JP6645544B2 - Polyurethane elastomer-forming composition used for industrial machine parts, and industrial machine parts using the same - Google Patents

Description

The present invention relates to a thermosetting polyurethane elastomer-forming composition used for industrial machine parts.

BACKGROUND ART Thermosetting polyurethane elastomers have high durability because of their high modulus, high breaking strength, low abrasion, and low distortion, and are widely and suitably used as parts of industrial machines.

Generally, a thermosetting polyurethane elastomer used for industrial equipment component members is obtained by mixing a main agent composed of an isocyanate component and a curing agent composed of an active hydrogen-containing component with a mixing head of a casting machine. Is poured into a mold, and the mixture is heated and cured (urethane-forming reaction) in the mold to produce the mixture.

Here, isocyanate group-terminated urethane prepolymer (A) composed of isocyanate and polyol (hereinafter abbreviated as "NCO group-terminated urethane prepolymer") as a component of a forming composition for molding a thermosetting polyurethane elastomer. A method in which a hydroxyl group-terminated curing agent (B) composed of a polyol (hereinafter abbreviated as “OH group-terminated curing agent”) is mixed and heated and cured is generally used.

For example, an NCO-terminated urethane prepolymer composed of diphenyl metadiisodianate (hereinafter abbreviated as “MDI”) as an isocyanate component, polybutylene adipate (hereinafter abbreviated as “PBA”) as a polyol, and 1,4- An OH group terminal curing agent obtained by mixing butanediol, trimethylolpropane and PBA is suitably used.

When the above-mentioned NCO-terminated urethane prelimer (A) is produced, phosphoric acid is used for the purpose of suppressing side reactions during synthesis, suppressing coloring and improving the storage stability of the obtained NCO-terminated urethane prelimer (A). It is manufactured by adding an acidic compound such as a compound as a reaction inhibitor (C) (for example, see Patent Documents 1 to 4).

In recent years, since the cost of industrial machine parts has been required to be reduced, the molding cycle has been shortened. This not only improves productivity, but also reduces energy costs. Further, since the rotation cycle of the mold is shortened, the number of molds can be reduced, so that the capital investment cost can be suppressed.

From the above circumstances, a nullating catalyst (D1) or an allophanating catalyst (D2) is used as the catalyst (D) in order to shorten the molding cycle. In order to improve the mechanical strength of the obtained thermosetting polyurethane elastomer, a method of molding with an excess of isocyanate groups (hydroxyl / isocyanate groups = 0.3 to 0.8 (molar ratio)) is used (for example, Patent Documents 5 to 7).

Particularly, a formulation using a nullating catalyst (D1) such as potassium acetate or a quaternary ammonium salt is preferably used because of easy control of reaction and control of mechanical strength.

JP-A-49-75505 JP-A-57-82358 JP-A-7-173240 JP-A-8-231669 JP-A-2002-20445 JP 2005-314502 A JP 2009-227875 A

However, in these formulations, the NCO group-terminated urethane prepolymer (A), which is excessively mixed, may not locally undergo a naturation reaction or an allophanation reaction during the heat curing treatment, and is very small. The unreacted NCO-terminated prepolymer (A) remains as unreacted foreign matter in the molded product, and the mechanical strength is reduced from this portion as a starting point, and breakage or the like is likely to occur. I have.

The present invention has been made based on the above circumstances, and the NCO group-terminated urethane prepolymer (A) of the thermosetting polyurethane elastomer-forming composition for industrial machine parts is used as a reaction inhibitor (C), By including 5 to 600 ppm of a phosphate compound having at least one ethylene oxide in the substituent skeleton, the molding cycle is short without impairing the properties of the prepolymer, and the generation of unreacted foreign substances in the molded product An object of the present invention is to provide a thermosetting polyurethane elastomer having high mechanical strength and high toughness for industrial machine parts.

The present invention is described in the following (1) to (4).
(1) In a thermosetting polyurethane elastomer-forming composition for industrial machine parts comprising at least an NCO-terminated urethane prepolymer (A) and an OH-terminated curing agent (B), the NC0-terminated urethane prepolymer (A) is And a phosphoric acid ester compound having at least one ethylene oxide in the substituent skeleton as a reaction inhibitor (C) in an amount of 5 to 600 ppm.
(2) The OH group-terminated curing agent (B) according to the above (1) contains, as the catalyst (D), at least a nullating catalyst for polyurethane (D1) and / or an allophanating catalyst for polyurethane (D2). It is characterized by.
(3) The mixing ratio (functional group ratio) of the NCO-terminated urethane prepolymer (A) and the OH-terminated curing agent (B) according to any one of (1) and (2) is hydroxyl group / isocyanate Groups (hereinafter abbreviated as “α value”) = 0.2 to 0.8 (molar ratio).
(4) JIS-A hardness of an industrial machine component member obtained by subjecting the thermosetting polyurethane elastomer-forming composition for an industrial machine component according to any one of (1) to (3) to a thermosetting treatment is 60. ~ 95.

By using the thermosetting polyurethane elastomer-forming composition for industrial machine parts of the present invention in industrial machines, it is possible to eliminate unreacted foreign substances in molded products which could not be achieved by conventional methods, and to obtain properties of urethane prepolymers having NCO group-terminated urethane. The thermosetting polyurethane elastomer for industrial machine parts having a short molding cycle and toughness can be obtained without impairing the molding cycle.

In the thermosetting polyurethane elastomer-forming composition for industrial machine parts of the present invention, at least the NCO-terminated urethane prepolymer (A) has at least one or more ethylene oxide as a reaction inhibitor (C) in the substituent skeleton. Is characterized by the fact that the phosphoric acid ester compound contained in 5 to 600 ppm is contained. As described above, by using a phosphate compound having one or more ethylene oxides in the substituent skeleton, the obtained NCO-terminated urethane prepolymer (A) can suppress side reactions during production and storage in stock. As a result, an NCO-terminated urethane prepolymer (A) having a low viscosity, a very low coloration and a low color number is obtained. When the addition amount of the phosphate compound having one or more ethylene oxides in the substituent skeleton is 5 ppm or less, an NCO-terminated urethane prepolymer having a high viscosity and a very high color number can be obtained and used in terms of quality. Is difficult. In addition, using the NCO-terminated urethane prepolymer (A), a formulation in which a nullating catalyst (D1) or an allophanate-forming catalyst (D2) is introduced as a catalyst (D) in order to shorten the molding cycle that has been recently performed. In the industrial machine parts of the thermosetting polyurethane elastomer obtained in the above, the NCO-terminated urethane prepolymer (A) excessively blended reacts neatly, and a uniform and tough cured product free from unreacted foreign matter can be obtained. When a reaction inhibitor other than the above-mentioned phosphate compound having one or more ethylene oxides in the substituent skeleton is used, the NCO-terminated urethane prepolymer (A) excessively mixed does not react cleanly. As a result, unreacted foreign matter is generated, resulting in a non-uniform, low-strength cured product. Further, when the addition amount of the phosphate compound having one or more ethylene oxides in the substituent skeleton is 600 ppm or more, the reaction balance with the catalyst (D) added to the OH group terminal curing agent is disrupted, and the heat curing is performed. During the treatment, the reaction does not proceed sufficiently, and the molding cycle cannot be shortened.
The phosphate ester compound having one or more ethylene oxides in the substituent skeleton used as the reaction inhibitor (C) used in the present invention is not particularly limited as long as the effects of the present invention can be obtained. Can be represented by general formulas 1 to 3 and the like.

一般式１〜３の具体例として、ｎ、ｍ、ｌ＝１〜１００であり、Ｒ₁、Ｒ₂、Ｒ₃は炭素数１〜６０の直鎖、分岐、又は環状の飽和又は不飽和アルキルがよく、特に好ましくはｎ、ｍ、ｌ＝１〜３０であり、Ｒ₁、Ｒ₂、Ｒ₃は炭素数６〜３０の直鎖、分岐、又は環状の飽和又は不飽和アルキル（フェニル基を含む）である。ｎ、ｍ、ｌの数及びＲ₁、Ｒ₂、Ｒ₃の構造は同一であっても、異なっていても良い。市販化されている具体例として、ジ（Ｃ１２−１５）パレス−２リン酸「ＮＩＫＫＯＬ ＤＤＰ−２ 日光ケミカルズ社製」、ジ（Ｃ１２−１５）−パレス４リン酸「ＮＩＫＫＯＬ ＤＤＰ−４ 日光ケミカルズ社製」、ジ（Ｃ１２−１５）−パレス６リン酸「ＮＩＫＫＯＬ ＤＤＰ−６ 日光ケミカルズ社製」、ジ（Ｃ１２−１５）−パレス８リン酸「ＮＩＫＫＯＬ ＤＤＰ−８ 日光ケミカルズ社製」、ジ（Ｃ１２−１５）−パレス１０リン酸「ＮＩＫＫＯＬ ＤＤＰ−１０ 日光ケミカルズ社製」、リン酸（モノ，ジ）ポリエチレングルコール（５ＥＯ）Ｃ１０−１２アルコール「Ｐｈｏｓｐｈｏｌａｎ ＰＳ−２３６ Ａｋｚｏ Ｎｐｂｅ社製」、リン酸（モノ，ジ）ポリエチレングルコール（３ＥＯ）Ｃ１０−１５アルコール「Ｐｈｏｓｐｈｏｌａｎ ＰＳ−２２２ Ａｋｚｏ Ｎｐｂｅ社製」、リン酸（モノ，ジ）Ｃ１０−１４アルコール−３−エトキシレート「Ｐｈｏｓｐｈｏｌａｎ ＰＳ−２２０ Ａｋｚｏ Ｎｐｂｅｌ社製」、リン酸（モノ，ジ）ポリエチレングルコール（６ＥＯ）＋トリデカノール「Ｐｈｏｓｐｈｏｌａｎ ＰＳ−１３１ Ａｋｚｏ Ｎｐｂｅ社製」、ポリオキシエチレントリデシルエーテルリン酸エステル「プライサーフ Ａ２１２Ｃ、プライサーフ Ａ２１５Ｃ 第一工業製薬社製」、ポリオキシエチレンアルキル（C８）リン酸エステル「プライサーフ Ａ２０８Ｆ、プライサーフ Ａ２１５C 第一工業製薬社製」、ポリオキシエチレンアルキル（C１２、１３）リン酸エステル「プライサーフ Ａ２０８Ｍ、プライサーフ Ａ２１５C 第一工業製薬社製」、ポリオキシエチレンラウリルエーテルリン酸エステル「プライサーフ Ａ２０８Ｂ、プライサーフ Ａ２１９Ｂ 第一工業製薬社製」、ポリオキシエチレンアルキル（Ｃ１０）エーテルリン酸エステル「プライサーフ Ａ２１０Ｄ 第一工業製薬社製」、ポリオキシエチレンスチレン化フェニルエーテルリン酸エステル「プライサーフ ＡＬ、プライサーフ ＡＬ１２Ｈ 第一工業製薬社製」、リン酸（モノ，ジ）ポリエチレングリコール（４Ｅ０）４−ノニフェニル「試薬 東京化成工業社製」、トリ（Ｃ１２−１５）パレス−２リン酸「ＮＩＫＫＯＬ ＴＤＰ−２ 日光ケミカルズ社製」、トリ（Ｃ１２−１５）パレス−４リン酸「ＮＩＫＫＯＬ ＴＤＰ−４ 日光ケミカルズ社製」、トリ（Ｃ１２−１５）パレス−６リン酸「ＮＩＫＫＯＬ ＴＤＰ−６ 日光ケミカルズ社製」、トリ（Ｃ１２−１５）パレス−８リン酸「ＮＩＫＫＯＬ ＴＤＰ−８ 日光ケミカルズ社製」、トリ（Ｃ１２−１５）パレス−１０リン酸「ＮＩＫＫＯＬ ＴＤＰ−１０ 日光ケミカルズ社製」、ホスフェートポリエーテルエステル「ＴＲＩＴＯＮ Ｈ−５５、Ｈ−６６、ＱＳ−４４、ＸＱＳ−２０ ダウサーファクタンツ社製」等が挙げられる。

As specific examples of the general formulas 1 to 3, n, m, l = 1 to 100, and R ₁ , R ₂ , and R ₃ are linear, branched, or cyclic saturated or unsaturated alkyl having 1 to 60 carbon atoms. And particularly preferably n, m and l = 1 to 30; R ₁ , R ₂ and R ₃ are linear, branched or cyclic saturated or unsaturated alkyl having 6 to 30 carbon atoms (a phenyl group; Including). The numbers n, m, and l and the structures of R ₁ , R ₂ , and R ₃ may be the same or different. Examples of commercially available di- (C12-15) Palace-2 phosphate “NIKKOL DDP-2 manufactured by Nikko Chemicals Co., Ltd.” and di (C12-15) -Palace 4-phosphate “NIKKOL DDP-4 Nikko Chemicals Inc.” Di (C12-15) -Palace 6-phosphate "NIKKOL DDP-6 Nikko Chemicals", di (C12-15) -Palace 8-phosphate "NIKKOL DDP-8 Nikko Chemicals", di (C12 -15) -Palace 10 phosphoric acid "NIKKOL DDP-10 manufactured by Nikko Chemicals", phosphoric acid (mono, di) polyethylene glycol (5EO) C10-12 alcohol "Phosphoran PS-236 Akzo Npbe", phosphoric acid ( (Mono, di) polyethylene glycol (3EO) C10-15 alcohol "Phosphoran PS-222 manufactured by Akzo Npbe ”, phosphoric acid (mono, di) C10-14 alcohol-3-ethoxylate“ Phosphoran PS-220 manufactured by Akzo Npbel ”, phosphoric acid (mono, di) polyethylene glycol (6EO) + Tridecanol “Phosphoran PS-131 manufactured by Akzo Npbe”, polyoxyethylene tridecyl ether phosphate “Plysurf A212C, Plysurf A215C Daiichi Kogyo Seiyaku”, polyoxyethylene alkyl (C8) phosphate “Plysurf” A208F, Plysurf A215C manufactured by Daiichi Kogyo Seiyaku Co., Ltd. ", polyoxyethylene alkyl (C12, 13) phosphate ester" Plysurf A208M, Plysurf A215C manufactured by Daiichi Kogyo Seiyaku Co., Ltd. ", polyoxyethylene lau Lil ether phosphate "Plysurf A208B, Plysurf A219B made by Daiichi Kogyo Seiyaku", polyoxyethylene alkyl (C10) ether phosphate "Plysurf A210D made by Daiichi Kogyo Seiyaku", polyoxyethylene styrenated phenyl Ether phosphate ester "Plysurf AL, Plysurf AL12H manufactured by Daiichi Kogyo Seiyaku Co., Ltd.", phosphoric acid (mono, di) polyethylene glycol (4E0) 4-noniphenyl "reagent manufactured by Tokyo Chemical Industry Co., Ltd.", tri (C12-15) Palace-2 Phosphate "NIKKOL TDP-2 Nikko Chemicals Co., Ltd.", Tri (C12-15) Palace-4 Phosphate "NIKKOL TDP-4 Nikko Chemicals Co., Ltd.", Tri (C12-15) Palace-6 Phosphate " NIKKOL TDP-6 manufactured by Nikko Chemicals Co., Ltd. " (C12-15) Palace-8 phosphate "NIKKOL TDP-8 manufactured by Nikko Chemicals Co., Ltd.", Tori (C12-15) Palace-10 phosphate "NIKKOL TDP-10 manufactured by Nikko Chemicals Co., Ltd.", phosphate polyetherester "TRITON H" -55, H-66, QS-44, XQS-20, manufactured by Dow Surfactants ".

The NCO group-terminated urethane prepolymer (A) used in the present invention can be obtained by a urethanization reaction of at least a polyisocyanate (A1) and a polyol (A2) using a reaction inhibitor (C). The NCO content of the NCO group-terminated urethane prepolymer (A) is preferably 5 to 25% by mass. When the NCO content is lower than 5% by mass, the viscosity of the prepolymer mainly increases, and the flowability of the urethane resin during casting is significantly deteriorated. If the content is higher than 25% by mass, the stability of properties during storage and during use is significantly deteriorated, and stable industrial machine parts are difficult to obtain, leading to molding defects. It is not suitable as a terminal urethane prepolymer.

The NCO group-terminated urethane prepolymer (A) is charged with the polyisocyanate (A1) and the reaction inhibitor (C) in a stirring vessel and stirred. Then, while maintaining the temperature in the stirring vessel at 40 to 70 ° C., the polyol (A2 ) And stirred. Then, the urethane prepolymer (A) can be obtained by proceeding the urethanization reaction for about 2 to 5 hours while maintaining the temperature in the stirring vessel at 70 to 90 ° C.

The polyisocyanate (A1) used in the present invention is not particularly limited as long as the effects of the present invention are exhibited, but from the viewpoint of mechanical properties and reaction control, it is preferable that at least one type is selected from aromatic diisocyanates. 4,4'-Diphenylmethane diisocyanate is particularly preferred.

<Polyisocyanate>
Specific examples of the polyisocyanate (A1) include hexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, cyclohexyl diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated trimethyl xylylene diisocyanate, and 2-methylpentane- 1,5-diisocyanate, 3-methylpentane-1,5-diisocyanate, 2,2,4-trimethylhexaethylene-1,6-diisocyanate, 2,4,4-trimethylhexaethylene-1,6-diisocyanate And aliphatic and alicyclic diisocyanates. 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, 1,5-naphthylene diisocyanate And aromatic diisocyanates such as paraphenylene diisocyanate, tolylene-2,4-diisocyanate and tolylene-2,6-diisocyanate. Non-yellowing diisocyanates such as ortho-xylylene diisocyanate, meta-xylylene diisocyanate, para-xylylene diisocyanate, and tetramethyl xylylene diisocyanate. Further, a urethane-modified, urea-modified, carbodiimide-modified, uretonimine-modified, uretdione-modified, isocyanurate-modified or allophanate-modified isocyanate of any isocyanate can also be used.

The polyol (A2) used in the present invention is not particularly limited as long as the effects of the present invention are exhibited, but from the viewpoint of mechanical properties and glass transition temperature, the number of average functional groups is 2 to 3, and the number average molecular weight is 250 to 5000. Preferably, at least one selected from the group consisting of polyester polyols, polyether polyols, and polycarbonate polyols is used. In addition, if necessary, a monomer polyol can be used in combination.

<Polyester polyol>
Specific examples of polyester polyols include phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, succinic acid, tartaric acid, oxalic acid, malonic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, glutaconic acid, azelaic acid, Dicarboxylic acids such as sebacic acid, 1,4-cyclohexyldicarboxylic acid, α-hydromuconic acid, β-hydromuconic acid, α-butyl-α-ethylglutaric acid, α, β-diethylsuccinic acid, maleic acid and fumaric acid Or one or more of these anhydrides and the like, and ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1, -Nonanediol, 3-methyl-1,5-pentanediol, 3,3-dimethylolheptane, diethylene glycol, dipropylene glycol, neopentyl glycol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, At least one of low molecular weight polyols having a molecular weight of 500 or less such as dimer acid diol, ethylene oxide and propylene oxide adducts of bisphenol A, bis (β-hydroxyethyl) benzene, xylylene glycol, glycerin, trimethylolpropane, and pentaerythritol And those obtained from a condensation polymerization reaction with Further, a polyester-amide polyol obtained by replacing a part of the low-molecular polyol with a low-molecular polyamine such as hexamethylenediamine, isophoronediamine, monoethanolamine or a low-molecular amino alcohol can also be used.

<Polyether polyol>
Specific examples of the polyether polyol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 3-methyl-1,5-pentanediol, 3,3-dimethylolheptane, diethylene glycol, dipropylene Glycol, neopentyl glycol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, diol dimer acid, bisphenol A, bis (β-hydroxyethyl) benzene, xylylene glycol, glycerin, trimethylolpropane, penta Small molecules such as erythritol Starting compounds having two or more, preferably two to three active hydrogen groups such as riols or low molecular weight polyamines such as ethylenediamine, propylenediamine, toluenediamine, metaphenylenediamine, diphenylmethanediamine, xylylenediamine, etc. As an agent, polyether polyols obtained by addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, or alkyl glycidyl ethers such as methyl glycidyl ether, and aryl glycidyl ethers such as phenyl glycidyl ether And polyether polyols obtained by ring-opening polymerization of a cyclic ether monomer such as tetrahydrofuran.

<Polycarbonate polyol>
Specific examples of the polycarbonate polyol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, and 1,5-butanediol. Pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 3-methyl-1,5-pentanediol, 3,3-dimethylolheptane, diethylene glycol, dipropylene glycol, neo Pentyl glycol, diethylene glycol, dipropylene glycol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, dimer acid diol, ethylene oxide and propylene oxide adducts of bisphenol A, bis (β-hydroxyethyl) benzene , Xylylene glycol, glycerin, trimethylolpropane, one or more low molecular polyols such as pentaerythritol, dimethyl carbonate, dialkyl carbonates such as diethyl carbonate, ethylene carbonate, alkylene carbonates such as propylene carbonate, diphenyl carbonate, diphenyl carbonate Examples thereof include those obtained by a dealcoholation reaction or a phenol reaction with a diaryl carbonate such as naphthyl carbonate, dianthryl carbonate, diphenanthryl carbonate, diindanyl carbonate, and tetrahydronaphthyl carbonate.

<Monomer polyol>
Specific examples of the monomer polyol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, and 1,5-pentane. Diol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 3-methyl-1,5-pentanediol, 3,3-dimethylolheptane, diethylene glycol, dipropylene glycol, neopentyl Glycol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, diol dimer acid, bisphenol A, bis (β-hydroxyethyl) benzene, xylylene glycol, glycerin, trimethylolpropane, pentaerythritol and the like. Can be

The polyol (B) may be a polyolefin polyol, an acrylic polyol, a (meth) acrylate, a hydroxy (meth) acrylate, a silicone polyol, a castor oil-based polyol, or a fluorine-based polyol alone as long as the performance is not deteriorated. Or two or more of them can be used in combination.

<Polyolefin polyol>
Specific examples of the polyolefin polyol include polybutadiene having two or more hydroxyl groups, hydrogenated polybutadiene, polyisoprene, and hydrogenated polyisoprene.

<Acrylic polyol>
Examples of the acrylic polyol include an acrylic ester and / or a methacrylic ester (hereinafter referred to as (meth) acrylic ester) and a hydroxy acrylate compound and / or methacrylic acid having at least one hydroxyl group in a molecule which can be a reaction site. A compound obtained by copolymerizing an acrylic monomer with a hydroxy compound (hereinafter referred to as (meth) acrylic acid hydroxy compound) and a polymerization initiator by using heat energy, light energy such as ultraviolet light or electron beam, or the like can be given.

<(Meth) acrylate>
Specific examples of (meth) acrylates include alkyl esters having 1 to 20 carbon atoms. Specific examples of such (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, (Meth) such as hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate Alkyl acrylates, esters of (meth) acrylic acid with alicyclic alcohols such as cyclohexyl (meth) acrylate, allyl (meth) acrylates such as phenyl (meth) acrylate and benzyl (meth) acrylate Can be mentioned. Such (meth) acrylic acid esters may be used alone or in combination of two or more.

<Hydroxy (meth) acrylate compound>
Specific examples of the hydroxy (meth) acrylate compound include at least one hydroxyl group in a molecule that can be a reaction point with the polyisocyanate composition, and specifically include 2-hydroxyethyl acrylate, And hydroxy acrylate compounds such as -hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 3-hydroxy-2,2-dimethylpropyl acrylate, and pentaerythritol triacrylate. In addition, hydroxy methacrylate compounds such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, 3-hydroxy-2,2-dimethylpropyl methacrylate, and pentaerythritol trimethacrylate are exemplified. These acrylic acid hydroxy compounds and / or methacrylic acid hydroxy compounds may be used alone or in combination of two or more.

<Polymerization initiator>
Examples of the polymerization initiator include a thermal polymerization initiator and a photopolymerization initiator, and are appropriately selected depending on a polymerization method.
Specific examples of the thermal polymerization initiator include peroxydicarbonates such as di-2-ethylhexyl peroxydicarbonate, t-butylperoxybenzoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisopropyl carbonate, Peroxyesters such as t-hexylperoxyisopropyl carbonate, di (t-butylperoxy) -2-methylcyclohexane, di (t-butylperoxy) 3,3,5-trimethylcyclohexane and di (t-butylperoxy) cyclohexane Peroxy ketals and the like.
Specific examples of the photopolymerization initiator include acetophenone, methoxyacetophenone, 2,2-diethoxyacetophenone, p-dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, α-hydroxy-α, α ′. Acetophenones such as -dimethylacetophenone, 2-hydroxy-2-cyclohexylacetophenone, 2-methyl-1 [4- (methylthio) phenyl] -2-monforinopropanone-1, benzoin, benzoin methyl ether, benzoin ethyl ether Benzoin ethers such as benzoin isopropyl butyl ether, benzophenone, 2-chlorobenzophenone, p, p'-dichlorobenzophenone, N, N'-tetramethyl-4,4'-diaminobenzophenone, 4- (2-hydroxy Ketones such as ethoxy) phenyl (2-hydroxy-2-propyl) ketone; thioxanthones such as thioxanthone, 2-chlorothioxanthone and 2-methylthioxanthone; and phosphine oxides such as bisacylphosphine oxide and benzoylphosphine oxide. And ketals such as benzyldimethyl ketal, and quinones such as camphan-2,3-dione and phenanthrenequinone.

<Silicone polyol>
Specific examples of the silicone polyol include a vinyl group-containing silicone compound obtained by polymerizing γ-methacryloxypropyltrimethoxysilane and the like, and α, ω-dihydroxypolydimethylsiloxane, α, ω-dihydroxypolydimethylsiloxane having at least one terminal hydroxyl group in the molecule. Polysiloxanes such as ω-dihydroxypolydiphenylsiloxane can be mentioned.

<Castor oil-based polyol>
Specific examples of the castor oil-based polyol include a linear or branched polyester polyol obtained by reacting a castor oil fatty acid with a polyol. Also, dehydrated castor oil, partially dehydrated castor oil partially dehydrated, and hydrogenated castor oil to which hydrogen has been added can be used.

<Fluorine-based polyol>
Specific examples of the fluorinated polyol include a linear or branched polyol obtained by a copolymerization reaction using a fluorinated monomer and a monomer having a hydroxy group as essential components. Here, the fluorinated monomer is preferably a fluoroolefin, for example, tetrafluoroethylene, chlorotrifluoroethylene, trichlorofluoroethylene, hexafluoropropylene, vinylidene fluoride, vinyl fluoride, trifluoromethyltrifluoroethylene Is mentioned. Examples of the monomer having a hydroxyl group include, for example, hydroxyalkyl vinyl ethers such as hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, and cyclohexanediol monovinyl ether; hydroxyalkyl allyl ethers such as 2-hydroxyethyl allyl ether; And a monomer having a hydroxyl group such as a hydroxyl group-containing vinyl carboxylate or allyl ester.

As the OH group terminal curing agent (B) used in the present invention, the above-mentioned polyol (A2) can be used, but is not particularly limited as long as the effects of the present invention are exhibited. From the viewpoint of improving mechanical properties and moldability, monomer polyols can be used alone or in combination of two or more. Further, a mixture obtained by further adding any one of polyester polyol, polyether polyol, and polycarbonate polyol having an average functional group number of 2 to 3 and a number average molecular weight of 250 to 5000 can be used. As the monomer polyol, a mixture of 1,4-butanediol and trimethylolpropane is preferable. Further, a mixture obtained by further adding a polyester polyol and a polyether polyol having an average number of functional groups of 2 and an average molecular weight of 500 to 3000 is preferable.

The nullating catalyst for polyurethane (D1) and the allophanating catalyst for polyurethane (D2) used as the catalyst (D) used in the present invention are not particularly limited as long as the effects of the invention are exhibited. From the viewpoint of improving mechanical properties and moldability, a potassium salt or a quaternary ammonium salt is preferable as the polyurethane-forming catalyst (D1). Aminoethylethanolamine and N, N-dimethylaminoethoxyethanol are preferred. In addition, as a urethanization catalyst for accelerating the urethanization reaction, an amine catalyst such as triethylenediamine, an imidazole-based catalyst such as 1-isobutyl-2-methylimidazole, a metal catalyst such as dioctyltin dilaurate, and the like, if necessary. They can be used together.

<Nullation catalyst for polyurethane>
The polyurethane-forming catalyst (D1) used in the nitration reaction can be appropriately selected from known catalysts, and specific examples include triethylamine, N-ethylpiperidine, N, N'-dimethylpiperazine. , N-ethylmorpholine, tertiary amines such as Mannich bases of phenolic compounds, tetramethylammonium hydrogencarbonate, methyltriethylammonium hydrogencarbonate, ethyltrimethylammonium hydrogencarbonate, propyltrimethylammonium hydrogencarbonate, butyltrimethylammonium Bicarbonate, pentyltrimethylammonium bicarbonate, hexyltrimethylammonium bicarbonate, heptyltrimethylammonium bicarbonate, octyltrimethylammonium bicarbonate, nonyltrimethylammonium Hydrogen carbonate, decyltrimethylammonium hydrogencarbonate, undecyltrimethylammonium hydrogencarbonate, dodecyltrimethylammonium hydrogencarbonate, tridecyltrimethylammonium hydrogencarbonate, tetradecyltrimethylammonium hydrogencarbonate, heptadecyltrimethylammonium hydrogencarbonate Hexadecyltrimethylammonium hydrogencarbonate, heptadecyltrimethylammonium hydrogencarbonate, octadecyltrimethylammonium hydrogencarbonate, (2-hydroxypropyl) trimethylammonium hydrogencarbonate, hydroxyethyltrimethylammonium hydrogencarbonate, 1-methyl-1- Such as azania-4-azabicyclo [2,2,2] octanium hydrogencarbonate or 1,1-dimethyl-4-methylpiperidinium hydrogencarbonate Quaternary ammonium bicarbonate, tetramethylammonium carbonate, methyltriethylammonium carbonate, ethyltrimethylammonium carbonate, propyltrimethylammonium carbonate, butyltrimethylammonium carbonate, pentyltrimethylammonium carbonate, hexyltrimethylammonium carbonate, heptyl Trimethylammonium carbonate, octyltrimethylammonium carbonate, nonyltrimethylammonium carbonate, decyltrimethylammonium carbonate, undecyltrimethylammonium carbonate, dodecyltrimethylammonium carbonate, tridecyltrimethylammonium carbonate, tetradecyltrimethylammonium carbonate, Heptadecyltrimethylammonium carbonate, hexadecyltrimethylammonium Carbonate, heptadecyltrimethylammonium carbonate, octadecyltrimethylammonium carbonate, (2-hydroxypropyl) trimethylammonium carbonate, hydroxyethyltrimethylammonium carbonate, 1-methyl-1-azania-4-azabicyclo [2,2 2] quaternary ammonium carbonates such as octanium carbonate or 1,1-dimethyl-4-methylpiperidinium carbonate, and hydroxyalkylammoniums such as trimethylhydroxypropylammonium, trimethylhydroxypropylammonium and triethylhydroxyethylammonium Alkali metal salts of carboxylic acids such as hydroxides and organic acid salts, acetic acid, propionic acid, butyric acid, caproic acid, capric acid, valeric acid, octylic acid, myristic acid, and naphthenic acid And the like. These isocyanurate-forming catalysts for polyurethane (D1) can be used alone or in combination of two or more. The amount of the isocyanurate-forming catalyst (D1) is in the range of 0.001 to 0.5% by mass based on the total weight of the NCO-terminated urethane prepolymer (A) and the OH-terminated curing agent (B). It is particularly preferable to use from 0.005 to 0.10% by mass from the viewpoint of easy reaction control.

<Allophanate-forming catalyst for polyurethane>
As the allophanation catalyst (D2) for polyurethane used in the allophanation reaction, a known catalyst can be appropriately selected and used, and for example, a metal salt of a carboxylic acid can be used.
Specific examples of carboxylic acids include acetic acid, propionic acid, butyric acid, caproic acid, octylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, saturated aliphatic carboxylic acids such as 2-ethylhexanoic acid, cyclohexanecarboxylic acid, Saturated monocyclic carboxylic acids such as cyclopentanecarboxylic acid, saturated bicyclic carboxylic acids such as bicyclo (4.4.0) decane-2-carboxylic acid, mixtures of the above carboxylic acids such as naphthenic acid, oleic acid, linoleic acid Monocarboxylic acids such as unsaturated aliphatic carboxylic acids such as linolenic acid, soybean oil fatty acid and tall oil fatty acid, aromatic aliphatic carboxylic acids such as diphenylacetic acid, benzoic acid and aromatic carboxylic acid such as toluic acid; phthalic acid; Isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, succinic acid, tartaric acid, oxalic acid, malonic acid, glutaric acid Adipic acid, pimelic acid, suberic acid, curtaconic acid, azelaic acid, sebacic acid, 1,4-cyclohexyldicarboxylic acid, α-hydromuconic acid, β-hydromuconic acid, α-butyl-α-ethylglutaric acid, α, Examples include polycarboxylic acids such as β-diethylsuccinic acid, maleic acid, fumaric acid, trimellitic acid, and pyromellitic acid.

Further, as the metal constituting the metal salt of the carboxylic acid, lithium, sodium, alkali metals such as potassium, magnesium, calcium, alkaline earth metals such as barium, tin, other typical metals such as lead, manganese, iron, Transition metals such as cobalt, nickel, copper, zinc, and zirconium are exemplified. These carboxylic acid metal salts can be used alone or in combination of two or more.

In addition, examples of the alkanolamine include N, N, N'-trimethylaminoethylethanolamine, N, N-dimethylaminoethoxyethanol, and the like. The amount of the allophanate-forming catalyst (D2) used is in the range of 0.001 to 0.5% by mass based on the total weight of the NCO-terminated urethane prepolymer (A) and the OH-terminated curing agent (B). It is preferably used, and from the viewpoint of ease of reaction control, it is more preferably used in the range of 0.005 to 0.10% by mass.

In the present invention, if necessary, an antioxidant, a defoaming agent, an ultraviolet absorber and the like can be introduced into the forming composition as additives.

In the present invention, a curing treatment (specifically, a treatment for accelerating curing by heating) is performed in a molding die as a step using the thermosetting polyurethane elastomer-forming composition described above. Then, a thermosetting polyurethane elastomer molded article having urethanization, nullation, and allophanation bonds is produced.

In this case, the method for producing a thermosetting polyurethane elastomer molded article using the formable composition according to the present invention is preferably produced by a method including the following steps.
Step (1):
NCO group-terminated prepolymer (A) and hydroxyl group-terminated curing agent (B). However, if catalyst (D) is not contained in advance in hydroxyl group-terminated curing agent (B), catalyst (D) is added separately, To form a forming composition. If air is entrained and bubbles are seen, the bubbles are removed by vacuum defoaming or the like. It is preferable to use a dedicated polyurethane casting machine for these steps.
Step (2):
Immediately after mixing the formable composition into the preheated mold, the mixture is poured into the mold (casting), and the formable composition is cured in the mold (specifically, a curing reaction is performed by heating. ). In this case, the temperature of the mold is preferably in the range of 80 to 170 ° C. from the viewpoint that the urethane-forming reaction, the nurate-forming reaction, and the allophanate-forming reaction can easily and surely proceed.
Step (3):
After the curable composition is cured, the cured product (that is, the thermosetting polyurethane elastomer molded product) is removed from the mold (demolding). In the present invention, the time required from the casting to the demolding is not particularly limited, but from the viewpoint of productivity of the thermosetting polyurethane elastomer intended by the present invention, the amount of the catalyst and the molding The preheating temperature of the mold is adjusted, and it is preferably in the range of 30 to 600 seconds.
Step (4):
After demolding the thermosetting polyurethane elastomer molded product (industrial machine parts), an aging treatment is performed at room temperature for one week.

The molar ratio between the NCO group content of the NCO group-terminated prepolymer and the OH group content of the OH group-terminated curing agent at the time of casting was α value = 0.2 to 0.8 (molar ratio). 3 to 0.7 is particularly preferred. If the ratio is less than 0.2, the formation of unreacted substances in the molded product is difficult to suppress due to excessive increase in the rate of nullification and allophanation due to excess isocyanate. Causes a decrease in On the other hand, if it exceeds 0.8, the number of crosslinking points due to nullation or allophanation decreases, leading to a decrease in initial modulus (stress at 100% elongation), insufficient strength at each hardness, and a large amount of deformation. It will be nothing.

The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In Examples and Comparative Examples, “%” means “% by mass”.

Examples 1 to 7, Comparative Examples 1 to 6
At a mixing ratio shown in Table 1, various polyisocyanates (A1), various reaction inhibitors (C) and antioxidants were charged and stirred in a 5 L stirring vessel filled with nitrogen. Thereafter, various polyols (A2) were charged and stirred while maintaining the temperature in the stirring vessel at 40 to 70 ° C. Subsequently, while the defoaming agent was charged and the temperature in the stirring vessel was kept at 70 to 90 ° C., the urethane reaction was allowed to proceed for about 2 to 5 hours to obtain various NCO-terminated urethane prepolymers (A).

In addition, various polyols (A1), various catalysts (D) and an appropriate amount of an antifoaming agent were charged into a 5 L stirring vessel filled with nitrogen at the mixing ratios shown in Tables 1 and 2, and the mixture was stirred. Various OH group terminal curing agents (B) were obtained by mixing and stirring for about 1 to 3 hours while maintaining the temperature at 40 to 70 ° C.

Next, the NCO-terminated urethane prepolymer (A) and the catalyst-containing OH-terminated curing agent (B) are mixed with a two-liquid urethane casting machine according to the α values shown in Tables 1 and 2. A thermosetting polyurethane elastomer-forming composition of the present invention is prepared, and the composition is poured into a mold for forming a 2 mm-thick flat sheet that has been preheated to a curing temperature, and the molded article is removed from the mold. The polyurethane elastomer molded article (sheet) of the present invention was obtained by heating and curing in a mold for a minimum time for taking out (demolding) and quickly removing the molded article.

The abbreviations of the raw materials used in Tables 1 and 2 are as follows.
[Isocyanate]
MDI; Millionate MT (manufactured by Nippon Polyurethane Industry Co., Ltd.), 4,4′-MDI, NCO content = 33.5%
TDI; Coronate T-100 (manufactured by Nippon Polyurethane Industry Co., Ltd.), 2,4-TDI, NCO content = 48.2%
[Polyol]
PBA-2500; Nipporan 3027 (manufactured by Nippon Polyurethane Industry Co., Ltd.), polybutylene adipate, hydroxyl value = 44.9 KOHmg / g
PBA-1000; Nipporan 4009 (manufactured by Nippon Polyurethane Industry Co., Ltd.), polybutylene ethylene adipate, hydroxyl value = 112.0 KOHmg / g
PEA-2000; Nipporan 4040 (manufactured by Nippon Polyurethane Industry Co., Ltd.), polyethylene adipate, hydroxyl value = 56.1 KOHmg / g
PTMG-1000; PTMG-1000 (manufactured by Mitsubishi Chemical Corporation), polytetramethylene glycol, hydroxyl value = 112.0 KOHmg / g
1.4-BG; 1,4-butanediol (manufactured by Mitsubishi Chemical Corporation), hydroxyl value = 1,245 KOHmg / g
TMP: trimethylolpropane (manufactured by Mitsubishi Gas Chemical Company), hydroxyl value = 1,254 KOHmg / g
[Reaction inhibitor]
DDK-2: NIKKOL DDP-2 (manufactured by Nikko Chemicals), di (C12-15) palace-2 phosphate (10) DDP-4; NIKKOL DDP-4 (manufactured by Nikko Chemicals), di (C12-15) Palace-4 phosphate (11) DDP-10; NIKKOL DDP-10 (manufactured by Nikko Chemicals), di (C12-15) Palace-10
Phosphoric acid (12) PS-236; Phosphoran PS-236 (manufactured by Akzo Nobel), Mono-di (C10-12) Palace-5 phosphate (13) A212C; Plysurf A212C (manufactured by Daiichi Kogyo Seiyaku), Polyoxyethylene tridecyl ether phosphate (14) PEGNPP; dipolyethylene glycol-4-nonylphenyl phosphate (Tokyo Kasei)
(15) TDP-6; NIKKOL TDP-6 (manufactured by Nikko Chemicals), tri (C12-15) Palace-6 phosphate (16) mono-dimethyl phosphate; methyl phosphate (manufactured by Tokyo Chemical Industry)
(17) dibutyl phosphate; dibutyl phosphate (manufactured by Tokyo Chemical Industry Co., Ltd.)
(18) JP-512; (manufactured by Johoku Chemical Co., Ltd.), alkyl (C12, C14, C16, C18) acid phosphate (19) JP-524; (manufactured by Johoku Chemical Co., Ltd.), tetracosyl acid phosphate
[catalyst]
(20) POLYCAT-46; (manufactured by Air Products), a mixture of potassium acetate and ethylene glycol (21) DABCO TMR; (manufactured by Air Products), a mixture of quaternary ammonium salt catalyst and ethylene glycol (22) TOYOCAT RX- 5; (manufactured by Tosoh Corporation), trimethylaminoethylethanolamine (23) TOYOCAT TEDA-L33E; (manufactured by Tosoh Corporation), a mixture of triethylenediamine and ethylene glycol
[Other additives]
(24) I-1010; Irganox 1010; (BASF Japan) pentaerythritol tetrakis [3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] antioxidant (25) BYK-052; (by BYK Japan KK) non-silicone antifoam

The property evaluation method of the obtained molded sheet is as follows.
(1) JIS-A hardness: Measured using an A-type hardness meter according to JIS K7312.
(2) Tensile strength, elongation rate; measured according to JIS K7312.
(3) Number of foreign matter on the cut surface: Immediately after the molded sheet is released from the mold, the sheet is cut into strips having a width of about 50 mm, a cut of about 1 mm is made at the center end, and the sheet is pulled laterally to break and cut. Regarded as a surface. Five cut surfaces each having a width of 20 mm and a thickness of 2 mm were prepared, and each cut surface was observed using a microscope with a magnification of 40 times, the number of irregularities was counted, and the total number of irregularities of the five sheets was measured. Is the number of foreign matters on the cut surface.

Examples 1 to 7 show the results of the present invention. Under any conditions, it is possible to obtain a thermosetting polyurethane elastomer having high mechanical strength and high toughness without shortening the molding cycle, generating no unreacted foreign matter in the molded product, without impairing the properties of the isocyanate group-terminated urethane prepolymer. Was completed.

Comparative Example 1 is an example in which the reaction inhibitor (C) was not used, and the viscosity and color number of the obtained NCO-terminated urethane prepolymer (A) were very high. Although the number of unreacted foreign substances in the molded product obtained by using the NCO-terminated urethane prepolymer (A) is small, in the casting operation, the liquid viscosity is high and the flowability is poor. It was difficult. Further, the molded product was unsuitable because coloring was also observed.

Comparative Example 2 is an example in which the reaction inhibitor (C) of the present invention was excessively blended, and the resulting NCO-terminated urethane prepolymer (A) had a high color number. The molded product obtained using this NCO-terminated urethane prepolymer (A) had a long molding time, and the obtained molded product had a large number of unreacted foreign substances and was unsuitable.

Comparative Examples 3 to 6 are examples in which a reaction inhibitor (C) other than the present invention was used, and the obtained molded article had a very large number of unreacted foreign substances, and these foreign substances served as starting points, and the tensile strength was low. It was low and unsuitable.

Claims (4)

A thermosetting polyurethane elastomer-forming composition for industrial machine parts including at least an isocyanate group-terminated urethane prepolymer (A), a hydroxyl group-terminated curing agent (B) and an antioxidant ,
The isocyanate group-terminated urethane prepolymer (A) is a reaction inhibitor (C) in the presence of a phosphate ester compound having one or more chain structures formed by ring opening or polymerization of ethylene oxide at 5 to 600 ppm. A thermosetting polyurethane elastomer-forming composition for industrial machine component parts, which is a reaction product obtained by a reaction. The thermosetting polyurethane elastomer-forming composition for industrial machine parts according to claim 1,
The thermosetting for industrial machine component parts, wherein the hydroxyl group-terminated curing agent (B) contains at least a catalyst for nullating polyurethane (D1) and / or a catalyst for forming allophanate (D2) for polyurethane as the catalyst (D). Polyurethane-forming composition. The thermosetting polyurethane elastomer-forming composition for industrial machine component parts according to claim 1 or 2,
The mixing ratio (functional group ratio) of the isocyanate group-terminated urethane prepolymer (A) and the hydroxyl group-terminated curing agent (B) is such that hydroxyl group / isocyanate group = 0.2 to 0.8 (molar ratio). Thermosetting polyurethane elastomer-forming composition for industrial machine parts.   The JIS-A hardness of the industrial machine component member obtained by subjecting the thermosetting polyurethane elastomer-forming composition for an industrial machine component member according to any one of claims 1 to 3 to a thermosetting treatment is in the range of 60 to 95. Industrial machine parts characterized by the following.