TWI490300B - Binder resin for baking, manufacturing method therefor, paste composition and inorganic sintered body - Google Patents

Description

Baking adhesive resin and its manufacturing method, paste composition and inorganic burning Conjunct

The present application claims the priority of Japanese Patent Application No. 2010-106439, filed on Jan.

The present invention relates to a method for producing a binder resin for baking which is used for shaping an inorganic powder such as a metal powder, a metal oxide powder, a fluorescent powder or a glass frit, and a manufacturing method therefor The resulting binder resin and paste composition.

In the field of electronic materials and the like, there is a phenomenon in which a molded body of an inorganic material or a pattern (for example, a wiring pattern, an insulating pattern, or the like) formed of the molded body is used. As a method of forming such a molded body or pattern, it is known that an inorganic powder such as a metal powder, a metal oxide powder, a fluorescent powder or a glass frit is mixed with a binder resin to prepare a paste composition, and the paste composition is used. After forming a predetermined shape or pattern, baking is performed to thermally decompose the binder resin.

The binder resin used at this time serves to improve the workability in the forming process or to bond the inorganic powder so as not to be damaged during the movement. Since the binder resin can be removed by thermal decomposition when the inorganic powder is sintered before being used as a final product, it is required to have high thermal decomposition property and excellent workability in each processing.

A method of processing a paste composition is known as a method of screen printing, and is formed into a thin film by a doctor blade or the like. A plate-like method, a dipping method, a dispensing method, and the like.

Among these methods, in the case where the screen printing method is applied, the higher the thixotropy of the paste composition in the high shear region, the more the printability is improved. Moreover, in the homogenization after printing, the lower the thixotropy in the low shear region, the better. Therefore, in the case of screen printing, as the paste composition, it is required that the thixotropic property is high in the high shear region and low in the low shear region.

To this requirement, a binder resin obtained by polymerizing a compound of (meth)acrylic acid alkyl ester having two or more radically polymerizable unsaturated doubles is proposed in Japanese Patent Laid-Open Publication No. 2003-183331. A compound of a bond or a (meth) acrylate containing a hydroxyl group.

Further, Japanese Laid-Open Patent Publication No. 2004-217686 proposes a binder resin having at least two kinds of methacrylic acid alkyl ester monomers as an essential component: 90% by weight to 99% by weight, selected from the group consisting of unsaturated At least one of a group of a carboxylic acid monomer, an amino group-containing (meth)acrylic acid alkyl ester monomer, and a hydroxyl group-containing alkyl (meth)acrylate monomer, 0.1% by weight to 5% by weight, polyfunctionality The alkyl (meth)acrylate monomer is from 0.001% by weight to 0.1% by weight.

However, even if the paste composition of the adhesive resin described in Japanese Laid-Open Patent Publication No. 2003-183331 is used, it is difficult to sufficiently satisfy the leveling property and the printability in screen printing. .

Further, even if the paste composition of the adhesive resin described in Japanese Laid-Open Patent Publication No. 2004-217686 is used, the thixotropy is less likely to be exhibited, and it is not suitable for screen printing.

The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a paste composition excellent in leveling property and printability in screen printing, a binder resin for baking which can easily obtain the paste composition, and The method for producing the same, and the inorganic sintered body obtained by baking the paste composition.

[1] A baking binder resin obtained by copolymerizing a monomer mixture (A) comprising the following components: (meth)acrylic acid alkyl ester (A-1) 60% by weight to 99.8% by weight, having 2 More than one radically polymerizable unsaturated double bond compound (A-2) 0.1% by weight to 5% by weight, water-soluble unsaturated monomer (A-3) (but having two or more radically polymerizable 0.1% by weight to 30% by weight of the monomer other than the unsaturated double bond compound (A-2), 0% by weight to 39.8% by weight of the other copolymerizable monomer (A-4), and the resin is dissolved in rosin alcohol The 15 wt% solution of the resin obtained in (terpineol) satisfies the following conditions: η ₁ /η _{10 is} less than 2.5 η ₁ /η ₅₀₀₀ is 5 or more

Here, η ₁ , η ₁₀ and η ₅₀₀₀ are resin solutions measured under the conditions of a cone-plate 0.5°/25 mm and a measurement temperature of 23° C. using a viscoelasticity measuring device (manufactured by Anton Paar Co., Ltd., "Physca MCR300"). Viscosity, η ₁ is the viscosity at a shear rate of 1 (1/s), η ₁₀ is the viscosity at a shear rate of 10 (1/s), and η ₅₀₀₀ is a shear rate of 5000 (1/s). Viscosity.

[2] A baking binder resin comprising a monomer mixture a second polymer obtained by radically polymerizing a monomer mixture (2) in the presence of a first polymer obtained by radical polymerization, (1) comprising: (methyl) Alkyl acrylate (a-1) 35 wt% to 99.7 wt%, compound (a-2) having 2 or more radically polymerizable unsaturated double bonds, 0.3 wt% to 5 wt%, water-soluble unsaturated monomer ( A-3) (but a monomer other than the compound (a-2) having two or more radically polymerizable unsaturated double bonds) 0 wt% to 40 wt%, and other monomers (a-4) 0 wt% ~64.7 wt%, the monomer mixture (2) comprises: (meth)acrylic acid alkyl ester (b-1) 35 wt% to 99.9 wt%, a compound having two or more radically polymerizable unsaturated double bonds (b-2) 0 wt% to 1 wt%, a water-soluble unsaturated monomer (b-3) (but the compound (b-2) having two or more radically polymerizable unsaturated double bonds The body is 0.1% by weight to 30% by weight, and the other monomer (b-4) is 0% by weight to 64.9% by weight.

[3] The resin according to the above [1], wherein the binder resin for baking is a particle having a volume average particle diameter of 100 μm or less.

[4] A paste composition, comprising the binder resin for baking according to any one of [1] to [3], an inorganic powder, and an organic solvent.

[5] An inorganic sintered body obtained by baking the paste composition according to [4].

[6] A method for producing a binder resin for baking, comprising: a first polymerization step of radically polymerizing a monomer mixture (1) to obtain a first polymer, wherein the monomer mixture (1) comprises: Methyl)alkyl acrylate (a-1) 35 wt% to 99.7 wt%, compound having two or more radically polymerizable unsaturated double bonds (a-2) 0.3 wt% to 5 wt%, water-soluble unsaturated Monomer (a-3) (but a monomer other than the compound (a-2) having two or more radically polymerizable unsaturated double bonds) 0 wt% to 40 wt%, other monomers (a-4) 0%% to 64.7 wt%; a second polymerization step of radically polymerizing the monomer mixture (2) in the presence of the first polymer to obtain a second polymer, the monomer mixture (2) comprising : (meth)acrylic acid alkyl ester (b-1) 35 wt% to 99.9 wt%, compound having two or more radically polymerizable unsaturated double bonds (b-2) 0 wt% to 1 wt%, water solubility not a saturated monomer (b-3) (but a monomer other than the compound (b-2) having two or more radically polymerizable unsaturated double bonds) 0.1 wt% to 30 wt%, other monomers (b -4) 0 wt% to 64.9 wt%.

When the binder resin for baking of the present invention is used, a paste composition excellent in homogenization properties and printability in screen printing can be easily obtained.

Moreover, the method for producing a binder resin for baking according to the present invention, A baking binder resin capable of easily obtaining a paste composition excellent in leveling property and printability in screen printing can be produced.

Further, the paste composition of the present invention is excellent in homogenization property and printability in screen printing.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

Hereinafter, the present invention will be described in detail.

Further, in the present specification, (meth) acrylate means both acrylate and methacrylate, and (meth)acrylic means both acrylic acid and methacrylic acid.

(Bake adhesive resin and its manufacturing method)

The baking binder resin of the present invention is obtained by copolymerizing a monomer mixture (A) containing the following components: (meth)acrylic acid alkyl ester (A-1) (hereinafter referred to as "ingredient (A-1)" 60% by weight to 99.8 wt% of a compound (A-2) having two or more radically polymerizable unsaturated double bonds (hereinafter referred to as "ingredient (A-2)") 0.1 wt% to 5 wt%, water-soluble Unsaturated monomer (A-3) (hereinafter referred to as "component (A-3)") 0.1% by weight to 30% by weight, and other copolymerizable monomer (A-4) (hereinafter referred to as "ingredient (A-4) ))) 0wt%~39.8wt%. A preferred method of production can be exemplified by the following methods.

A method for producing a binder resin for baking, comprising: a first polymerization step of radically polymerizing a monomer mixture (1) comprising the following components to obtain a first polymer: alkyl (meth)acrylate (a) -1) (hereinafter referred to as "component (a-1)") 35 wt% to 99.7 wt% of a compound (a-2) having two or more radically polymerizable unsaturated double bonds (hereinafter referred to as "component (a-2) )) 0.3% by weight to 5% by weight of the water-soluble unsaturated monomer (a-3) (but the monomer other than the compound (a-2) having two or more radically polymerizable unsaturated double bonds) (hereinafter referred to as "component (a-3)") 0 wt% to 40 wt%, and other monomer (a-4) (hereinafter referred to as "component (a-4)") 0 wt% to 64.7 wt%; In the polymerization step, a monomer mixture (2) containing the following components is subjected to radical polymerization in the presence of the first polymer to obtain a second polymer: (meth)acrylic acid alkyl ester (b-1) (hereinafter Compound (b-2) having two or more radically polymerizable unsaturated double bonds (hereinafter referred to as "component (b-2)", which is called "component (b-1)"), 35 wt% to 99.9 wt% 0% by weight to 1% by weight, a water-soluble unsaturated monomer (b-3) (but a monomer other than the compound (b-2) having two or more radically polymerizable unsaturated double bonds) (below) It is called "component (b-3)") 0.1 wt% - 30 wt%, and the other monomer (b-4) (hereinafter referred to as "component (b-4)") is 0 wt% to 64.9 wt%.

<Monomer mixture (A)>

The monomer mixture (A) contains the component (A-1), the component (A-2), and the component (A-3).

Component (A-1) is an alkyl (meth)acrylate. The component (A-1) is preferably an alkyl (meth)acrylate having an alkyl group having 1 to 8 carbon atoms, and specific examples thereof include methyl (meth)acrylate and ethyl (meth)acrylate. A mono(meth)acrylate such as butyl (meth)acrylate or 2-ethylhexyl (meth)acrylate. The component (A-1) may be used alone or in combination of two or more.

The weight ratio of the component (A-1) in the monomer mixture (A) is 60% by weight to 99.8% by weight when the monomer mixture (A) is 100% by weight. By setting the ratio of the component (A-1) to 60% by weight to 99.8% by weight, it is possible to impart excellent baking properties to the obtained binder resin for baking, and it can be suitably used as a baking material. The lower limit of the ratio of the component (A-1) is preferably 65 wt% or more, more preferably 70 wt% or more.

The component (A-2) is a compound having two or more radically polymerizable unsaturated double bonds. Examples of the component (A-2) include ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, and 1,4. - Butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(a) Acrylate, polypropylene glycol di(meth)acrylate, polybutylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane (meth) acrylate, propoxylated trimethylolpropane tri (meth) acrylate, glycerol tri (meth) acrylate, ethoxylated glycerol tri (meth) acrylate, Dipentaerythritol hexa(meth) acrylate. These compounds are excellent in the balance between the viscosity-increasing effect and the thermal decomposition property, and are difficult to produce drawing even if they are highly viscous. The component (A-2) may be used alone or in combination of two or more.

The weight ratio of the component (A-2) in the monomer mixture (A) is from 0.1% by weight to 5% by weight based on 100% by weight of the monomer mixture (A). By setting the ratio of the component (A-2) to 0.1% by weight to 5% by weight, the viscosity of the paste composition containing the obtained binder resin for baking can be improved to improve printability, and it can be suitably used as a baking material. .

The lower limit of the ratio of the component (A-2) is preferably 0.5% by weight or more. When the ratio of the component (A-2) is 0.5% by weight or more, the balance between the viscosity increasing effect and the thermal decomposition property is improved, and the printability excellent in screen printing can be imparted. On the other hand, the upper limit of the ratio of the component (A-2) is preferably 3% by weight or less from the viewpoint of solubility in the organic solvent.

The component (A-3) is a water-soluble unsaturated monomer other than the component (A-2). The component (A-3) is a compound having an unsaturated bond and having a solubility in water of 10% or more, and specific examples thereof include (meth)acrylic acid, 2-hydroxyethyl (meth)acrylate, and (methyl). Hydroxypropyl acrylate, 4-hydroxybutyl acrylate, acrylamide, maleic acid, fumaric acid, and the like. The component (A-3) may be used alone or in combination of two or more.

The weight ratio of the component (A-3) in the monomer mixture (A) is from 0.1% by weight to 30% by weight based on 100% by weight of the monomer mixture (A). The reason for this is that the ratio of the component (A-3) is 0.1% by weight or more, whereby the viscosity of the paste composition containing the obtained binder resin for baking can be improved, and the printability can be improved, and excellent properties can be imparted. Homogenization. Further, when the paste composition is formed, the dispersion stability of the inorganic powder can be improved. By setting the ratio of the component (A-3) to 30% by weight or less, the baking property of the binder resin for baking can be improved.

The monomer mixture (A) may contain the component (A-4) in addition to the above component (A-1), component (A-2), and component (A-3).

Examples of the component (A-4) include styrene, α-methylstyrene, acrylonitrile, diethylaminoethyl methacrylate, and vinyl acetate. The types of the radical polymerizable monomers can be formulated according to the binder resin for baking. The type of the inorganic powder or the organic solvent is appropriately selected.

The weight ratio of the component (A-4) in the monomer mixture (A) is from 0% by weight to 39.8% by weight, preferably 30% by weight or less, based on 100% by weight of the monomer mixture (A). The reason for this is that the binder resin for baking can be efficiently produced by making the weight ratio of the component (A-4) 30% by weight or less. The ratio of the component (A-4) is more preferably 20% by weight or less.

<Monomer mixture (1)>

The monomer mixture (1) contains the component (a-1) and the component (a-2).

The component (a-1) is an alkyl (meth)acrylate, and is the same as the above component (A-1). The weight ratio of the component (a-1) is from 35 to 99.7 wt% when the monomer mixture (1) is set to 100% by weight. By making the ratio of the component (a-1) 35 wt% to 99.7 wt%. The resulting baking adhesive resin can be imparted with excellent baking properties, and can be suitably used as a baking material. The lower limit of the ratio of the component (a-1) is preferably 50% by weight or more, more preferably 70% by weight or more.

The component (a-2) is a compound having two or more radically polymerizable unsaturated double bonds, and is the same as the above component (A-2). The weight ratio of the component (a-2) is from 0.3% by weight to 5% by weight when the monomer mixture (1) is made 100% by weight. By setting the ratio of the component (a-2) to 0.3% by weight to 5% by weight, the viscosity of the paste composition containing the obtained binder resin for baking can be improved to improve printability, and it can be applied as a baking material. . The lower limit of the ratio of the component (a-2) is preferably 0.5% by weight or more. When the ratio of the component (a-2) is 0.5% by weight or more, the balance between the viscosity increasing effect and the thermal decomposition property is improved, and excellent printability in screen printing can be imparted. On the other hand, since In view of solubility in the organic solvent, the upper limit of the ratio of the component (a-2) is preferably 3% by weight or less.

The monomer mixture (1) may also contain the component (a-3). The component (a-3) is a water-soluble unsaturated monomer, and is the same as the above component (A-3). The weight ratio of the component (a-3) is from 0% by weight to 40% by weight based on 100% by weight of the monomer mixture (1). The upper limit of the component (a-3) is preferably 30% by weight or less. The reason for this is that the baking property of the binder resin for baking can be improved by making the weight ratio of the component (a-3) 30% by weight or less.

In the monomer mixture (1), the component (a-4) may be contained in addition to the above component (a-1), component (a-2), and component (a-3). The component (a-4) is the same as the above component (A-4). The weight ratio of the component (a-4) is from 0 wt% to 64.7 wt%, preferably 40 wt% or less, when the monomer mixture (1) is 100 wt%. The reason for this is that the binder resin for baking can be efficiently produced by setting the weight ratio of the component (a-4) to 40% by weight or less. The ratio of the component (a-4) is more preferably 30% by weight or less.

<Monomer mixture (2)>

The monomer mixture (2) contains the component (b-1) and the component (b-3).

The component (b-1) is an alkyl (meth)acrylate, and is the same as the above component (A-1). The component (b-1) is preferably an alkyl (meth)acrylate having an alkyl group having an alkyl group having 2 to 8 carbon atoms, and specific examples thereof include ethyl (meth)acrylate and (methyl). (Meth) acrylate such as butyl acrylate, 2-ethylhexyl (meth)acrylate or cyclohexyl (meth)acrylate. The alkyl (meth)acrylate having an alkyl group having 2 to 8 carbon atoms in the alkyl group has good solubility in an organic solvent, and is suitable for use in a binder resin for baking. Ingredient (b-1) It is the same as component (a-1) and may be different. The component (b-1) may be used alone or in combination of two or more.

The weight ratio of the component (b-1) in the monomer mixture (2) is from 35 to 99.9 wt% when the monomer mixture (2) is set to 100 wt%. By setting the ratio of the component (b-1) to 35 wt% to 99.9 wt%, the obtained binder resin for baking can be swollen in an organic solvent to exhibit good printability. The lower limit of the ratio of the component (b-1) is preferably 50% by weight or more, more preferably 70% by weight or more.

The monomer mixture (2) may also contain the component (b-2). The component (b-2) is a compound having two or more radically polymerizable unsaturated double bonds, and is the same as the above component (A-2). The component (b-2) may be the same as or different from the component (a-2). The weight ratio of the component (b-2) is from 0% by weight to 1% by weight based on 100% by weight of the monomer mixture (2). When the weight ratio of the component (b-2) is 1% by weight or less, the degree of swelling of the obtained binder resin for baking in an organic solvent can be increased, and the printability can be easily exhibited. The weight ratio of the component (b-2) in the monomer mixture (2) is preferably 0.5% by weight or less.

The component (b-3) is a water-soluble unsaturated monomer, and is the same as the above component (A-3). The component (b-3) may be the same as or different from the component (a-3). The component (b-3) may be used alone or in combination of two or more.

The weight ratio of the component (b-3) in the monomer mixture (2) is from 0.1% by weight to 30% by weight based on 100% by weight of the monomer mixture (2). When the ratio of the component (b-3) is 0.1% by weight or more, the viscosity of the paste composition including the obtained binder resin for baking can be improved, and the printability can be improved, and It can impart excellent homogenization. Further, when the paste composition is formed, the dispersion stability of the inorganic powder can be improved. Further, by setting the ratio of the component (b-3) to 30% by weight or less, the baking property of the binder resin for baking can be improved.

The monomer mixture (2) may contain a component (b-4) other than the above component (b-1), component (b-2), and component (b-3). The component (b-4) is the same as the above component (A-4). The component (b-4) may be the same as or different from the component (a-4). The weight ratio of the component (b-4) is from 0 to 64.9 mass%, preferably 30 wt% or less, when the monomer mixture (2) is 100 wt%. The reason for this is that the binder resin for baking can be efficiently produced by making the weight ratio of the component (b-4) 30% by weight or less.

The method for producing a binder resin for baking according to the present invention is produced by radically polymerizing a monomer mixture (2) in the presence of a polymer obtained by radical polymerization of a monomer mixture (1).

The weight ratio of the monomer mixture (1) is preferably from 20% by weight to 80% by weight based on 100% by weight of the total monomer mixture. By making the ratio of the monomer mixture (1) 20% by weight to 80% by weight, the thixotropy of the paste composition can be exhibited, and the printability can be improved.

On the other hand, the weight ratio of the monomer mixture (2) is preferably from 20% by weight to 80% by weight based on 100% by weight of the total monomer mixture. By making the ratio of the monomer mixture (2) 20% by weight to 80% by weight, the viscosity of the paste composition can be made moderate, and sagging or the like can be prevented.

Further, in the present invention, in the case of producing a binder resin for baking, before the first polymerization step of radical polymerization of the monomer mixture (1), / or after the second polymerization step of the radical polymerization of the monomer mixture (2), or between the steps, the monomer mixture (1), the monomer mixture other than the monomer mixture (2) (0) The step of free radical polymerization. Further, in the case where the other monomer mixture (0) is radically polymerized before the radical polymerization of the monomer mixture (1), the polymer of the other monomer mixture (0) functions as a seed particle. .

The other monomer mixture (0) contains one or two or more kinds of monomers which are free-radically polymerizable, and the kind thereof is not particularly limited, and is preferably based on the polymerization timing of the other monomer mixture (0). (timing) contains at least one of the above components (a-1) to (a-4) and (b-1) to (b-4). Further, the other monomer mixture (0) may be the same composition as the monomer mixture (1) or the monomer mixture (2), or may be a different composition.

The weight ratio of the other monomer mixture (0) is preferably less than 50% by weight when the total monomer mixture is set to 100% by weight. The reason for this is that the particle diameter of the obtained binder resin for baking can be easily controlled by making the weight ratio of the other monomer mixture (0) less than 50% by weight. The upper limit of the ratio of the other monomer mixture (0) is more preferably less than 30% by weight. Particularly, in the case where the other monomer mixture (0) is polymerized only before the monomer mixture (1), the ratio of the other monomer mixture (0) is preferably less than 20% by weight.

The polymerization method in the case of the radical polymerization of the monomer mixture is a known method such as a suspension polymerization method, an emulsion polymerization method, or a solution polymerization method, and from the viewpoint of easily controlling the particle diameter of the obtained binder resin for baking, Preferred is an emulsion polymerization method.

In the emulsion polymerization method, specifically, a monomer mixture (1), an emulsifier, and a polymerization initiator are added to water, and heating is carried out to carry out polymerization. Thereafter, the monomer mixture (2) was added to the reaction system to carry out polymerization.

As the emulsifier, for example, an anionic emulsifier (sodium dodecylbenzenesulfonate, sodium laurylsulfonate, sodium lauryl sulfate, etc.), an anionic emulsifier containing a polyoxyethylene group, and a nonionic emulsifier (poly) can be used. A reactive emulsifier having a vinyl polymerizable double bond in the molecule, such as oxyethylene nonylphenyl ether or polyoxyethylene lauryl ether.

As the polymerization initiator, for example, a peroxide such as benzamidine peroxide, cumene hydroperoxide or hydrogen peroxide; an azo compound such as azobisisobutyronitrile; a persulfate compound such as ammonium persulfate or potassium persulfate; A redox initiator which is composed of a perchloric acid compound, a perboric acid compound or a combination of a peroxide and a reducing sulfur compound.

Moreover, in the emulsion polymerization, the chain transfer agent may use a mercaptan such as n-dodecyl mercaptan, tert-dodecyl mercaptan, n-octyl mercaptan, n-tetradecyl mercaptan or n-hexyl mercaptan. Wait.

In the case of emulsion polymerization, it is preferred to use seed polymerization, and even a small amount of other monomer mixture (0) is batch-polymerized to prepare seed particles, and then the monomer mixture is added dropwise to carry out polymerization. The reason for this is that the particle size of the obtained baking binder resin can be more easily controlled by using seed polymerization. In the case of the seed granules, the weight ratio of the other monomer mixture (0) is preferably from 1% by weight to 10% by weight based on 100% by weight of the total monomer mixture.

In addition, when forming seed particles, a monomer mixture (1) can also be used. Part of it is used as a mixture of other monomers (0).

As a binder resin for baking obtained in this way, as the particle diameter becomes smaller, the solubility in an organic solvent increases. Therefore, the volume average particle diameter of the baking binder resin is preferably 100 μm or less, and more preferably 50 μm or less. Further preferably, it is 5 μm or less. When the volume average particle diameter of the baking binder resin is 100 μm or less, the solubility of the baking binder resin in an organic solvent can be sufficiently improved.

Here, the volume average particle diameter is a value measured using a light scattering photometer. In addition, the particle diameter in the present invention means a primary particle diameter at the time of production by radical polymerization, and is different from the secondary particle diameter (that is, the particle diameter after radical polymerization, granulation, etc.) ).

As a result of examination by the inventors of the present invention, it has been found that the paste composition for baking which is obtained by the present invention can easily obtain a paste composition excellent in both homogenizability and printability in screen printing. The reason for this is considered to be that, as described above, the monomer mixture (2) is radically polymerized in the presence of the polymer of the monomer mixture (1) to produce a binder resin for baking, whereby the structure is sticky. The thixotropy caused by sex, and the fluidity in the paste is improved.

It is considered that the binder resin for baking obtained by the above production method has a core shell structure (the polymer obtained by radical polymerization of the monomer mixture (1) is cored to make a monomer mixture (2) The polymer obtained by radical polymerization is an outer shell, and it is inferred that the structure contributes to thixotropy and fluidity.

The baking binder resin of the present invention is preferably dissolved in rosin alcohol. The resulting 15 wt% solution of the resin satisfies the following conditions.

η ₁ /η _{10 is} less than 2.5 η ₁ /η ₅₀₀₀ is 5 or more

Here, η ₁ , η ₁₀ and η ₅₀₀₀ are resin solutions measured under the conditions of a cone-plate 0.5°/25 mm and a measurement temperature of 23° C. using a viscoelasticity measuring device (manufactured by Anton Paar Co., Ltd., "Physca MCR300"). Viscosity, η ₁ is the viscosity at a shear rate of 1 (1/s), η ₁₀ is the viscosity at a shear rate of 10 (1/s), and η ₅₀₀₀ is a shear rate of 5000 (1/s). Viscosity. In addition, the rosin alcohol used in the measurement of the viscosity is a mixture of α-rosin alcohol, β-rosin alcohol, and γ-rosin alcohol, and is a “rosin alcohol (trade name)” manufactured by Nippon Spice Pharmaceutical Co., Ltd.

(paste composition)

The paste composition of the present invention comprises the above-mentioned binder resin for baking, an inorganic powder, and an organic solvent.

Further, the paste composition may optionally contain a plasticizer, a dispersing aid, an antifoaming agent, and the like.

The inorganic powder is not particularly limited as long as it is an inorganic powder which can be dispersed in the binder resin for baking.

Specific examples of the inorganic powder include oxides such as alumina, zirconia, titania, and barium titanate; nitrides such as aluminum oxynitride, tantalum nitride, and boron nitride; metals such as copper, silver, and nickel, and low-melting glass. A cerium oxide powder such as powder, various phosphors, and the like.

The preferred weight ratio of the binder resin to the inorganic powder varies depending on the specific gravity of the inorganic powder, for example, relative to 100 parts by weight of the inorganic powder. In other words, the solid content of the binder resin for baking is preferably from 3 parts by weight to 30 parts by weight. When the solid content of the binder resin for baking is 3 parts by weight or more, the inorganic powder can be easily formed, and if it is 30 parts by weight or less, the target molded body or pattern can be surely obtained after baking.

As the organic solvent, an organic solvent which dissolves the binder resin for baking is used.

The organic solvent is preferably an organic solvent having a boiling point of 100 ° C or higher, more preferably an organic solvent having a boiling point of 120 ° C or higher. When the boiling point is 100 ° C or more, the organic solvent becomes difficult to evaporate, and therefore the workability of the obtained paste composition at the time of printing or coating is good. Further, the "boiling point" in the present invention is a boiling point at 1 atm (1013 hPa).

Examples of the organic solvent having a boiling point of 100 ° C or higher include α,β,γ-rosinol, propylene glycol monomethyl ether, ethyl 3-ethoxypropionate, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, and B. Glycol monomethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2, 2 ,4-trimethyl-1,3-pentanediol monoisobutyrate, isophorone,-3-methoxybutyl acetate, benzyl alcohol, 1-octanol, 1-nonanol, 2- Ethyl-1-hexanol, 1-nonanol, 1-undecyl alcohol, 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3 -butanediol, 1,4-butanediol, 1,5-pentanediol, toluene, dimethylhydrazine, dimethylformamide, dimethylacetamide, N-methylpyrrolidone Wait. The organic solvent may be used singly or in combination of two or more.

Among the organic solvents, α,β,γ-rosinol and propylene glycol monomethyl ether are preferred from the viewpoint of excellent solubility.

In order to improve the viscosity of the paste composition, screen printing or dip coating can be made Preferably, it is preferable to contain 50% by weight or more of α,β,γ-rosin alcohol in an organic solvent, and more preferably 70% by weight or more.

The content of the organic solvent in the paste composition is preferably from 5% by weight to 70% by weight based on 100% by weight of the paste composition. When the content of the organic solvent is 5 wt% or more, the paste fluidity can be imparted, and when it is 70 wt% or less, high printability can be exhibited.

Since the paste composition contains the binder resin for baking of the present invention, it is excellent in both homogenizability and printability in screen printing.

Since the paste composition is excellent in printability in screen printing, it is preferable to apply screen printing when forming a pattern on a substrate, but it is also applicable to a method other than screen printing. When the viscosity of the paste composition is high, the dip coating method or the dispensing method can be applied. When the viscosity is low, the doctor blade coating method or the casting coating method can be applied.

Examples of the substrate for printing or coating the paste composition include a ceramic substrate, a condenser, and the like.

(inorganic sintered body)

The inorganic sintered body of the present invention is an inorganic sintered body obtained by baking the above-mentioned paste composition. The baking method includes a method of disposing a substrate on which the paste composition is printed or coated in a high-temperature environment, but is not limited thereto. During the baking, the organic substance containing the baking binder resin contained in the paste composition is decomposed and removed, and the inorganic powder is melted and sintered to obtain an inorganic sintered body. The baking temperature is appropriately determined depending on the melting temperature of the substrate or the type of the organic substance contained in the inorganic powder or the paste composition, but is usually 200 ° C to 1500 ° C, preferably 300 ° C to 1000 ° C.

[Example]

Hereinafter, the present invention will be described by way of examples and comparative examples. In addition, in the following examples, "parts" means "parts by weight", and "%" means "wt%".

The measurement, the evaluation method, and the method for producing the binder resin for baking in the following examples are as follows.

<Measurement and evaluation method>

(Measurement of volume average particle size)

The volume average particle diameter of the particles of the binder resin for baking was measured using a light scattering photometer (manufactured by Otsuka Electronics Co., Ltd., "FPAR-1000 type").

(evaluation of homogenization)

The viscosity of the baking binder resin solution was measured using a viscoelasticity measuring apparatus (manufactured by Anton Paar Co., Ltd., "Physca MCR300") under the conditions of a cone-and-cone plate of 0.5 ° / 25 mm and a measurement temperature of 23 ° C. The viscosity is obtained when the shear rate of 1 (1 / s) is set to η _1, the viscosity when the shear rate of 10 (1 / s) to η η ₁₀ when the ₁ / _η value of _10. Then, the homogenization was evaluated by the following evaluation criteria. Further, the smaller the value of η ₁ /η ₁₀ is, the more excellent the homogenization property is.

◎: η ₁ /η _{10 is} less than 2.0.

○: η ₁ /η ₁₀ is 2.0 or more and less than 2.5.

×: η ₁ /η ₁₀ is 2.5 or more.

(evaluation of printability)

The viscosity was measured in the same manner as the evaluation of the homogenization, and the viscosity when the shear rate was 1 (1/s) was η ₁ and the viscosity at the shear rate of 5000 (1/s) was determined. η ₅₀₀₀ η ₁ / η ₅₀₀₀ value. Then, the printability was evaluated by the following evaluation criteria. Further, the larger the value of η ₁ /η ₅₀₀₀ , the more excellent the printability.

◎: η ₁ /η ₅₀₀₀ is 10 or more.

○: η ₁ /η ₅₀₀₀ is 5 or more and less than 10.

×: η ₁ /η _{5000 is} less than 5.

(Evaluation of heat reduction rate)

According to the following formula, the differential thermal balance TG-DTA (manufactured by RIGAKU Co., Ltd., trade name: Thermo plus EVO) was used, and 5 mg of the measurement sample was applied to the air at a rate of 15 ° C/min from the start temperature of 30 ° C. The heat reduction rate (%) at 450 ° C when the temperature is raised to 500 ° C.

Heat reduction rate (%) = (sample weight (mg) - weight of residue (mg)) / sample weight (mg)

<Method for Producing Binder Resin Resin>

(Manufacturing Example 1 to Manufacturing Example 9)

In a polymerization apparatus which can be heated and cooled, 100 parts of water, sodium dialkyl sulfosuccinate (manufactured by Kao Co., Ltd., "Pelex OTP"), as shown in Table 1 as an emulsifier, was charged as a polymerization. The starting agent was potassium persulfate 0.05 part. Further, 4 parts of isobutyl methacrylate was added to the polymerization apparatus, and the mixture was heated at 80 ° C for 0.5 hour while stirring at 150 rpm in a nitrogen atmosphere to be polymerized to obtain an emulsion containing seed particles.

25 parts of deionized water, sodium dialkyl sulfosuccinate as emulsifier (Part 1 of the "Pelex OTP" manufactured by Kao Co., Ltd.) and 48 parts of the monomer mixture (1) in the weight ratio (mixed composition) shown in Tables 1 and 2 were emulsified and added dropwise to the mixture for 2 hours. The emulsion containing the seed granules was then heated at 80 ° C for 0.5 hours to polymerize.

Then, 25 parts of deionized water, 1 part of sodium dialkyl sulfosuccinate (produced by Kao Co., Ltd., "Pelex OTP") as an emulsifier, and a weight ratio of the monomers shown in Table 1 and Table 2 48 parts of the mixture (2) was emulsified, added dropwise to the reaction solution over 2 hours, and then kept at 80 ° C for 1 hour to obtain an emulsion of the binder resin for baking.

Using a spray drying device (manufactured by Okawara Chemical Co., Ltd., "L-8 type"), the chamber inlet temperature was 150 ° C, the chamber outlet temperature was 55 ° C, and the atomizer rotation speed was 20000 rpm. The obtained emulsion of the binder resin for baking is spray-dried to obtain particles (A1 to A9) of the binder resin for baking.

The measurement results of the volume average particle diameter of the obtained binder resin for baking are shown in Table 1.

(Manufacturing Example 10)

The emulsion containing the seed granules was prepared in the same manner as in Production Example 1 to Production Example 9.

15 parts of deionized water, sodium dialkyl sulfosuccinate (produced by Kao Co., Ltd., "Pelex OTP") as an emulsifier, 0.5 parts by weight, and monomer mixture (1) 30 in the weight ratio shown in Table 2 The emulsification treatment was carried out by dropwise addition to the emulsion containing the seed granules for 1.5 hours, followed by heating at 80 ° C for 0.5 hours to polymerize.

Then, 35 parts of deionized water, 1.5 parts of sodium dialkyl sulfosuccinate ("Pelex OTP" manufactured by Kao Co., Ltd.) as an emulsifier, and a weight ratio of the monomer mixture shown in Table 2 (2) 66 parts were emulsified, added dropwise to the reaction solution over 2.5 hours, and then kept at 80 ° C for 1 hour to obtain an emulsion of the binder resin for baking.

The obtained emulsion of the binder resin for baking was spray-dried in the same manner as in Production Example 1 to Production Example 9 to obtain a binder resin for baking (A10).

The measurement results of the volume average particle diameter of the obtained binder resin for baking are shown in Table 1.

(Manufacturing Example 11)

In a heating and cooling polymerization apparatus, 100 parts of water and 0.05 parts of potassium persulfate as a polymerization initiator were charged. The mixture was heated to 80 ° C while stirring at 150 rpm in a nitrogen atmosphere.

35 parts of deionized water, 1.5 parts of sodium dialkyl sulfosuccinate ("Pelex OTP" manufactured by Kao Co., Ltd.) as an emulsifier, and a monomer mixture (1) 75 in a weight ratio shown in Table 2 The mixture was emulsified, added dropwise thereto over 2.5 hours, and then polymerized by heating at 80 ° C for 0.5 hours.

Then, 15 parts of deionized water, sodium dialkyl sulfosuccinate (manufactured by Kao Co., Ltd., "Pelex OTP") as an emulsifier, 0.5 parts by weight, and a monomer mixture of the weight ratio shown in Table 2 (2) 25 parts of the emulsion were emulsified, added dropwise to the reaction solution over 1.5 hours, and then kept at 80 ° C for 1 hour to obtain an emulsion of the binder resin for baking.

In the same manner as in Production Example 1 to Production Example 9, the obtained emulsion of the binder resin for baking was spray-dried to obtain a binder resin for baking (A11).

The measurement results of the volume average particle diameter of the obtained binder resin for baking are shown in Table 1.

(Comparative Manufacturing Example 1)

A solution of 7.5 parts of polyvinyl alcohol dissolved in 1000 parts of pure water was placed in a four-liter flask which was heated and cooled in 2 L (liter). Further, 225 parts of isobutyl methacrylate, 269.75 parts of 2-ethylhexyl methacrylate, 5 parts of methacrylic acid, and dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., "KAYARAD") were further added. DPHA") 0.25 parts of the monomer mixture (1) and 2.5 parts of lauryl peroxide were stirred vigorously at 300 rpm to be suspended, and the mixture was heated to 80 ° C for 5 hours to complete the polymerization.

The obtained suspension was washed, dehydrated, and dried to obtain a binder resin for baking (A12).

The measurement results of the weight ratio of each monomer component when the monomer mixture (1) is 100% by weight and the average particle diameter of the obtained binder resin for baking are shown in Table 2.

(Comparative Manufacturing Example 2)

Into a heating and cooling polymerization apparatus, 100 parts of water, sodium dialkyl sulfosuccinate (manufactured by Kao Co., Ltd., "Pelex OTP"), as shown in Table 2 as an emulsifier, was introduced as a polymerization. The initial agent of potassium persulfate 0.05 parts. Further adding methyl methacrylate 2 to the polymerization device The mixture was mixed with 2 parts of isobutyl methacrylate, and the mixture was heated at 80 ° C for 0.5 hour while stirring at 150 rpm in a nitrogen atmosphere to obtain an emulsion containing seed particles.

Monomer mixture of 50 parts of deionized water, sodium dialkyl sulfosuccinate (produced by Kao Co., Ltd., "Pelex OTP") as an emulsifier, and weight ratio (mixed composition) shown in Table 2 (1) 96 parts were subjected to emulsification treatment, added dropwise to the emulsion containing the seed particles in 4 hours, and then heated at 80 ° C for 1 hour to obtain an emulsion of the binder resin for baking.

Using a spray drying device (manufactured by Okawara Chemical Co., Ltd., "L-8 type"), the obtained baking bonding was carried out under the conditions of a chamber inlet temperature of 150 ° C, a chamber outlet temperature of 55 ° C, and an atomizer rotation speed of 20,000 rpm. The emulsion of the resin was spray-dried to obtain a binder resin for baking (A13).

The measurement results of the volume average particle diameter of the obtained baking binder resin are shown in Table 2.

[Example 1 to Example 11, Comparative Example 1 to Comparative Example 2]

150 parts of the baking binder resin (A1 to A13) of the types shown in Table 1 and Table 2 were placed in a 2-L 3-neck flask, and rosin alcohol (α-, β) was further placed in the 3-neck flask. - 850 parts of γ-rosin alcohol mixture, manufactured by Japan Cosmetics Co., Ltd. (trade name). Thereafter, the temperature was raised to 80 ° C and dissolved for 3 hours to obtain a binder resin solution for baking.

The obtained binder resin solution for baking was evaluated for homogeneity and printability. The results are shown in Table 1.

[Example 12, Example 13]

The heat loss rate of the binder resin A1 for baking and the binder resin A4 for baking were evaluated. The results are shown in Table 3.

[Reference example]

Ethyl cellulose (manufactured by Nisshin Chemical Co., Ltd., trade name: STD100) was evaluated for heat reduction rate. The results are shown in Table 3.

The symbols in Tables 1 and 2 are as follows. In addition, the amounts of the monomers in the monomer mixture (0) to the monomer mixture (2) shown in Tables 1 and 2 are 100 wt% of the monomer mixture (0) to the monomer mixture (2), respectively. % weight ratio. Further, the seed (0) in Tables 1 and 2 indicates the same meaning as the other monomer mixture (0).

‧IBMA: isobutyl methacrylate

‧nBMA: n-butyl methacrylate

‧MMA: Methyl methacrylate

‧EHMA: 2-ethylhexyl methacrylate

‧EDMA: ethylene glycol dimethacrylate

‧DPHA: dipentaerythritol hexaacrylate

‧HEMA: 2-hydroxyethyl methacrylate

‧MAA: Methacrylic acid

‧AA: Acrylic

As is clear from Tables 1 and 2, in any of the baking binder resin solutions obtained in each of the examples, the homogenization property and the printability were good.

Moreover, as is clear from Table 3, the baking binder resin A1 and the baking binder resin A4 are more excellent in thermal decomposition property than ethyl cellulose.

[Industrial availability]

The binder resin for baking of the present invention can be used as a component of a paste composition excellent in homogenization and printability in screen printing. Further, by the production method of the present invention, such a binder resin for baking can be easily obtained and used.

Although the present invention has been disclosed above in the preferred embodiment, it is not intended to be used The invention is intended to be limited to the scope of the invention, and the scope of the invention is defined by the scope of the appended claims.

Claims (6)

A baking binder resin obtained by copolymerizing a monomer mixture (A) comprising the following components: (meth)acrylic acid alkyl ester (A-1) 60% by weight to 99.8% by weight, having two or more The radically polymerizable unsaturated double bond compound (A-2) is 0.1% by weight to 5% by weight, and the water-soluble unsaturated monomer (A-3) (but the above-mentioned unsaturated double polymerizable polymer having two or more radicals) 0.1% by weight to 30% by weight of the monomer other than the compound (A-2), 0% by weight to 39.8% by weight of the other copolymerizable monomer (A-4), and the baking binder resin is dissolved in The 15 wt% solution of the baking binder resin obtained in the rosin alcohol satisfies the following conditions: η ₁ /η1 _{0 is} less than 2.5 η ₁ /η ₅₀₀₀ is 5 or more, where η ₁ , η ₁₀ and η ₅₀₀₀ are used. Viscoelasticity measuring device ("Physca MCR300" manufactured by Anton Paar Co., Ltd.), the viscosity of the baking adhesive resin solution measured under the conditions of a cone plate of 0.5 ° / 25 mm and a measurement temperature of 23 ° C, η ₁ is a shear The viscosity at a cutting speed of 1 (1/s), η ₁₀ is the viscosity at a shear rate of 10 (1/s), and η ₅₀₀₀ is the viscosity at a shear rate of 5000 (1/s). A baking binder resin comprising a second polymer obtained by radically polymerizing a monomer mixture (2) in the presence of a first polymer obtained by radical polymerization of a monomer mixture (1) The monomer mixture (1) comprises: (meth)acrylic acid alkyl ester (a-1) 35 wt% to 99.7 wt%, a compound having two or more radically polymerizable unsaturated double bonds (a-2) 0.3 wt% to 5 wt%, a water-soluble unsaturated monomer (a-3) (but a monomer other than the compound (a-2) having two or more radically polymerizable unsaturated double bonds) 0 wt %~40wt%, other monomers (a-4) 0wt%~64.7wt%, the monomer mixture (2) comprises: (meth)acrylic acid alkyl ester (b-1) 35wt%~99.9wt%, Compound (b-2) having 2 or more radically polymerizable unsaturated double bonds, 0% by weight to 1% by weight, water-soluble unsaturated monomer (b-3) (but having two or more radically polymerizable 0.1% by weight to 30% by weight of the monomer other than the unsaturated double bond compound (b-2), and other monomer (b-4) 0% by weight to 64.9% by weight, and the baking binder resin is dissolved in terpineol and the resultant of the following conditions are satisfied with baking 15wt% solution of binder resin: η ₁ / ₁₀ is less than 2.5 η ₁ / η ₅₀₀₀ is 5 or more Here, η _1, η ₁₀ η ₅₀₀₀ and using a viscoelasticity measuring apparatus (manufactured by Anton Paar company, "Physca MCR300"), in a cone-plate 0.5 ° / 25mm, measurement temperature The viscosity of the baking binder resin solution measured at 23 ° C, η ₁ is the viscosity at a shear rate of 1 (1/s), and η ₁₀ is a shear rate of 10 (1/s). The viscosity at the time, η ₅₀₀₀ is the viscosity at a shear rate of 5000 (1/s). The baking binder resin according to the above-mentioned item, wherein the baking binder resin is a particle having a volume average particle diameter of 100 μm or less. A paste composition comprising the binder resin for baking, an inorganic powder, and an organic solvent according to any one of claims 1 to 3. An inorganic sintered body obtained by baking a paste composition as described in claim 4 of the patent application. A method for producing a binder resin for baking, comprising: a first polymerization step of radically polymerizing a monomer mixture (1) to obtain a first polymer, wherein the monomer mixture (1) comprises: (methyl) Alkyl acrylate (a-1) 35 wt% to 99.7 wt%, compound (a-2) having 2 or more radically polymerizable unsaturated double bonds, 0.3 wt% to 5 wt%, water-soluble unsaturated monomer ( A-3) (but a monomer other than the compound (a-2) having two or more radically polymerizable unsaturated double bonds) 0 wt% to 40 wt%, and other monomers (a-4) 0 wt% ~64.7 wt%; a second polymerization step of radically polymerizing the monomer mixture (2) in the presence of the first polymer to obtain a second polymer, the monomer mixture (2) comprising: Alkyl acrylate (b-1) 35 wt% to 99.9 wt%, compound having two or more radically polymerizable unsaturated double bonds (b-2) 0 wt% to 1 wt%, water-soluble unsaturated monomer (b-3) (but a monomer other than the compound (b-2) having two or more radically polymerizable unsaturated double bonds) 0.1 wt% to 30 wt%, and other monomers (b-4) 0 wt% to 64.9 wt%, and the baking binder resin is dissolved in rosin alcohol The 15 wt% solution of the binder resin for baking satisfies the following conditions: η ₁ /η _{10 is} less than 2.5 η ₁ /η ₅₀₀₀ is 5 or more. Here, η ₁ , η ₁₀ and η ₅₀₀₀ are using a viscoelasticity measuring device (Anton Paar) Manufactured by the company, "Physca MCR300", the viscosity of the baking adhesive resin solution measured under the conditions of a cone plate of 0.5 ° / 25 mm and a measurement temperature of 23 ° C, η ₁ is a shear rate of 1 (1/ s) viscosity, η ₁₀ is the viscosity at a shear rate of 10 (1/s), and η ₅₀₀₀ is the viscosity at a shear rate of 5000 (1/s).