Resin composition

Abstract

Provided is resin composition containing an aliphatic polycarbonate, wherein the aliphatic polycarbonate has, in a side chain, a substituted or unsubstituted hydrocarbon group having 2 carbon atoms and directly bonded to the main chain, and the mass-average molecular weight (Mw) of the aliphatic polycarbonate is less than 86,000.

Description

resin composition

[0001] This invention relates to a resin composition.

[0002] Polycarbonate resins are excellent in mechanical strength, heat resistance, and transparency, and are widely used in various industrial fields such as electrical and electronics, automotive, and optics. Among polycarbonate resins, aliphatic polycarbonates are also used as binders for firing in semiconductor manufacturing and other applications. For example, Patent Document 1 discloses a technology for using polypropylene carbonate as a binder in a sintering bonding composition containing conductive metal-containing sinterable particles, the average particle size being 70 nm to 2 μm, and the proportion of particles with a particle size of 100 nm or less being 80% by mass or more.

[0003] Japanese Patent Publication No. 2023-41064

[0004] Generally, when a resin composition that does not have sufficient elongation at break is molded into a film or the like, there is a problem that the molded product is prone to cracking. Therefore, resin compositions that are molded into films and the like are required to have excellent elongation at break. However, conventional resin compositions containing aliphatic polycarbonates still have insufficient elongation at break, and there is room for improvement.

[0005] This invention has been made in view of the above circumstances, and aims to provide a resin composition that has good elongation at break or a resin composition that can form a molded article having good elongation at break.

[0006] As a result of diligent research, the inventors have found that the above problems can be solved by a resin composition containing an aliphatic polycarbonate having a specific chemical structure and molecular weight, and have completed the present invention described below.

[0007] That is, the present invention relates to the following [1] to [8]. [1] A resin composition containing an aliphatic polycarbonate, wherein the aliphatic polycarbonate has, in a side chain thereof, a substituted or unsubstituted C2 hydrocarbon group directly bonded to the main chain, and the mass average molecular weight (Mw) of the aliphatic polycarbonate is less than 86,000. (wherein, R １ , R ２ , R ３ and R ４ are each independently a hydrogen atom or a substituted or unsubstituted C2 hydrocarbon group, and among R １ , R ２ , R ３ and R ４ , at least one is said substituted or unsubstituted C2 hydrocarbon group.) [3] The resin composition according to [2] above, wherein only any one of R １ , R ２ , R ３ and R ４ is the substituted or unsubstituted C2 hydrocarbon group. [4] The resin composition according to any one of [1] to [3] above, wherein the substituted or unsubstituted C2 hydrocarbon group is an unsubstituted C2 hydrocarbon group. [5] The resin composition according to any one of [1] to [4] above, wherein the aliphatic polycarbonate does not contain an ether bond, or the aliphatic polycarbonate contains an ether bond and the content of the ether bond is 20 mol% or less based on the total amount (100 mol%) of carbonate bonds and ether bonds. [6] The resin composition according to any one of [1] to [5] above, further containing a solvent. [7] The resin composition according to [6] above, wherein the solid content concentration of the resin composition is 50 mass% or more based on the total mass of the resin composition. [8] The resin composition according to any one of [1] to [5] above, which is in the form of a film.

[0008] According to the present invention, there can be provided a resin composition having good elongation at break, or a resin composition capable of forming a molded article having good elongation at break.

[0009] In this specification, the lower and upper limits described in steps for a preferred numerical range can be combined independently. For example, from the description "preferably 10 to 90, more preferably 30 to 60," the "preferred lower limit (10)" and the "more preferred upper limit (60)" can be combined to arrive at "10 to 60."

[0010] In this specification, the "thickness" of an object refers to the total thickness of the object. For example, if the object consists of multiple layers, it refers to the total thickness of all the layers constituting the object. Unless otherwise specified, the "thickness" of an object in this specification refers to the average value of the thickness measured at five randomly selected locations on the object, and can be obtained using a constant-pressure thickness measuring instrument in accordance with JIS K 7130:1999.

[0011] In this specification, "solids" refers to the components of the composition in question, excluding the solvent.

[0012] In this specification, "paste" means a mixture in which some or all of the solid components are dispersed in a solvent.

[0013] Furthermore, the mechanism of action described herein is speculative and does not limit the mechanism by which the present invention achieves its effects.

[0014] [Resin Composition] The resin composition of this embodiment is a resin composition containing an aliphatic polycarbonate, wherein the aliphatic polycarbonate has substituted or unsubstituted carbon-2 hydrocarbon groups in its side chains that are directly bonded to the main chain, and the mass-average molecular weight (Mw) of the aliphatic polycarbonate is less than 86,000.

[0015] In the following description, the aliphatic polycarbonate contained in the resin composition of this embodiment may be referred to as "aliphatic polycarbonate (A)".

[0016] The resin composition of this embodiment has good elongation at break. The details of the reason for this are unknown, but it is presumed that the following is the reason for the good elongation at break. The aliphatic polycarbonate (A) contained in the resin composition of this embodiment has a mass-average molecular weight (Mw) of less than 86,000, which makes it less likely for molecular chains to become entangled, and this is presumed to be the reason for the good elongation at break.

[0017] <Aliphatic Polycarbonate (A)> The resin composition of this embodiment contains aliphatic polycarbonate (A). Aliphatic polycarbonate (A) may be used alone or in combination of two or more types.

[0018] Aliphatic polycarbonate (A) has side chains of substituted or unsubstituted carbon-2 hydrocarbon groups directly bonded to the main chain. In this embodiment, the side chain of aliphatic polycarbonate (A) refers to an atomic group containing carbon atoms that branch off from the carbon chains that are linearly connected to the adjacent carbonate groups, within a molecular chain formed by linking structural units (hereinafter also referred to as "carbonate units") consisting of a divalent aliphatic hydrocarbon group and a carbonate group (-O-C(=O)-O-). Furthermore, the main chain of aliphatic polycarbonate (A) refers to the molecular chain formed by linking the above carbonate units, excluding the side chains. For example, when a carbonate unit consisting of a branched divalent aliphatic hydrocarbon group and a carbonate group (-O-C(=O)-O-) is linked, the carbon chain linearly connected to the carbonate group constitutes the main chain, and the carbon chains branching off from the linearly connected carbon chain among the branched divalent aliphatic hydrocarbon groups constitute the side chains.

[0019] In the following explanation, the "substituted or unsubstituted C2 hydrocarbon group" in the side chain of aliphatic polycarbonate (A) may be referred to as "hydrocarbon group (X)".

[0020] The hydrocarbon group (X) has 2 carbon atoms. Because the hydrocarbon group (X) has this number of carbon atoms, the aliphatic polycarbonate (A) has good breaking elongation and is excellent in thermal decomposability. The number of carbon atoms of the above-mentioned hydrocarbon group (X) does not include the number of carbon atoms of substituents.

[0021] Examples of substituents that the hydrocarbon group (X) may have include a hydroxy group; a thiol group; a cyano group; an amino group; a silyl group; halogen atoms such as fluorine atom, chlorine atom, bromine atom, iodine atom; an alkoxy group; an alkenyloxy group; an aryl group such as phenyl group; a heteroaryl group containing, as a heteroatom, an oxygen atom, a nitrogen atom, a sulfur atom, a selenium atom, a phosphorus atom or the like; an aryloxy group such as phenoxy group; a heteroaryloxy group containing, as a heteroatom, an oxygen atom, a nitrogen atom, a sulfur atom, a selenium atom, a phosphorus atom or the like; an alkylsilyl group; an alkylsilyloxy group; and the like. From the viewpoint of thermal decomposability, the number of carbon atoms of the substituent that the hydrocarbon group (X) may have is preferably 6 or less, more preferably 3 or less, still more preferably 2 or less, even more preferably 1 or less, and particularly preferably 0. From the viewpoint of thermal decomposability, the hydrocarbon group (X) preferably does not have a substituent containing a hydrocarbon group, and more preferably has no substituent.

[0022] As the hydrocarbon group (X), a substituted or unsubstituted ethyl group is preferred, and an unsubstituted ethyl group is more preferred.

[0023] The main chain of the aliphatic polycarbonate (A) may or may not have a group other than the hydrocarbon group (X) as a side chain or a substituent. From the viewpoint of thermal decomposability, the group other than the above-mentioned hydrocarbon group (X) is preferably a group that does not contain a hydrocarbon group having 2 or more carbon atoms. Examples of the group that does not contain a hydrocarbon group having 2 or more carbon atoms include a substituted or unsubstituted methyl group; a substituted or unsubstituted methoxy group; a hydroxy group; a thiol group; a cyano group; an amino group; a silyl group; halogen atoms such as fluorine atom, chlorine atom, bromine atom, iodine atom; and the like. However, from the viewpoint of thermal decomposability, the aliphatic polycarbonate (A) preferably does not have any groups other than the hydrocarbon group (X) directly bonded to the main chain.

[0024] From the viewpoint of fracture elongation and thermal decomposition properties, the structural unit having a hydrocarbon group (X) in its side chain is preferably a structural unit represented by the following general formula (1).

[0025] (In the formula, R １ and R ２ Each of these is a group that does not contain a hydrogen atom, a hydrocarbon group (X), or a hydrocarbon group having 2 or more carbon atoms, and all R contained in the structural unit １ and R ２ At least one of these is a hydrocarbon group (X). n is an integer between 1 and 10.

[0026] R １ and R ２ The explanations for the "hydrocarbon group (X)" and "groups that do not contain hydrocarbon groups with two or more carbon atoms" are as described above.

[0027] All R included in the structural unit represented by the general formula (1) above １ and R ２ Of these, at least one is a hydrocarbon group (X), and from the viewpoint of fracture elongation and thermal decomposition, it is preferable that one to three are hydrocarbon groups (X), more preferably that one or two are hydrocarbon groups (X), and even more preferably that only one is a hydrocarbon group (X).

[0028] All R included in the structural unit represented by the general formula (1) above １ and R ２ Of these, it is preferable that all those that are not hydrocarbon groups (X) are hydrogen atoms.

[0029] In the above general formula (1), n ​​is an integer from 1 to 10, and from the viewpoint of fracture elongation and thermal decomposition, it is preferably 1 to 8, more preferably 2 to 6, even more preferably 2 to 4, even more preferably 2 to 3, and particularly preferably 2.

[0030] The structural unit represented by the above general formula (1) in the aliphatic polycarbonate (A) may be a single type or two or more types.

[0031] From the viewpoint of fracture elongation and thermal decomposition properties, the structural unit represented by the above general formula (1) is preferably the structural unit represented by the following general formula (1a).

[0032] (In the formula, R １ , R ２ , R ３ and R ４ Each is independently a hydrogen atom or a hydrocarbon group (X), and R １ , R ２ , R ３ and R ４ At least one of these is a hydrocarbon group (X).

[0033] From the viewpoint of fracture elongation and thermal decomposition properties, the structural unit represented by the above general formula (1a) is preferably the structural unit represented by the following formula (1a-1) or the structural unit represented by the following formula (1a-2).

[0034]

[0035] Aliphatic polycarbonate (A) may or may not contain structural units other than carbonate units having a hydrocarbon group (X) in their side chains. From the viewpoint of elongation at break and thermal decomposition properties, the content of carbonate units having a hydrocarbon group (X) in their side chains, structural units represented by the above general formula (1), or structural units represented by the above general formula (1a) in aliphatic polycarbonate (A) is preferably 50 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, and even more preferably 99 mol% or more, and may be 100 mol%. Note that "total structural units" of aliphatic polycarbonate (A) means the total number of structural units based on one monomer molecule. Structures derived from carbon dioxide are not counted as a single unit; rather, a structure formed from one monomer molecule and one carbon dioxide molecule (i.e., a structure consisting of a divalent hydrocarbon group derived from one monomer molecule and a carbonate group (-O-C(=O)-O-))) is considered a single unit.

[0036] As the aliphatic polycarbonate (A), polybutylene carbonate is preferred from the viewpoint of elongation at break and thermal decomposition properties.

[0037] (Ether bond content of aliphatic polycarbonate (A)) From the viewpoint of improving thermal decomposition properties, aliphatic polycarbonate (A) preferably contains no ether bonds or contains ether bonds, and the content of said ether bonds (hereinafter also simply referred to as "ether ratio") is 20 mol% or less relative to the total amount of carbonate bonds and ether bonds (100 mol%). From a similar viewpoint, the ether bond content in aliphatic polycarbonate (A) is preferably 15 mol% or less, more preferably 10 mol% or less, even more preferably 5 mol% or less, and even more preferably 2 mol% or less, relative to the total amount of carbonate bonds and ether bonds (100 mol%). The ether bond content in aliphatic polycarbonate (A) may be 0 mol%, or it may be 1 mol% or more. Note that the -O- bond in the carbonate bond (-O-C(=O)-O-) does not fall under the category of ether bond. The ether bond content in aliphatic polycarbonate (A) can be measured by the method described in the examples.

[0038] (99% thermal decomposition temperature of aliphatic polycarbonate (A)) The 99% thermal decomposition temperature of aliphatic polycarbonate (A) in a nitrogen atmosphere with an oxygen partial pressure of 0.1 kPa or less is preferably 400°C or less, more preferably 380°C or less, even more preferably 350°C or less, even more preferably 320°C or less, and particularly preferably 310°C or less. When the 99% thermal decomposition temperature of aliphatic polycarbonate (A) in a nitrogen atmosphere with an oxygen partial pressure of 0.1 kPa or less is below the above upper limit, excellent thermal decomposition properties are easily obtained in an inert atmosphere. Furthermore, aliphatic polycarbonate (A) exhibits excellent thermal decomposition properties due to its carbonate structure, specifically through a unique reaction, namely the backbiting reaction. The lower limit of the 99% thermal decomposition temperature of aliphatic polycarbonate (A) in a nitrogen atmosphere with an oxygen partial pressure of 0.1 kPa or less is not particularly limited, but from the viewpoint of suppressing the decomposition of aliphatic polycarbonate (A) in the drying process for removing the solvent from the resin composition, it may be 170°C or higher, 200°C or higher, or 230°C or higher. The 99% thermal decomposition temperature in a nitrogen atmosphere with an oxygen partial pressure of 0.1 kPa or less shall be measured by thermogravimetric analysis (TGA) under atmospheric pressure, and specifically can be measured by the method described in the examples.

[0039] (Glass transition temperature (Tg) of aliphatic polycarbonate (A)) The glass transition temperature (Tg) of aliphatic polycarbonate (A) is preferably -40 to +25°C, more preferably -20 to +20°C, even more preferably -10 to +17°C, even more preferably 0 to +15°C, and particularly preferably +8 to +13°C, from the viewpoint of easily obtaining high elongation at break. The glass transition temperature (Tg) is measured by differential scanning calorimetry (DSC), and specifically can be measured by the method described in the examples.

[0040] (Mass-average molecular weight (Mw) of aliphatic polycarbonate (A)) The mass-average molecular weight (Mw) of aliphatic polycarbonate (A) is less than 86,000 from the viewpoint of obtaining good elongation at break. From a similar viewpoint, the mass-average molecular weight (Mw) of aliphatic polycarbonate (A) is preferably 80,000 or less, more preferably 70,000 or less, even more preferably 60,000 or less, even more preferably 50,000 or less, and particularly preferably 45,000 or less. The mass-average molecular weight (Mw) refers to the value on a standard polystyrene basis measured by gel permeation chromatography (GPC), and can be measured by the method described in the examples.

[0041] (Elongation at break of aliphatic polycarbonate (A) at 23°C) The elongation at break of aliphatic polycarbonate (A) at 23°C is preferably 3500% or more, more preferably 4500% or more, and even more preferably 5500% or more, from the viewpoint of increasing the flexibility of the resin composition. The elongation at break of aliphatic polycarbonate (A) at 23°C can be measured by the method described in the examples.

[0042] (Method for producing aliphatic polycarbonate (A)) The method for producing aliphatic polycarbonate (A) is not particularly limited, but for example, carbon dioxide (CO2) ２ It can be produced by polymerizing a monomer that forms a divalent aliphatic hydrocarbon group constituting the main chain (hereinafter simply referred to as "raw material monomer"). The conditions for the above polymerization reaction can be, for example, those described in International Publication No. 2011 / 142259.

[0043] Examples of raw material monomers include 1,2-butylene oxide and derivatives of 1,2-butylene oxide. One raw material monomer may be used alone, or two or more may be used in combination.

[0044] The polymerization reaction described above is preferably carried out in the presence of a metal catalyst. Examples of metal catalysts include metal salen complex catalysts, complex metal cyanide complex catalysts (DMC catalysts), and organometallic catalysts. Among these, metal salen complex catalysts and organozinc catalysts are preferred from the viewpoint of exhibiting high polymerization activity, and metal salen complex catalysts are preferred from the viewpoint of being easy to adjust the mass-average molecular weight (Mw) to less than 86,000 and easy to reduce the ether ratio of the product, with cobalt salen complex being more preferred as the metal salen complex catalyst. One type of metal catalyst may be used alone, or two or more types may be used in combination. The amount of metal catalyst used is preferably 0.001 to 10 parts by mass, more preferably 0.01 to 3 parts by mass, per 100 parts by mass of raw material monomer used.

[0045] The polymerization reaction described above may also use a co-catalyst in addition to the metal catalyst. Examples of co-catalysts include bis(triphenylphosphoranylidene)ammonium chloride, 4-dimethylaminopyridine, tetrabutylammonium chloride, tetrabutylammonium bromide, triphenylphosphine, 1,5,7-triazabicyclo[4.4.0]deca-5-ene, and 1,4-diazabicyclo[2.2.2]octane. One co-catalyst may be used alone, or two or more may be used in combination. The amount of co-catalyst used is preferably 0.001 to 20 parts by mass, more preferably 0.01 to 14 parts by mass, per 100 parts by mass of the raw material monomer.

[0046] The method for carrying out the polymerization reaction is not particularly limited as long as the target product is obtained, but for example, one method involves charging a starting monomer, a metal catalyst, a co-catalyst, and a solvent to be used as needed into an autoclave, mixing them, and then injecting carbon dioxide into the resulting mixture to carry out the reaction. The solvent used as needed in the polymerization reaction is not particularly limited, but an organic solvent is preferred. The amount of solvent used is preferably 10 to 10,000 parts by mass per 100 parts by mass of monomer used.

[0047] The pressure at which carbon dioxide is injected during the polymerization reaction is preferably 0.1 to 20 MPa, more preferably 0.1 to 10 MPa, and even more preferably 0.1 to 5 MPa. If the pressure at which carbon dioxide is injected is above the lower limit, the polymerization reaction proceeds more easily. Also, if the pressure at which carbon dioxide is injected is below the upper limit, excessive use of carbon dioxide is suppressed, improving economic efficiency.

[0048] The reaction temperature during the polymerization reaction is preferably 20 to 100°C, more preferably 25 to 80°C, from the viewpoint of reaction rate and suppression of side reactions. The reaction time for the polymerization reaction can be adjusted as appropriate according to the reaction temperature, but is preferably 2 to 40 hours.

[0049] During the polymerization reaction, it is preferable to keep the amount of water in the reaction system at 3 mol% or less relative to the amount (moles) of metal catalyst used.

[0050] After the polymerization reaction is complete, the target aliphatic polycarbonate (A) can be isolated by known methods after performing any known post-treatment procedures. The obtained aliphatic polycarbonate (A) may also be purified if necessary.

[0051] (Content of Aliphatic Polycarbonate (A)) In one embodiment of the resin composition of this embodiment, the content of aliphatic polycarbonate (A) in the resin composition of this embodiment is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, even more preferably 90 to 100% by mass, and even more preferably 95 to 100% by mass, based on the total mass (100% by mass) of all components other than the solvent. In one embodiment of the resin composition of this embodiment, the content of aliphatic polycarbonate (A) in the resin composition of this embodiment is preferably 1 to 30% by mass, more preferably 1.2 to 25% by mass, even more preferably 1.5 to 20% by mass, and even more preferably 2 to 15% by mass, based on the total mass (100% by mass) of all components other than the solvent.

[0052] <Solvent> The resin composition of this embodiment preferably further contains a solvent. The resin composition containing a solvent is suitable as a paste-like resin composition. One solvent may be used alone, or two or more solvents may be used in combination.

[0053] Examples of solvents include ketones such as methyl ethyl ketone (2-butanone), methyl isobutyl ketone, cyclohexanone, acetylacetone, and isophorone; ethers such as dioxane and tetrahydrofuran; aliphatic hydrocarbons such as n-hexane and n-heptane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; aromatic hydrocarbons such as toluene and xylene; halogenated carbons such as dichloromethane and dichloroethane; esters such as methyl acetate, ethyl acetate, and butyl acetate; isopropanol, butanol, cyclohexanol, 1-decanol, and isobornyl. Examples include alcohols such as cyclohexanol; cellosolves such as methyl cellosolve and ethyl cellosolve; glycol ethers or glycol ether acetates such as butyl carbitol, propylene glycol monomethyl ether acetate, butyl carbitol acetate (diethylene glycol monobutyl ether acetate), and ethyl carbitol acetate (diethylene glycol monoethyl ether acetate); cellosolve acetates; sulfoxides such as dimethyl sulfoxide; amides such as dimethylformamide and dimethylacetamide; and so on.

[0054] When the resin composition of this embodiment contains a solvent, the solid content concentration of the resin composition of this embodiment is preferably 45% by mass or more, more preferably 50% by mass or more, and even more preferably 55% by mass or more, based on the total mass of the resin composition. The aliphatic polycarbonate contained in the resin composition of this embodiment, having a mass-average molecular weight (Mw) of less than 86,000, has excellent solubility in the solvent, thus enabling the above solid content concentration. As a result, the resin composition of this embodiment can be suitably used in applications requiring a high solid content concentration. Furthermore, the amount of solvent used can be reduced, leading to a reduction in environmental impact. When the resin composition of this embodiment contains a solvent, the solid content concentration of the resin composition of this embodiment may be 99% by mass or less, 95% by mass or less, or 90% by mass or less, based on the total mass of the resin composition.

[0055] If the resin composition of this embodiment contains a solvent, the content of aliphatic polycarbonate (A) relative to the total amount of aliphatic polycarbonate (A) and solvent (100% by mass) is preferably 45% by mass or more, more preferably 50% by mass or more, and even more preferably 55% by mass or more, and may also be 99% by mass or less, 95% by mass or less, or 90% by mass or less.

[0056] <Sintering Particles> The resin composition of this embodiment is suitable as a resin composition containing sintering particles such as metals and ceramics, and is more suitable as a resin composition containing one or more sintering particles selected from the group consisting of metal oxide precursor particles and metal oxide particles. When the resin composition of this embodiment contains sintering particles, the aliphatic polycarbonate (A) plays a role as a firing binder, enhancing the shape retention, flexibility, etc., of the resin composition. Hereinafter, the resin composition of this embodiment containing sintering particles will also be referred to as the "firing resin composition".

[0057] Sintering particles are those that form a sintered body when a sintering resin composition is fired. Metal oxide precursor particles are a general term for substances that can become metal oxides when fired in an oxygen atmosphere. Depending on the intended use of the sintered body, metal oxide precursor particles may be used in a manner that transforms them into metal oxides during the manufacturing process, or they may be used in a manner that forms a sintered body composed of metal oxide precursors without transforming them into metal oxides. Sintering particles may be used individually or in combination of two or more types.

[0058] Examples of metal oxide precursor particles include gold particles, silver particles, copper particles, aluminum particles, nickel particles, tungsten particles, silicon carbide particles, silicon nitride particles, and aluminum nitride particles. Copper particles may consist solely of copper or of a copper alloy. Similarly, aluminum particles may consist solely of aluminum or of an aluminum alloy. Examples of metal oxide particles include oxides of the metal oxide precursor particles described above.

[0059] Average particle size of sintering particles (D ５０ The average particle size (D) of the sintering particles is preferably 0.3 to 15 μm, more preferably 0.8 to 10 μm, and even more preferably 1 to 6 μm. ５０ This can be measured, for example, by laser diffraction and scattering methods.

[0060] In the firing resin composition of this embodiment, the content of sintering particles is preferably 60 to 99% by mass, more preferably 70 to 98% by mass, even more preferably 80 to 97% by mass, and even more preferably 85 to 96% by mass, based on the total mass (100% by mass) of all components other than the solvent. The total content of aliphatic polycarbonate (A) and sintering particles in the firing resin composition is preferably 90 to 100% by mass, more preferably 95 to 100% by mass, even more preferably 97 to 100% by mass, and even more preferably 99 to 100% by mass, based on the total mass (100% by mass) of all components other than the solvent, and may be 100% by mass.

[0061] <Other Optional Components> The resin composition of this embodiment may further contain other optional components besides aliphatic polycarbonate (A), solvent, and sintering particles. Examples of other optional components include resins other than aliphatic polycarbonate (A), dispersants, plasticizers, tackifiers, preservatives, defoamers, thermal decomposition accelerators, antioxidants, sintering aids, and surfactants. Each of these may be used individually or in combination of two or more. These additives can be appropriately selected from those commonly used in this field. Examples of sintering aids include fluorides such as aluminum fluoride, potassium fluoride, and calcium fluoride. Examples of surfactants include betaine-based, sulfobetaine-based, and alkylbetaine-based surfactants. The content of the above optional components in the resin composition of this embodiment is not particularly limited and may be used as needed, within a range that does not hinder the effects of this embodiment. Furthermore, the resin composition of this embodiment may not contain the above optional components, depending on the desired performance.

[0062] <Form of Resin Composition> The resin composition of this embodiment can take the form of a solution, paste, or film. The resin composition of this embodiment has good elongation at break, so when it is in the form of a film, cracks are less likely to occur in the film during molding or other processing.

[0063] The thickness of the film-like resin composition is not particularly limited and can be determined appropriately depending on the application, but from the viewpoint of film formation properties and versatility, it is preferably 50 to 5000 μm, more preferably 100 to 4000 μm, and even more preferably 200 to 3000 μm.

[0064] <Method for Producing the Resin Composition> If a solution in which aliphatic polycarbonate (A) is dissolved in a solvent is obtained by the method described in "Method for Producing Aliphatic Polycarbonate (A)" above, the solution can be used as is as the resin composition of this embodiment. Alternatively, if necessary, the aliphatic polycarbonate (A) may be isolated and then mixed with a solvent, sintering particles, and other optional components to produce the resin composition. The method of mixing each component is not particularly limited, and known mixing methods using mixing devices such as a rotary-orbiting agitator, kneader, three-roll mixer, ball mill, sand mill, planetary mixer, paint shaker, homomixer, homodisper, homogenizer, and ultrasonic disperser can be employed.

[0065] A solution-type resin composition can be produced, for example, by mixing an aliphatic polycarbonate (A) and a solvent. A paste-type resin composition can be produced, for example, by mixing an aliphatic polycarbonate (A), sintering particles, and a solvent. A film-type resin composition can be produced, for example, by coating and drying a solution-type resin composition or a paste-type resin composition.

[0066] <Uses of the Resin Composition> The resin composition of this embodiment is suitable for manufacturing sintered bodies as the above-mentioned firing resin composition. The sintered body manufactured from the firing resin composition of this embodiment (hereinafter also referred to as "the sintered body of this embodiment") may be an article composed solely of the sintered body of this embodiment, or it may constitute a composite of the sintered body of this embodiment and other components (hereinafter also referred to as "other components").

[0067] The above composite has a structure in which the sintered body of this embodiment and other members are bonded together. For example, it may be a composite body in which two or more other members are joined together by the sintered body of this embodiment, or it may be a composite body in which one other member is bonded to the sintered body of this embodiment.

[0068] Examples of materials for the other components mentioned above include metallic materials such as copper, gold, and aluminum; semiconductor materials such as silicon (Si), germanium, gallium arsenide, gallium phosphide, cadmium sulfide, silicon nitride, graphite, yttrium oxide, magnesium oxide, silicon carbide (SiC), and gallium nitride; plastic materials such as polyimide, polyethylene, polypropylene, polyethylene terephthalate, polycarbonate, and polyethylene naphthalate; and ceramic materials such as glass. Examples of the other components mentioned above include substrates, semiconductor elements, LED elements, leads, frames, and heat sinks.

[0069] The sintered body of this embodiment may be a metal oxide precursor sintered body or a metal oxide sintered body. The shape of the sintered body of this embodiment is not particularly limited and can be any desired shape, such as layered, plate-shaped, or block-shaped.

[0070] Next, the method for manufacturing the sintered body of this embodiment will be described. The method for manufacturing the sintered body of this embodiment (hereinafter also referred to as "the manufacturing method of this embodiment") is a method for manufacturing a sintered body that involves heating the firing resin composition of this embodiment.

[0071] In the method for manufacturing a sintered body according to this embodiment, first, the firing resin composition is molded into a desired shape. When manufacturing a layered sintered body, it is preferable to mold it by applying a paste-like firing resin composition to a desired object and then removing the solvent by drying. Examples of such objects include the other members mentioned above. When manufacturing plate-shaped, block-shaped, or other sintered bodies, the firing resin composition can be molded by filling a desired mold or the like. Next, it is preferable to degrease the firing resin composition molded into the desired shape to obtain a sintered body precursor. Degreasing is a process to remove organic matter from the firing composition, and the degreasing method is not particularly limited, but examples include heating the firing resin composition in a heating furnace. The degreasing temperature is preferably below the 99% thermal decomposition temperature of aliphatic polycarbonate (A). This allows for the thermal decomposition of a portion of the aliphatic polycarbonate (A) to obtain a sintered body precursor. In this embodiment, since the firing resin composition contains aliphatic polycarbonate (A) which has excellent low-temperature decomposition properties, degreasing can be performed at a relatively low temperature. The degreasing temperature may be, for example, 200 to 400°C, 210 to 350°C, or 220 to 300°C. The degreasing time may be appropriately selected to allow sufficient time for the aliphatic polycarbonate (A) to be degreased, for example, 0.05 to 5 hours, 0.07 to 3 hours, or 0.1 to 1 hour.

[0072] The heating atmosphere during degreasing may be an oxygen atmosphere such as air, or an oxygen-free atmosphere, but an oxygen-free atmosphere is preferred from the viewpoint of preventing oxidation of the metal oxide precursor. The partial pressure of oxygen in the oxygen-free atmosphere is preferably 5.0 kPa or less, more preferably 3.0 kPa or less, even more preferably 1.0 kPa or less, even more preferably 0.5 kPa or less, and particularly preferably 0.1 kPa or less, from the viewpoint of preventing oxidation of the metal oxide precursor. Aliphatic polycarbonate (A) exhibits low-temperature decomposition even in an oxygen-free atmosphere, so it can be degreased at a relatively low temperature, thereby preventing oxidation of the metal oxide precursor. The oxygen-free atmosphere may be a single-gas atmosphere, a mixed-gas atmosphere, or a vacuum atmosphere. Examples of single gases include nitrogen, argon, helium, ammonia, and formaldehyde. Examples of mixed gases include forming gases, and examples of forming gases include nitrogen gas mixed with 5 volume% or less of hydrogen. Among these, a nitrogen atmosphere is preferred. The pressure conditions during degreasing may be atmospheric pressure, reduced pressure, or increased pressure.

[0073] Next, the degreased sintered body precursor is fired to obtain a sintered body. The firing method is not particularly limited and includes methods such as heating in a heating furnace.

[0074] In the manufacturing method of this embodiment, the firing temperature is preferably between half and below the melting point (absolute temperature) of the material to be fired. This causes the aliphatic polycarbonate (A) to decompose thermally, and the sintering particles to harden, resulting in a sintered body. The firing time can be appropriately selected to allow the sintering particles to be sufficiently sintered, for example, it may be 0.1 to 48 hours, 1 to 36 hours, or 5 to 24 hours. The sintering atmosphere may be an oxygen atmosphere such as air, or an oxygen-free atmosphere, but an oxygen-free atmosphere is preferred from the viewpoint of preventing oxidation of the metal oxide precursor powder. The preferred form of the oxygen-free atmosphere is the same as the preferred form of the heating atmosphere when degreasing. The pressure conditions of the sintering atmosphere may be atmospheric pressure, reduced pressure, or increased pressure.

[0075] The resin composition of this embodiment is not limited to the above-described resin composition for firing, but is also suitable for applications such as temporary fixing materials and biodegradable adhesives.

[0076] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0077] [Measurement of Mass-Average Molecular Weight (Mw)] The mass-average molecular weight (Mw) of the polymers produced in each example was measured using a gel permeation chromatograph (Tosoh Corporation, product name "HLC-8320") under the following conditions, and the results were expressed in terms of standard polystyrene. The results are shown in Table 1. <GPC Measurement Conditions> ・Column: "TSK guard column SuperH-H", "TSK gel SuperHM-H", "TSK gel SuperHM-H", and "TSK gel SuperH2000" (all manufactured by Tosoh Corporation) linked in sequence ・Column temperature: 40℃ ・Developing solvent: Tetrahydrofuran (polymer concentration 1% by mass) ・Injection volume: 20 μl ・Flow rate: 0.6 mL / min ・Detector: Differential refractometer ・Standard sample: Polystyrene

[0078] [Measurement of Glass Transition Temperature (Tg)] The glass transition temperature (Tg) of the polymers produced in each example and the comparative polymer was determined by differential scanning calorimetry (DSC) using a DSC Q2000 manufactured by T.A. Instruments Japan Co., Ltd. Specifically, an aluminum pan was used as the container, and under a nitrogen atmosphere, the temperature was increased from -70°C to 150°C at a rate of 10.0°C / min, held for 5 minutes, then cooled to -70°C at a rate of 10.0°C / min, held for 5 minutes, and then increased to 150°C at a rate of 10.0°C / min for measurement. The results are shown in Table 1.

[0079] [Measurement of ether ratio] The polymers produced in each example are used as the measurement target, under the following conditions: １ 1H-NMR measurements were performed, and the results were obtained. １In the 1H-NMR spectrum, the integral value A from 4.7 to 5.2 ppm was taken as 1H (one hydrogen), indicating the presence of one carbonate bond, and the integral value B from 3.2 to 3.9 ppm was taken as 3H (three hydrogens), indicating the presence of one ether bond. The ether ratio, which is the content of ether bonds relative to the total amount of carbonate bonds and ether bonds (100 mol%) in each polymer, was calculated using the following formula. The results are shown in Table 1. Ether ratio (mol%) = (B / 3) × 100 / [A + (B / 3)] １ H-NMR measurement conditions: Equipment: Bruker, product name "AV-500" １ H-NMR resonance frequency: 500 MHz Probe: 5 mmφ solution probe Deuterated solvent: Deuterated chloroform (CDCl) ３ ) Internal standard substance: TMS (tetramethylsilane) Sample amount: 20-50 mg Measurement temperature: 25°C Number of cumulative measurements: 16 (Method of preparing measurement samples) The measurement sample was dissolved in deuterated chloroform containing TMS as an internal standard so that the measurement sample concentration was 3% by mass. １ The sample used for 1H-NMR measurement was selected.

[0080] [Synthesis of Metal Catalysts] Production Example 1 (Synthesis of Cobalt Salen Complex) (R,R)-N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminocyclohexanecobalt(II) and pentafluorobenzoic acid were weighed in a molar ratio of 1:1.1 and placed in a flask, where dehydrated toluene was added. The flask was shielded from light with aluminum foil and reacted at 23°C for 20 hours with stirring. The chemical reaction equation is as follows. After the reaction was complete, the solvent was removed under reduced pressure and washed several times with an excess amount of hexane. Then, the mixture was vacuum dried at 23°C to obtain the cobalt salen complex, which is the product of the chemical reaction equation shown below.

[0081]

[0082] Manufacturing Example 2 (Synthesis of Zinc Glutarate) 160 g of zinc oxide, 249 g of glutaric acid, and 2000 g of zirconia balls were placed in a 1000 mL polypropylene container with a lid in an air-filled container, and the lid was closed to seal it. The polypropylene container was placed on the rotating rollers of a ball mill stand (manufactured by Ito Seisakusho Co., Ltd., product name "BMU-100") set on a horizontal table, and the reaction was carried out by rotating it at a set rotation speed of 220 rpm at room temperature (23°C) for 5 hours. The zirconia balls were removed by sieving, and the resulting white powder was dried in a vacuum dryer at 120°C for 5 hours to obtain zinc glutarate.

[0083] Manufacturing Example 3 (Synthesis of DMC Catalyst) Potassium hexacyanocobalt(III) (K ３ [Co(CN) ６ Dissolve 1.33 g in 20 mL of deionized water and stir vigorously to make a zinc chloride solution at 50°C (11.42 g of ZnCl). ２ The Zn catalyst was added dropwise over 45 minutes to a mixture of 60 mL of deionized water and 30 mL of t-butyl alcohol. The mixture was then vigorously stirred for 60 minutes. The resulting white suspension was centrifuged at 5000 rpm to isolate the white solid. The isolated white solid was resuspended in a mixture of t-butyl alcohol and deionized water (volume ratio: t-butyl alcohol:deionized water = 5:5) while being vigorously stirred for 30 minutes. Subsequently, the amount of t-butyl alcohol relative to water was gradually increased (changing the volume ratio of t-butyl alcohol:deionized water from 6:4 to 7:3, 8:2, and 9:1), and isolation by centrifugation and resuspension were repeated several times. Finally, the white solid was resuspended in t-butyl alcohol and isolated by centrifugation. The Zn catalyst was then dried at 50°C under vacuum until a predetermined mass was obtained. ３ (Co[CN] ６ ) ２ I obtained it.

[0084] [Production of Resin Composition] Example 1 (Synthesis of Polybutylene Carbonate 1) 1,600 parts by mass of 1,2-butylene oxide as a raw material monomer, 9 parts by mass of cobalt salen complex prepared in Production Example 1 as a polymerization catalyst, and 6.3 parts by mass of bis(triphenylphosphoranylidene)ammonium chloride as a co-catalyst were dissolved in 400 parts by mass of toluene to obtain a mixture. Next, the system of a 4 L autoclave equipped with a stirrer, gas inlet pipe and thermometer was pre-filled with a nitrogen atmosphere, and the above mixture was charged in. Subsequently, while stirring the mixture in the autoclave, carbon dioxide gas was filled into the reaction system until the pressure reached 3 MPa. After that, the temperature was raised to 40°C, and the polymerization reaction was carried out for 5 hours while replenishing the carbon dioxide consumed by the reaction. After the reaction was completed, the autoclave was cooled and depressurized, the contents were diluted with toluene, and the catalyst was removed by reprecipitation purification to obtain a resin composition containing polybutylene carbonate 1.

[0085] Comparative Example 1 (Synthesis of Polybutylene Carbonate 2) 415 parts by mass of 1,2-butylene oxide as a raw material monomer, 83 parts by mass of zinc glutarate prepared in Production Example 2 as a polymerization catalyst, and 3.0 parts by mass of n-butanol as an additive were mixed with 1075 parts by mass of toluene to obtain a mixture. Next, the system of a 2 L autoclave equipped with a stirrer, gas inlet pipe and thermometer was pre-filled with a nitrogen atmosphere, and the above mixture was charged in. Subsequently, while stirring the mixture in the autoclave, carbon dioxide gas was filled into the reaction system until the pressure reached 4 MPa. After that, the temperature was raised to 70°C, and the polymerization reaction was carried out for 4 hours while replenishing the carbon dioxide consumed by the reaction. After the reaction was completed, the autoclave was cooled and depressurized, the contents were diluted with toluene, the catalyst was removed by filtration, and reprecipitation purification was performed to obtain a resin composition containing polybutylene carbonate 2.

[0086] Comparative Example 2 (Synthesis of Polybutylene Carbonate 3) 500 parts by mass of 1,2-butylene oxide as a raw material monomer and 0.5 parts by mass of DMC catalyst prepared in Production Example 3 as a polymerization catalyst were dissolved in 500 parts by mass of ethyl acetate to obtain a mixture. Next, the system of a 4 L autoclave equipped with a stirrer, gas inlet pipe and thermometer was pre-filled with a nitrogen atmosphere, and the above mixture was charged in. Subsequently, while stirring the mixture in the autoclave, carbon dioxide gas was filled into the reaction system until the pressure reached 4 MPa. After that, the temperature was raised to 60°C, and the polymerization reaction was carried out for 18 hours while replenishing the carbon dioxide consumed by the reaction. After the reaction was completed, the autoclave was cooled and depressurized, the contents were diluted with ethyl acetate, and the catalyst was removed by reprecipitation purification to obtain a resin composition containing polybutylene carbonate 3.

[0087] Comparative Example 3 (Synthesis of Polybutylene Carbonate 4) 415 parts by mass of 1,2-butylene oxide as a raw material monomer and 83 parts by mass of zinc glutarate prepared in Production Example 2 as a polymerization catalyst were mixed with 1075 parts by mass of toluene to obtain a mixture. Next, the system of a 2 L autoclave equipped with a stirrer, gas inlet pipe and thermometer was pre-filled with a nitrogen atmosphere, and the above mixture was charged in. Subsequently, while stirring the mixture in the autoclave, carbon dioxide gas was filled into the reaction system until the pressure reached 4 MPa. After that, the temperature was raised to 70°C, and the polymerization reaction was carried out for 4 hours while replenishing the carbon dioxide consumed by the reaction. After the reaction was completed, the autoclave was cooled and depressurized, the contents were diluted with toluene, and the catalyst was removed by filtration to obtain a resin composition containing polybutylene carbonate 4.

[0088] Comparative Example 4 (Synthesis of Polypropylene Carbonate) 1,437 parts by mass of propylene oxide as a raw material monomer, 10.1 parts by mass of cobalt salen complex prepared in Production Example 1 as a polymerization catalyst, and 7.1 parts by mass of bis(triphenylphosphoranylidene)ammonium chloride as a co-catalyst were dissolved in 479 parts by mass of ethyl acetate to obtain a mixture. Next, the system of a 4 L autoclave equipped with a stirrer, gas inlet pipe and thermometer was pre-filled with a nitrogen atmosphere, and the above mixture was charged in. Subsequently, while stirring the mixture in the autoclave, carbon dioxide gas was filled into the reaction system until the pressure reached 3 MPa. After that, the temperature was raised to 40°C, and the polymerization reaction was carried out for 5 hours while replenishing the carbon dioxide consumed by the reaction. After the reaction was completed, the autoclave was cooled and depressurized, the contents were diluted with ethyl acetate, and the catalyst was removed by reprecipitation purification to obtain a resin composition containing polypropylene carbonate.

[0089] Comparative Example 5: Butyral resin (manufactured by Sekisui Chemical Co., Ltd., product name "BL-1") was prepared as a comparative polymer.

[0090] Comparative Example 6: As a comparative polymer, an acrylic resin (manufactured by Kyoeisha Chemical Co., Ltd., product name "Oricox KC-1300") was prepared.

[0091] Comparative Example 7: Ethyl cellulose (manufactured by Dow Chemical Japan Ltd., product name "ETHOCEL Standard 7 Premium") was prepared as a comparative polymer.

[0092] [Evaluation Method] The resin compositions obtained above were evaluated by the following method. The results are shown in Table 1.

[0093] [Method for Measuring Elongation at Breaking] Polymers and comparative polymers obtained by vacuum drying the resin compositions obtained in each example were sandwiched between two release films (38 μm thick, manufactured by Lintec Corporation, product name "SP-PET382150") and pressed using a screw-type heater press (manufactured by NPA System Co., Ltd., product name "N4046-00") at 100°C (Example 1, Comparative Examples 1-4, 6) or 120°C (Comparative Examples 5 and 7) and 4000 N to form a 200 μm thick polymer film with release films on both sides. After removing the release films from both sides of the polymer film obtained above, the film was cut into 10 mm x 50 mm pieces to be used as test specimens. These test specimens were mounted on a tensile testing machine (manufactured by Shimadzu Corporation, product name "Autograph AG-Xplus") with a chuck distance of 30 mm, and the elongation at breaking was measured at 23°C and a tensile speed of 200 mm / min. In Table 1, the notation ">6000" means that the polymer film did not break when the elongation reached 6000%.

[0094] [Thermal Decomposition Test] The polymers and comparative polymers obtained by vacuum drying of the resin compositions obtained in each example were used as measurement samples, and thermal decomposition tests were performed using a thermogravimetric analyzer (TGA; manufactured by Shimadzu Corporation, product name "DTG-60") under the conditions shown below. The temperature at which the mass loss rate of the measurement sample reached 5%, 50%, or 99% was defined as the 5% thermal decomposition temperature (T), respectively. ｄ５ ), 50% thermal decomposition temperature (T ｄ５０ ) and 99% thermal decomposition temperature (T ｄ９９ ) was obtained as [a specific result]. In addition, the mass retention rate of the measured sample at 500°C in the pyrolysis test was defined as the 500°C residue rate. (TGA measurement conditions) Heating rate: 10°C / min Sample amount: 20-30 mg Measurement temperature range: 40-500°C Measurement pressure: atmospheric pressure Measurement atmosphere: air or nitrogen atmosphere with oxygen partial pressure of 0.1 kPa or less

[0095] *1: This means that the mass loss rate did not reach 99% in the thermal decomposition test.

[0096] Table 1 shows that the resin composition of this embodiment can form molded articles with good elongation at break.

Claims

1. A resin composition containing an aliphatic polycarbonate, wherein the aliphatic polycarbonate has substituted or unsubstituted carbon-2 hydrocarbon groups in its side chains that are directly bonded to the main chain, and the mass-average molecular weight (Mw) of the aliphatic polycarbonate is less than 86,000.

2. The resin composition according to claim 1, wherein the aliphatic polycarbonate has a structural unit represented by the following general formula (1a). (In the formula, R １ , R ２ , R ３ and R ４ Each is independently a hydrogen atom or a substituted or unsubstituted 2-carbon hydrocarbon group, R １ , R ２ , R ３ and R ４ (At least one of these is the aforementioned substituted or unsubstituted C2 hydrocarbon group.) 3. In the general formula (1a), R １ , R ２ , R ３ and R ４ , only any one of which is the substituted or unsubstituted C2 hydrocarbon group, the resin composition according to claim 2.

4. The resin composition according to any one of claims 1 to 3, wherein the substituted or unsubstituted C2 hydrocarbon group is an unsubstituted C2 hydrocarbon group.

5. The resin composition according to any one of claims 1 to 3, wherein the aliphatic polycarbonate does not contain ether bonds, or the aliphatic polycarbonate contains ether bonds, and the content of the ether bonds is 20 mol% or less with respect to the total amount (100 mol%) of carbonate bonds and ether bonds.

6. The resin composition according to any one of claims 1 to 3, further comprising a solvent.

7. The resin composition according to claim 6, wherein the solid content concentration of the resin composition is 50% by mass or more with respect to the total mass of the resin composition.

8. A resin composition according to any one of claims 1 to 3, which is in the form of a film.

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