Carbodiimide Composition

Abstract

To provide a carbodiimide composition which can suppress foaming in a resin during molding and gives a resin molding having good hydrolysis resistance.SOLUTION: The carbodiimide composition comprises (A) a carbodiimide compound, (B) a phosphite-based antioxidant, and (C) a hindered phenolic antioxidant. The phosphite-based antioxidant (B) is contained in an amount of 1.5 pts.mass or more and 5 pts.mass or less based on 100 pts.mass of the carbodiimide compound (A). The hindered phenolic antioxidant (C) is contained in an amount of 1.5 pts.mass or more and 6 pts.mass or less based on 100 pts.mass of the carbodiimide compound (A).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a carbodiimide composition. [Background technology]

[0002] Carbodiimide compounds have a carbodiimide group, represented by [-N=C=N-], in their molecule and have properties such as the ability to react with active hydrogen (carboxylic acids, amines, alcohols, thiols, etc.), good adhesion, excellent heat resistance, and the ability to take various forms (varnish, powder, film, etc.), and are used for a variety of purposes such as crosslinking agents, adhesives, resin modifiers, insulation materials, sound-absorbing materials, and gaskets.

[0003] Conventionally, many resin compositions containing a polycarbodiimide compound and a thermoplastic resin are known, and all of them achieve improvements in the durability and mechanical properties of the thermoplastic resin. For example, Patent Document 1 discloses a polyester resin composition obtained by blending a thermoplastic polyester with a carbodiimide compound, an epoxy compound, and a reinforcing filler in predetermined amounts. Patent Document 2 discloses a carbodiimide composition in which an antioxidant is dispersed in a carbodiimide compound, and a resin composition containing an aliphatic polyester resin and the like. Patent Document 3 discloses a polybutylene terephthalate resin composition containing a polybutylene terephthalate resin, a carbodiimide compound, an alkali compound, a hindered phenol-based antioxidant, a thioether-based antioxidant, and a phosphorus-based compound, each in a predetermined ratio.

[0004] However, the technology of Patent Document 1 has a problem in that a small amount of isocyanate groups contained in the carbodiimide reacts with the remaining carbodiimide catalyst to cause foaming during molding, resulting in air bubbles being contained in the molded product. In this regard, even the compositions of Patent Documents 2 and 3 which contain an antioxidant cannot be said to be sufficient in terms of suppressing foaming during molding or in terms of the hydrolysis resistance of the resulting resin molded article, and there is room for improvement in these respects. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Unexamined Patent Publication No. 56-161452 [Patent Document 2] JP 2005-053870 A [Patent Document 3] International Publication No. 2017 / 038864 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a carbodiimide composition which can suppress foaming in a resin during molding and give a resin molded article having good hydrolysis resistance. [Means for solving the problem]

[0007] Means for Solving the Problems The present inventors have conducted extensive research in order to achieve the above object and have found that a composition containing a carbodiimide compound and two specific types of antioxidants in predetermined amounts, when added to a resin, can suppress foaming in the resin during molding and also give a resin molded product with good hydrolysis resistance, thereby completing the present invention.

[0008] That is, the present invention provides 1. (A) a carbodiimide compound, (B) a phosphite-based antioxidant, and (C) a hindered phenol-based antioxidant; a carbodiimide composition comprising the (B) phosphite-based antioxidant in an amount of 1.5 parts by mass or more and 5 parts by mass or less relative to 100 parts by mass of the (A) carbodiimide compound, and the (C) hindered phenol-based antioxidant in an amount of 1.5 parts by mass or more and 6 parts by mass or less relative to 100 parts by mass of the (A) carbodiimide compound; 2. A carbodiimide composition comprising, in terms of mass ratio, 1 part of the (B) phosphite-based antioxidant and 1 or more parts of the (C) hindered phenol-based antioxidant; 3. A carbodiimide composition according to claim 2, comprising, in terms of mass ratio, 1 part of the phosphite-based antioxidant (B) and 1 to 2 parts of the hindered phenol-based antioxidant (C); 4. The carbodiimide composition according to any one of 1 to 3, wherein the carbodiimide compound (A) is obtained using at least one selected from the group consisting of dicyclohexylmethane diisocyanate, diphenylmethane diisocyanate, tetramethylxylylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and tolylene diisocyanate. 5. The carbodiimide composition according to any one of 1 to 4, wherein the (B) phosphite-based antioxidant is a compound having a pentaerythritol structure. 6. The carbodiimide composition according to 1 or 2, wherein the (C) hindered phenol-based antioxidant is a compound having a pentaerythritol structure. 7. A resin composition comprising the carbodiimide composition according to any one of 1 to 6 and a resin. 8. The resin composition according to 7, wherein the resin is a polyester resin. 9. A step of preparing a carbodiimide composition by blending (A) 100 parts by mass of a carbodiimide compound, (B) 1.5 parts by mass or more and 5 parts by mass or less of a phosphite-based antioxidant, and (C) 1.5 parts by mass or more and 6 parts by mass or less of a hindered phenol-based antioxidant; and A method for producing a resin composition, comprising a step of mixing the obtained carbodiimide composition with a resin; 10. A molded body of the resin composition according to 7 or 8. 11. A cured product of the resin composition of 7. 12. The molded article of 10 which is a film or sheet; 13. A foaming inhibitor for resin molding comprising the carbodiimide composition according to any one of 1 to 6. 14. A method for inhibiting foaming during resin molding, comprising blending any one of the carbodiimide compositions according to 1 to 6 into a resin. to provide. Effect of the Invention

[0009] The carbodiimide composition of the present invention contains a phosphite-based antioxidant and a hindered phenol-based antioxidant in a specified ratio, and therefore, by blending it with a resin, it is possible to efficiently suppress foaming during molding, and to give a resin molded article that is excellent in hydrolysis resistance and mechanical properties and has a good appearance (fewer bubbles). A carbodiimide compound having such properties can be suitably used as an additive in the production of resin processed products having various shapes, such as sheets, films, various resin molded articles, and cured resin products. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will be described in further detail below. The carbodiimide composition according to the present invention comprises (A) a carbodiimide compound, (B) a phosphite-based antioxidant, and (C) a hindered phenol-based antioxidant, and is characterized in that the phosphite-based antioxidant (B) is contained in an amount of 1.5 parts by mass or more and 5 parts by mass or less per 100 parts by mass of the carbodiimide compound (A), and the hindered phenol-based antioxidant (C) is contained in an amount of 1.5 parts by mass or more and 6 parts by mass or less per 100 parts by mass of the carbodiimide compound (A).

[0011] [1] Carbodiimide composition (A) Carbodiimide compound The carbodiimide compound is not particularly limited as long as it is a carbodiimide compound (including a polycarbodiimide compound) having one or more carbodiimide groups in the molecule, and those produced using various polyisocyanate raw materials by conventionally known methods can be used.

[0012] The isocyanate compound used as the raw material for the carbodiimide compound is not particularly limited as long as it is a compound having two or more isocyanate groups in one molecule, and can be appropriately selected from various conventionally known diisocyanate compounds and the like. Specific examples thereof include aliphatic isocyanates such as hexamethylene diisocyanate, 1,4-tetramethylene diisocyanate, 2-methylpentane-1,5-diisocyanate, dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate; 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, 2,2-bis(4-isocyanatomethyl)cyclohexane, and the like. Cyclohexyl)propane, isophorone diisocyanate, norbornane diisocyanate, dicyclomethane diisocyanate (HMDI), hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated tetramethylxylylene diisocyanate and other alicyclic diisocyanates; 1,5-naphthalene diisocyanate, 2,2'-diphenylmethane diisocyanate, methylene diphenyl 4,4'-Diisocyanate (4,4'-diphenylmethane diisocyanate) and other diphenylmethane diisocyanates, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylether diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 2,4,6-triisopropylbenzene-1,3-diyl diisocyanate, o-tolidine diisocyanate, naphthylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate Examples of the diisocyanate include aromatic diisocyanates such as m-xylylene diisocyanate (m-xylylene diisocyanate), aromatic aliphatic diisocyanates such as tetramethylxylylene diisocyanate, and nurates, adducts, and biurets obtained by trimerizing these, and those in which the ends are blocked with a blocking agent or the like. These may be used alone or in combination of two or more.

[0013] In the production of the polycarbodiimide compound, the polymerization reaction can be stopped midway by cooling or the like to control the degree of polymerization to an appropriate level. In this case, the terminals become isocyanate groups. In addition, the remaining terminal isocyanates can be all or partly blocked with a terminal blocking compound having a functional group capable of reacting with an isocyanate group to control the degree of polymerization to an appropriate level. By controlling the degree of polymerization, it is possible to improve compatibility with resins and improve the storage stability of the polycarbodiimide compound.

[0014] The terminal blocking compound is preferably a compound having one group selected from an amino group, an isocyanate group, an epoxy group, a carboxy group, and a hydroxyl group. The end-capping compound may be a hydrophobic or hydrophilic compound.

[0015] Examples of compounds having one amino group include monoamines having a hydrocarbon group having 1 to 18 carbon atoms. Specific examples thereof include methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, octylamine, dodecylamine, diethylamine, dipropylamine, dibutylamine, cyclohexylamine, adamantanamine, allylamine, aniline, diphenylamine, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 2,2-difluoroamine, fluorobenzylamine, trifluoroethylamine, [[4-(trifluoromethyl)cyclohexyl]methyl]amine, and derivatives thereof, and the like. These may be used alone or in combination of two or more. Among these, cyclohexylamine is preferred from the viewpoint of versatility and the like. When the terminal is blocked with a compound having one amino group, the terminal isocyanate group reacts with the amino group to form a urea bond.

[0016] Examples of compounds having one isocyanate group include monoisocyanates having a hydrocarbon group having 1 to 18 carbon atoms. Specific examples thereof include butyl isocyanate, pentyl isocyanate, hexyl isocyanate, octyl isocyanate, dodecyl isocyanate, cyclohexyl isocyanate, 1-adamantyl isocyanate, 3-isocyanatepropyltriethoxysilane, 2-isocyanatoethyl acrylate, benzyl isocyanate, 2-phenylethyl isocyanate, and derivatives thereof, and these may be used alone or in combination of two or more. Among these, cyclohexyl isocyanate is preferred from the viewpoint of reactivity and the like. When the terminal is blocked with a compound having one isocyanate group, the terminal isocyanate group reacts with the isocyanate group of the terminal blocking compound to form a carbodiimide bond (carbodiimide group).

[0017] Specific examples of the compound having one epoxy group include 1,2-epoxyheptane, 1,2-epoxyhexane, 1,2-epoxydecane, 1,2-epoxy-5-hexene, ethyl glycidyl ether, 2-ethylhexyl glycidyl ether, glycidyl lauryl ether, allyl glycidyl ether, diethoxy(3-glycidyloxypropyl)methylsilane, 3-[2-(perfluorohexyl)ethoxy]-1,2-epoxypropane, and derivatives thereof, and these may be used alone or in combination of two or more. When the terminal is blocked with a compound having one epoxy group, the terminal isocyanate group reacts with the epoxy group to form an oxazolidone ring.

[0018] Examples of compounds having one carboxy group include monocarboxylic acids having a hydrocarbon group having 1 to 18 carbon atoms. Specific examples thereof include acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, cyclohexanecarboxylic acid, adamantaneacetic acid, phenylacetic acid, benzoic acid, undecenoic acid, and derivatives thereof, and these may be used alone or in combination of two or more. When the terminal isocyanate group is blocked with a compound having one carboxy group, the terminal isocyanate group reacts with the carboxy group to form an amide bond.

[0019] Examples of compounds having one hydroxyl group include monoalcohols having a hydrocarbon group having 1 to 18 carbon atoms. Specific examples thereof include cyclohexanol, oleyl alcohol, benzyl alcohol, dodecyl alcohol, octanol, hexanol, pentanol, butanol, propanol, and ethanol. These may be used alone or in combination of two or more. Among these, n-octanol, isopropanol, oleyl alcohol, and benzyl alcohol are preferred from the viewpoints of reactivity, versatility, and the like. When the terminal is blocked with a compound having one hydroxyl group, the terminal isocyanate group reacts with the hydroxyl group to form a urethane bond.

[0020] As the monoalcohols, the compounds as described above are preferable from the viewpoint of the water resistance of the cured resin product. In addition, for example, alkylene glycol derivatives such as alkylene glycol monoethers and alkylene glycol monoesters can also be used, and the compound represented by the following formula (1) is preferable. R 2 (OCHR 1 CH2) m OH (1) (In the formula, R 1 represents a hydrogen atom or a methyl group, and R 2 represents a hydrocarbon group having 1 to 18 carbon atoms or an acyl group having 1 to 18 carbon atoms, and m represents an integer of 1 to 6.

[0021] The hydrocarbon group having 1 to 18 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include linear, branched, and cyclic alkyl groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, isopropyl, isobutyl, sec-butyl, tert-butyl, thexyl, 2-ethylhexyl, cyclopentyl, and cyclohexyl groups. Among these, alkyl groups having 1 to 7 carbon atoms are preferred, and alkyl groups having 1 to 4 carbon atoms are more preferred.

[0022] Specific examples of the acyl group having 1 to 18 carbon atoms include formyl, acetyl, propionyl, butyryl, isobutyryl, palmitoyl, and benzoyl groups. Among these, acyl groups having 1 to 7 carbon atoms are preferred, and acyl groups having 1 to 4 carbon atoms are more preferred. m is an integer of 1 to 6, preferably an integer of 1 to 5, and more preferably an integer of 1 to 4.

[0023] Specific examples of the compound represented by formula (1) include ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol isopropyl ether, diethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, ethylene glycol monohexyl ether, ethylene glycol mono-2-ethylhexyl ether, ethylene glycol monoallyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, propylene glycol mono-n-butyl ether, and polymers thereof; polyethylene glycol glyceryl ether, polypropylene glycol glyceryl ether, polypropylene glycol diglyceryl ether, and the like.

[0024] The carbodiimide compound can be produced by various methods using the various diisocyanate compounds exemplified as the isocyanate compounds as raw materials, and a representative example of the production method is a method of producing an isocyanate-terminated carbodiimide compound by a decarboxylation condensation reaction accompanied by decarbonation of a diisocyanate compound (U.S. Pat. No. 2,941,956, Japanese Patent Publication No. 47-33279, J. Org. Chem, 28, 2069-2075 (1963), Chemical Review 1981, Vol. 81, No. 4, p. 619-621, etc.). When terminal blocking is performed, the carbodiimide compound may be reacted with a predetermined terminal blocking compound after or simultaneously with its synthesis. In addition to the diisocyanate compound, a compound having three or more isocyanate groups can also be used as a reaction raw material.

[0025] In particular, from the viewpoints of availability and ease of synthesis of carbodiimide compounds, dicyclohexylmethane diisocyanate (HMDI), isophorone diisocyanate (IPDI), xylylene diisocyanate (XDI), hexamethylene diisocyanate (HDI), methylene diphenyl 4,4'-diisocyanate (MDI), tolylene diisocyanate (TDI), and tetramethylxylylene diisocyanate (TMXDI) are preferred as diisocyanate compounds serving as raw materials for synthesis of carbodiimide compounds. Among these, from the viewpoint of storage stability, aliphatic, alicyclic or araliphatic diisocyanates are preferred over aromatic diisocyanates, and in particular, HMDI, IPDI and TMXDI having secondary or tertiary diisocyanate groups are more preferred, with HMDI being even more preferred.

[0026] In the decarboxylation condensation reaction of a diisocyanate compound, a carbodiimidization catalyst is usually used. Specific examples of carbodiimide catalysts include phospholene oxides such as 1-phenyl-2-phospholene-1-oxide, 3-methyl-1-phenyl-2-phospholene-1-oxide, 1-ethyl-2-phospholene-1-oxide, 3-methyl-2-phospholene-1-oxide, and 3-phospholene isomers thereof, and these may be used alone or in combination of two or more kinds. Among these, 3-methyl-1-phenyl-2-phospholene-1-oxide is preferred from the viewpoint of reactivity. The amount of the carbodiimidization catalyst used is not particularly limited, but is preferably 0.01 to 2.0 parts by mass based on 100 parts by mass of the diisocyanate compound.

[0027] The above decarboxylation condensation reaction can be carried out without a solvent, but a solvent may be used. Specific examples of usable solvents include alicyclic ethers such as tetrahydrofuran, 1,3-dioxane, and dioxolane; 1-(2-methoxy-2-methylethoxy)-2-propanol, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, dipropylene glycol methyl ethyl ether, dipropylene glycol diethyl ether, dipropylene glycol dimethyl ether, triethylene glycol methyl ethyl ether, triethylene glycol diethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol methyl ethyl ether, tetraethylene glycol diethyl ether, and tetraethylene glycol. Examples of the solvent include aprotic water-soluble solvents such as dimethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether acetate, γ-butyrolactone, N-methylpyrrolidone, N-ethylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide; aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; halogenated hydrocarbons such as chlorobenzene, dichlorobenzene, trichlorobenzene, perclene, trichloroethane, and dichloroethane; and cyclohexanone. These may be used alone or in combination of two or more. When the reaction is carried out in a solvent, the concentration of the diisocyanate compound is preferably from 5 to 55% by mass, more preferably from 5 to 20% by mass.

[0028] The reaction temperature is not particularly limited, but is preferably 40 to 250° C., more preferably 80 to 195° C. When the reaction is carried out in a solvent, the reaction temperature is preferably from 40° C. to the boiling point of the solvent. The reaction time is preferably from 0.5 to 80 hours, more preferably from 1 to 70 hours. The reaction atmosphere is not particularly limited, but an inert gas atmosphere such as nitrogen gas or a rare gas is preferable.

[0029] In the case of terminal blocking, when the terminal blocking compound is a compound having one isocyanate group, for example, the terminal blocking compound and a diisocyanate compound can be stirred and mixed in the presence of a carbodiimide catalyst at preferably 40 to 200°C, more preferably 80 to 195°C, for about 10 to 70 hours to obtain a terminal-blocked carbodiimide compound. When the terminal blocking compound is other than a compound having one isocyanate group, for example, the terminal blocking compound can be added to an isocyanate-terminated carbodiimide compound at preferably 40 to 250°C, more preferably 80 to 195°C, and then stirred and mixed at about 80 to 200°C for about 0.5 to 5 hours to obtain a terminal-blocked carbodiimide compound.

[0030] The degree of polymerization of the carbodiimide compound (degree of polymerization of the carbodiimide group) is not particularly limited, but from the viewpoint of compatibility with resins, etc., it is preferably 5 or more, more preferably 5 to 30, even more preferably 5 to 25, and still more preferably 5 to 20. In this specification, the "degree of polymerization of carbodiimide groups" refers to the number of carbodiimide groups formed by a decarboxylation condensation reaction between diisocyanate compounds in a carbodiimide compound. The carbodiimide compounds may be used alone or in combination of two or more.

[0031] (B) Phosphite antioxidants The phosphite-based antioxidant used in the carbodiimide composition of the present invention can be appropriately selected from conventionally known compounds. Specific examples thereof include tris-(2,4-di-tert-butylphenyl)phosphite (Irgaphos 168 manufactured by BASF Japan Ltd., Adeka STAB 2112 manufactured by ADEKA Corporation, etc.), bis-(2,4-di-tert-butylphenyl)pentaerythritol diphosphite (Irgaphos 126 manufactured by BASF Japan Ltd., Adeka STAB PEP-24G manufactured by ADEKA Corporation, etc.), 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5] Examples of such undecane include undecane (bis-(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite) (ADEKA STAB PEP-36, manufactured by ADEKA CORPORATION), 3,9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane (distearyl-pentaerythritol diphosphite) (ADEKA STAB PEP-8, manufactured by ADEKA CORPORATION, JPP-2000PT, manufactured by Johoku Chemical Co., Ltd., etc.), and these may be used alone or in combination of two or more.

[0032] Among these, those having a pentaerythritol structure are preferred in terms of suppressing foaming during molding of the resin composition and improving the hydrolysis resistance of the resin molded body, and 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane and 3,9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane are more preferred.

[0033] (C) Hindered phenol antioxidants The hindered phenol-based antioxidant used in the carbodiimide composition of the present invention can be appropriately selected from conventionally known compounds. In order to prevent scattering and volatilization, to prevent bleeding out from the resin molded article, and to prevent migration to contacting articles, and to improve the heat resistance of the resin molded article, it is preferable to use one having a molecular weight of 400 or more, and more preferably one having a molecular weight of 500 or more.

[0034] Specific examples of hindered phenol-based antioxidants include 4,4'-methylene-bis-(2,6-di-tert-butylphenol) (MW=420), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (MW=531) (Irganox 1076 manufactured by BASF Japan Ltd., Adeka STAB AO-50 manufactured by ADEKA Corporation), bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid][2,2-bis[[1-oxo-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propoxy]methyl]propane]-1,3-diyl(pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]) (MW= 1178, Irganox 1010 manufactured by BASF Japan Co., Ltd., Adeka STAB AO-60 manufactured by ADEKA Corporation), bis[3-[3-(tert-butyl)-4-hydroxy-5-methylphenyl]propanoic acid]2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diylbis(2-methylpropane-2,1-diyl)(3,9-bis[2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane) (MW=741, Sumitomo Chemical Co., Ltd., trade name Sumilizer GA-80, Adeka STAB AO-80 manufactured by ADEKA Corporation), and the like may be used alone or in combination of two or more.

[0035] Among these, from the viewpoints of suppressing foaming during molding of the resin composition and improving the hydrolysis resistance of the resin molded body, those having a pentaerythritol structure like the phosphite-based antioxidants are preferred, and bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid][2,2-bis[[1-oxo-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propoxy]methyl]propane]-1,3-diyl and bis[3-[3-(tert-butyl)-4-hydroxy-5-methylphenyl]propanoic acid]2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diylbis(2-methylpropane-2,1-diyl) are more preferred.

[0036] As already described, the carbodiimide composition of the present invention contains (B) a phosphite-based antioxidant in an amount of 1.5 parts by mass or more and 5 parts by mass or less, preferably 1.7 to 4.9 parts by mass, and more preferably 1.7 to 4.5 parts by mass, relative to 100 parts by mass of the (A) carbodiimide compound, and (C) a hindered phenol-based antioxidant in an amount of 1.5 parts by mass or more and 6 parts by mass or less, preferably 1.7 to 4.9 parts by mass, and more preferably 1.7 to 4.5 parts by mass, relative to 100 parts by mass of the (A) carbodiimide compound. By using these two types of antioxidants in the above-mentioned respective addition amounts in combination, foaming during molding of the resin composition can be efficiently suppressed and the hydrolysis resistance of the obtained resin molded article can be improved. In particular, when the content of each of the (B) phosphite-based antioxidant and the (C) hindered phenol-based antioxidant is less than 1.5 mass%, the foaming suppression effect during resin molding becomes insufficient, and when the content of the (B) phosphite-based antioxidant exceeds 5 parts by mass and when the content of the (C) hindered phenol-based antioxidant exceeds 6 parts by mass, the hydrolysis suppression effect of the obtained resin molded body becomes insufficient. In addition, if either one of the phosphite-based antioxidants or the hindered phenol-based antioxidants has a pentaerythritol structure, the performance will be improved, but the performance will be even better if both the phosphite-based antioxidant and the hindered phenol-based antioxidant have a pentaerythritol structure.

[0037] In the present invention, the ratio of the phosphite-based antioxidant (B) to the hindered phenol-based antioxidant (C) used is not particularly limited as long as the desired effects of the present invention are exhibited. However, in consideration of further enhancing the effect of suppressing foaming during resin molding and the effect of improving the hydrolysis resistance of a resin molded body, it is preferable that the amount of the hindered phenol-based antioxidant (C) used is the same as or greater than the amount of the phosphite-based antioxidant (B) used; that is, it is preferable that the carbodiimide composition contains, in mass ratio, 1 part of the phosphite-based antioxidant (B) to 1 part of the hindered phenol-based antioxidant (C), and more preferably 1 to 2 parts by mass.

[0038] There is no particular limitation on the method for producing the carbodiimide composition of the present invention, and the composition may be prepared by mixing the above-mentioned components (A) to (C) in any order. As disclosed in the above-mentioned Patent Document 2, two kinds of antioxidants, components (B) and (C), may be added in advance when synthesizing the carbodiimide compound of component (A) so that the above-mentioned amounts are added in the final composition, and by doing so, coloring during the synthesis of the carbodiimide compound can be suppressed. In this case, the timing of adding the antioxidants is preferably at the stage of charging the raw materials, but they may also be during the reaction.

[0039] (D) Other ingredients In addition to the various components described above, the carbodiimide composition of the present invention may contain additives such as antioxidants other than the components (B) and (C), ultraviolet absorbers, thickeners, defoamers, and wettability improvers, within the range that does not impair the effects of the present invention. However, it is preferable that the carbodiimide composition does not contain any other components other than the components (A) to (C).

[0040] [2] Resin composition The resin composition of the present invention contains the above-mentioned carbodiimide composition and a resin. Since this resin composition contains the above-mentioned carbodiimide composition, foaming during molding is effectively suppressed, resulting in a resin molded article with fewer internal bubbles and good appearance.

[0041] The resin constituting the resin composition may be a thermoplastic resin or a thermosetting resin. The thermoplastic resin is not particularly limited, and can be appropriately selected from conventionally known thermoplastic resins, such as polyester resins such as polylactic acid, polyethylene terephthalate, and polybutylene terephthalate; polycarbonate resins; polyamide resins; polyetherimide resins; polyolefin resins such as polyethylene and polypropylene; polystyrene resins; polyurethane resins; polyamideimide resins; polybenzimidazole resins; polycarbonate resins; polyvinyl chloride resins, polyvinylidene chloride resins; polysulfone resins; polyphenylene sulfide resins; polyethersulfone resins; and polyarylene sulfide resins.

[0042] The thermosetting resin is not particularly limited, and can be appropriately selected from conventionally known thermosetting resins such as phenolic resin, epoxy resin, melamine resin, urea resin, unsaturated polyester resin, polyurethane resin, alkyd resin, and silicone resin.

[0043] Since the resin molded product obtained from the resin composition of the present invention contains two types of antioxidants derived from the carbodiimide composition, it exhibits hydrolysis resistance. Therefore, it is more effective to use a resin containing an ester bond, such as a polyester resin, which is easily hydrolyzed, as the above resin.

[0044] The method for producing the resin composition is not particularly limited, but a method in which a carbodiimide composition previously prepared by the above-mentioned method is mixed with a resin is preferable. In this case, a solvent may be used as necessary. Examples of the solvent include the same solvents as those exemplified for the above dehydration condensation reaction.

[0045] In the resin composition of the present invention, the content of the carbodiimide composition is not particularly limited as long as the desired foaming inhibition effect and hydrolysis resistance are exhibited. However, the blending ratio of the antioxidant in the carbodiimide composition is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 10 parts by mass, and even more preferably 0.5 to 5 parts by mass, of the carbodiimide composition per 100 parts by mass of the thermoplastic resin.

[0046] In addition, various additive components may be added to the resin composition of the present invention, if necessary, depending on the application, etc., such as reinforcing materials, clay, layered silicates, talc, mica, inorganic or organic fillers, other antioxidants, heat stabilizers, hindered amine light stabilizers, ultraviolet absorbers, flame retardants, lubricants, waxes, pigments, dyes, colorants, crystallization accelerators, titanium oxide, decomposable organic substances such as starch, and the like.

[0047] The resin composition of the present invention can be made into various molded articles such as extrusion molded articles, sheets, films, injection molded articles, and the like, or into cured resin products, by various molding methods applicable depending on the resin used, for example, extrusion molding, injection molding, calendar molding, blow molding, transfer molding, compression molding, and the like. In this case, the carbodiimide composition and the resin may be separately charged into a molding machine and kneaded with a screw or the like to prepare a resin composition while molding. The various molding conditions such as the heating temperature during molding may be selected according to the resin used. EXAMPLES

[0048] The present invention will be described in more detail below with reference to Synthesis Examples, Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[0049] Details of the compounds used in the synthesis examples and working examples are as follows. (1) Diisocyanate compounds Dicyclohexylmethane diisocyanate (HMDI, manufactured by Tokyo Chemical Industry Co., Ltd.) Tetramethylxylylene diisocyanate (TMXDI, manufactured by Tokyo Chemical Industry Co., Ltd.) Diphenylmethane diisocyanate (MDI, Lupranate MI, 2,4-MDI / 4,4-MDI=3 / 7, manufactured by BASF INOAC Polyurethanes Co., Ltd. Isophorone diisocyanate (IPDI, manufactured by Tokyo Chemical Industry Co., Ltd.) Tolylene diisocyanate (TDI, manufactured by Tokyo Chemical Industry Co., Ltd.) m-Xylylene diisocyanate (XDI, manufactured by Tokyo Chemical Industry Co., Ltd.) Hexamethylene diisocyanate (HDI, manufactured by Tokyo Chemical Industry Co., Ltd.) (2) Terminal capping compound Cyclohexylamine (CHA, manufactured by Tokyo Chemical Industry Co., Ltd.) Dibutylamine (DBA, manufactured by Tokyo Chemical Industry Co., Ltd.) Polyethylene glycol monomethyl ether 220 (MPEG, Kanto Chemical Co., Ltd.) 1-Octanol (OA, manufactured by Tokyo Chemical Industry Co., Ltd.) Cyclohexyl isocyanate (CHI, manufactured by Tokyo Chemical Industry Co., Ltd.) (3) Carbodiimidization catalyst 3-Methyl-1-phenyl-2-phospholene-1-oxide (Tokyo Chemical Industry Co., Ltd.) (4) Phosphite antioxidants 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane (phosphite compound BA, Adeka STAB PEP-36 manufactured by ADEKA Corporation) 3,9-Bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane (phosphite compound BB, Adeka STAB PEP-8 manufactured by ADEKA Corporation) Trisnonylphenyl phosphite (Phosphite compound BC, Adeka STAB 2112 manufactured by ADEKA Corporation) (5) Hindered phenol-based antioxidants Bis[3-[3-(tert-butyl)-4-hydroxy-5-methylphenyl]propanoic acid]2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diylbis(2-methylpropane-2,1-diyl) (hindered phenol compound CA, Adeka STAB AO-60 manufactured by ADEKA Corporation) Bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid][2,2-bis[[1-oxo-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propoxy]methyl]propane]-1,3-diyl (hindered phenolic compound CB, Adeka STAB AO-80 manufactured by ADEKA Corporation) Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (hindered phenolic compound CC, Adeka STAB AO-50 manufactured by ADEKA Corporation) (6) Solvent Cyclohexanone (Tokyo Chemical Industry Co., Ltd.) (7) Other compounds Tetrakis[3-(dodecylthio)propionic acid]pentaerythritol (thioether compound, ADEKA STAB AO-412S manufactured by ADEKA Corporation)

[0050] [1] Preparation of polycarbodiimide composition In the following, infrared absorption (IR) spectra were measured using an FTIR-8200PC manufactured by Shimadzu Corporation. In the following synthesis examples, the degree of polymerization of the carbodiimide groups was determined as follows depending on the synthesis method. (1) When a polycarbodiimide compound is synthesized by simultaneously blending a diisocyanate compound and a terminal blocking compound, the degree of polymerization of the carbodiimide group is a calculated value. (2) In the case where an isocyanate-terminated polycarbodiimide was synthesized by polycarbodiimidization reaction of a diisocyanate compound, and then a terminal isocyanate group was blocked using a terminal blocking compound to synthesize a polycarbodiimide compound, the degree of polymerization of the carbodiimide group was determined by potentiometric titration for the isocyanate-terminated polycarbodiimide (apparatus used: automatic titration apparatus "COM-900", manufactured by Hiranuma Sangyo Co., Ltd.). Specifically, a toluene solution of di-n-butylamine of known concentration was mixed with the isocyanate-terminated polycarbodiimide obtained by the carbodiimidization reaction to react the terminal isocyanate group with di-n-butylamine, and the remaining di-n-butylamine was neutralized and titrated with a standard hydrochloric acid solution to calculate the remaining amount of isocyanate group (terminal NCO amount [mass %]). The degree of polymerization of the carbodiimide group was determined from this terminal NCO amount.

[0051] [Synthesis Example 1] 262 parts by mass of HMDI and 2.6 parts by mass of a carbodiimidization catalyst were placed in a reaction vessel equipped with a reflux tube and a stirrer, and stirred at 170°C for 18 hours under a nitrogen stream to obtain an isocyanate-terminated polycarbodiimide compound having isocyanate groups at both ends (terminal isocyanate group amount 3.43% by mass). -1 Absorption peaks due to carbodiimide groups before and after were confirmed (degree of polymerization of the carbodiimide compound: 10). The obtained isocyanate-terminated polycarbodiimide compound was dissolved at 150°C, to which 18.0 parts by mass of cyclohexylamine was added as a terminal blocking compound, and the mixture was heated to 180°C and reacted for 2 hours with stirring. Then, 4.0 parts by mass of a phosphite-based compound BA and 4.0 parts by mass of a hindered phenol-based compound CA were added and mixed for 0.5 hours. The mixture was removed from the reaction vessel and cooled to room temperature (25°C) to obtain a polycarbodiimide composition (1) (theoretical carbodiimide group concentration 14.6%).

[0052] [Synthesis Examples 2-9, 23-28] In Synthesis Example 1, the polymerization degree of the carbodiimide compound (A), the end-capping compound, the carbodiimide catalyst, the phosphite compound, the hindered phenol compound and other compounds were changed according to Table 1 to obtain polycarbodiimide compositions (2) to (9) and (23) to (28), respectively.

[0053] [Synthesis Example 10] 262 parts by mass of HMDI and 2.6 parts by mass of a carbodiimidization catalyst were placed in a reaction vessel equipped with a reflux condenser and a stirrer, and stirred for 24 hours at 170°C under a nitrogen stream to obtain an isocyanate-terminated polycarbodiimide compound having isocyanate groups at both ends (terminal isocyanate group amount: 1.81% by mass). -1 Absorption peaks due to carbodiimide groups before and after were confirmed (degree of polymerization of the carbodiimide compound: 20). To the obtained isocyanate-terminated polycarbodiimide compound, 10.0 parts by mass of a phosphite-based compound BA and 10.0 parts by mass of a hindered phenol-based compound CA were added and mixed for 0.5 hours. The mixture was removed from the reaction vessel and cooled to room temperature (25°C) to obtain a polycarbodiimide composition (10) (theoretical carbodiimide group concentration: 15.8%).

[0054] [Synthesis Examples 11-15, 29] In Synthesis Example 10, the polymerization degree of the carbodiimide compound (A), the carbodiimide catalyst, the phosphite compound and the hindered phenol compound were changed according to Tables 1 and 2 to obtain polycarbodiimide compositions (11) to (15) and (29), respectively.

[0055] [Synthesis Example 16] 262 parts by mass of HMDI, 41.7 parts by mass of CHI, and 2.6 parts by mass of a carbodiimide catalyst were placed in a reaction vessel equipped with a reflux condenser and a stirrer, and the mixture was reacted under stirring at 180°C for 47 hours under a nitrogen stream. -1 The absorption peak of the isocyanate group and the wave number of 2000 to 2200 cm -1It was confirmed that the ratio of the absorption peak of the carbodiimide group in was reduced to 0.05 or less. Then, 5.0 parts by mass of the phosphite compound BA and 5.0 parts by mass of the hindered phenol compound CA were added and mixed for 0.5 hours. The mixture was removed from the reaction vessel and cooled to room temperature (25°C) to obtain a polycarbodiimide composition (16) (theoretical carbodiimide group concentration 17.8%).

[0056] [Synthesis Example 17] 244 parts by mass of TMXDI and 2.4 parts by mass of a carbodiimidization catalyst were placed in a reaction vessel equipped with a reflux tube and a stirrer, and the mixture was stirred and mixed at 170°C for 18 hours under a nitrogen stream to carry out a carbodiimidization reaction, yielding an isocyanate-terminated polycarbodiimide compound having isocyanate groups at both ends (terminal isocyanate group amount 3.74% by mass). -1 Absorption peaks due to carbodiimide groups before and after were confirmed (degree of polymerization of the carbodiimide compound: 10). The obtained isocyanate-terminated polycarbodiimide compound was dissolved at 150°C, to which 23.5 parts by mass of dibutylamine was added as a terminal blocking compound, and the mixture was heated to 180°C and reacted for 2 hours with stirring. Then, 6.0 parts by mass of a phosphite-based compound BA and 4.0 parts by mass of a hindered phenol-based compound CA were added and mixed for 0.5 hours. The mixture was removed from the reaction vessel and cooled to room temperature (25°C) to obtain a polycarbodiimide composition (17) (theoretical carbodiimide group concentration 15.3%).

[0057] [Synthesis Example 18] 252 parts by mass of MDI, 2.5 parts by mass of a carbodiimide catalyst, 43.4 parts by mass of dibutylamine as an end-capping compound, and 190 parts by mass of cyclohexanone as a solvent were placed in a reaction vessel equipped with a reflux condenser and a stirrer, and the mixture was reacted by stirring at 120°C for 5 hours under a nitrogen gas flow. In IR spectrum measurement, -1 The absorption peak of the isocyanate group and the wave number of 2000 to 2200 cm -1It was confirmed that the ratio of the absorption peak of the carbodiimide group in was reduced to 0.05 or less. Thereafter, 6.0 parts by mass of the phosphite compound BA and 4.0 parts by mass of the hindered phenol compound CA were added and mixed for 0.5 hours. After mixing was completed, the solvent was distilled off under reduced pressure, and the reaction product was taken out of the reaction vessel and cooled to room temperature (25° C.) to obtain a polycarbodiimide composition (18) (theoretical carbodiimide group concentration: 12.5%).

[0058] [Synthesis Example 19] 222 parts by mass of IPDI, 43.4 parts by mass of dibutylamine as an end-capping compound, and 2.2 parts by mass of a carbodiimide catalyst were placed in a reaction vessel equipped with a reflux condenser and a stirrer, and the mixture was reacted by stirring at 150°C for 24 hours under a nitrogen gas flow. -1 The absorption peak of the isocyanate group and the wave number of 2000 to 2200 cm -1 It was confirmed that the ratio of the absorption peak of the carbodiimide group in the 1H-CuO-1 solution was reduced to 0.05 or less. Thereafter, 3.0 parts by mass of a phosphite-based compound BA and 4.0 parts by mass of a hindered phenol-based compound CA were added and mixed for 0.5 hours. After mixing was completed, the mixture was removed from the reaction vessel and cooled to room temperature (25° C.) to obtain a polycarbodiimide composition (19) (theoretical carbodiimide group concentration: 17.1%).

[0059] [Synthesis Example 20] 175 parts by mass of TDI, 43.3 parts by mass of dibutylamine as an end-capping compound, 1.8 parts by mass of a carbodiimide catalyst, and 205 parts by mass of cyclohexanone as a solvent were placed in a reaction vessel equipped with a reflux condenser and a stirrer, and the mixture was reacted by stirring at 150°C for 4 hours under a nitrogen gas flow. In IR spectrum measurement, -1 The absorption peak of the isocyanate group and the wave number of 2000 to 2200 cm -1 It was confirmed that the ratio of the absorption peak of the carbodiimide group in the 1H-CuO-1 solution was reduced to 0.05 or less. Then, 3.0 parts by mass of a phosphite-based compound BA and 4.0 parts by mass of a hindered phenol-based compound CA were added and mixed for 0.5 hours. After mixing was completed, the solvent was distilled off under reduced pressure, and the reaction product was taken out of the reaction vessel and cooled to room temperature (25°C) to obtain a polycarbodiimide composition (20) (theoretical carbodiimide group concentration: 17.8%).

[0060] [Synthesis Example 21] 188 parts by mass of XDI, 43.0 parts by mass of dibutylamine as an end-capping compound, 1.9 parts by mass of a carbodiimide catalyst, and 205 parts by mass of cyclohexanone as a solvent were placed in a reaction vessel equipped with a reflux condenser and a stirrer, and the mixture was reacted by stirring at 100°C for 4 hours under a nitrogen gas flow. In IR spectrum measurement, -1 The absorption peak of the isocyanate group and the wave number of 2000 to 2200 cm -1 It was confirmed that the ratio of the absorption peak of the carbodiimide group in the 1H-CuO-1 solution was reduced to 0.05 or less. Thereafter, 3.0 parts by mass of a phosphite-based compound BA and 4.0 parts by mass of a hindered phenol-based compound CA were added and mixed for 0.5 hours. After mixing was completed, the solvent was distilled off under reduced pressure, and the reaction product was taken out of the reaction vessel and cooled to room temperature (25° C.) to obtain a polycarbodiimide composition (21) (theoretical carbodiimide group concentration: 16.5%).

[0061] [Synthesis Example 22] 168 parts by mass of HDI, 43.0 parts by mass of dibutylamine as an end-capping compound, 1.7 parts by mass of a carbodiimide catalyst, and 205 parts by mass of cyclohexanone as a solvent were placed in a reaction vessel equipped with a reflux condenser and a stirrer, and the mixture was reacted by stirring at 150°C for 18 hours under a nitrogen gas flow. In IR spectrum measurement, -1 The absorption peak of the isocyanate group and the wave number of 2000 to 2200 cm -1 It was confirmed that the ratio of the absorption peak of the carbodiimide group in the 1H-CuO-1 solution was reduced to 0.05 or less. Thereafter, 3.0 parts by mass of a phosphite-based compound BA and 4.0 parts by mass of a hindered phenol-based compound CA were added and mixed for 0.5 hours. After mixing was completed, the solvent was distilled off under reduced pressure, and the reaction product was taken out of the reaction vessel and cooled to room temperature (25° C.) to obtain a polycarbodiimide composition (22) (theoretical carbodiimide group concentration: 18.4%).

[0062] The above synthesis examples are summarized in Tables 1 and 2.

[0063] [Table 1]

[0064] [Table 2]

[0065] [2] Preparation of resin composition In the following, various resin compositions were prepared so that the carbodiimide group in the obtained polycarbodiimide composition was 0.15 parts by mass per 100 parts by mass of resin, using the theoretical carbodiimide group concentration of the obtained polycarbodiimide composition. [Example 1] 100 parts by mass of PBAT resin (BASF ecoflex F Blend C1200, the same applies below) was melted at 160°C using a laboratory mixer, and then 1.0 part by mass of the polycarbodiimide composition (1) obtained in Synthesis Example 1 was added while mixing, and the mixture was kneaded for 3 minutes to obtain a PBAT resin composition.

[0066] [Examples 2 to 22, Comparative Examples 1 to 7] As shown in Tables 3 and 4, PBAT resin compositions were obtained in the same manner as in Example 1, except that the polycarbodiimide composition (1) was changed to the polycarbodiimide compositions (2) to (29) obtained in Synthesis Examples 2 to 29 and the amounts of each were as shown in Tables 3 and 4. In Tables 3 and 4, blank spaces indicate an amount of 0 added.

[0067] [Comparative Example 8] As shown in Table 4, 100 parts by mass of the PBAT resin was melted at 160°C using a laboratory mixer, and then 1.0 part by mass of the polycarbodiimide composition (22) obtained in Synthesis Example 22, 0.04 part by mass of the phosphite-based compound BA, and 0.04 part by mass of the hindered phenol-based compound CA were added while mixing, and the mixture was kneaded for 3 minutes to obtain a PBAT resin composition.

[0068] [Example 23] 100 parts by mass of PBSA resin (FD92PM manufactured by Mitsubishi Chemical Corporation, the same applies below) was melted at 130°C using a lab mixer, and then 1.0 part by mass of the polycarbodiimide composition (1) obtained in Synthesis Example 1 was added while mixing, and the mixture was kneaded for 3 minutes to obtain a PBSA resin composition.

[0069] [Example 24, Comparative Example 9] As shown in Table 5, PBSA resin compositions were obtained in the same manner as in Example 23, except that the polycarbodiimide composition (1) was changed to the polycarbodiimide compositions (10) and (22) obtained in Synthesis Examples 10 and 22, respectively. In Table 5, blanks indicate an addition amount of 0.

[0070] [Comparative Example 10] As shown in Table 5, 100 parts by mass of PBSA resin was melted under the condition of 130°C using a laboratory mixer, and then 1.0 part by mass of the polycarbodiimide composition (22) obtained in Synthesis Example 22, 0.04 part by mass of the phosphite-based compound BA, and 0.04 part by mass of the hindered phenol-based compound CA were added while mixing, and the mixture was kneaded for 3 minutes to obtain a PBSA resin composition.

[0071] [Example 25] 100 parts by mass of PLA resin (Nature Works 4032D, the same applies below) was melted at 200°C using a lab mixer, and then 1.0 part by mass of the polycarbodiimide composition (1) obtained in Synthesis Example 1 was added while mixing, and the mixture was kneaded for 3 minutes to obtain a PLA resin composition.

[0072] [Example 26, Comparative Example 11] As shown in Table 5, PLA resin compositions were obtained in the same manner as in Example 25, except that the polycarbodiimide composition (1) was changed to the polycarbodiimide compositions (10) and (22) obtained in Synthesis Examples 10 and 22, respectively.

[0073] [Comparative Example 12] 100 parts by mass of PLA resin was melted at 200°C using a laboratory mixer, and then 1.0 part by mass of the polycarbodiimide composition (22) obtained in Synthesis Example 22, 0.04 part by mass of the phosphite-based compound BA, and 0.04 part by mass of the hindered phenol-based compound CA were added while mixing, and the mixture was kneaded for 3 minutes to obtain a PLA resin composition.

[0074] [Example 24] 100 parts by mass of PET resin (manufactured by China Petroleum & Chemical Corporation, the same applies below) was melted at 270°C using a lab mixer, and then 0.5 parts by mass of the polycarbodiimide composition (1) obtained in Synthesis Example 1 was added while mixing, and the mixture was kneaded for 3 minutes to obtain a PET resin composition.

[0075] [Example 25, Comparative Example 13] As shown in Table 5, PET resin compositions were obtained in the same manner as in Example 24, except that the polycarbodiimide composition (1) was changed to the polycarbodiimide compositions (10) and (22) obtained in Synthesis Examples 10 and 22, respectively.

[0076] [Comparative Example 14] 100 parts by mass of PET resin was melted under the condition of 270°C in a laboratory mixer, and then 0.5 parts by mass of the polycarbodiimide composition (22) obtained in Synthesis Example 22, 0.02 parts by mass of the phosphite-based compound BA, and 0.02 parts by mass of the hindered phenol-based compound CA were added while mixing, and the mixture was kneaded for 3 minutes to obtain a PET resin composition.

[0077] The above examples and comparative examples are summarized in Tables 3 to 5. Furthermore, for each of the resin compositions obtained in the above Examples and Comparative Examples, a hydrolysis resistance test and confirmation of foaming in the sheet were carried out by the following methods. The results are also shown in Tables 3 to 5.

[0078] (1) Hydrolysis resistance test (PBAT) The melt-kneaded resin was pressed on a flat plate at a temperature equal to or higher than the softening point to prepare a sheet with a thickness of about 300 μm, and a strip sheet with a width of 10 mm and a length of 70 mm was prepared from the sheet. Next, the tensile strength of the prepared strip sheet was measured using a tensile tester (manufactured by INSTRON, product name "INSTRON3365", the same below), and this was taken as the initial strength. The tensile strength was measured using a tensile tester at room temperature (20°C ± 5°C) for five samples (five strip sheets), and the average value of the measured values ​​(N = 5) was taken as the tensile strength of the sample (the same below). Furthermore, the prepared strip sheet was placed in a moist heat tester (manufactured by Espec, constant temperature and humidity chamber), and the sample was taken out after 240 hours under conditions of 80°C and 95% Rh, and the tensile strength of the strip sheet was measured using a tensile tester. The ratio of [tensile strength after wet heat test] / [tensile strength before wet heat test] (strength retention rate) was determined as an index for evaluating hydrolysis resistance. <Evaluation criteria> A: Strength change rate less than 15% B: Strength change rate 15% or more but less than 30% C: Strength change rate 30% or more but less than 45% D: Strength change rate 45% or more In addition, the initial tensile strength of Example 1 was taken as 100, and the performance degradation rate of the tensile strength was confirmed according to the following criteria. <Evaluation criteria> A: Decrease rate less than 3% B: Decrease rate 3% or more, less than 5% C: Decrease rate 5% or more, less than 10% D: Decrease rate of 10% or more

[0079] (2) Hydrolysis resistance test (PBSA) The melt-kneaded resin was pressed on a flat plate at a temperature equal to or higher than the softening point to prepare a sheet having a thickness of about 300 μm, and a strip sheet having a width of 10 mm and a length of 70 mm was prepared from the sheet. Next, the tensile strength of the prepared strip sheet was measured using a tensile tester, and this was taken as the initial strength. Furthermore, the prepared strip sheet was placed in a moist heat tester (Espec Corporation, thermohygrostat), and after 168 hours under conditions of 70° C. and 90% Rh, a sample was taken out, and the tensile strength of the strip sheet was measured using a tensile tester. The ratio of [tensile strength after moist heat test] / [tensile strength before moist heat test] (strength retention rate) was obtained as an evaluation index of hydrolysis resistance. <Evaluation criteria> A: Strength change rate less than 15% B: Strength change rate 15% or more but less than 30% C: Strength change rate 30% or more but less than 45% D: Strength change rate 45% or more In addition, the initial tensile strength of Example 19 was set at 100, and the performance degradation rate of the tensile strength was confirmed according to the following criteria. <Evaluation criteria> A: Decrease rate less than 3% B: Decrease rate 3% or more, less than 5% C: Decrease rate 5% or more, less than 10% D: Decrease rate of 10% or more

[0080] (3) Hydrolysis resistance test (PLA) The melt-kneaded resin was pressed on a flat plate at a temperature equal to or higher than the softening point to prepare a sheet having a thickness of about 300 μm, and a strip sheet having a width of 10 mm and a length of 70 mm was prepared from the sheet. Next, the tensile strength of the prepared strip sheet was measured using a tensile tester, and this was taken as the initial strength. Furthermore, the prepared strip sheet was placed in a moist heat tester (Espec Corporation, thermohygrostat), and after 75 hours under conditions of 80° C. and 95% Rh, a sample was taken out and the tensile strength of the strip sheet was measured using a tensile tester. The ratio of [tensile strength after moist heat test] / [tensile strength before moist heat test] (strength retention rate) was obtained as an evaluation index of hydrolysis resistance. <Evaluation criteria> A: Strength change rate less than 15% B: Strength change rate 15% or more but less than 30% C: Strength change rate 30% or more but less than 45% D: Strength change rate 45% or more In addition, the initial tensile strength of Example 19 was set at 100, and the performance degradation rate of the tensile strength was confirmed according to the following criteria. <Evaluation criteria> A: Decrease rate less than 3% B: Decrease rate 3% or more, less than 5% C: Decrease rate 5% or more, less than 10% D: Decrease rate of 10% or more

[0081] (4) Hydrolysis resistance test (PET) The melt-kneaded resin was pressed on a flat plate at a temperature equal to or higher than the softening point to prepare a sheet having a thickness of about 300 μm, and a strip sheet having a width of 10 mm and a length of 70 mm was prepared from the sheet. Next, the tensile strength of the prepared strip sheet was measured using a tensile tester, and this was taken as the initial strength. Furthermore, the prepared strip sheet was placed in a PCT tester (Hust Chamber, manufactured by Espec Corporation), and after 40 hours had passed under the conditions of 121°C and 100% Rh, a sample was taken out, and the tensile strength of the strip sheet was measured using a tensile tester. The ratio of [tensile strength after PCT test] / [tensile strength before PCT test] (strength retention) was obtained as an evaluation index of hydrolysis resistance. <Evaluation criteria> A: Strength change rate less than 15% B: Strength change rate 15% or more but less than 30% C: Strength change rate 30% or more but less than 45% D: Strength change rate 45% or more In addition, the initial tensile strength of Example 23 was set as 100, and the performance degradation rate of the tensile strength was confirmed according to the following criteria. <Evaluation criteria> A: Decrease rate less than 3% B: Decrease rate 3% or more, less than 5% C: Decrease rate 5% or more, less than 10% D: Decrease rate of 10% or more

[0082] (5) Foaming in the sheet After the tensile test, the stretched fracture site of the sample was visually confirmed, and the average number of bubbles that could be confirmed was counted. <Evaluation criteria> A: Average number of bubbles: 0 B: Average number of bubbles: 1 to 2 C: Average number of bubbles: 3 to 5 D: Average number of bubbles: 6 or more

[0083] [Table 3]

[0084] [Table 4]

[0085] [Table 5]

[0086] As shown in Tables 3 to 5, the carbodiimide composition of the present invention not only has less foaming in the sheet produced therefrom and is excellent in appearance, but also has excellent hydrolysis resistance. In addition, the reduced foaming also results in good tensile strength before the wet heat test.

Claims

1. (A) a carbodiimide compound, (B) a phosphite-based antioxidant, and (C) a hindered phenol-based antioxidant; The foaming inhibitor for resin molding comprises a carbodiimide composition comprising the (B) phosphite-based antioxidant in an amount of 1.5 parts by mass or more and 5 parts by mass or less per 100 parts by mass of the (A) carbodiimide compound, and the (C) hindered phenol-based antioxidant in an amount of 1.5 parts by mass or more and 6 parts by mass or less per 100 parts by mass of the (A) carbodiimide compound.

2. 2. The foam inhibitor for resin molding according to claim 1, comprising, in terms of mass ratio, 1 part of the phosphite-based antioxidant (B) and 1 or more parts of the hindered phenol-based antioxidant (C).

3. 3. The foam inhibitor for resin molding according to claim 2, wherein the mass ratio of the phosphite-based antioxidant (B) to the hindered phenol-based antioxidant (C) is 1 to 2 parts by mass.

4. The foaming inhibitor for resin molding according to any one of claims 1 to 3, wherein the carbodiimide compound (A) is obtained using at least one selected from the group consisting of dicyclohexylmethane diisocyanate, diphenylmethane diisocyanate, tetramethylxylylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate and tolylene diisocyanate.

5. 5. The foaming inhibitor for resin molding according to claim 1, wherein the phosphite antioxidant (B) is a compound having a pentaerythritol structure.

6. 3. The foam inhibitor for resin molding according to claim 1, wherein the hindered phenol-based antioxidant (C) is a compound having a pentaerythritol structure.

7. A method for inhibiting foaming during resin molding, which comprises blending the foaming inhibitor for resin molding according to any one of claims 1 to 6 with a resin.

8. 8. The method for suppressing foaming during resin molding according to claim 7, wherein the resin is a polyester resin.

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