Resins and resin components

Abstract

The resin of the present invention has a chlorine atomic weight and a free acid content of 0.03% by mass or less, and satisfies the requirements of Formula I and Formula II below: Formula I: (A-B) / A < 0.01, Formula II: (A-C) / A > 0.87 (wherein, in the thermal analysis, the weight at time point 100°C is designated as A, the weight at time point 200°C is designated as B, and the weight at time point 600°C held for 10 minutes is designated as C. The thermal analysis is performed using TG / DTA at atmospheric temperature, with the temperature increased from 40°C to 600°C at a rate of 5°C / min, and held at 600°C for 10 minutes). According to the present invention, a resin capable of providing good stability of inorganic powder solutions, good shape stability after being formed into a specified shape, and good decarbonization properties can be provided.

Description

Technical Field

[0001] This invention relates to a resin that can be used as an adhesive, etc., and a resin composition containing the resin. Prior Technology

[0002] Polyvinyl acetal resins, acrylic resins, polyvinyl alcohol resins, and other resins are widely used as organic adhesives. Besides being used in interlayer films for laminated glass, organic adhesives are also sometimes used in inks, coatings, enamels for firing, varnishes, ceramic green sheets, thermophotographic photosensitive materials, and ink receiving layers.

[0003] For example, polyethylene acetal resin is generally an acetalized form of unmodified polyvinyl alcohol, and unmodified polyethylene acetal resins with acetyl, hydroxyl, and acetal groups in their side chains are widely used. Furthermore, modified polyethylene acetal resins with functional groups other than acetyl, hydroxyl, and acetal groups (modifying groups) have been explored in the past to impart various functions. For example, Patent Documents 1-3 disclose a modified polyethylene acetal resin with polyoxyalkylene groups in its side chains.

[0004] Furthermore, adhesive resins sometimes incorporate carboxyl groups to ensure a certain level of cohesiveness. For example, acrylic resins typically contain building blocks derived from monomers containing carboxyl groups, such as (meth)acrylic acid. [Previous Technical Documents] [Patent Literature]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2014-136796 [Patent Document 2] No. WO2012 / 115223 [Patent Document 3] Japanese Patent Application Publication No. 2019-065166 Summary of the Invention

[0006] [The problem that the invention aims to solve]

[0007] In the aforementioned applications, organic binders are sometimes used together with inorganic powders in slurry solutions. In such cases, it is required that the inorganic powder solution does not increase viscosity and that the inorganic powder is properly dispersed to maintain stability. Furthermore, resin compositions containing organic binders are mostly formed into sheets, films, or other shapes, but most are required to maintain shape stability after being formed into a specified shape. Furthermore, when organic binders are used in ceramic green sheets, they undergo decarburization during firing. However, if organic residue remains after decarburization, defects may occur in the fired product, reducing the yield after firing. Therefore, it is necessary to improve the decarburization properties when removing organic binders.

[0008] However, resins such as polyvinyl acetal or acrylic resins, which have been used as adhesives in the past, are difficult to make good inorganic powder solutions, shape stability after being formed into a specified shape, and decarburization properties during firing.

[0009] Therefore, the objective of this invention is to provide a resin that provides good stability of inorganic powder solution, good shape stability after being formed into a specified shape, and good decarbonization properties. [Technical means to solve the problem]

[0010] Generally, in the synthesis of resins, chlorine-containing compounds such as hydrochloric acid are often used, resulting in the introduction of trace amounts of chlorine. Furthermore, in adhesive resins, compounds with carboxyl groups are often introduced to enhance cohesion. The inventors have discovered that trace amounts of chlorine or carboxyl groups can hinder the stability of inorganic powder solutions. Therefore, after further in-depth research, the inventors found that resins with low chlorine atomic weights and carboxyl group content, and exhibiting a defined weight loss curve in thermal analysis, can solve the aforementioned problems, thus completing the following invention.

[0011] The present invention provides the following [1] to

[14] . [1] A resin having a chlorine atomic weight and a free acid content of 0.03% by mass or less, and satisfying the requirements of Formula I and Formula II below. Formula I: (AB) / A<0.01, Equation II: (AC) / A > 0.87 (Among them, in the thermal analysis, the weight at the time point of 100℃ is designated as A, the weight at the time point of 200℃ is designated as B, and the weight at the time point of holding at 600℃ for 10 minutes is designated as C. The thermal analysis is performed using TG / DTA, under atmospheric conditions, by heating from 40℃ to 600℃ at a rate of 5℃ / min, and holding at 600℃ for 10 minutes). [2] The resin described in [1] above is a thermoplastic resin. [3] The resin described in [2] above, wherein the thermoplastic resin is selected from at least one of the groups consisting of polyvinyl acetal resins and polyvinyl alcohol resins. [4] The resin described in [3] above, wherein at least one of the resins selected from the group consisting of polyvinyl acetal resins and polyvinyl alcohol resins has a polyalkylene oxide structure. [5] As described in [4] above, the polyepoxide structure is represented by the following formula (1), (In formula (1), A1O is an oxoalkyl group with 2 to 6 carbon atoms, m is the average repeating number, which is 10 to 200; R1 is an alkyl group or hydrogen atom with 1 to 8 carbon atoms; in addition, the oxoalkyl group can be a single type or mixed with two or more types; * indicates the bonding position with other groups). [6] As described in [4] or [5] above, the average number of repeating alkyl groups in the polyepoxide structure is 15 to 80. [7] The resin described in any of [4] to [6] above, wherein the oxyalkyl group in the polyepoxide structure comprises at least one of oxyethyl and oxypropyl. [8] The resin described in any of [4] to [7] above, wherein the modified mass due to the polyoxyalkylene structure is more than 0.2 mol% and less than 8 mol%. [9] The resin described in any of [1] to [8] above has a weight average molecular weight of 15,000 or more and 1,000,000 or less.

[10] The resin described in any of [1] to [9] above is used in ceramic green sheets or electrode paste.

[11] A resin composition containing the resin described in at least one of [1] to

[10] above.

[12] The resin composition described in

[11] above does not contain plasticizer, or contains less than 40 parts by weight of plasticizer relative to 100 parts by weight of the resin.

[13] The resin composition described in

[11] or

[12] above contains inorganic powder.

[14] The resin composition described in

[13] above, wherein the inorganic powder is ceramic powder. [Effects of the Invention]

[0012] According to the present invention, a resin is provided that provides good stability of inorganic powder solution, good shape stability after being formed into a specified shape, and good decarbonization properties. Simple Explanation of the Diagram

[0013] none Implementation

[0014] <Resin> [Chlorine atomic weight and free acid weight (hereinafter also referred to as carboxyl group weight)] The resin of this invention (hereinafter, for convenience, sometimes referred to as resin (X)) has a chlorine atomic weight and free acid content of 0.03% by mass or less. In this invention, if the chlorine atomic weight is greater than 0.03% by mass, or the free acid content is greater than 0.03% by mass, the slurry containing resin (X) and inorganic powder will become unstable due to the influence of chlorine atoms or free acid content, resulting in thickening or phase separation, making it difficult to improve the stability of the inorganic powder solution. Furthermore, sometimes the decarburization during firing will decrease, leading to a reduction in yield. From the perspective of the stability of inorganic powder solutions, the atomic weight of chlorine is preferably below 0.024% by mass, more preferably below 0.020% by mass, and even more preferably below 0.016% by mass. The lower the atomic weight of chlorine, the better, and it can be above 0.0% by mass.

[0015] From the viewpoint of the stability of inorganic powder solutions, the above-mentioned free acid content is preferably 0.024% by mass or less, more preferably 0.020% by mass or less, and even more preferably 0.016% by mass or less. From the viewpoint of the stability of inorganic powder solutions, the above-mentioned free acid content can be 0.0% by mass or more, but depending on the type of resin (X), it can also contain a certain amount or more. For example, in the acrylic resin described later, in order to improve cohesion and adhesion, it is preferable to contain a certain amount or more, for example, it can be 0.005% by mass or more, or it can be 0.01% by mass or more. Additionally, regarding the atomic weight of chlorine and the amount of free acid, when the determination methods described later are below the detection limit, they are set to 0.0 mass in this specification.

[0016] From the viewpoint of the stability of inorganic powder solutions, the resin (X) of the present invention preferably has a combined chlorine atomic weight and free acid content of 0.05% by mass or less, more preferably 0.03% by mass or less, even more preferably 0.024% by mass or less, even more preferably 0.016% by mass or less, and may also be 0.0% by mass or more.

[0017] Regarding the atomic weight of chlorine and the amount of free acid, these values ​​can be appropriately adjusted to be below the aforementioned upper limit by modifying the manufacturing method of resin (X) or the composition of resin (X). Furthermore, the atomic weight of chlorine can be determined by ion analysis using ion chromatography, and the amount of free acid can be determined by titration. Specifically, it can be determined by the method described in the examples.

[0018] [Thermal Analysis and Determination] The resin (X) of the present invention satisfies the requirements of Formula I and Formula II below. Formula I: (AB) / A<0.01, Equation II: (AC) / A > 0.87 (In the thermal analysis, the weight at time 100°C is designated as A, the weight at time 200°C as B, and the weight at time 600°C held for 10 minutes as C. This thermal analysis is performed using a TG / DTA (differential calorimetry and thermogravimetric analysis device) under atmospheric conditions, with the temperature increased from 40°C to 600°C at a rate of 5°C / min, and held at 600°C for 10 minutes.) In this invention, as described above, the atomic weight of chlorine and the amount of free acid are below a specified value, and the requirements of Formulas I and II are satisfied at the same time. This allows the inorganic powder solution to have good stability, and at the same time, the shape stability and decarbonization properties after being formed into a specified shape such as a sheet are also good.

[0019] The value of (AB) / A shown in Formula I is an indicator of the content of high-boiling-point low-molecular-weight components in resin (X). Therefore, if (AB) / A is greater than 0.01, the high-boiling-point low-molecular-weight components in resin (X) will increase. If it is stored for a long period of time after being formed into a sheet or other specified shape, the following adverse situation will occur: due to the volatilization of a portion of resin (X) during storage, the shape will change and the shape stability will decrease. Furthermore, the weight reduction of resin (X) when heated from room temperature to 100°C is mainly due to the evaporation of moisture. Therefore, in this invention, the temperature for measuring weight A is set to 100°C instead of room temperature, thereby ensuring that the value of (AB) / A accurately reflects the proportion of low molecular weight components after eliminating the influence of moisture.

[0020] From the viewpoint of achieving good shape stability, a lower (AB) / A value is better, preferably below 0.009, more preferably below 0.008, and even more preferably below 0.007. However, there are no particular limitations if the (AB) / A value is above 0.

[0021] The value of (AC) / A shown in Formula II is an indicator of the decomposition rate of resin (X) when heated at high temperature. If the value of (AC) / A is below 0.87, the resin (X) will not decompose sufficiently even when heated at high temperature. Therefore, for example, when decarburization is performed by firing, the amount of residual carbon will increase, resulting in defects and making it difficult to obtain fired products with high yield. From the viewpoint of reducing the amount of residual carbon during decarburization and obtaining fired products with high yield, (AC) / A is preferably 0.88 or higher, more preferably 0.9 or higher, and even more preferably 0.91 or higher. The higher the (AC) / A value shown in Formula II, the better. If it is less than 1, there is no particular limitation. However, it is generally difficult to make the amount of residual carbon during firing zero. Therefore, it is typically less than 1, for example, less than 0.99.

[0022] Furthermore, in this invention, the value of (AB) / A can be decreased by reducing the low molecular weight components of resin (X). Also, (AC) / A can be increased by appropriately adjusting the type of resin (X) or the components constituting resin (X).

[0023] The resin (X) used in this invention is preferably a thermoplastic resin. By using a thermoplastic resin, the resin composition containing the resin (X) can be easily molded into a specified shape such as a sheet. Specific examples of thermoplastic resins include polyvinyl acetal resins, acrylic resins, polyvinyl alcohol resins, polyvinyl acetate, ethylene / vinyl acetate copolymers, polyurethane resins, and ionomer resins. One of these can be used alone, or two or more can be used in combination. By using these resins, the value of (AB) / A can be easily reduced, while simultaneously increasing the value of (AC) / A. Furthermore, by appropriately adjusting the manufacturing method of resin (X) or the monomer composition of resin (X), the values ​​of both the atomic weight of chlorine and the amount of free acid groups can be reduced.

[0024] Among the aforementioned thermoplastic resins, from the viewpoint of excellent shape stability after molding into a specified shape and excellent decarbonization properties, at least one of polyvinyl acetal resins and polyvinyl alcohol resins is preferred. Furthermore, among these, polyvinyl acetal resins are preferred because they readily provide good stability to inorganic powder solutions. These thermoplastic resins can be used alone or in combination with two or more.

[0025] The weight-average molecular weight (Mw) of the resin (X) of the present invention is preferably 15,000 or more and 1,000,000 or less. By setting the weight-average molecular weight to the lower limit or above, it is easy to reduce (AB) / A; conversely, by setting it to the upper limit or below, it is easy to increase (AC) / A. Furthermore, from the viewpoint of improving shape stability after forming into a predetermined shape such as a sheet or film, the weight-average molecular weight (Mw) of the resin (X) is preferably 50,000 or more, more preferably 100,000 or more, and even more preferably 150,000 or more. Moreover, the weight-average molecular weight (Mw) is preferably 600,000 or less, more preferably 500,000 or less, and even more preferably 400,000 or less. Additionally, the weight-average molecular weight (Mw) represents the weight-average molecular weight converted to polystyrene, measured using gel permeation chromatography (GPC). When the resin (X) contains polyvinyl alcohol resin, all hydroxyl groups of the polyvinyl alcohol resin are reacetylated before measurement.

[0026] [Polyvinyl acetal resin] As described above, it is preferable to use a polyvinyl acetal resin as resin (X). The polyvinyl acetal resin can be a modified polyvinyl acetal resin or an unmodified polyvinyl acetal resin, but a modified polyvinyl acetal resin is preferred. One type of polyvinyl acetal resin can be used alone, or two or more types can be used in combination. The modified polyethylene acetal resin, as described below, may have a structure other than acetal, hydroxyl, and acetyl groups (modifying groups), preferably having modifying groups on the side chains. In this invention, by appropriately selecting the type of modifying group, the value of (AC) / A can be increased. Furthermore, for polyvinyl acetal resins, even modified polyvinyl acetal resins can be manufactured using the methods described later, which can reduce the low molecular weight components and thus easily decrease the (AB) / A value.

[0027] In this invention, the modified group is preferably a polyepoxyalkylene structure. In this invention, the polyvinyl acetal resin possesses a polyepoxyalkylene structure, resulting in excellent thermal decomposition properties and a readily increased (AC) / A ratio, making it an excellent decarbonization agent.

[0028] The polyepoxide structure, specifically, is shown in the following formula (1). (In formula (1), A1O is an oxoalkyl group with 2 to 6 carbon atoms, m is the average repeating number, which is 10 to 200. R1 refers to alkyl groups or hydrogen atoms with 1 to 8 carbon atoms. In addition, the oxoalkyl group can be a single type or mixed with two or more types. * indicates the bonding position with other groups.)

[0029] The oxoalkyl group in A 1O is an oxoalkyl group with 2 to 6 carbon atoms, preferably an oxoalkyl group with 2 to 4 carbon atoms, and more preferably an oxoalkyl group with 2 or 3 carbon atoms. The alkyl group in the oxyalkylene group can be straight-chain or branched. Examples of oxyalkylene groups include oxyethyl, oxypropyl, or oxybutyl, with oxyethyl and oxypropyl being preferred. One oxyalkylene group can be used alone, or two or more can be used in combination. When two or more are used in combination, each oxyalkylene group can undergo random addition or block addition, but random addition is more preferred. When a polyepoxide structure has two or more oxyalkylene groups, the random structure makes it easier to increase the (AC) / A ratio compared to the block structure.

[0030] The oxyalkylene group in the polyepoxide structure preferably includes at least one of oxyethyl and oxypropyl groups, and more preferably includes both oxyethyl and oxypropyl groups. When both oxyethyl and oxypropyl groups are included, a block structure can be formed, but as mentioned above, a random structure is more preferably formed. In this invention, the alkylene oxide structure is composed of alkylene ethyl or alkylene propyl groups, or has both alkylene ethyl and alkylene propyl groups, and these have a random structure, thereby easily increasing the (AC) / A value. When oxypropyl (EO) and oxypropyl (PO) are present, the ratio of oxypropyl to oxyethyl (PO / EO) in molar ratio is, for example, 1 / 9 to 9 / 1, preferably 2 / 8 to 8 / 2, and more preferably 3 / 7 to 7 / 3.

[0031] In formula (1), m is the average number of repeating alkyl groups in the polyoxyalkylene structure, for example, 10 to 200. Furthermore, from the viewpoint that increasing the average number of repetitions (i.e., m in equation (1)) to increase the value of (AC) / A improves decarburization, it is preferably 15 to 80, more preferably 20 to 78, more preferably 25 to 75, and even more preferably 30 to 70. In addition, by increasing the number of repetitions, it is easier to ensure softness, etc., and the formability when forming sheets, etc., is also easier to improve.

[0032] The alkyl group in R1 can be straight-chain or branched. Examples of branched alkyl groups in R1 include methyl, ethyl, n-propyl, isopropyl, n-butyl, secondary butyl, tertiary butyl, etc.; n-pentyl, branched pentyl, n-hexyl, branched hexyl, n-heptyl, isoheptyl, 3-heptyl, etc.; n-octyl, isooctyl, 2-ethylhexyl, etc. R1 can be either an alkyl group or a hydrogen atom. The number of carbon atoms in the alkyl group is as described above, and can be 1 to 8, but is more preferably 1 to 6, and even more preferably 1 to 4.

[0033] The aforementioned polyepoxide structure can be linked to the main chain via linking groups. As a linking group, examples include ether bonds (-O-), ester bonds (-COO-), amide bonds (-CONR-: R is a hydrogen atom or an alkyl group with 1 to 4 carbon atoms), or a hydrocarbon group having at least any of these bonds. The number of carbon atoms in the linking group is not particularly limited; for example, it can be about 10 or less, preferably 4 or less. Furthermore, the linking group does not need to have carbon atoms; therefore, the number of carbon atoms in the linking group can be 0 or more. Also, R in -CONR- is preferably a hydrogen atom. Furthermore, the number of carbon atoms in the hydrocarbon group in the linking group can be, for example, about 1 to 10, preferably 1 to 4. Furthermore, the aforementioned polyepoxide structure is preferably bonded to the main chain via either an ether bond or -CH₂O-. The manufacture of the polyepoxide structure is facilitated by bonding it to the main chain via either an ether bond or -CH₂O-. Additionally, in -CH₂O-, oxygen atoms can be bonded to the aforementioned polyepoxide structure.

[0034] Polyvinyl acetal resins typically contain acetal, hydroxyl, and acetylated groups. However, polyvinyl acetal resins may also lack hydroxyl groups due to functional group modification. Furthermore, the so-called acetal, hydroxyl, and acetylated groups, as shown in formulas (3-1) to (3-3) described later, are groups directly or through oxygen atoms bonded to the main chain, and do not contain the hydroxyl groups present in polyepoxide structures. Furthermore, the polyvinyl acetal resin is preferably modified to have the polyepoxide structure shown in formula (1) above.

[0035] The modification of the modified polyethylene acetal resin due to the polyepoxide structure (i.e., the functional group shown in formula (1)) is preferably 0.1 mol% to 10 mol%. By making the modification within the above range, it is easy to increase the value of (AC) / A, and at the same time, it is easy to make the various physical properties of the resin (X) such as adhesion good. From this perspective, the modified content due to the polyepoxide structure is preferably 0.2 mol% or more, more preferably 0.3 mol% or more, even more preferably 0.4 mol% or more, and preferably 8 mol% or less, even more preferably 6 mol% or less, and even more preferably 4 mol% or less.

[0036] Furthermore, in this specification, the term "modified mass due to functional groups" refers to the proportion of functional groups relative to the total monomer units (usually total ethylene monomer units) constituting the polyvinyl acetal resin or the polyvinyl alcohol resin described later. This modified mass can be calculated from the obtained spectra by proton NMR determination of the polyvinyl acetal resin or polyvinyl alcohol resin. Similarly, the degree of acetalization, hydroxyl content, and degree of acetylation described later can also be calculated from the obtained spectra by proton NMR determination.

[0037] Polyvinyl acetal resins have vinyl groups as the main chain, and the functional groups shown in formula (1) can be bonded to the vinyl groups constituting the main chain. Therefore, polyvinyl acetal resins preferably have the constituent units shown in formula (2), and more preferably have any of the constituent units shown in formulas (2-1) and (2-2).

[0038] (In formula (2), A1O, R1, and m are the same as above. R2 can be an ether bond (-O-), an ester bond (-COO-), a amide bond (-CONR-: R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms), or a hydrocarbon group having at least one of these bonds.) The number of carbons in R2 in formula (2) is, for example, 0 to 10, preferably 0 to 4. R2 is preferably an ether bond (-O-) as described above, or at least a hydrocarbon group having an ether bond.

[0039] (In equations (2-1) and (2-2), A1O, R1, and m are the same as above.)

[0040] Furthermore, the explanations of A1O, R1, and m in equations (2), (2-1), and (2-2) are omitted as described above.

[0041] Polyvinyl acetal resins typically have acetal groups, hydroxyl groups, and acetylation groups. That is, polyvinyl acetal resins typically have the constituent units shown in formulas (3-1), (3-2), and (3-3). Therefore, modified polyvinyl acetal resins are preferably those having the constituent units shown in formulas (3-1), (3-2), and (3-3) and the constituent unit shown in formula (2) above. However, polyvinyl acetal resins may also lack hydroxyl groups and the constituent units shown in formula (3-2). That is, polyvinyl acetal resins have the constituent units shown in formulas (3-1) and (3-3) below, and may also arbitrarily have the constituent units shown in formula (3-2) below.

[0042] (In formula (3-1), R represents a hydrogen atom or a hydrocarbon group with 1 to 19 carbon atoms.)

[0043] Polyethylene acetal resins may also lack the aforementioned polyepoxide structure. Such polyethylene acetal resins can be modified polyethylene acetal resins with modifying groups other than the polyepoxide structure, or unmodified polyethylene acetal resins without modifying groups. Furthermore, polyethylene acetal resins can also be modified polyethylene acetal resins with the aforementioned polyepoxide structure and modifying groups other than the polyepoxide structure.

[0044] The number of carbon atoms in the acetal group of the polyvinyl acetal resin is not particularly limited, as shown in formula (3-1) above, for example 1 to 20, but preferably 2 to 10, more preferably 2 to 6, and even more preferably 2, 3, or 4. Therefore, the number of carbon atoms in R shown in formula (3-1) above is preferably 1 to 9, more preferably 1 to 5, and even more preferably 1 to 3. R is preferably linear, but may also be partially alicyclic or aromatic. As an acetal group, particularly butyraldehyde group, it is preferred to be a polyvinyl acetal resin.

[0045] The degree of acetalization (i.e., acetal content) of the polyethylene acetal resin is preferably 40 mol% or more, more preferably 55 mol% or more, even more preferably 60 mol% or more, and even more preferably 64 mol% or more. Furthermore, the degree of acetalization is preferably 90 mol% or less, more preferably 88 mol% or less, even more preferably 85 mol% or less, and even more preferably 79 mol% or less. By making the degree of acetalization within these ranges, it is easy to contain a certain amount of hydroxyl groups or the functional groups shown in formula (1). Additionally, the term "degree of acetalization" refers to the degree of acetalization when the acetal group in the polyethylene acetal resin is an acetoacetal group, and the degree of butyraldehyde when the acetal group is a butyraldehyde group. Furthermore, the degree of acetalization indicates the ratio of acetalized vinyl alcohol units to the total monomer units constituting polyethylene acetal resin.

[0046] The hydroxyl content of the polyvinyl acetal resin is preferably 50 mol% or less, more preferably 45 mol% or less, even more preferably 40 mol% or less, and even more preferably 35 mol% or less. Furthermore, the hydroxyl content of the polyvinyl acetal resin may be 0 mol% or more, but it may contain a certain amount of hydroxyl groups, preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 15 mol% or more, and even more preferably 20 mol% or more. By keeping the amount of hydroxyl groups within the above range, it has the advantages of increased strength when formed into sheets or films, or excellent dispersibility when used in ceramic sheets, etc. Additionally, the hydroxyl content indicates the proportion of hydroxyl groups relative to the total monomer units constituting polyvinyl acetal resins.

[0047] The degree of acetylation (acetylated content) of the aforementioned polyvinyl acetal resin is, for example, 0.01 mol% or more and 50 mol% or less. However, for example, in order to make the mass change caused by the functional group shown in formula (1) a certain value or more, the degree of acetylation is also preferably set to a certain value or less. Therefore, the degree of acetylation of the polyvinyl acetal resin is preferably 20 mol% or less, more preferably 15 mol% or less, even more preferably 12 mol% or less, and even more preferably 5 mol% or less. Furthermore, the degree of acetylation of the modified polyethylene acetal resin (A) is, for example, 0.01 mol% or more, as described above, but preferably 0.1 mol% or more, and even more preferably 0.5 mol% or more.

[0048] [Manufacturing Method of Polyvinyl Acetal Resin] The polyvinyl acetal resin used in this invention, when it is a modified polyvinyl acetal resin, can be obtained by acetalizing polyvinyl alcohol (also referred to as "raw material polyvinyl alcohol") with an aldehyde, and then reacting it with a modifier. In this case, modified polyvinyl alcohol can be used as the raw material polyvinyl alcohol, but unmodified polyvinyl alcohol is usually sufficient. Furthermore, modified polyvinyl acetal resins can also be obtained by using modified polyvinyl alcohol as a raw material, and then acetalizing the modified polyvinyl alcohol with aldehydes. As a raw material, polyvinyl alcohol is generally used with a saponification degree of 80~99.8 moles.

[0049] The aldehydes used in the manufacture of polyvinyl acetal resins are not particularly limited, for example, aldehydes with 1 to 20 carbon atoms, but generally, aldehydes with 2 to 10 carbon atoms are preferred. The aforementioned aldehydes with 2 to 10 carbon atoms are not particularly limited, and examples include acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-pentanaldehyde, 2-ethylbutyraldehyde, n-hexanaldehyde, n-octanaldehyde, n-nonanaldehyde, n-decanaldehyde, and benzaldehyde. Among these, aldehydes with 2 to 6 carbon atoms, such as acetaldehyde, n-butyraldehyde, n-hexanaldehyde, and n-pentanaldehyde, are preferred, aldehydes with 2, 3, or 4 carbon atoms are more preferred, and n-butyraldehyde is even more preferred. These aldehydes can be used alone or in combination of two or more.

[0050] Polyvinyl acetal resins, for example, when manufacturing modified polyvinyl acetal resins having a polyepoxide structure, are preferably manufactured by the following manufacturing method.

[0051] In this manufacturing method, firstly, polyoxyethylene-modified polyvinyl alcohol is produced as a raw material. Specifically, this can be achieved by polymerizing ethylene ester with a monomer containing an ethylene monomer having a polyoxyethylene group, followed by saponification of the polymer. Saponification can generally be performed using an alkali or acid, but an alkali is preferred. Furthermore, a chlorine-free alkali or acid can be used as the alkali or acid, such as inorganic alkalis like sodium hydroxide or potassium hydroxide. By using a chlorine-free inorganic alkali, the atomic weight of chlorine in the resin (X) can be reduced, while saponification is carried out appropriately at the same time. As a polyoxyethylene-modified polyvinyl alcohol, only one type can be used, or two or more types can be used together.

[0052] The vinyl ester used in the above manufacturing method may be vinyl acetate, vinyl formate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, trimethylvinyl acetate, vinyl versatic acid, vinyl hexanoate, vinyl octanoate, vinyl laurate, vinyl palmitate, vinyl stearate, vinyl oleate, vinyl benzoate, etc. Among these, vinyl acetate is preferred.

[0053] Furthermore, as the ethylene monomer with polyoxyalkylene groups used in the above manufacturing method, specifically, the compounds shown in the following formula (4) can be used. Among them, polyoxyalkylene vinyl ether shown in the following formula (4-1) and polyoxyalkylene allyl ether shown in formula (4-2) are preferred.

[0054] (In equation (4), A1O, R1, R2, and m are the same as above.)

[0055] (In equations (4-1) and (4-2), A1O, m, and R1 are the same as those described above.)

[0056] Preferred examples of ethylene monomers having a polyoxyalkylene group include polyoxyethylene monoethylene ether, polyoxyethylene polyoxypropylene monoethylene ether, polyoxypropylene monoethylene ether, polyoxyethylene monoallyl ether, polyoxyethylene polyoxypropylene monoallyl ether, polyoxypropylene monoallyl ether, polyoxyethylene alkylethylene ether, polyoxyethylene polyoxypropylene alkylethylene ether, polyoxypropylene alkylethylene ether, polyoxyethylene alkylallyl ether, polyoxyethylene alkylallyl ether, polyoxyethylene polyoxypropylene alkylallyl ether, and polyoxypropylene alkylallyl ether.

[0057] Next, the modified polyvinyl alcohol obtained above is acetalized with an aldehyde to obtain modified polyvinyl acetal resin. The acetalization reaction can be carried out by adding an acid catalyst and an aldehyde to a polyvinyl alcohol solution prepared by dissolving the modified polyvinyl alcohol in water, causing the obtained polyvinyl acetal resin to precipitate in the form of particles. Here, the particle size of the precipitated polyvinyl butyral resin is preferably adjusted to an appropriate size. If the particle size of the precipitated polyvinyl butyral resin is reduced, the acid catalyst will have difficulty penetrating the particles, and even if hydrochloric acid is used as the acid catalyst, the atomic weight of chlorine in the resin (X) can be reduced. Furthermore, by ensuring that the precipitated polyvinyl butyral resin particles are of a certain size or larger, the solution after precipitation will not turn into an emulsion, and the particles will be easier to recover. There are no particular limitations on the methods for adjusting particle size. Examples include adjusting the concentration of modified polyvinyl alcohol in the polyvinyl alcohol solution, adjusting the temperature during the precipitation of polyvinyl acetal resin or the temperature during the continued reaction after precipitation, or combining these methods.

[0058] The acetalization reaction is explained in more detail below. Acetalization begins by adding modified polyvinyl alcohol to water and heating the solution to obtain a polyvinyl alcohol solution in which the modified polyvinyl alcohol dissolves in water. At this point, the concentration of modified polyvinyl alcohol in the polyvinyl alcohol solution is, for example, 3% by mass to 15% by mass, preferably 5% by mass to 13% by mass, and even more preferably 7.5% by mass to 11% by mass. If the concentration is above the lower limit, the solution can be prevented from becoming an emulsion after precipitation, and the precipitated polyvinyl butyral resin particles can be appropriately recovered. Furthermore, if the concentration is below the upper limit, it is easier to appropriately reduce the particle size, and even when hydrochloric acid is used as an acid catalyst, the chlorine atomic mass in the resin can be reduced. Furthermore, when dissolving modified polyvinyl alcohol in water, the polyvinyl alcohol solution can be heated to a temperature between 50°C and 100°C, preferably between 60°C and 100°C. It is preferable to use a multi-stage dissolution temperature process, depending on the length or mass of the modified chain and the degree of saponification. Specifically, it is preferable to hold the solution at 60°C for 1 hour, then raise the temperature to above 90°C and hold it there for another hour. By using a multi-stage, temperature-controlled dissolution process, the solubility of the modified base portion and the hydroxyl portion of the polyvinyl alcohol can be improved.

[0059] Next, the polyvinyl alcohol solution is cooled to, for example, -5°C to 60°C, preferably 10°C to 55°C. Then, an acid catalyst and an aldehyde are added to the polyvinyl alcohol solution maintained within the above temperature range, and the liquid temperature is lowered to, for example, -10°C to 55°C, preferably 0°C to 50°C, more preferably 20°C to 45°C, and even more preferably 23°C to 40°C. Then, an acetalization reaction can be carried out within this temperature range for, for example, 30 seconds to 60 minutes, preferably 1 minute to 30 minutes, more preferably 25 minutes, and even more preferably 20 minutes, to precipitate the reaction product. Then, the liquid temperature can be raised to, for example, above 35°C but below 80°C, preferably above 40°C but below 75°C, more preferably above 43°C but below 70°C, and even more preferably above 45°C but below 65°C, and maintained within this temperature range, so that the reaction can proceed for, for example, more than 10 minutes but less than 360 minutes, preferably more than 30 minutes but less than 300 minutes. As mentioned above, setting the temperature before the reaction to a relatively high range ensures good compatibility with the catalyst or aldehyde, while setting the temperature at which the reaction products precipitate, or the temperature during subsequent reactions, to a relatively low range, reduces the particle size of the precipitated particles. Furthermore, it prevents the precipitated particles from becoming too small, thus avoiding the formation of an emulsion.

[0060] As the acid catalyst used in the acetalization reaction, various inorganic acids can be used, but hydrochloric acid or sulfuric acid is preferred to facilitate the acetalization reaction. The amount of acid catalyst used relative to 100 parts by mass of modified polyvinyl alcohol as raw material is, for example, 0.5% to 6% by mass, preferably 1% to 4% by mass.

[0061] After the acetalization reaction, the precipitated reaction product can be obtained as modified polyethylene acetal resin by neutralization, washing, and drying using conventional methods. Furthermore, regarding washing, when hydrochloric acid or similar acid catalysts are used, multiple washing and dehydration processes can be performed to reduce the chlorine atomic weight in the modified polyethylene butyral resin.

[0062] [Polyvinyl alcohol based resins] The polyvinyl alcohol (PVA) resin used as resin (X) can be obtained by polymerizing ethylene esters according to conventionally known methods, followed by saponification, i.e., hydrolysis, of the polymer. PVA can be used alone or in combination with two or more types. Furthermore, as described in the manufacture of polyvinyl acetal resins, vinyl acetate is preferred as the ethylene ester used in the manufacture of PVA.

[0063] PVA can be unmodified PVA or modified PVA, but modified PVA is preferred. Modified PVA is preferably PVA with a polyoxyalkylene structure. In this invention, by having a polyoxyalkylene structure, the (AC) / A ratio of the PVA is easily increased, making it easier to form a product with excellent decarbonization properties. The polyepoxide structure, as described in the above-mentioned polyethylene acetal resin, is a constituent of formula (1), and its modified quality and other details are as described above.

[0064] Unmodified PVA can be exemplified by saponified polyethylene ester. Modified PVA can be exemplified by saponified polymers of ethylene ester and other unsaturated monomers. The degree of saponification of polyvinyl alcohol is generally 70–99.9 mol%. Here, other unsaturated monomers may include unsaturated monomers with modified groups, but preferably unsaturated monomers with a polyepoxide structure. The unsaturated monomer with a polyepoxide structure is preferably an ethylene monomer with a polyoxyalkylene group as shown in formula (4) above. Further details regarding the ethylene monomer with a polyoxyalkylene group are as described in the above description of polyvinyl acetal resins. Furthermore, polyvinyl alcohol-based resins can be manufactured in the same manner as the aforementioned raw material, polyvinyl alcohol. By manufacturing polyvinyl alcohol-based resins, for example, using the methods described above, the low molecular weight components can be reduced, thus making it easier to reduce the (AB) / A ratio.

[0065] While PVA generally possesses the constituent units of formula (3-2) above, it may also possess the constituent units of formula (3-3) above, in addition to those of formula (3-2). Furthermore, as mentioned above, PVA preferably has a polyepoxide structure, and therefore, it is more preferably possessing the constituent units shown in formula (2), and even more preferably possessing any one of the constituent units shown in formulas (2-1) and (2-2). Details of formulas (2), (2-1), and (2-2) are as described above.

[0066] [Acrylic resins] The acrylic resin used as resin (X) is an acrylic polymer. An acrylic polymer is a homopolymer of acrylic monomers containing (meth)acrylic groups within the molecule, or a copolymer formed by copolymerizing monomers containing acrylic monomers. One type of acrylic resin may be used alone, or two or more may be used in combination. Additionally, in this specification, "(meth)acryl" means acrylonitrile or methacrylonitrile, "(meth)acrylate" means acrylate or methacrylate, and other similar terms are used in the same way.

[0067] Acrylic acid monomers that constitute acrylic acid polymers are, for example, monofunctional monomers having one (meth)acrylic acid group. Examples of such acrylic acid monomers include alkyl (meth)acrylates, (meth)acrylates containing alicyclic structures, and (meth)acrylates containing aromatic rings. Furthermore, the monofunctional monomers constituting acrylic polymers can also be monomers having functional groups such as cyclic ether groups, hydroxyl groups, carboxyl groups, amino groups, amide groups, polyoxyethylene groups, and alkoxy groups (hereinafter also referred to as "monomers containing functional groups"). Specifically, examples of monomers containing functional groups include (meth)acrylates containing cyclic ether groups, (meth)acrylates containing hydroxyl groups, monomers containing carboxyl groups, monomers containing amino groups, monomers containing amide groups, monomers containing polyoxyethylene groups, and monomers containing alkoxy groups.

[0068] Examples of alkyl methacrylates include those having an alkyl group having 1 to 18 carbon atoms. Specifically, examples include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tributyl methacrylate, n-pentyl methacrylate, n-hexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, 2-ethylhexyl methacrylate, isodecanyl methacrylate, lauryl methacrylate, tetradecyl methacrylate, isotetradecyl methacrylate, stearyl methacrylate, and isostearyl methacrylate. Among these, alkyl methacrylates having an alkyl group having 1 to 8 carbon atoms are preferred.

[0069] Examples of (meth)acrylates containing an alicyclic structure include cyclohexyl (meth)acrylate, isoborneol (meth)acrylate, and dicyclopentyl (meth)acrylate. Examples of (meth)acrylates containing an aromatic ring include benzyl (meth)acrylate and phenoxyethyl (meth)acrylate. Furthermore, these (meth)acrylates containing an alicyclic structure and (meth)acrylates containing an aromatic ring are (meth)acrylates that do not possess the aforementioned functional groups.

[0070] Examples of (meth)acrylates containing cyclic ether groups include those with an epoxy ring. Examples of (meth)acrylates containing an epoxy ring include glycidyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate glycidyl ether, 3-hydroxypropyl (meth)acrylate glycidyl ether, 4-hydroxybutyl acrylate glycidyl ether, 5-hydroxypentyl (meth)acrylate glycidyl ether, and 6-hydroxyhexyl (meth)acrylate glycidyl ether.

[0071] Examples of monomers containing carboxyl groups include acrylic acid, methacrylic acid, ω-carboxylated polycaprolactone mono(meth)acrylate, β-carboxyethyl(meth)acrylate, 2-(meth)acrylic acetoethyl phthalic acid, and 2-(meth)acrylic acetoethyl hexahydrophthalic acid. The number of repeating units of polycaprolactone in ω-carboxylated polycaprolactone mono(meth)acrylate is approximately 2 to 5, preferably 2 to 3. The acrylic acid monomer containing a carboxyl group is preferably selected from at least one monomer in the group consisting of acrylic acid or methacrylic acid. Examples of acrylic monomers containing hydroxyl groups include 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate, among which 2-hydroxyethyl methacrylate is preferred. Examples of monomers containing an amino group include (meth)acrylate-N,N-dimethylaminoethyl ester, (meth)methacrylate-N,N-dimethylaminoethyl ester, and (meth)acrylate-N,N-diethylaminoethyl ester. Examples of monomers containing amide groups include N,N-dimethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, and N-hydroxyethyl (meth)acrylamide. As a (meth)acrylate containing polyoxyethylene, diethyl glycol monoethyl ether (meth)acrylate is an example. As a monomer containing an alkoxy group, 3-methoxybutyl (meth)acrylate can be cited as an example.

[0072] Furthermore, the monomers constituting the acrylic polymer are preferably one or more of the group consisting of alkyl (meth)acrylates and (meth)acrylates containing alicyclic structures. Regarding the total content of the monomers selected from these monomers, based on the total amount of monomers constituting the acrylic polymer, it is preferably 50% by mass or more, and more preferably 70% by mass or more. Furthermore, among the monomers constituting the acrylic polymer, alkyl (meth)acrylates are preferably used. More preferably, the alkyl (meth)acrylate is used in combination with one selected from (meth)acrylates containing an alicyclic structure, and more preferably in combination with a (meth)acrylate containing an alicyclic structure.

[0073] The acrylic monomers constituting the acrylic polymer preferably contain, in addition to acrylic monomers selected from the group consisting of alkyl (meth)acrylates and (meth)acrylates containing alicyclic structures, the aforementioned monomers containing functional groups. The total content of monomers containing functional groups, based on the total amount of monomers constituting the acrylic polymer, is preferably 0.05% by mass to 50% by mass, more preferably 0.1% by mass to 40% by mass, and even more preferably 1% by mass to 30% by mass.

[0074] Among the monomers containing functional groups mentioned above, monomers containing carboxyl groups are preferred. By including carboxyl-containing monomers in the acrylic monomers constituting the acrylic polymer, the cohesiveness of the resin is improved, resulting in good adhesion and making it a better adhesive. However, as mentioned above, carboxyl-containing monomers must be used in small quantities to reduce the amount of carboxyl groups. Therefore, the content of carboxyl-containing monomers, based on the total amount of monomers constituting the acrylic polymer, is preferably 0.003% by mass or more and 5% by mass, more preferably 0.05% by mass or more and 3% by mass, and even more preferably 0.01% by mass or more and 1% by mass.

[0075] The monomers constituting the acrylic polymer may also include monomers other than those mentioned above. Furthermore, in order not to impair the scope of the invention, polyfunctional monomers may be used in addition to monofunctional monomers as monomers constituting the acrylic polymer. Known polyfunctional (meth)acrylates may be used as polyfunctional monomers.

[0076] Acrylic polymers can be polymerized by solution polymerization, suspension polymerization, etc., but they can also be polymerized by irradiation with active energy lines. As mentioned above, to reduce the (AB) / A ratio of acrylic polymers, the amount of low molecular weight components must be reduced. Therefore, acrylic polymers are preferably polymerized by irradiation with active energy lines, especially ultraviolet (UV) light. Polymerization using active energy lines can be carried out in the presence of a polymerization initiator. More preferably, polymerization is carried out by UV irradiation without introducing any components other than monomers and initiators (solvents, etc.) into the reaction system. By using this method, side reactions such as polymerization termination reactions can be reduced, thus reducing the amount of low molecular weight components.

[0077] <Resin Composition> The resin composition of this invention is a resin composition containing resin (X). Furthermore, the resin composition may also contain components other than resin (X) depending on its intended use; for example, it may appropriately contain plasticizers or additives other than plasticizers. Specifically, additives other than plasticizers include ultraviolet absorbers, infrared absorbers, antioxidants, light stabilizers, adhesion modifiers, pigments, dyes, fluorescent whitening agents, nucleating agents, surfactants, and dispersants. Furthermore, the resin composition of this invention may also contain resin components other than resin (X) to the extent that it does not impair the effects of this invention. Furthermore, the resin composition of this invention may also contain a solvent, and be used after dilution with the solvent.

[0078] The resin composition of the present invention may also contain plasticizers as described above. The presence of plasticizers makes the resin composition softer and easier to mold into predetermined shapes such as sheets. However, the resin composition of the present invention preferably does not contain plasticizers, or if it does, it is in a small amount. By containing only a small amount of plasticizers or no plasticizers at all, the shape stability after the resin composition is molded into predetermined shapes such as sheets is easily improved. Furthermore, even if the resin composition of the present invention contains a small amount of plasticizer or does not contain plasticizer, by using the resin (X) specified above, good adhesion to various materials can be achieved, and the physical properties as an adhesive can be fully ensured.

[0079] The content of plasticizer in the resin composition may be less than 40 parts by mass relative to 100 parts by mass of resin (X) contained in the resin composition. By keeping the plasticizer content less than 40 parts by mass, it is easier to improve the shape stability after the resin composition is molded into a specified shape such as a sheet. The plasticizer content is preferably 30 parts by weight or less, more preferably 15 parts by weight or less, even more preferably 10 parts by weight or less, and even more preferably 5 parts by weight or less. Furthermore, the plasticizer content can be 0 parts by weight or more, and the resin composition is preferably free of plasticizer, that is, in a state where the plasticizer content is 0 parts by weight.

[0080] Examples of plasticizers include organic ester plasticizers, as well as organophosphate plasticizers and organophosphorus plasticizers, polyalkylene glycol plasticizers, polyoxyethylene ether plasticizers, and alcohol plasticizers. A single plasticizer can be used, or two or more can be used in combination. Among the above, organic ester plasticizers and polyalkylene glycol plasticizers are preferred, with organic ester plasticizers being even more preferred. Preferred organic ester plasticizers include monomeric organic acid esters and polymeric organic acid esters. Furthermore, the type of plasticizer used can be appropriately selected according to the type of resin (X). For example, when the resin (X) is either a polyvinyl acetal resin or an acrylic resin, it is preferable to use an organic ester plasticizer, while when the resin (X) is a polyvinyl alcohol resin, it is preferable to use an organic ester plasticizer or a polyalkylene glycol plasticizer.

[0081] Examples of monobasic organic acid esters include esters of diols and monobasic organic acids. Examples of diols include polyalkyl glycols in which each alkyl unit has 2 to 4 carbon atoms (preferably 2 or 3 carbon atoms) and the repeating number of the alkyl units is 2 to 10 (preferably 2 to 4). Also, monoalkyl glycols in which each alkyl unit has 2 to 4 carbon atoms (preferably 2 or 3 carbon atoms) can be used (i.e., the repeating unit is 1). As diols, examples include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, and butanediol. As monoprotic organic acids, examples include organic acids with 3 to 10 carbon atoms, such as butyric acid, isobutyric acid, hexanoic acid, 2-ethylbutyric acid, heptanoic acid, octanoic acid, 2-ethylhexanoic acid, nonanoic acid, and decanoic acid.

[0082] Examples of specific monomeric organic acids include triethylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol di-octanoate, triethylene glycol di-n-octanoate, triethylene glycol di-n-heptanoate, triethylene glycol di-n-heptanoate, triethylene glycol di-n-ethylhexanoate, triethylene glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylhexanoate, and triethylene glycol di-2-ethylbutyrate. 1,2-ethylvalerate, triethylene glycol di-2-ethylbutyrate, diethylene glycol didecanoate, triethylene glycol di-n-heptanoate, triethylene glycol di-n-heptanoate, triethylene glycol di-2-ethylbutyrate, ethylene glycol di-2-ethylbutyrate, 1,2-propanediol di-2-ethylbutyrate, 1,3-propanediol di-2-ethylbutyrate, 1,4-butanediol di-2-ethylbutyrate, 1,2-butanediol di-2-ethylbutyrate, etc.

[0083] Furthermore, examples of polybasic organic acid esters include ester compounds of dibasic organic acids with 4 to 12 carbon atoms, such as adipic acid, sebacic acid, azelaic acid, and phthalic acid, and alcohols with 4 to 10 carbon atoms. Alcohols with 4 to 10 carbon atoms can be straight-chain, branched, or cyclic. Specifically, examples include dibutyl sebacate, dioctyl azelate, dihexyl adipate, dioctyl adipate, hexylcyclohexyl adipate, diisononyl adipate, heptylnonyl adipate, dibutyl carbitol adipate, mixed adipates, dioctyl phthalate, and dibutyl phthalate. Oil-modified sebacate alcohols are also possible. As mixed adipates, examples include adipates prepared from two or more alcohols selected from alkyl alcohols and cyclic alcohols having 4 to 9 carbon atoms. Examples of organophosphorus plasticizers include phosphate esters such as tributyloxyethyl phosphate, isodecylphenyl phosphate, and triisopropyl phosphate.

[0084] As an organic ester plasticizer, it is not limited to the complete esters mentioned above, but can also be a partial ester. For example, it can be a partial ester of a diol and a monobasic organic acid, or a partial ester of a dibasic organic acid and an alcohol. Specifically, triglyceride mono-2-ethylhexanoate can be cited as an example. Furthermore, it can be a partial ester of an alcohol with a valence of 3 or higher, such as glycerol, and a monocarboxylic organic acid. Examples of monocarboxylic organic acids include those with 3 to 24 carbon atoms (preferably 6 to 18 carbon atoms). Specific examples of partial esters of an alcohol with a valence of 3 or higher and a monocarboxylic organic acid include mono- or diesters of glycerol and stearic acid, and mono- or diesters of glycerol and 2-ethylhexanoic acid. As organic ester plasticizers, triglyceride di-2-ethylhexanoate (3GO) and dioctyl adipate (DOA) are particularly preferred.

[0085] Examples of polyalkylene glycol plasticizers include polyethylene glycol, polypropylene glycol, poly(ethylene oxide / propylene oxide) block copolymers, poly(ethylene oxide / propylene oxide) random copolymers, and polybutylene glycol, among which polypropylene glycol is preferred.

[0086] Polyoxyethylene ether plasticizers are ether compounds of mono- or polyols and polyoxyethylene. Specific examples of polyoxyethylene ether plasticizers include polyoxyethylene hexyl ether, polyoxyethylene heptyl ether, polyoxyethylene octyl ether, polyoxyethylene-2-ethylhexyl ether, polyoxyethylene nonyl ether, polyoxyethylene decyl ether, polyoxyethylene allyl ether, polyoxypropylene allyl ether, polyoxyethylene glycerol ether, polyoxypropylene glycerol ether, polyoxyethylene diglycerol ether, polyoxypropylene diglycerol ether, polyoxyethylene neopentyl tetraglycerol ether, and polycaprolactone triol. The preferred plasticizers are polyoxyethylene ether compounds, which are ether compounds of polyols and polyoxyethylene, more preferably ether compounds of glycerol or diglycerol and polyoxypropylene, and even more preferably ether compounds of glycerol or diglycerol and polyoxypropylene. Alcohol-based plasticizers can be categorized as alcohols other than polyalkylene glycol plasticizers and polyoxyethylene ether plasticizers. Specifically, examples include various polyols such as ethylene glycol, propylene glycol, butanediol, hexanediol, trimethylolpropane, neopentyl tertrol, glycerol, and diglycerol. Among these, ethylene glycol is preferred.

[0087] The resin other than resin (X) that can be used in combination with resin (X) is preferably a thermoplastic resin. Specific examples of thermoplastic resins that can be used in combination with resin other than resin (X) include polyvinyl acetal resins, acrylic resins, polyvinyl alcohol resins, polyvinyl acetate, ethylene / vinyl acetate copolymers, polyurethane resins, and ionomer resins. Among these, polyvinyl acetal resins, acrylic resins, and polyvinyl alcohol resins are preferred, and polyvinyl acetal resins are even more preferred. One of these resins may be used alone, or two or more may be used in combination. When resins other than resin (X) are used in the resin composition, the content of the resins other than resin (X) should be an amount that does not impair the purpose of the present invention. This is preferably 50 parts by weight or less, more preferably 30 parts by weight or less, and even more preferably 15 parts by weight or less, relative to 100 parts by weight of resin (X). The lower limit is not particularly limited and can be 0 parts by weight or more.

[0088] The resin (X) and resin composition of the present invention can be used for various applications. The resin (X) and resin composition can also be used as interlayers for laminated glass, and preferably as adhesives in inks, coatings, enamels for firing, varnishes, ceramic green sheets, electrode pastes, thermophotographic photosensitive materials, ink receiving layers, lithium-ion batteries, solar cells, adhesive sheets, modifiers, etc. Furthermore, it can also be used as an additive or dispersant in these applications or other applications. Furthermore, in addition to the above-mentioned uses, the sheet containing the above-mentioned resin (X) can also be attached to the substrate during the manufacturing process to serve as a protective sheet for the substrate. The protective sheet can be attached to wafers or the like during semiconductor manufacturing to protect them. The sheet containing the resin (X) of the present invention exhibits excellent shape stability after forming, thus easily protecting various substrates. When used as a protective sheet, the protective sheet only needs to have at least one layer composed of a resin composition containing the above-mentioned resin (X).

[0089] In the above, the resin (X) and resin composition are preferably used, in particular, in conjunction with inorganic powder as described later; wherein, it is more preferably used for firing. When the resin (X) or resin composition is used for firing, it is more preferably used in the following method, that is, after shaping the resin composition containing the inorganic powder described later into a predetermined shape such as a sheet, it is fired to obtain a fired product. Furthermore, of the above, resin (X) and resin composition are preferably used in ceramic green sheets or electrode paste.

[0090] (Inorganic powder) The resin composition of the present invention preferably contains inorganic powder in addition to the resin (X). Furthermore, when the resin composition contains inorganic powder, as described above, it may appropriately contain plasticizers or additives other than plasticizers. In the following description, for convenience, the resin composition containing inorganic powder will be referred to as "inorganic powder-containing resin composition," and sometimes the slurry-like inorganic powder-containing resin composition described later will be referred to as "slurry composition."

[0091] The inorganic powder resin composition, generally speaking, preferably further contains a solvent, and is used in the form of a slurry. The resin (X) of the present invention, as described above, has high stability in inorganic powder solutions and can be used in conjunction with inorganic powder in slurries, thus ensuring good dispersibility of the inorganic powder and preventing slurry thickening. The resin (X) content in the slurry composition is preferably 1% by mass or more and 20% by mass or less relative to the total amount of the slurry composition. By ensuring the resin (X) content in the slurry composition is 1% by mass or more, good film-forming properties and flexibility of ceramic green sheets are achieved, preventing cracks after sintering. Furthermore, by ensuring the resin (X) content is 20% by mass or less, excessively high viscosity of the slurry composition is prevented, and reduced dispersibility is avoided. Additionally, good decarburization during firing is achieved. More preferably, the resin (X) content in the slurry composition is 2% by mass or more and 10% by mass, and even more preferably 2.5% by mass or more and 5% by mass or less.

[0092] As an inorganic powder, its type can be appropriately used depending on its application, with ceramic powder being the preferred choice. By using ceramic powder, the inorganic powder-containing resin composition can be better used for ceramic green sheets. There are no particular limitations on the ceramic powder used; examples include alumina, zirconium oxide, aluminum silicate, titanium dioxide, zinc oxide, barium titanate, magnesium oxide, aluminum silicate nitride, spinel mullite, crystal glass, silicon carbide, silicon nitride, and aluminum nitride powders. These ceramic powders can be used alone or in combination of two or more. Furthermore, glass adhesives such as MgO-SiO₂-CaO, B₂O₂-SiO₂, PbO-B₂O₂-SiO₂, CaO-SiO₂-MgO-B₂O₂, or PbO-SiO₂-B₂O₂-CaO series can be further added to the aforementioned ceramic powders.

[0093] By using conductive powder as inorganic powder, inorganic powder-containing resin compositions can be better used in electrode pastes. There are no particular limitations on conductive powders, such as nickel, copper, aluminum, silver, gold, platinum, palladium, solder, tin oxide, antimony-doped tin oxide (ATO), indium oxide, and tin-doped indium oxide (ITO).

[0094] The content of inorganic powder relative to the total amount of the slurry composition is preferably 20% by mass or more and 80% by mass or less. Maintaining a content of 20% by mass or more prevents excessively low viscosity and improves the treatment properties when forming ceramic green sheets. Furthermore, if the content of inorganic powder is 80% by mass or less, it prevents the viscosity of the slurry composition from becoming too high. The content of inorganic powder is more preferably 30% by mass or more and 70% by mass or less.

[0095] The solvent contained in the slurry composition (i.e., the resin composition) can be water or an organic solvent, preferably an organic solvent. There are no particular limitations on the type of organic solvent; examples include ketones such as acetone, methyl ethyl ketone, dipropyl ketone, and diisobutyl ketone; alcohols such as methanol, ethanol, isopropanol, and butanol; aromatic hydrocarbons such as toluene and xylene; esters such as methyl propionate, ethyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, butyl butyrate, methyl valerate, ethyl valerate, butyl valerate, methyl hexanoate, ethyl hexanoate, butyl hexanoate, 2-ethylhexyl acetate, and 2-ethylhexyl butyrate; diols such as methyl cellulose, ethyl cellulose, butyl cellulose, α-terpineol, butyl cellulose acetate, and butyl carbitol acetate; and terpenoids. These organic solvents can be used alone or in combination of two or more.

[0096] The solvent content is preferably 20% by mass or more and 80% by mass or less relative to the total amount of the slurry composition. Within this range, the slurry composition will have appropriate mixability, and the viscosity will be within an appropriate range, resulting in better treatment when forming ceramic green sheets, etc. The solvent content is more preferably 30% by mass or more and 70% by mass or less.

[0097] As described above, the slurry composition is preferably used for ceramic green sheets or electrode paste. Therefore, one embodiment of the present invention also provides a ceramic green sheet or electrode paste obtained using the above-described slurry composition. There are no particular limitations on the manufacturing method of ceramic green sheets, and they can be manufactured using conventional manufacturing methods. For example, the following method can be used: after defoaming the above-mentioned slurry composition as needed, it is coated in a film onto a peelable support such as a polyethylene terephthalate film, and after removing the solvent by distillation through heating or the like, it is peeled off from the support. Furthermore, regarding the ceramic green sheet, it can be fired as described later to decompose the resin (X) and thereby decarbonize it to obtain a fired ceramic body. The fired ceramic body is generally used as a dielectric layer. Electrode paste can be prepared by mixing resin (X), conductive powder, and solvents as needed.

[0098] Ceramic green sheets are typically used to manufacture multilayer ceramic capacitors. Multilayer ceramic capacitors are preferably obtained by using the above-mentioned ceramic green sheets and electrode paste, and more preferably by laminating ceramic green sheets coated with electrode paste.

[0099] Multilayer ceramic capacitors can be manufactured using conventional manufacturing methods. For example, multiple sheets coated with electrode paste (which serves as internal electrodes) onto the surface of the ceramic green sheet of the present invention are overlapped by means of screen printing, and then heated and pressed to obtain a multilayer body. Next, the multilayer body can be heated to thermally decompose and remove the resin (X) and other substances contained in the multilayer body, thereby firing to obtain a fired body, and then forming external electrodes on the fired body, thereby manufacturing the capacitor. [Example]

[0100] The present invention will be described in more detail by way of examples, but the present invention is not limited to these examples. Furthermore, the methods for measuring and evaluating the various physical properties in the present invention are as follows.

[0101] <Weight-average molecular weight (Mw)> Polyvinyl acetal resin, polyvinyl alcohol resin, or acrylic resin (resin (X) or resin (x)) was dissolved in tetrahydrofuran to a concentration of 0.05% by weight. The solution was then filtered through a syringe filter (Merck, Millex-LH 0.45 μm) and the molecular weight was determined using a gel permeation chromatography system (GPC, Waters, e2690). The weight-average molecular weight (Mw) was calculated using a molecular weight calibration curve prepared from monodisperse polystyrene standard samples. A Shodex GPC KF-806L column (Showa Denko) was used, and tetrahydrofuran was used as the precipitate.

[0102] <Chlorine atomic weight and free acidity> Regarding the atomic weight of chlorine, the content of chlorine atoms was determined using an ion chromatography instrument (IC-2000 model manufactured by Dionex) equipped with an automatic combustion device. Regarding the amount of free acid, 1.0 g of polyvinyl acetal resin, polyvinyl alcohol resin, or acrylic resin (resin (X) or resin (x)) was accurately weighed and added to 40 mL of an ethanol / water mixture (volume ratio 9:1), and the mixture was shaken for 5 hours. Using 0.5% phenolphthalein ethanol solution as an indicator, the resulting solution was titrated with 0.02 mol / L potassium hydroxide ethanol solution. A control experiment was also conducted, and the amount of free acid was determined by comparing the results (the mass percentage of carboxyl groups in the resin was calculated and recorded as the amount of carboxyl groups).

[0103] <Improved quality, degree of acetalization, acetylation content, and hydroxyl content> Polyvinyl acetal resin or polyvinyl alcohol resin was dissolved in DMSO-d6 and measured using 1H-NMR (nuclear magnetic resonance spectroscopy) to analyze the molar ratio of each unit and thus determine the molar ratio.

[0104] <Thermal Analysis and Determination> The resins (X) obtained in each embodiment and the resin (x) obtained in the comparative example were used as test samples and measured using a thermal analysis apparatus (Hitachi Advanced Scientific Corporation, TG / DTA7300). In the thermal analysis, the temperature was increased from 40°C to 600°C at 5°C / min under atmospheric conditions, and held at 600°C for 10 minutes. The weight at time 100°C was designated as A, the weight at time 200°C as B, and the weight at time 600°C after holding for 10 minutes as C. The values ​​of (AB) / A and (AC) / A were calculated from the measured values ​​of A, B, and C.

[0105] <Stability of Inorganic Powder Solutions> The particle size distribution of the slurry compositions obtained in each example and comparative example was measured using a laser diffraction particle size analyzer (manufactured by Horiba Corporation, LA-910), and the average particle size was determined. Furthermore, the average particle size was also measured after being placed at 23°C for one week, and the rate of change of average particle size was evaluated according to the following criteria. Additionally, the lower the rate of change of average particle size, the higher the stability of the inorganic powder solution. I: Less than 40% II: Above 40%, but below 80% III:More than 80%

[0106] <Shape Stability of Sheets> Using a coating machine, the obtained slurry composition was coated onto a PET film after demolding to a thickness of 20 μm. When the solvent was an ethanol / toluene mixture, the film was heated and dried at 70°C for 30 minutes; when the solvent was terpineol, it was heated and dried at 120°C for 30 minutes. This process produced sheets containing inorganic powder. After storing the sheets containing inorganic powder in an oven at 40°C for one month, their appearance was evaluated visually according to the following criteria. I: No abnormalities in appearance II: Very slight wrinkles were found. III: Any abnormal appearance such as wrinkles or cracks is found.

[0107] <Dielectric layer appearance> Ten layers of inorganic powder-containing sheets, prepared using the same method as the aforementioned sheet shape stability evaluation, were heated and pressurized at 80°C and 20 MPa / cm², then heated to 350°C at an atmospheric temperature at a rate of 0.5°C / min and held for 8 hours. Next, the temperature was increased to 1000°C at a rate of 5°C / min and held for 2 hours, before cooling to room temperature. The vertical surfaces of the resulting fired product were cut and ground, and evaluated using SEM (Scanning Electron Microscopy) according to the following evaluation criteria. Furthermore, if the dielectric layer has defects or other appearance abnormalities, performance abnormalities are likely to occur, leading to a decrease in product yield. Also, defects are generally caused by low decarburization during firing. I: No abnormalities observed in appearance III: Has defects

[0108] (Example 1) Synthesis of Propylene Oxide-Modified Polyvinyl Alcohol Prepare the allyl ether monomer (1) shown in formula (4-2). In formula (4-2), A1O is an oxypropyl group (PO) with an average repeat number of 25, and the terminal group (R1) is a hydrogen atom. 723 parts by mass of vinyl acetate, 257 parts by mass of allyl ether monomer (1), and 20 parts by mass of methanol were added to a flask equipped with a stirrer, thermometer, dropping funnel, and reflux condenser. After nitrogen purging of the system, the temperature was raised to 60°C. 1 part by mass of 2,2-azobisisobutyronitrile was added to the system to start polymerization. Polymerization was stopped 5 hours after it started. The copolymer was heated in an oven to remove unreacted monomers and methanol, yielding a 40% by mass methanol solution of the copolymer. The unreacted monomers were removed under reduced pressure to obtain a 40% by mass methanol solution of the copolymer. 100 parts by weight of a methanol solution of the copolymer obtained by stirring at 40°C were added simultaneously with 7.4 parts by weight of a 3% by weight NaOH methanol solution. The mixture was then placed after being thoroughly mixed. After 2 hours, the cured polymer was pulverized using a pulverizer, washed with methanol, and dried to obtain polymer powder (propylene oxide modified polyvinyl alcohol (PO-PVA)).

[0109] Synthesis of Modified Polyvinyl Butyral Resin (PO-PVB1) 280 parts by weight of the obtained polymer powder were added to 2300 parts by weight of pure water, and stirred at 60°C for about 1 hour, followed by stirring at 90°C for about 1 hour to dissolve it. The solution was cooled to 50°C, and 160 parts by weight of 35% hydrochloric acid and 150 parts by weight of n-butyraldehyde were added. After the addition, the liquid temperature was lowered to 30°C and maintained at this temperature to carry out the acetalization reaction, causing the reaction product to precipitate. Then, the liquid temperature was maintained at 60°C for 3 hours to end the reaction, and the product was neutralized using conventional methods and then removed. The product was then washed with water, and the dehydration process was repeated 3 times. After drying, a white powder of modified polyethylene butyral resin (PO-PVB1) was obtained. The structure and properties of the obtained modified polyethylene butyral resin (resin (X)) are shown in Table 1.

[0110] [Preparation of Resin Solution (X')] 90 parts by mass of resin (X) and 10 parts by mass of triethylene glycol di-2-ethylhexanoate (3GO) as a plasticizer were added to 900 parts by mass of a mixed solvent of ethanol / toluene (mass ratio 1:1) and stirred to dissolve, thereby preparing resin solution (X').

[0111] [Preparation of Slurry Composition] One part by weight of polyvinyl acetal resin (manufactured by Sekisui Chemicals Co., Ltd., BL-1) was added to a mixed solvent of 20 parts by weight of ethanol and 20 parts by weight of toluene, and the mixture was dissolved and stirred. Then, 100 parts by weight of barium titanate powder (manufactured by Sakai Chemical Co., Ltd., BT01) was added, and the mixture was stirred in a bead mill for 60 minutes. Then, 100 parts by weight of the previously obtained resin solution (X') was added, and the mixture was stirred in a bead mill (manufactured by AIMEX, Ready Mill) for 180 minutes to obtain an inorganic dispersion (slurry composition). The obtained slurry composition was used for various evaluations. The evaluation results are shown in Table 1.

[0112] (Example 2) The allyl ether monomer used is allyl ether monomer (2). Allyl ether monomer (2) is in formula (4-2), where A1O is doped with oxypropyl (PO) and oxyethyl (EO), with average repeat numbers of 34 and 34, respectively. Also, the terminal group (R1) is a hydrogen atom. Except for the changes to vinyl acetate (515 parts by mass), allyl ether monomer (2) (152 parts by mass), and methanol (333 parts by mass), the modified polyvinyl butyral resin (EO / PO-PVB) was obtained in the same manner as in Example 1. The structure and properties of the obtained modified polyvinyl butyral resin (resin (X)) are shown in Table 1. Furthermore, the modified polyvinyl butyral resin (EO / PO-PVB) obtained was used instead of PO-PVB1, and the proportions (by mass) of resin (X) and plasticizer in the resin solution (X') were changed as described in Table 1 without the use of plasticizer. All other aspects were the same as in Example 1 to prepare the slurry composition. The prepared slurry composition was used for various evaluations. The evaluation results are shown in Table 1.

[0113] (Example 3) The allyl ether monomer used is allyl ether monomer (3). Allyl ether monomer (3) is in formula (4-2), where A1O is oxyethyl (EO) and its average repeat number is 33. Also, the terminal group (R1) is a hydrogen atom. Except for the changes to allyl ether monomer (3), 834 parts by mass of vinyl acetate, 147 parts by mass of allyl ether monomer (3), and 20 parts by mass of methanol, the modified polyvinyl butyral resin (EO-PVB) was obtained in the same manner as in Example 1. The structure and properties of the obtained modified polyvinyl butyral resin (resin (X)) are shown in Table 1. Furthermore, the modified polyvinyl butyral resin (EO-PVB) obtained was used instead of PO-PVB1, and the proportions (by weight) of resin (X) and plasticizer in the resin solution (X') were changed as described in Table 1. All other aspects were handled in the same manner as in Example 1 to prepare the slurry composition. The prepared slurry composition was used for various evaluations. The evaluation results are shown in Table 1.

[0114] (Example 4) The propylene oxide-modified polyvinyl alcohol (PO-PVA) prepared in Example 1 was used as resin (X). The structure and properties of PO-PVA (resin (X)) are shown in Table 1. In addition, when determining the weight-average molecular weight, the obtained PO-PVA was subjected to reacetylation of all hydroxyl groups using conventional methods before the determination. 90 parts by weight of propylene oxide-modified polyvinyl alcohol (PO-PVA) replacing PO-PVB1 and 10 parts by weight of ethylene glycol (EG) as a plasticizer were added to 900 parts by weight of water and stirred to dissolve, thereby preparing a resin solution (X'). Except for changing the mixed solvent used to adjust the slurry composition to water, the composition was prepared in the same manner as in Example 1. The prepared slurry composition was used for various evaluations. The evaluation results are shown in Table 1.

[0115] (Example 5) 30 parts by weight of 2-ethylhexyl acrylate (2EHA), 45 parts by weight of isoborneol acrylate (IBOA), 15 parts by weight of dimethyl acrylamide, 9.99 parts by weight of 2-hydroxyethyl acrylate (HEA), 0.01 parts by weight of acrylic acid (Aac), and 0.2 parts by weight of photopolymerization initiator ("IRGACURE 184", manufactured by BASF) were mixed. The mixture was sandwiched between two PET sheets that had undergone single-sided demolding treatment, with spacers arranged to a thickness of 100 μm. The mixture was then irradiated with ultraviolet light using a chemical lamp at 3 mW and a dose of 3000 mJ / cm², dissolving in THF and reprecipitating with ethanol. The mixture was dried at 100°C for 1 hour to obtain acrylic polymer 1. The physical properties of the obtained acrylic polymer 1 (resin (X)) are shown in Table 1. The acrylic polymer 1 obtained in 97 parts by weight was used instead of PO-PVB1, and dioctyl adipate (DOA) was used as a plasticizer, with its content changed to 3 parts by weight. The resin solution (X') was prepared in the same manner as in Example 1, and a slurry composition was obtained from the resin solution (X'). The obtained slurry composition was used for various evaluations. The evaluation results are shown in Table 1.

[0116] (Example 6) [Preparation of Resin Solution (X')] Five parts by weight of the modified polyvinyl butyral resin (EO-PVB) obtained in Example 3 were added to 90 parts by weight of terpineol solvent and stirred to dissolve, thereby preparing a resin solution (X'). No plasticizer was used. [Preparation of Slurry Composition] One part by weight of ethyl cellulose resin (manufactured by Dow Chemical, STD45) was added to 10 parts by weight of terpineol solvent and stirred to dissolve. Then, 95 parts by weight of the previously obtained resin solution (X') and 20 parts by weight of barium titanate powder (manufactured by Sakai Chemical Industry Co., Ltd., BT01) were added, and the mixture was dispersed using a bead mill (manufactured by AIMEX, Ready Mill). The mixture was then transferred to a three-roll mill, and 100 parts by weight of nickel powder (manufactured by Sumitomo Metal Mining Co., Ltd., average particle size 0.2 μm) were added. The mixture was kneaded for 180 minutes to prepare an inorganic dispersion (slurry composition), and various evaluations were performed.

[0117] (Comparative Example 1) Prepare the ethylene monomer shown in formula (4). The ethylene monomer used in Comparative Example 1 is in formula (4), where A1O is oxyethyl (EO) and oxypropyl (PO), with average repeat numbers of 8 and 18, respectively. EO and PO are present in the blocks, having polyoxyethylene blocks and polyoxypropylene blocks, respectively. Furthermore, the terminal group (R1) is a hydrogen atom. The bonding group (R2) is an amide bond (-CONH-*). * indicates the bonding position with A1O. Using 65 parts by mass of the above-mentioned ethylene monomer, except for replacing it with 425 parts by mass of vinyl acetate and 510 parts by mass of methanol, the rest were obtained as polymer powder of modified polyvinyl alcohol resin (EO / PO block-PVA) using the same method as in Example 2.

[0118] Synthesis of Modified Polyvinyl Butyral Resin (EO / PO Block-PVB) 200 parts by weight of the obtained polymer powder were added to 2800 parts by weight of pure water and stirred at 90°C for about 2 hours to dissolve. The solution was cooled to 38°C, and 150 parts by weight of 20% hydrochloric acid and 110 parts by weight of n-butyraldehyde were added. After the addition, the liquid temperature was lowered to 30°C and maintained at this temperature to carry out the acetalization reaction, causing the reaction product to precipitate. Then, the liquid temperature was maintained at 75°C for 3 hours to end the reaction. After neutralization by conventional methods, the product was removed. It was then washed with water and dehydrated. After drying, a white powder of modified polyethylene butyral resin (EO / PO block-PVB) was obtained. The structure and properties of the obtained modified polyethylene butyral resin (resin (x)) are shown in Table 1. Except for replacing PO-PVB1 with the obtained modified polyvinyl butyral resin (EO / PO block-PVB), the slurry composition was prepared in the same manner as in Example 1. The prepared slurry compositions were used for various evaluations. The evaluation results are shown in Table 1.

[0119] (Comparative Example 2) Prepare unmodified polyvinyl butyral resin (PVB1) as shown in Table 1 as resin (x) to replace modified polyvinyl butyral resin (PO-PVB1), and determine the various physical properties of PVB1. Furthermore, using 65 parts by weight of polyvinyl butyral resin (PVB1) and changing the amount of plasticizer to 35 parts by weight, the resin solution (x') was prepared in the same manner as in Example 1, and a slurry composition was obtained from the resin solution (x'). The obtained slurry composition was used for various evaluations. The evaluation results are shown in Table 1.

[0120] (Comparative Example 3) 150 parts by weight of polyvinyl butyral resin (PVB1), 180 parts by weight of 2-ethylhexyl acrylate (2EHA), 20 parts by weight of 2-hydroxyethyl methacrylate (HEMA), 16 parts by weight of glycidyl methacrylate, 8 parts by weight of acrylic acid (Aac), and 500 parts by weight of butyl acetate were placed in a reaction vessel. Next, nitrogen bubbling was performed for 30 minutes, followed by stirring with a nitrogen stream and simultaneous heating to 70°C. 0.8 parts by weight of a thermal polymerization initiator ("Perbutyl PV", manufactured by Nippon Oil Co., Ltd.) was added. After the initial addition of the thermal polymerization initiator, 0.8 parts by weight were added every hour until 5 hours (a total of 6 additions, including the initial addition, totaling 4.8 parts by weight). Seven hours after the initial addition of the polymerization initiator, the mixture was cooled to room temperature to obtain PVB-acrylic acid. The physical properties of the obtained PVB-acrylic acid (resin (x)) are shown in Table 1. The obtained PVB-acrylic acid was used instead of PO-PVB1, and dioctyl phthalate (DOP) was used as a plasticizer. Except for the changes in the amount of these admixtures as shown in Table 1, the resin solution (x') was prepared in the same manner as in Example 1, and a slurry composition was obtained from the resin solution (x'). The obtained slurry composition was used for various evaluations. The evaluation results are shown in Table 1.

[0121] (Comparative Example 4) 180 parts by weight of 2-ethylhexyl acrylate (2EHA), 20 parts by weight of 2-hydroxyethyl methacrylate (HEMA), 16 parts by weight of glycidyl methacrylate, 8 parts by weight of acrylic acid (Aac), and 500 parts by weight of butyl acetate were placed in a reaction vessel. Next, nitrogen bubbling was performed for 30 minutes, followed by stirring with a nitrogen stream and simultaneous heating to 70°C. 0.8 parts by weight of a thermal polymerization initiator (manufactured by Nippon Oil Co., Ltd., "Perbutyl PV") was added. After the initial addition of the thermal polymerization initiator, 0.8 parts by weight of the initiator was added every hour until 5 hours (a total of 6 additions, totaling 4.8 parts by weight). The mixture was cooled to room temperature 7 hours after the initial addition of the initiator to obtain the acrylic polymer. The properties of the obtained acrylic polymer (resin (x)) are shown in Table 1. The obtained acrylic polymer was used instead of PO-PVB1, and dioctyl phthalate (DOP) was used as a plasticizer. Except for the changes in the amount of these admixtures as shown in Table 1, the resin solution (x') was prepared in the same manner as in Example 1, and a slurry composition was obtained from the resin solution (x'). The obtained slurry composition was used for various evaluations. The evaluation results are shown in Table 1.

[0122] [Table 1]

[0123] In Examples 1-6, the chlorine atomic weight and carboxyl group content of resin (X) are both low, and (AB) / A is less than 0.01 while (AC) / A is greater than 0.87. Therefore, the inorganic powder solution stability of the resin composition containing resin (X) and the shape stability after being formed into a sheet are good. Furthermore, since resin (X) has good decarburization properties, the dielectric layer obtained by firing the sheet is free of defects, which can improve the yield. In contrast, in Comparative Examples 1 and 2, (AC) / A was less than 0.87, resulting in insufficient decarburization of the resin (x), leading to defects in the dielectric layer obtained after firing the sheet and hindering yield improvement. Furthermore, in Comparative Examples 1, 3, and 4, the inorganic powder solution exhibited poor stability because either the atomic weight of chlorine or the amount of carboxyl groups exceeded 0.03% by mass. Additionally, in Comparative Examples 3 and 4, decarburization was also reduced, resulting in decreased yield during firing. Moreover, in Comparative Examples 3 and 4, the (AB) / A ratio was as high as 0.01 or more, leading to insufficient shape stability after sheet formation.

[0124] none

Claims

1. A resin having a chlorine atomic weight and a free acid content of 0.03% by mass or less, and satisfying the requirements of Formula I and Formula II below, wherein the resin is selected from at least one of the group consisting of polyvinyl acetal resins and polyvinyl alcohol resins having a polyalkylene oxide structure, Formula I: (A-B) / A < 0.01, Formula II: (A-C) / A > 0.87 (wherein, In the thermal analysis, the weight at time 100°C is designated as A, the weight at time 200°C as B, and the weight at time 600°C after holding for 10 minutes as C. This thermal analysis is performed using a differential thermal and thermogravimetric analysis (TG / DTA) device, under atmospheric conditions, by heating from 40°C to 600°C at a rate of 5°C / min, and holding at 600°C for 10 minutes.

2. The resin as requested in item 1, wherein, The average repeating number of oxyalkyl groups in this polyepoxide structure is 15–80.

3. The resin described in claim 1 or 2 is used in ceramic green sheets or electrode paste.

4. A resin composition comprising at least one of claims 1 to 3.

5. The resin composition of claim 4 is free of plasticizer, or contains less than 40 parts by weight of plasticizer relative to 100 parts by weight of the resin.

6. The resin composition of claim 4 or 5 contains inorganic powder.