimethylsilyl (TMS) derivatization method was used.

The TMS derivatization method is a method of replacing the H of the hydroxyl group contained in the carboxyl group of ethylcellulose with a trimethylsilyl group (Si(CH ₃ ) ₃ ). Through this derivatization, the number of hydrogens in the carboxyl group changes from 1H to 9H. Therefore, the detection sensitivity in ¹ H-NMR is 9 times.

The derivatization product was obtained by adding ethylcellulose and a derivatization reagent (BSTFA) to a dehydrated chloroform solvent and heating at 70°C for 1 hour. The derivatization reagent acts on both the hydroxyl group and the carboxyl group of ethyl cellulose. Therefore, the amount of reagent added is about 1.5 times the molar amount of the hydroxyl group and terminal carboxyl group of ethyl cellulose. Furthermore, it was confirmed that even if the added reagent amount exceeds 1.5 times the molar amount, the quantitative value of the TMS-containing hydroxyl group or carboxyl group does not change. The reaction solution was returned to room temperature, dried under vacuum, and then separated by GPC to obtain a dry and hardened product of the derivatization product from which the solvent and unreacted derivatization reagent were removed. The dried and hardened product was redissolved in deuterated chloroform as a solvent for NMR measurement, and ¹ H-NMR measurement was performed. The ¹ H-NMR spectrum of the ethylcellulose derivatization product is shown in Figure 1.

In the ¹ H-NMR spectrum of the ethylcellulose derivatization product, a peak derived from the derivatization of the carboxyl group was detected at 0.3 ppm indicated by the arrow in Figure 1. Based on the peak area ratios of cellulose skeleton, ethoxy groups, carboxyl groups, and hydroxyl groups observed in ¹ H-NMR, the molar ratio of each was calculated to determine the concentration of carboxyl groups in ethyl cellulose. Table 1 shows the quantitative results of carboxyl groups and the corresponding average molecular weight of the sample. In addition, GPC was measured in THF solvent, and the number average molecular weight was calculated in polystyrene conversion.

[Table 1] Table 1 Sample number Average molecular weight Mn (GPC) Amount of carboxyl group (mmol/g) σ(n=3) CV% 1 13000 0.172 0.006 3.5 2 20000 0.111 0.006 5.0 3 54000 0.042 0.003 6.0 4 88000 0.026 0.003 5.5

The greater the molecular weight of the carboxyl groups in ethyl cellulose, the smaller the number, which implies that the carboxyl groups exist in positions that depend on the molecular weight. The terminal concentration of a polymer decreases as the molecular weight of one molecular chain increases. Therefore, it is considered that a certain amount of carboxyl groups are present at the terminals. Furthermore, from the synthesis reaction scheme of the sample, it can be determined that the carboxyl group analyzed by NMR is present at one end.

Furthermore, assuming that the carboxyl group quantified by NMR is present at one terminal of ethyl cellulose, the molecular weight of ethyl cellulose is calculated by determining the number of repeats of ethyl cellulose. Table 2 shows the average molecular weight determined by NMR and the average molecular weight determined by GPC.

[Table 2] Table 2 Sample number Average molecular weight (Mn) NMR measurement value GPC measured value 1 5800 13000 2 9000 20000 3 24000 54000 4 40000 88000

The average molecular weight determined by GPC is converted into polystyrene, so the absolute value of the average molecular weight determined by NMR and the average molecular weight determined by GPC do not match. On the other hand, as shown in Figure 2, when the molecular weight values calculated by the two methods for samples with different molecular weights are compared, a relatively high correlation appears. This shows that carboxyl groups are present at one terminal of ethyl cellulose, and it can be said that NMR quantifies the carboxyl groups present at one terminal.

Next, the cellulose derivatives having a single-terminal carboxyl group (each of the 1st to 4th single-terminal carboxylated ethylcellulose) obtained in the above manner were synthesized and linked to different types of resins as shown in Table 3. Each copolymer of 1 to 14.

[Example 1] (Synthesis of the first copolymer of single-terminal carboxylated ethyl cellulose and polyvinyl acetal resin) 5 parts by mass of the first single-terminal carboxylated ethyl cellulose, which is a cellulose derivative having a single-terminal carboxyl group, and a polyvinyl acetal-based resin having a hydroxyl group (manufactured by Sekisui Chemical Industry Co., Ltd., which is a different type of resin) BL-S", number average molecular weight Mn=27000) 5 parts by mass were dried under reduced pressure, 90 parts by mass of ethyl acetate was added, and dissolved at 50°C in a nitrogen atmosphere. To the obtained solution, diisopropylcarbodiimide as a condensing agent was added in an amount of 1.1 times the molar amount of the first single-terminal carboxylated ethyl cellulose, and the molar amount of the condensing agent A 0.01 molar amount of dimethylaminopyridine as a reaction accelerator was stirred at a temperature of 50° C. for 24 hours to react to prepare a binder solution. Thereafter, the ethyl acetate is distilled off, thereby obtaining in solid form a copolymer obtained by ester bonding between a cellulose derivative having a single terminal carboxyl group and a polyvinyl acetal resin.

The obtained copolymer was analyzed based on FT-IR (fourier transform infrared radiation, Fourier transform infrared spectroscopy) and ¹ H-NMR. The results confirmed that the formation of ester bonds was greater than that of the raw material resin in the analysis based on GPC. number average molecular weight, so the progress of the reaction can be confirmed.

Then, in order to prepare a conductive paste, 10 parts by mass of the obtained copolymer was dissolved in 90 parts by mass of terpineol dihydroacetate to prepare an adhesive solution.

[Example 2] (Synthesis of the 4th copolymer of single-terminal carboxylated ethyl cellulose and polyvinyl acetal resin) The cellulose derivative having a single-terminal carboxyl group was changed to the fourth single-terminal carboxylated ethyl cellulose, and a different type of resin was changed to a polyvinyl acetal-based resin having a hydroxyl group ("BH-S manufactured by Sekisui Chemical Industry" ”, number average molecular weight Mn = 63000), except that the reaction was carried out under the same conditions as in Example 1 to produce an ester bond using a cellulose derivative having a single terminal carboxyl group and a polyvinyl acetal resin. The resulting copolymer binder solution.

[Example 3] (Synthesis of the first copolymer of single-terminal carboxylated ethyl cellulose and polyvinyl acetal resin) The same conditions were used as in Example 1 except that the different type of resin was changed to a polyvinyl acetal resin having a hydroxyl group ("BH-S" manufactured by Sekisui Chemical Industry, number average molecular weight Mn = 63000). The reaction is carried out to prepare a binder solution containing a copolymer obtained by ester bonding between a cellulose derivative having a single terminal carboxyl group and a polyvinyl acetal resin.

[Example 4] (Synthesis of the 4th copolymer of single-terminal carboxylated ethyl cellulose and polyvinyl acetal resin) Except that the cellulose derivative having a single terminal carboxyl group was changed to the fourth single terminal carboxylated ethyl cellulose, the reaction was carried out under the same conditions as in Example 1 to produce a cellulose derivative having a single terminal carboxyl group. Binder solution of copolymer obtained by ester bonding between polyvinyl acetal resin and polyvinyl acetal resin.

[Example 5] (Synthesis of the first copolymer of single-terminal carboxylated ethyl cellulose and acrylic resin) Change different types of resins into acrylic resins with hydroxyl groups (the main monomer is isobutyl methacrylate, an acrylic resin containing 5 mol% of 2-hydroxyethyl methacrylate, number average molecular weight Mn=21000 ), except that the reaction was carried out under the same conditions as in Example 1 to prepare a binder solution containing a copolymer obtained by ester bonding between a cellulose derivative having a single terminal carboxyl group and an acrylic resin.

[Example 6] (Synthesis of the first copolymer of single-terminal carboxylated ethyl cellulose and aliphatic polycarbonate resin) A different type of resin was changed to an aliphatic polycarbonate resin having a hydroxyl group (polypropylene carbonate, number average molecular weight Mn = 24000), except that the reaction was carried out under the same conditions as in Example 1 to produce a composition containing A binder solution using a copolymer obtained by ester bonding a cellulose derivative with a single terminal carboxyl group and a polycarbonate resin.

[Example 7] (Synthesis of the first copolymer of single-terminal carboxylated ethyl cellulose and polyurethane resin) Change different types of resins into polyurethane resins with hydroxyl groups (including polyester polyol PMPA (poly(3-methyl 1,5-pentanediol adipate) glycol), poly In the prepolymer of ether polyol PPG (poly(propylene glycol) glycol) and diisocyanate IPDI (isophorone diisocyanate), IPDI (isophorone diamine) and DETA (diethylene diamine) are added as chain extenders. Triamine), ethanolamine as a stopping agent, number average molecular weight Mn = 24000), except that the reaction was carried out under the same conditions as in Example 1 to produce a cellulose derivative having a single terminal carboxyl group and a polyamine. Binder solution of copolymer obtained by ester bonding of methyl formate resin.

[Example 8] (Synthesis of the first copolymer of single-terminal carboxylated ethyl cellulose and polyurethane resin) Change different types of resins into polyurethane resins with amine groups (including polyester polyol PMPA (poly(3-methyl 1,5-pentanediol adipate) glycol), In the prepolymer of polyether polyol PPG (poly(propylene glycol) glycol) and diisocyanate IPDI (isophorone diisocyanate), IPDI (isophorone diamine) and DETA (isophorone diamine) are added as chain extenders. Ethyltriamine), ethylenediamine as a stopping agent, number average molecular weight Mn = 26000), except for this, the reaction was carried out under the same conditions as in Example 1 to produce a cellulose derivative having a single terminal carboxyl group. Binder solution of a copolymer obtained by amide bonding with polyurethane resin.

[Example 9] (Synthesis of the first copolymer of single-terminal carboxylated ethyl cellulose and polyether resin) A different type of resin was changed to a polyether resin having a hydroxyl group (mPEG, number average molecular weight Mn = 10000), except that the reaction was carried out under the same conditions as in Example 1 to produce a resin containing a single terminal carboxyl group. Binder solution of ester-bonded copolymer of cellulose derivatives and polyether resin.

[Example 10] (Synthesis of the 4th copolymer of single-terminal carboxylated ethyl cellulose and aliphatic polyester resin) A different type of resin was changed to an aliphatic polyester resin having a hydroxyl group (polycaprolactone, number average molecular weight Mn = 45000). In addition, the reaction was carried out under the same conditions as in Example 2 to produce a product containing A binder solution of a copolymer obtained by ester bonding a cellulose derivative with a single terminal carboxyl group and a polyester resin.

In the following Examples 11 to 14, the content ratio of the cellulose derivative having a single terminal carboxyl group and different types of resins was changed to some ratio different from 50:50.

[Example 11] (Synthesis of the first copolymer of single-terminal carboxylated ethyl cellulose and polyvinyl acetal resin) The first single-terminal carboxylated ethyl cellulose, which is a cellulose derivative having a single-terminal carboxyl group, was changed to 6 parts by mass, and a different type of resin was changed to a polyvinyl acetal-based resin having a hydroxyl group (manufactured by Sekisui Chemical Industry) "BL-S", number average molecular weight Mn = 27000) and changed to 4 parts by mass, except that the reaction was carried out under the same conditions as in Example 1 to produce a cellulose derivative having a single terminal carboxyl group and Binder solution of copolymer obtained by ester bonding of polyvinyl acetal resin.

[Example 12] (Synthesis of the first copolymer of single-terminal carboxylated ethyl cellulose and polyvinyl acetal resin) The first single-terminal carboxylated ethyl cellulose, which is a cellulose derivative having a single-terminal carboxyl group, was changed to 8 parts by mass, and a different type of resin was changed to a polyvinyl acetal-based resin having a hydroxyl group (manufactured by Sekisui Chemical Industry) "BL-S", number average molecular weight Mn = 27000) and changed to 2 parts by mass, except that the reaction was carried out under the same conditions as in Example 1 to produce a cellulose derivative having a single terminal carboxyl group and Binder solution of copolymer obtained by ester bonding of polyvinyl acetal resin.

[Example 13] (Synthesis of the first copolymer of single-terminal carboxylated ethyl cellulose and polyvinyl acetal resin) The first single-terminal carboxylated ethyl cellulose, which is a cellulose derivative having a single-terminal carboxyl group, was changed to 4 parts by mass, and a different type of resin was changed to a polyvinyl acetal-based resin having a hydroxyl group (manufactured by Sekisui Chemical Industry) "BL-S", number average molecular weight Mn = 27000) and changed to 6 parts by mass, except that the reaction was carried out under the same conditions as in Example 1 to produce a cellulose derivative having a single terminal carboxyl group and Binder solution of copolymer obtained by ester bonding of polyvinyl acetal resin.

[Example 14] (Synthesis of the first copolymer of single-terminal carboxylated ethyl cellulose and polyvinyl acetal resin) The first single-terminal carboxylated ethyl cellulose, which is a cellulose derivative having a single-terminal carboxyl group, was changed to 2 parts by mass, and a different type of resin was changed to a polyvinyl acetal-based resin having a hydroxyl group (manufactured by Sekisui Chemical Industry) "BL-S", number average molecular weight Mn = 27000) and changed to 8 parts by mass, except that the reaction was carried out under the same conditions as in Example 1 to produce a cellulose derivative having a single terminal carboxyl group and Binder solution of copolymer obtained by ester bonding of polyvinyl acetal resin.

Then, as Comparative Examples 1 to 10, a binder solution obtained by simply mixing a cellulose derivative having a single terminal carboxyl group and a different type of resin was obtained. In addition, in each of Comparative Examples 1 to 10, different types of resin are the same as those in Examples 1 to 10.

[Comparative example 1] (Preparation of the first mixture of single-terminal carboxylated ethyl cellulose and polyvinyl acetal resin) 5 parts by mass of the first single-terminal carboxylated ethyl cellulose, which is a cellulose derivative having a single-terminal carboxyl group, and a polyvinyl acetal-based resin having a hydroxyl group (manufactured by Sekisui Chemical Industry Co., Ltd., which is a different type of resin) BL-S", number average molecular weight Mn = 27000) 5 parts by mass were dissolved in 90 parts by mass of terpineol dihydroacetate to prepare an adhesive solution.

[Comparative example 2] (Preparation of the fourth mixture of single-terminal carboxylated ethyl cellulose and polyvinyl acetal resin) The cellulose derivative having a single-terminal carboxyl group was changed to the fourth single-terminal carboxylated ethyl cellulose, and a different type of resin was changed to a polyvinyl acetal-based resin having a hydroxyl group ("BH-S manufactured by Sekisui Chemical Industry" ", number average molecular weight Mn = 63000), except for this, a binder solution was prepared under the same conditions as Comparative Example 1.

[Comparative example 3] (Preparation of the first mixture of single-terminal carboxylated ethyl cellulose and polyvinyl acetal resin) The conditions were the same as Comparative Example 1 except that the different type of resin was changed to a polyvinyl acetal-based resin having a hydroxyl group ("BH-S" manufactured by Sekisui Chemical Industry, number average molecular weight Mn = 63000). Make an adhesive solution.

[Comparative example 4] (Preparation of the fourth mixture of single-terminal carboxylated ethyl cellulose and polyvinyl acetal resin) A binder solution was prepared under the same conditions as Comparative Example 1, except that the cellulose derivative having a single-terminal carboxyl group was changed to the fourth single-terminal carboxylated ethylcellulose.

[Comparative example 5] (Preparation of the first mixture of single-terminal carboxylated ethyl cellulose and acrylic resin) Change different types of resins into acrylic resins with hydroxyl groups (the main monomer is isobutyl methacrylate, an acrylic resin containing 5 mol% of 2-hydroxyethyl methacrylate, number average molecular weight Mn=21000 ), except for this, a binder solution was prepared under the same conditions as Comparative Example 1.

[Comparative example 6] (Preparation of the first mixture of single-terminal carboxylated ethyl cellulose and aliphatic polycarbonate resin) A binder solution was prepared under the same conditions as Comparative Example 1, except that the different type of resin was changed to an aliphatic polycarbonate resin having a hydroxyl group (polypropylene carbonate, number average molecular weight Mn = 24000).

[Comparative Example 7] (Preparation of the first mixture of single-terminal carboxylated ethyl cellulose and polyurethane resin) Change different types of resins into polyurethane resins with hydroxyl groups (including polyester polyol PMPA (poly(3-methyl 1,5-pentanediol adipate) glycol), poly In the prepolymer of ether polyol PPG (poly(propylene glycol) glycol) and diisocyanate IPDI (isophorone diisocyanate), IPDI (isophorone diamine) and DETA (diethylene diamine) are added as chain extenders. A binder solution was prepared under the same conditions as Comparative Example 1, except for ethanolamine as a stopper (number average molecular weight Mn = 24000).

[Comparative example 8] (Preparation of the first mixture of single-terminal carboxylated ethyl cellulose and polyurethane resin) Change different types of resins into polyurethane resins with amine groups (including polyester polyol PMPA (poly(3-methyl 1,5-pentanediol adipate) glycol), In the prepolymer of polyether polyol PPG (poly(propylene glycol) glycol) and diisocyanate IPDI (isophorone diisocyanate), IPDI (isophorone diamine) and DETA (isophorone diamine) are added as chain extenders. A binder solution was prepared under the same conditions as Comparative Example 1, except for ethyltriamine) and ethylenediamine as a stopping agent, number average molecular weight Mn = 26000).

[Comparative Example 9] (Preparation of the first mixture of single-terminal carboxylated ethyl cellulose and polyether resin) A binder solution was prepared under the same conditions as Comparative Example 1, except that the different type of resin was changed to a polyether resin having a hydroxyl group (mPEG, number average molecular weight Mn=10000).

[Comparative Example 10] (Preparation of the fourth mixture of single-terminal carboxylated ethyl cellulose and aliphatic polyester resin) A binder solution was produced under the same conditions as Comparative Example 2, except that the different type of resin was changed to an aliphatic polyester-based resin having a hydroxyl group (polycaprolactone, number average molecular weight Mn=45000).

The following synthesis examples 1 to 3 are copolymers in which a cellulose derivative having a single terminal carboxyl group and different types of resins are connected via a binding agent.

＜Synthesis example 1＞ (Synthesis of cellulose derivatives containing allyl alcohol introduced into the first single-terminal carboxylated ethyl cellulose) 10 parts by mass of the first single-terminal carboxylated ethyl cellulose was dried under reduced pressure, 90 parts by mass of ethyl acetate was added, and the mixture was dissolved at 50° C. in a nitrogen atmosphere. To the obtained solution, 0.045 parts by mass of allyl alcohol, diisopropylcarbodiimide as a condensing agent in an amount of 1.1 times the molar number of the cellulose derivative having a single terminal carboxyl group, and The molar amount of dimethylaminopyridine as a reaction accelerator was 0.01 times the molar number of the condensing agent, and the reaction was carried out by stirring at a temperature of 50°C for 24 hours to prepare a binder solution.

Thereafter, the ethyl acetate was distilled off, thereby obtaining the cellulose derivative of Synthesis Example 1 in which allyl alcohol was introduced into the cellulose derivative having a single terminal carboxyl group in a solid form.

The cellulose derivative obtained in Synthesis Example 1 was analyzed based on FT-IR and ¹ H-NMR. As a result, the formation of an ester bond and an allyl group derived from allyl alcohol was confirmed, and the progress of the reaction was confirmed. .

＜Synthesis example 2＞ (Synthesis of a polyvinyl acetal resin derivative in which methacrylic acid is introduced into a polyvinyl acetal resin having a hydroxyl group) As a different type of resin, 10 parts by mass of a polyvinyl acetal-based resin having a hydroxyl group ("BL-S" manufactured by Sekisui Chemical Industry, number average molecular weight Mn = 27000) was dried under reduced pressure, and 90 mass parts of ethyl acetate were added. part, and dissolve it at 50°C in a nitrogen atmosphere. To the obtained solution, 0.032 parts by mass of methacrylic acid and 1.1 times the molar amount of diisopropylcarbodiimide as a condensing agent were added to the polyvinyl acetal-based resin having a hydroxyl group. , and a molar amount of dimethylaminopyridine as a reaction accelerator that is 0.01 times the molar number of the condensation agent, stir at a temperature of 50°C for 24 hours to react, and prepare a binder solution.

Thereafter, the ethyl acetate was distilled off, thereby obtaining the polyvinyl acetal resin derivative of Synthesis Example 2 in which methacrylic acid was introduced into a polyvinyl acetal resin having a hydroxyl group in a solid form.

The polyvinyl acetal-based resin derivative obtained in Synthesis Example 2 was analyzed based on FT-IR and ¹ H-NMR. As a result, it was confirmed that an ester bond and the formation of a vinyl group derived from methacrylic acid were confirmed. to the reaction.

＜Synthesis Example 3＞ (Synthesis of a polyvinyl acetal resin derivative in which thioglycolic acid is introduced into a polyvinyl acetal resin having a hydroxyl group) As a different type of resin, 10 parts by mass of a polyvinyl acetal-based resin having a hydroxyl group ("BL-S" manufactured by Sekisui Chemical Industry, number average molecular weight Mn = 27000) was dried under reduced pressure, and 90 mass parts of ethyl acetate were added. part, and dissolve it at 50°C in a nitrogen atmosphere. To the obtained solution, 0.034 parts by mass of thioglycolic acid and diisopropylcarbodiimide as a condensing agent were added in an amount of 1.1 times the molar number of the polyvinyl acetal-based resin having a hydroxyl group. and dimethylaminopyridine as a reaction accelerator in a molar amount 0.01 times the molar number of the condensation agent, stir at a temperature of 50°C for 24 hours to react, and prepare a binder solution.

Thereafter, the ethyl acetate was distilled off, thereby obtaining the polyvinyl acetal resin derivative of Synthesis Example 3 in which thioglycolic acid was introduced into a polyvinyl acetal resin having a hydroxyl group in a solid form.

The polyvinyl acetal-based resin derivative obtained in Synthesis Example 3 was analyzed by FT-IR and ¹ H-NMR. As a result, an ester bond was confirmed, and the progress of the reaction was confirmed.

Then, the resin derivatives of Synthesis Examples 1 to 3 were combined to synthesize the copolymers of each of Examples 15 and 16.

[Example 15] (Synthesis of a copolymer of a cellulose derivative introduced with allyl alcohol and a polyvinyl acetal resin derivative introduced with methacrylic acid) 5 parts by mass of the cellulose derivative introduced with allyl alcohol in Synthesis Example 1 and 5 parts by mass of the polyvinyl acetal resin derivative introduced with methacrylic acid in Synthesis Example 2, which are different types of resins, were reduced. Press-dry, add 90 parts by mass of terpineol dihydroacetate thereto, and dissolve it at 50° C. in a nitrogen atmosphere. Then, 0.05 parts by mass of azobisisobutyronitrile as a polymerization initiator was added to the solution, and the reaction was carried out at 80° C. for 5 hours to prepare the allyl alcohol-introduced cellulose derivative of Synthesis Example 1 and the synthesis method. Example 2 is a binder solution of a copolymer of a polyvinyl acetal resin derivative.

In order to analyze the obtained copolymer, the binder solution was injected into methanol to precipitate the binder, and then dried under reduced pressure to obtain the copolymer in solid form.

The obtained copolymer was analyzed based on FT-IR and ¹ H-NMR. As a result, it was confirmed that the allyl and vinyl groups disappeared. In the analysis based on GPC, it was greater than the number average molecular weight of the raw material resin, so it can be The progress of the reaction was confirmed.

[Example 16] (Synthesis of a copolymer of a cellulose derivative introduced with allyl alcohol and a polyvinyl acetal resin derivative introduced with thioglycolic acid) The different types of resin were changed to the polyvinyl acetal resin derivative introduced with thioglycolic acid in Synthesis Example 3, and the reaction was carried out under the same conditions as in Example 15 to prepare a copolymer-containing adhesive solution. , from this binder solution, a copolymer of the allyl alcohol-introduced cellulose derivative of Synthesis Example 1 and the polyvinyl acetal resin derivative of Synthesis Example 3 was obtained.

The obtained copolymer was analyzed based on FT-IR and ¹ H-NMR. As a result, the disappearance of the allyl group was confirmed. In the analysis based on GPC, it was greater than the number average molecular weight of the raw material resin, so the reaction was confirmed. proceed.

[Example 17] (Preparation of binder resin that introduces terminal functional groups from different types of low molecules into cellulose derivatives with single-terminal carboxyl groups) 10 parts by mass of the fourth single-terminal carboxylated ethyl cellulose, which is a cellulose derivative having a single-terminal carboxyl group, was dried under reduced pressure, 90 parts by mass of ethyl acetate was added, and dissolved at 50° C. in a nitrogen atmosphere. . To the obtained solution, ethanol in an amount 5 times the molar number of the fourth single-terminal carboxylated ethyl cellulose, diisopropylcarbodiimide as a condensing agent in an amount 5 times the molar amount, A molar amount of dimethylaminopyridine as a reaction accelerator was 0.01 times the molar number of the condensation agent, and the reaction was carried out by stirring at a temperature of 50° C. for 24 hours to prepare a binder solution.

Thereafter, ethyl acetate and ethanol are distilled away, thereby obtaining a binder resin in which a terminal functional group is introduced into a cellulose derivative having a single terminal carboxyl group in a solid form.

The obtained binder resin was analyzed based on FT-IR and ¹ H-NMR, and the formation of ester bonds was confirmed. In the analysis based on GPC, it was greater than the number average molecular weight of the raw material resin, so the reaction was confirmed. conduct.

Then, in order to prepare a conductive paste, 10 parts by mass of the obtained adhesive resin was dissolved in 90 parts by mass of terpineol dihydroacetate to prepare an adhesive solution.

[Preparation of conductive paste] 44.0 parts by mass of nickel powder with a BET diameter of 177 nm (SSA (specific surface area) = 3.8 m ² /g) and a BET diameter of 13 nm (SSA = 77 m ² /g) were mixed with barium titanate The main components are 2.9 parts by mass of ceramic powder, 0.7 parts by mass of polycarboxylic acid-based polymer dispersant, 21.2 parts by mass of the binder solution obtained in the above examples and comparative examples, and 31.2 parts by mass of dihydroterpineol acetate. parts are mixed and dispersed using a three-roller mill to produce a conductive paste.

In addition, the dispersion method is not limited to the above-mentioned method, and various methods such as a roller mill, a ball mill, a bead mill, and high-pressure dispersion can be applied.

[Evaluation of resin components in paste] The conductive paste prepared in the above manner containing the binder solution of Example 1 was processed with a centrifugal separator (Hitachi Kokai "CS100FNX", rotation speed: 29000 rpm, 20 minutes) to precipitate nickel particles and ceramic particles and separate them. supernatant. After fractionating the polymer component by GPC (Gel Permeation Chromatography), the polymer component was processed with HPLC (High Performance Liquid Chromatography). The result was confirmed to be equivalent to ethyl cellulose. There is also a peak between the peak and the peak corresponding to PVB (polyvinyl butyral). It can be seen that the copolymer was successfully synthesized.

Furthermore, the polymer component separated by GPC was dried, and the resulting dry solid component of the supernatant liquid was subjected to TMS (trimethylsilyl)ization and NMR measurement was performed. As a result, ¹ H-NMR derived from the carboxyl group was not confirmed. peak.

Furthermore, the dry solid content of the supernatant liquid obtained by the above-mentioned drying is reacted with sodium hydroxide in a water-methanol mixed solvent to perform thermal hydrolysis. After fractionating the polymer component by GPC, the cellulose-based resin was fractionated from the polymer component by HPLC, and the resulting dry solid fraction was TMS-formed and subjected to NMR measurement. As a result, it was confirmed that ¹ H- derived from the carboxyl group was The peak of NMR.

From this, it was confirmed that the adhesive of Example 1, which was synthesized from the first single-terminal carboxylated ethyl cellulose and the polyvinyl acetal resin, was present in the paste. Furthermore, it was confirmed that the adhesive of Example 1 synthesized from the first single-terminal carboxylated ethyl cellulose and the polyvinyl acetal resin did not deteriorate in the paste.

[Evaluation of smoothness of electrode coating] Perform the following operations on the prepared conductive paste to evaluate the smoothness of the electrode coating.

The conductive paste as a sample was applied on a glass substrate using a 9 μm doctor blade, and a hybrid laser microscope (OPTELICS) manufactured by Lasertec Co., Ltd. was used to evaluate the smoothness of the electrode coating film after heating and drying. The measurement conditions for measurement using this hybrid laser microscope are as follows: measurement mode: surface shape; magnification: 50 times; resolution in the height direction: 0.04 μm; measurement area: 1.44 mm ² .

When the compatibility between cellulose derivatives and different types of resins is low, when agglomerates are formed and the degree of cross-linking is high, a gel is formed. However, it is speculated that these products are not the main components and are produced less frequently. Therefore, the Sz (in-plane distribution of the maximum height) value in the electrode coating film was determined as the sum of Sp (the in-plane distribution of the maximum peak height) and Sv (the in-plane distribution of the maximum valley depth). Smoothness was evaluated based on the following evaluation criteria based on the average value of 16 measurements. ◎: Sz value is less than 1.80 μm. ○: The Sz value is 1.80 or more and less than 1.90 μm. ×: Sz value is 1.90 μm or more.

The number average molecular weight Mn and smoothness evaluation results of the copolymers of Examples and Comparative Examples are summarized in Table 3.

[table 3] table 3 Types of cellulose with a carboxyl group at one end Different types of resin types Functional groups of different types of resins Ratio Cellulose: Different Types of Resins 1st bonding part Type of binder 2nd bonding part Number average molecular weight Mn cellulose/different types of resins Number average molecular weight of the compound Mn In-plane distribution of maximum height Sz/μm Smoothness Example 1 CC1 BL-S OH 50:50 ester bond - - 13000/27000 32000 1.66 ◎ Example 2 CC2 BH-S OH 50:50 ester bond - - 88000/63000 94000 1.76 ◎ Example 3 CC1 BH-S OH 50:50 ester bond - - 13000/63000 82000 1.72 ◎ Example 4 CC2 BL-S OH 50:50 ester bond - - 88000/27000 96000 1.74 ◎ Example 5 CC1 acrylic resin OH 50:50 ester bond - - 13000/21000 23000 1.64 ◎ Example 6 CC1 polycarbonate OH 50:50 ester bond - - 13000/24000 26000 1.76 ◎ Example 7 CC1 polyurethane OH 50:50 ester bond - - 13000/24000 27000 1.70 ◎ Example 8 CC1 polyurethane NH ₂ 50:50 amide bond - - 13000/26000 29000 1.72 ◎ Example 9 CC1 polyether OH 50:50 ester bond - - 13000/10000 14000 1.68 ◎ Example 10 CC2 polyester OH 50:50 ester bond - - 88000/45000 96000 1.74 ◎ Example 11 CC1 BL-S OH 60:40 ester bond - - 13000/27000 34000 1.72 ◎ Example 12 CC1 BL-S OH 80:20 ester bond - - 13000/27000 38000 1.84 〇 Example 13 CC1 BL-S OH 40:60 ester bond - 13000/27000 30000 1.70 ◎ Example 14 CC1 BL-S OH 20:80 ester bond - - 13000/27000 28000 1.82 〇 Example 15 CC1 BL-S OH 50:50 ester bond alkyl ester bond 13000/27000 35000 1.86 〇 Example 16 CC1 BL-S OH 50:50 ester bond thioether group ester bond 13000/27000 34000 1.68 ◎ Example 17 CC2 ethanol OH - ester bond - - 88000/- 89000 1.55 ◎ Comparative example 1 CC1 BL-S OH 50:50 - - - 13000/27000 - 1.96 × Comparative example 2 CC2 BH-S OH 50:50 - - - 88000/63000 - 2.02 × Comparative example 3 CC1 BH-S OH 50:50 - - - 13000/63000 - 1.98 × Comparative example 4 CC2 BL-S OH 50:50 - - - 88000/27000 2.00 × Comparative example 5 CC1 acrylic resin OH 50:50 - - - 13000/21000 - 1.94 × Comparative example 6 CC1 polycarbonate OH 50:50 - - - 13000/24000 - 2.00 × Comparative example 7 CC1 polyurethane OH 50:50 - - - 13000/24000 - 1.98 × Comparative example 8 CC1 polyurethane NH ₂ 50:50 - - - 13000/26000 - 2.04 × Comparative example 9 CC1 polyether OH 50:50 - - - 13000/10000 - 1.96 × Comparative example 10 CC2 polyester OH 50:50 - - - 88000/45000 - 1.98 ×

According to the results of Examples 1 to 16 in Table 3, it was confirmed that the conductive paste contained a binder in which the carboxyl group at one end of the molecular chain of the cellulose resin was combined with different types of resins to make the cellulose resin The compatibility of the resin with different types of resins is improved without damaging the smoothness of the coating film. In addition, this effect is obtained even if alkyl cellulose is used as the cellulose-based resin, polyvinyl acetal-based resin, acrylic resin, polycarbonate-based resin, or polyurethane-based resin having a hydroxyl group or an amine group is used. Resin, polyether resin, and polyester resin are also available as different types of resins, and the content ratio of the cellulose-based resin and the different types of resins is 80:20 to 20:80 in terms of mass. can be reliably obtained within the range.

According to Example 17 in Table 3, it was confirmed that the smoothness of the coating film was not impaired by making the conductive paste contain a cellulose-based resin having an ester group as a functional group at one end of the molecular chain.

The above has been explained about the examples of the conductive paste containing nickel particles as metal particles. However, it can be seen that as long as it is a binder that can form a smooth coating film by combining with nickel particles, it can be combined with other metal particles such as copper particles. , or a combination with ceramic particles such as BaTiO ₃ particles, the same effect can be obtained. Therefore, it can be seen that the inorganic particles contained in the paste for electronic parts can be any inorganic particles.

Figure 1 is a diagram showing the ¹ H-NMR spectrum of an ethylcellulose derivatization product. FIG. 2 is a diagram showing the correlation between the molecular weight of ethyl cellulose determined by NMR and the molecular weight of ethyl cellulose determined by GPC.

Claims (11)

A paste for electronic parts, which contains inorganic particles, a dispersant, a binder and an organic solvent. The above-mentioned binder at least contains: (A) The first bonding part at a single end of the molecular chain of the cellulose-based resin is an ester bond or an ester bond. A copolymer represented by the general formula of Formula 1 below or the general formula of Formula 2 below that is linked to different types of resins or different types of low molecules through an amine bond, or (B) a single molecular chain of a cellulose-based resin The general formula of the following formula 3 or the following formula 4 in which the first bonding part at the terminal is an ester bond or an amide bond and is connected to the second bonding part (X) and a different type of resin through a binding agent (R ₃ ) Copolymer represented by the general formula; [Chemical 1] [Chemicalization 2] In the formula, R ₁ represents hydrogen, alkyl, hydroxyalkyl or hydroxyl group, R ₂ represents different types of resin or alkyl group; [Chemical 3] [Chemical 4] In the formula, R ₁ represents hydrogen, alkyl, hydroxyalkyl or amide group, R ₄ represents different types of resins, R ₃ represents a binding agent containing an alkyl or sulfide group, and X represents an ester bond or amide bond. The paste for electronic parts of claim 1, wherein the cellulose-based resin is a cellulose ether having a carboxyl group at one end of the molecular chain. The paste for electronic parts of claim 2, wherein the cellulose ether is alkyl cellulose. Such as the paste for electronic parts of claim 1, wherein the different types of resins include polyvinyl acetal resins, acrylic resins, polycarbonate resins, and polyurethane resins having hydroxyl or amine groups. At least one of the group consisting of resin, polyether resin and polyester resin. For example, in claim 1, the paste for electronic parts is characterized in that the content ratio of the above-mentioned cellulose-based resin and the above-mentioned different types of resins is in the range of 80:20 to 20:80 in terms of mass. The paste for electronic components according to any one of claims 1 to 5, wherein the inorganic particles include at least one of ceramic particles and metal particles. The paste for electronic parts of claim 6, wherein the ceramic particles contain at least one element selected from the group consisting of Ba, Ti, Ca, Zr and Sr. The paste for electronic parts of claim 6, wherein the metal particles include at least one metal selected from the group consisting of Cu, Ni, Au and Ag. The paste for electronic parts according to any one of claims 1 to 5, wherein the dispersant is a polymer dispersant. A paste for electronic parts as claimed in claim 9, wherein the polymer dispersant is a polycarboxylic acid dispersant. The paste for electronic parts according to any one of claims 1 to 5, wherein the alkyl group as _R2 has 1 to 4 carbon atoms.