Pentamethylene diisocyanate-based prepolymer

Abstract

This application provides a method for producing an isocyanate-terminated prepolymer, comprising the reaction of a polyisocyanate compound A) with an isocyanate-reactive compound B), and may include a subsequent step to reduce the residual monomer content, wherein the polyisocyanate compound A) comprises at least 30% by weight, preferably at least 50% by weight, and more preferably at least 70% by weight of pentamethylene diisocyanate relative to the weight of polyisocyanate compound A), and the isocyanate-reactive compound B) comprises at least 80% by weight of isocyanate-reactive compound B) comprising (I) poly(1,3-propanediol) having a number average molar mass in the range of 100 g / mol to 1300 g / mol, or (II) poly(ε-caprolactone) having an OH functional value of 2 and a number average molar mass in the range of 160 g / mol to 800 g / mol, or (III) any combination of (I) and (II).

Description

Technical Field

[0001] The present invention relates to an isocyanate-terminated prepolymer, a method for producing the isocyanate-terminated prepolymer, and use of the isocyanate-terminated prepolymer of the present invention in a coating composition for coating a substrate.

Background Art

[0002] Among the group of isocyanate-terminated prepolymers, prepolymers based on hexamethylene diisocyanate (HDI) are attractive due to their low viscosity, which allows for many different processing options without the need for diluents or solvents. The most common polyol species used in isocyanate-terminated prepolymers is polypropylene glycol polyol. Prepolymers based on polypropylene polyol are attractive due to their high availability and their non-crystallization even at low temperatures. However, prepolymers based on other polyol species, such as poly(tetrahydrofuran), poly(1,3-propanediol), and poly(ε-caprolactone), have advantages in mechanical properties or UV resistance. Further, it is beneficial to remove excess diisocyanate after synthesis to obtain an isocyanate prepolymer with a low diisocyanate monomer content. Many such HDI prepolymers are described in European Patent Application No. 22169156.1, which is an unpublished application.

[0003] Unfortunately, the preparation of prepolymers with a low monomer content from HDI and poly(tetrahydrofuran), poly(1,3-propanediol), or poly(ε-caprolactone) results in prepolymers that crystallize when stored at low temperatures, such as 5°C, and do not melt at 23°C. When the prepolymer crystallizes, an additional melting step is required before processing, which is undesirable. When an additional melting step is required, it is at least desirable to melt at a moderate temperature, such as room temperature, to avoid the need for heating equipment.

[0004] International Publication No. 2016 / 116376 discloses a method for suppressing crystallization using a polyester polyol with a high branched diol content. Example 17 of International Publication No. 2016 / 116376 discloses a PDI-based prepolymer containing poly(ε-caprolactone) with a molar mass of 650 g / mol, combined with the branched polyester polyol with a molar mass of 431 g / mol. However, the use of the branched polyester polyol according to International Publication No. 2016 / 116376 increases the viscosity of the prepolymer. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] European Patent No. 22169156.1 [Patent Document 2] International Publication No. 2016 / 116376 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Therefore, the present invention aims to provide an isocyanate-terminated prepolymer having low viscosity that melts at 23°C and does not crystallize when stored preferably at 5°C. [Means for solving the problem]

[0007] Therefore, the subject of the present invention is an isocyanate-terminated prepolymer comprising a structural unit derived from polyisocyanate compound A) and a structural unit derived from isocyanate-reactive compound B), -Polyisocyanate compound A) comprises at least 30% by weight, preferably at least 50% by weight, and more preferably at least 70% by weight of pentamethylene diisocyanate relative to the weight of polyisocyanate compound A), -Isocyanate-reactive compound B) is at least 80% by weight relative to the weight of isocyanate-reactive compound B) (I) Poly(1,3-propanediol) having a number-average molar mass in the range of 100 g / mol to 1300 g / mol, (II) Poly(ε-caprolactone) having an OH functional value of 2 and a number-average molar mass in the range of 160 g / mol to 800 g / mol, or Any mixture of (III)(I) or (II) It is an isocyanate-terminated prepolymer containing [the specified compound].

[0008] In the present invention, it has been surprisingly discovered that combining pentamethylene diisocyanate (PDI) with poly(1,3-propanediol) or poly(ε-caprolactone) within a clearly defined molar mass range yields a low-viscosity prepolymer that melts at 23°C, i.e., has a melting point below 23°C. In some embodiments, the prepolymer does not even crystallize when stored at 5°C.

[0009] Another subject of the present invention is a method for producing an isocyanate-terminated prepolymer, comprising the reaction of a polyisocyanate compound A) and an isocyanate-reactive compound B), and which may include a subsequent step for reducing the residual monomer content. -Polyisocyanate compound A) comprises at least 30% by weight, preferably at least 50% by weight, and more preferably at least 70% by weight of pentamethylene diisocyanate relative to the weight of polyisocyanate compound A), -Isocyanate-reactive compound B) is at least 80% by weight relative to the weight of isocyanate-reactive compound B) (I) Poly(1,3-propanediol) having a number-average molar mass in the range of 100 g / mol to 1300 g / mol, (II) Poly(ε-caprolactone) having an OH functional value of 2 and a number-average molar mass in the range of 160 g / mol to 800 g / mol, or (III) Any combination of (I) and (II) This is a manufacturing method that includes [the following].

[0010] Polyisocyanate compound A) The polyisocyanate compound A) used in the method of the present invention comprises at least 30% by weight of pentamethylene diisocyanate (PDI) relative to the weight of polyisocyanate compound A), preferably 50% by weight, more preferably 70% by weight, and most preferably 100% by weight of pentamethylene diisocyanate. Suitable polyisocyanates that can be used as further polyisocyanates are aliphatic diisocyanates, such as hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), butylene diisocyanate (BDI), bisisocyanatocyclohexylmethane (HMDI), 2,2,4-trimethylhexamethylene diisocyanate, bisisocyanatomethylcyclohexane, bisisocyanatomethyltricyclodecane, xylene diisocyanate, tetramethylxylylene diisocyanate, norbornane diisocyanate, cyclohexane diisocyanate, or diisocyanatododecane, with hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), butylene diisocyanate (BDI), and bis(isocyanatocyclohexyl)methane (HMDI) being preferred. Preferred aliphatic diisocyanates are linear diisocyanates, such as HDI or BDI.

[0011] Even more suitable are aromatic diisocyanates, such as toluene 2,4-diisocyanate (2,4-TDI), toluene 2,6-diisocyanate (2,6-TDI), or methylenediphenyl 2,2'-diisocyanate (2,2'-MDI), methylenediphenyl 2,2'-diisocyanate (2,4'-MDI), methylenediphenyl 4,4'-diisocyanate (4,4'-MDI), or a mixture of at least two of these.

[0012] It is even more appropriate to use diisocyanates having uretdione, isocyanurate, allophanate, urea, biuret, iminooxadiazinedione, and / or oxadiazinetrione structures, also known as modified diisocyanates. Modified diisocyanates can be obtained from the aliphatic and aromatic diisocyanates described above.

[0013] In a preferred embodiment, the diisocyanate comprises at least 70% by weight of PDI and up to 30% by weight of HDI and / or modified diisocyanate.

[0014] Isocyanate-reactive compound B) The isocyanate-reactive compound used in the preparation of the isocyanate-terminated prepolymer is at least 80% by weight relative to the weight of isocyanate-reactive compound B).

[0015] (I) Poly(1,3-propanediol) having a number-average molar mass in the range of 100 g / mol to 1300 g / mol, preferably 100 g / mol to 1100 g / mol, more preferably 200 g / mol to 900 g / mol, or (II) A poly(ε-caprolactone) having an OH functional value of 2, preferably starting from butanediol, hexanediol, neopentyl glycol, and / or diethylene glycol, with a number average molar mass in the range of 160 g / mol to 800 g / mol, preferably 200 g / mol to 600 g / mol, more preferably 280 g / mol to 600 g / mol, or (III) Any combination of (I) and (II) Includes.

[0016] In the present invention, the term poly(1,3-propanediol) (I) is used interchangeably with polytrimethylene ether glycol (PO3G) and represents a polyol of formula (i), where n represents an integer from 2 to 24, preferably from 2 to 22, more preferably from 4 to 10. This can be produced by various methods. One method is ring-opening polymerization from oxetane. However, the more commonly used method is polycondensation of 1,3-propanediol as exemplified in European Patent No. 3689943.

[0017]

Chemical formula

[0018] Examples of poly(ε-caprolactone) (II) include polyols as shown in formula (ii). In the formula, R represents a starting material having no OH group, and this starting material is preferably butanediol, hexanediol, neopentyl glycol, and / or diethylene glycol. o and p are independent of each other and are integers in the range of 0 to 3, preferably 1 or 2, and the sum of o and p is at least 1.

[0019]

Chemical formula

[0020] It is preferable that the isocyanate-reactive compound B) contains at least 90% by weight, more preferably at least 95% by weight, and most preferably 100% by weight of the compound described in any one of (I) to (III), relative to the weight of the isocyanate-reactive compound B). It is also appropriate to use further isocyanate-reactive compounds not included in the range of (I) to (III), such as monohydric and polyhydric alcohols, or monofunctional and polyfunctional amines, or mixtures thereof, which are known to those skilled in the art. The polyhydric alcohol is, for example, a polyether polyol having a number-average molar mass preferably in the range of 200 to 10000 g / mol, more preferably in the range of 400 to 2500 g / mol, and an OH functional value preferably in the range of 1.8 to 6, more preferably in the range of 1.9 to 2.1, and most preferably in the range of 1.9 to 2.0. The polyether polyol is obtained by ring-opening polymerization of a cyclic ether in the presence of a starting compound having a hydroxyl group.

[0021] Suitable starting compounds having a hydroxyl group are water or compounds with an OH functional value of 2 to 6, such as propylene glycol, 1,3-propanediol, ethylene glycol, diethylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, hexanediol, pentanediol, 3-methylene-1,5-pentanediol, 1,12-dodecanediol, glycerin, trimethylolpropane, triethanolamine, pentaerythritol, sorbitol, sucrose, hydroquinone, catechol, resorcinol, bisphenol F, bisphenol A, benzene-1,3,5-triol, or condensation products of formaldehyde and phenol containing a methylol group. The starting compounds can be used alone or in mixtures. The starting compound is preferably selected from the group consisting of propylene glycol, 1,3-propanediol, glycerin, trimethylolpropane, and pentaerythritol.

[0022] Suitable cyclic ethers include ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, 2-methyl-1,2-propylene oxide, 1,2-pentylene oxide, 2,3-pentylene oxide, 2-methyl-1,2-butylene oxide, 3-methyl-1,2-butylene oxide, 1,2-hexylene oxide, 2,3-hexylene oxide, 3,4-hexylene oxide, 2-methyl-1,2-pentylene oxide, 4-methyl-1,2-pentylene oxide, 2-ethyl-1,2-butylene oxide, 1,2-heptylene oxide, 1,2-octylene oxide, 1,2-nonylene oxide, 1,2-decylene oxide, 1 These include 2-undecylene oxide, 1,2-dodecylene oxide, 4-methyl-1,2-pentylene oxide, butadiene monooxide, isoprene monooxide, cyclopentene oxide, cyclohexene oxide, cycloheptene oxide, cyclooctene oxide, styrene oxide, methylstyrene, pinene oxide, and derivatives of glycidol, such as methyl glycidyl ether, ethyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, trimethylene oxide, tetramethylene oxide (THF), pentamethylene oxide, hexamethylene oxide, heptamethylene oxide, and decamethylene oxide. Two or more of the above cyclic ethers can also be copolymerized. The cyclic ethers are preferably propylene oxide, ethylene oxide, and / or tetramethylene oxide (THF), and more preferably propylene oxide and / or tetramethylene oxide (THF).

[0023] It is also appropriate to use so-called chain extenders. Suitable chain extenders are preferably aliphatic diols having 2 to 14 carbon atoms, such as ethanediol, butane-1,4-diol, hexane-1,6-diol, octane-1,8-diol, decane-1,10-diol, dodecane-1,12-diol, diethylene glycol, and dipropylene glycol. However, diesters of terephthalic acid with glycols having 2 to 4 carbon atoms, such as bis-ethylene glycol terephthalate or bis-butane-1,4-diol terephthalate, hydroxyalkylene ethers of hydroquinones, such as 1,4-di(hydroxyethyl)hydroquinone, and ethoxylated bisphenol are also suitable. It is particularly preferable to use ethanediol, butane-1,4-diol, hexane-1,6-diol, and 1,4-di(hydroxyethyl)hydroquinone. Mixtures of the above chain extenders may also be used.

[0024] In preferred embodiments, the isocyanate-reactive compound B) does not contain a polyester polyol different from (II).

[0025] It is preferable to react polyisocyanate compound A) and isocyanate-reactive compound B) in an NCO / OH equivalent ratio of 1.5:1 to 20:1, preferably 2:1 to 18:1, and most preferably 4:1 to 16:1. The reaction is carried out at a temperature of 20°C to 200°C, preferably 40°C to 140°C, and more preferably 50°C to 120°C. Preferably, if an excess of polyisocyanate compound A) is used in a ratio greater than 2:1, the excess monomer polyisocyanate is removed after the reaction by distillation or extraction methods known in the art (e.g., thin-film distillation).

[0026] In the method for producing isocyanate-terminated prepolymers, further additives may be used, which may remain in the isocyanate-terminated prepolymer after the method. Preferably, the amount of additives in the method is in the range of 0 to 5% by weight, more preferably 0 to 4% by weight, and most preferably 0 to 2% by weight, relative to the total weight percent of polyisocyanate compound A), isocyanate-reactive compound B), and additives. Examples of additives are light stabilizers, e.g., UV absorbers and sterically hindered amines (HALS), further stabilizers, e.g., acid stabilizers, defoamers, crater inhibitors, and / or wetting agents, gradient agents, film-forming aids, reactive diluents, biocides, solvents, or substances for rheological control. It is preferable to use UV absorbers such as substituted benzotriazoles, S-phenyltriazines, or oxalanilides, and as light stabilizers, particularly sterically hindered amines (referred to as HALS) having a 2,2,6,6-tetramethyl-piperidyl structure.

[0027] Stabilizers, such as radical scavengers, and other polymerization inhibitors, such as sterically hindered phenols, stabilize the paint components during storage and are intended to prevent discoloration during curing. Wetting agents and gradient agents improve surface wetting and / or the paint gradient. Examples include fluorinated surfactants, silicone surfactants, and special polyacrylates. Rheology-controlling additives are important for controlling the properties of the two-component system during application to the substrate and during the progression stage, and are known, for example, from International Publication No. 9422968, European Patent No. 0276501, European Patent No. 0249201, or International Publication No. 9712945 of the Patent Specifications. Furthermore, water scavengers, such as triethyl orthoformate, toluene sulfisocyanate, monooxazolidine, or molecular sieves, and hydrolysis inhibitors, such as carbodiimide, can be used. As acid stabilizers, phosphoric acid, dibutyl phosphate, isophthaloyl chloride, and / or benzoyl chloride are preferred.

[0028] Examples of organic solvents include ketones, such as acetone, methyl ethyl ketone, or hexanone; esters, such as ethyl acetate, butyl acetate, methoxypropyl acetate, substituted glycols, and other ethers; aromatic substances, such as xylene or solvent naphtha, such as Exxon-Chemie; and mixtures of the aforementioned solvents. Water is also suitable as a solvent or diluent if the NCO-reactive portion of the composition is present as an aqueous dispersion.

[0029] Suitable catalysts include, for example, organotin compounds, bismuth compounds, zinc compounds, titanium compounds, zirconium compounds, or amine catalysts. When one or more catalysts are used, preferably 0.001% to 5% by weight, more preferably 0.002% to 2% by weight, of the total weight of the isocyanate-terminated prepolymer.

[0030] In a preferred embodiment, the method for producing an isocyanate-terminated prepolymer is preferably in the presence of 0 to 5% by weight of an additive, which includes a catalyst. A polyisocyanate compound A) comprising 20-96% by weight, preferably 40-96% by weight, and containing at least 30% by weight, preferably at least 50% by weight, and more preferably at least 70% by weight of pentamethylene diisocyanate relative to the weight of polyisocyanate compound A), and 4 to 80% by weight, preferably 4 to 60% by weight, of isocyanate-reactive compound B), wherein at least 80% by weight relative to the weight of isocyanate-reactive compound B) (I) Poly(1,3-propanediol) having a number-average molar mass in the range of 100 g / mol to 1300 g / mol, (II) Poly(ε-caprolactone) having an OH functional value of 2 and a number-average molar mass in the range of 160 g / mol to 800 g / mol, or (III) Any combination of (I) and (II) The reaction includes a reaction with an isocyanate-reactive compound B), The sum of the weight percentages of polyisocyanate compound A), isocyanate-reactive compound B), and additives is equal to 100% by weight. This method may include a subsequent step to reduce the residual monomer content, preferably by thin-film distillation.

[0031] In another preferred embodiment, the isocyanate-terminated prepolymer consists of structural units derived from polyisocyanate compound A) and structural units derived from isocyanate-reactive compound B), -Polyisocyanate compound A) consists of 30% to 100% by weight, preferably 50% to 100% by weight, more preferably 70% to 100% by weight of pentamethylene diisocyanate, and 0 to 70% by weight, preferably 0 to 50% by weight, more preferably 0 to 30% by weight of at least one compound selected from hexamethylene diisocyanate, isophorone diisocyanate, butylene diisocyanate, or bis(isocyanatocyclohexyl)methane. -Isocyanate-reactive compound B) is, (I) Poly(1,3-propanediol) having a number-average molar mass in the range of 100 g / mol to 1300 g / mol, (II) Poly(ε-caprolactone) having an OH functional value of 2 and a number-average molar mass in the range of 160 g / mol to 800 g / mol, or (III) Consists of any mixture of (I) or (II).

[0032] The isocyanate-terminated prepolymer of the present invention can be used as a coating composition for coating substrates, preferably objects subjected to (repeated) mechanical stress, such as aircraft, helicopters, and automobiles, particularly parts that move at very high speeds, such as rotor blades of wind turbines, rotor blades of helicopters, or propellers of ships; or for applications requiring a highly elongated coating, such as filling gaps, such as parking lot coatings (flooring), coating compositions for waterproofing roofs and balconies; or for protective purposes, such as coating compositions for corrosion protection of infrastructure equipment; or for pipe coatings.

[0033] The coating composition can be applied by conventional application methods. Examples of application methods include brush-on, brushing, squeegee, rolling, and spray application, with roll-on application being preferred for building applications.

[0034] A suitable coating composition may be a two-component (2K) coating comprising at least the isocyanate-terminated prepolymer of the present invention and an isocyanate-reactive component, such as a polyol or polyamine.

[0035] A suitable specific example of a coating composition in which the isocyanate-reactive component is a polyamine is given by general formula (iii)

[0036] [ka] A two-component (2K) coating comprising at least one polyaspartate ester and an isocyanate-terminated prepolymer according to the present invention, wherein, X is an m-valent organic group which may contain heteroatoms, and is obtained by removing primary amino groups from a corresponding polyamine which contains (alicyclic) aliphatic and / or aromatic aliphatic primary amino groups with a molecular weight of 60 to 6000 g / mol, and is reactive to isocyanate groups and / or may contain further functional groups which are inert at temperatures up to 100°C. R1 and R2 are either the same or different organic groups. m is an integer greater than 1.

[0037] [Examples] experiment method Unless otherwise specified, all percentages are weight percentages.

[0038] Unless otherwise specified, viscosity was measured according to DIN 53019 at 23°C and a shear rate of 50 / s.

[0039] The isocyanate content was determined according to DIN-EN ISO 11909.

[0040] The residual content of diisocyanates was determined according to DIN EN ISO 10283.

[0041] To test the crystallization behavior, 50 mL of prepolymer was placed in a 100 mL glass bottle and stored at 5°C. After storage periods of 1 day and 4 days, the samples were visually evaluated for crystal formation or the formation of a white solid, respectively. If crystallization was observed, the sample was subsequently stored at 23°C for up to 24 hours. If neither crystals nor white solids remained and the sample became a clear liquid again, this test was considered to "melt at 23°C".

[0042] Unless otherwise specified, molar mass is the number-average molar mass determined by gel permeation chromatography according to DIN 55672-1 (August 2007).

[0043] Materials and Abbreviations HDI: Hexamethylene diisocyanate (Desmodur® H, Covestro Deutschland AG) PDI: Pentamethylene diisocyanate (Covestro Deutschland AG) PTHF (bifunctional poly(tetrahydrofuran)) products with number-average molar masses of 250, 1000, 1400, and 2000 g / mol were purchased from BASF. Poly(tetrahydrofuran) with an average molar mass of 650 g / mol was purchased from Merck. PO3G: Poly(1,3-propanediol) PCL: Poly(ε-caprolactone) PPG: Poly(propylene glycol) Velvetol® H250: A bifunctional poly(1,3-propanediol) with a number-average molar mass of 250 g / mol was purchased from Alessa GmbH. Velvetol® H500: A bifunctional poly(1,3-propanediol) with a number-average molar mass of 500 g / mol was purchased from Alessa GmbH. Ecoprol® H1000: A bifunctional poly(1,3-propanediol) with a number-average molar mass of 1000 g / mol (OH value of 112 mg KOH / g) was supplied by SK Chemicals. Velvetol® H1400: A bifunctional poly(1,3-propanediol) with a number-average molar mass of 1400 g / mol was purchased from Alessa GmbH. Ecoprol® H2000: A bifunctional poly(1,3-propanediol) with a number-average molar mass of 2000 g / mol (OH value of 56 mg KOH / g) was provided by SK Chemicals. CAPA(registered trademark)2043: A bifunctional poly(ε-caprolactone) with a number-average molar mass of 400 g / mol, starting from 1,4-butanediol, was provided by Ingevity. CAPA(registered trademark)2067A: A bifunctional poly(ε-caprolactone) with a number-average molar mass of 650 g / mol, starting from 1,6-hexanediol, was provided by Ingevity. CAPA(registered trademark)2101A: A bifunctional poly(ε-caprolactone) with a number-average molar mass of 1000 g / mol, starting from 2,2-dimethylpropane-1,3-diol, was supplied by Ingevity. CAPA(registered trademark)3031: A trifunctional poly(ε-caprolactone) with a number-average molar mass of 300 g / mol, starting from trimethylolpropane, was provided by Ingevity. B1: A bifunctional polypropylene glycol with a number-average molar mass of 218 g / mol.

[0044] Branched polyester polyol 1 Polyester polyol A1 is described on page 15, lines 3-10 of International Publication No. 2016 / 116376.

[0045] Example 1 (Comparative Example) 3360 g of HDI was heated to 80°C. 454 g of Velvetol H250 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for a further 1.5 hours until the NCO content reached 39.4%. Excess HDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.5 mbar).

[0046] Example 1 (Comparative Example) 3360 g of HDI was heated to 80°C. 454 g of Velvetol H250 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for a further 1.5 hours until the NCO content reached 39.4%. Excess HDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.5 mbar).

[0047] Example 2 (Comparative Example) 2520 g of HDI was heated to 80°C. 833.3 g of Velvetol H500 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for a further 2.5 hours until the NCO content reached 33.6%. Excess HDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.4 mbar).

[0048] Example 3a (Comparative Example) 1638 g of HDI was heated to 80°C. 975 g of Ecoprol H1000 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for a further 2.5 hours until the NCO content reached 28.0%. Excess HDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.1 mbar).

[0049] Example 3b (Comparative Example) 840 g of HDI was heated to 80°C. 500 g of Ecoprol H1000 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for a further 2 hours until the NCO content reached 28.0%. Excess HDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.05 mbar).

[0050] Example 4 (Comparative Example) 675.5 g of HDI was heated to 80°C. 500 g of Velvetol H1400 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for a further 2 hours until the NCO content reached 25.8%. Excess HDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.06 mbar).

[0051] Example 5 (Comparative Example) 840 g of HDI was heated to 80°C. 1000 g of Ecoprol H2000 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for a further 5 hours until the NCO content reached 20.5%. Excess HDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.1 mbar).

[0052] Example 6 (Comparative Example) 3080 g of PDI was heated to 80°C. 152 g of 1,3-propanediol was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for a further 2.5 hours until the NCO content reached 47%. Excess PDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.06 mbar).

[0053] Example 7 (Example of the present invention) 3080 g of PDI was heated to 80°C. 454.3 g of Velvetol H250 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for a further 2.5 hours until the NCO content reached 42.7%. Excess PDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.05 mbar).

[0054] Example 8 (Example of the present invention) 2217.6g of PDI was heated to 80°C. 681.4g of Velvetol H250 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for a further 1.75 hours until the NCO content reached 32.9%. Excess PDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.06mbar). 2.9g of Irganox E201 was added, and the mixture was slowly stirred until the Irganox dissolved.

[0055] Example 9 (Example of the present invention) 924 g of PDI was heated to 80°C. 454.4 g of Velvetol H250 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for a further 2 hours until the NCO content reached X%. Excess PDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.3 mbar).

[0056] Example 10 (Example of the present invention) 2310 g of PDI was heated to 80°C. 833.3 g of Velvetol H500 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for another 1 hour until the NCO content reached 35.8%. Excess PDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.06 mbar).

[0057] Example 11a (Example of the present invention) 1155 g of PDI was heated to 80°C. 750 g of Ecoprol H1000 was added dropwise over 1.5 hours with stirring. The reaction mixture was stirred at 80°C for a further 1.75 hours until the NCO content reached 29.2%. Excess PDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.06 mbar).

[0058] Example 11b (Example of the present invention) 1155 g of PDI was heated to 80°C. 750 g of Ecoprol H1000 was added dropwise over 1.5 hours with stirring. The reaction mixture was stirred at 80°C for a further 5 hours until the NCO content reached 26.6%. Excess PDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.4 mbar).

[0059] Example 12 (Comparative Example) 619 g of PDI was heated to 80°C. 500 g of Velvetol H1400 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for a further 1.75 hours until the NCO content reached 29.7%. Excess PDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.05 mbar).

[0060] Example 13 (Comparative Example) 577.5 g of PDI was heated to 80°C. 750 g of Ecoprol H2000 was added dropwise over 1.5 hours with stirring. The reaction mixture was stirred at 80°C for a further 2.5 hours until the NCO content reached 21.4%. Excess PDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.06 mbar).

[0061] Example 14 (Comparative Example) 1680g of HDI was heated to 80°C. 250g of PTHF 250 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for a further 2 hours until the NCO content reached 38.6%. Excess HDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.08mbar).

[0062] Example 15 (Comparative Example) 1680g of HDI was heated to 80°C. 650g of PTHF 650 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for a further 2 hours until the NCO content reached 32.1%. Excess HDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.08mbar).

[0063] Example 16 (Comparative Example) 2520 g of HDI was heated to 80°C. 1500 g of PTHF 1000 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for a further 1.25 hours until the NCO content reached 27.9%. Excess HDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.08 mbar).

[0064] Example 17 (Comparative Example) 840 g of HDI was heated to 80°C. 700 g of PTHF 1400 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for a further 2 hours until the NCO content reached 24.3%. Excess HDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.03 mbar).

[0065] Example 18 (Comparative Example) 630 g of HDI was heated to 80°C. 750 g of PTHF 2000 was added dropwise over 0.5 hours with stirring. The reaction mixture was stirred at 80°C for a further 4.5 hours until the NCO content reached 20.4%. Excess HDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.06 mbar).

[0066] Example 19 (Comparative Example) 3080g of PDI was heated to 80°C. 500g of PTHF 250 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for a further 2 hours until the NCO content reached 41.9%. Excess PDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.06mbar).

[0067] Example 20 (Comparative Example) 770g of PDI was heated to 80°C. 500g of PTHF 1000 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for a further 5 hours until the NCO content reached 29.4%. Excess PDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.08mbar).

[0068] Example 21 (Comparative Example) 577.5 g of PDI was heated to 80°C. 750 g of PTHF 2000 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for another hour until the NCO content reached 21.2%. Excess PDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.05 mbar).

[0069] Example 22 (Comparative Example) 3360 g of HDI was heated to 80°C. 813.6 g of CAPA 2043 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for another 1 hour until the NCO content reached 36.1%. Excess HDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.06 mbar).

[0070] Example 23 (Comparative Example) Example 3, page 18, lines 25-35 of International Publication No. 2016 / 116376.

[0071] Example 24 (Comparative Example) 2520 g of HDI was heated to 80°C. 1500 g of CAPA 2101A was added dropwise over 1.5 hours with stirring. The reaction mixture was stirred at 80°C for a further 1.5 hours until the NCO content reached 28.1%. Excess HDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.08 mbar).

[0072] Example 25 (Example of the present invention) 2215.4 g of PDI was heated to 80°C. 584.6 g of CAPA 2043 was added dropwise over 0.5 hours with stirring. The reaction mixture was stirred at 80°C for a further 1 hour until the NCO content reached 38.0%. Excess PDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.2 mbar).

[0073] Example 26 (Example of the present invention) 1119.6 g of PDI was heated to 90°C. 480.4 g of CAPA 2067A was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 100°C for a further 2 hours until the NCO content reached 34%. Excess PDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.4 mbar).

[0074] Example 27 (Comparative Example) 577.5 g of PDI was heated to 80°C. 750 g of CAPA 2101A was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for another hour until the NCO content reached 28.5%. Excess PDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.06 mbar).

[0075] Example 28 (Comparative Example) 1770.5g of HDI was heated to 80°C. 229.5g of B1 was added dropwise over 0.5 hours with stirring. The reaction mixture was stirred at 80°C for a further 4 hours until the NCO content reached 39.6%. Excess HDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.05mbar).

[0076] Example 29 (Comparative Example) 1622.6 g of PDI was heated to 80°C. 229.5 g of B1 was added dropwise over 0.5 hours with stirring. The reaction mixture was stirred at 80°C for a further 4 hours until the NCO content reached 43.5%. Excess PDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.4 mbar).

[0077] Example 30 (Comparative Example) 3673.2 g of HDI was heated to 80°C. 626.8 g of branched polyester polyol 1 was added dropwise over 0.5 hours with stirring. The reaction mixture was stirred at 100°C for a further 0.75 hours until the NCO content reached 40.0%. Excess HDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.5 mbar).

[0078] Example 31 (Comparative Example) 3478.2 g of HDI was heated to 80°C. 229.5 g of CAPA 3031 was added dropwise over 0.75 hours with stirring. The reaction mixture was stirred at 80°C for a further 3 hours until the NCO content reached 40.2%. Excess HDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.4 mbar).

[0079] Example 32 (Comparative Example) 3.3 g of the prepolymer from Example 11 of the present invention was mixed with 6.7 g of the prepolymer from Comparative Example 3.

[0080] Example 33 (Comparative Example) 5.0 g of the prepolymer from Example 11 of the present invention was mixed with 5.0 g of the prepolymer from Comparative Example 3.

[0081] Example 34 (Comparative Example) 6.7 g of the prepolymer from Example 11 of the present invention was mixed with 3.3 g of the prepolymer from Comparative Example 3.

[0082] Example 35 (Comparative Example) 3.3 g of the prepolymer from Example 11 of the present invention was mixed with 6.7 g of the prepolymer from Comparative Example 20.

[0083] Example 36 (Comparative Example) 5.0 g of the prepolymer from Example 11 of the present invention was mixed with 5.0 g of the prepolymer from Comparative Example 20.

[0084] Example 37 (Comparative Example) 6.7 g of the prepolymer from Example 11 of the present invention was mixed with 3.3 g of the prepolymer from Comparative Example 20.

[0085] Example 38 (Example of the present invention) 2310 g of PDI and 840 g of HDI were heated to 80°C. 454.2 g of Velvetol H250 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for a further 3 hours until the NCO content reached 42.1%. Excess PDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.05 mbar).

[0086] Example 39 (Example of the present invention) 577.5 g of PDI and 210 g of HDI were heated to 80°C. 500 g of Ecoprol H1000 was added dropwise over 1 hour with stirring. The reaction mixture was stirred at 80°C for a further 3.5 hours until the NCO content reached 29.5%. Excess PDI was removed by distillation using a short-pass distiller (preliminary distiller at 130°C, main distiller at 120°C, pressure 0.05 mbar). [Table 1] TIFF2026524779000005.tif239150

[0087] [Table 2]

[0088] Comparative Examples 1-5, 14-18, and 22-24 demonstrate that prepolymers obtained from HDI with PTHF diols, PO3G diols, or PCL diols solidify at low temperatures and do not melt at room temperature (23°C). However, Examples 7-11 and 25-26 of the present invention show that when the molar mass of the PO3G diol or PCL diol is selected within a defined range specific to the polyol species, PDI-based prepolymers containing the PO3G diol or PCL diol either do not crystallize at 5°C or melt at least 23°C. In particular, for PO3G polyols, it is clear that both a lower and upper limit exists for the molar mass of the polyol. Example 11a and its replicated example, Example 11b, demonstrate that the results were reproducible near the upper limit. Examples 7-9 of the present invention demonstrate that the effect is valid for various NCO / OH ratios during synthesis.

[0089] Surprisingly, the suppression of crystallization was not observed in prepolymers obtained from PDI and PTHF. Comparative Examples 14-21 show that both HDI and PDI prepolymers containing PTHF crystallize at 5°C without melting at 23°C, regardless of the molar mass of PTHF used in the synthesis of the prepolymer.

[0090] Comparative Examples 30 and 31 demonstrate that while crystallization can be suppressed by using branched polyester polyols or polyfunctional polyester polyols, these prepolymers have significantly higher viscosity than prepolymers containing unbranched polyester diols.

[0091] Comparative Examples 32-37 demonstrate that cold blends of the PDI-based prepolymer of the present invention with HDI-based prepolymers not of the present invention do not effectively suppress crystallization. In contrast, Examples 38 and 39 of the present invention demonstrate that a mixture of HDI and PDI (hot blend) exhibits the desired effect during synthesis.

Claims

1. An isocyanate-terminated prepolymer comprising a structural unit derived from polyisocyanate compound A) and a structural unit derived from isocyanate-reactive compound B), - The polyisocyanate compound A) comprises at least 30% by weight, preferably at least 50% by weight, and more preferably at least 70% by weight of pentamethylene diisocyanate, based on the weight of the polyisocyanate compound A). - The isocyanate-reactive compound B) is at least 80% by weight relative to the weight of the isocyanate-reactive compound B). (I) Poly(1,3-propanediol) having a number-average molar mass in the range of 100 g / mol to 1300 g / mol, (II) Poly(ε-caprolactone) having an OH functional value of 2 and a number-average molar mass in the range of 160 g / mol to 800 g / mol, or Any mixture of (III), (I), or (II). An isocyanate-terminated prepolymer containing [the specified compound].

2. The isocyanate-terminated prepolymer according to claim 1, wherein (I) is a poly(1,3-propanediol) having a number-average molar mass in the range of 100 g / mol to 1100 g / mol.

3. The isocyanate-terminated prepolymer according to claim 1, wherein (I) is a poly(1,3-propanediol) having a number-average molar mass in the range of 200 g / mol to 900 g / mol.

4. The isocyanate-terminated prepolymer according to claim 1, wherein (II) is poly(ε-caprolactone) having a number-average molar mass in the range of 160 g / mol to 600 g / mol.

5. An isocyanate-terminated prepolymer according to any one of claims 1 to 4, wherein the residual monomer content is 1% or less, preferably 0.5% or less, and more preferably 0.3% or less.

6. The isocyanate-terminated prepolymer according to any one of claims 1 to 5, wherein the isocyanate-reactive compound B) does not contain a polyester polyol different from (II).

7. The isocyanate-terminated prepolymer according to any one of claims 1 to 6, wherein the isocyanate-reactive compound B) comprises at least 90% by weight of (I), (II), or (III).

8. The isocyanate-terminated prepolymer according to any one of claims 1 to 6, wherein the isocyanate-reactive compound B) consists of 100% by weight of (I), (II), or (III).

9. A method for producing an isocyanate-terminated prepolymer, comprising a reaction between a polyisocyanate compound A) and an isocyanate-reactive compound B), and may include a subsequent step to reduce the residual monomer content. - The polyisocyanate compound A) comprises at least 30% by weight, preferably at least 50% by weight, and more preferably at least 70% by weight of pentamethylene diisocyanate, based on the weight of the polyisocyanate compound A). - The isocyanate-reactive compound B) is at least 80% by weight relative to the weight of the isocyanate-reactive compound B). (I) Poly(1,3-propanediol) having a number-average molar mass in the range of 100 g / mol to 1300 g / mol, (II) Poly(ε-caprolactone) having an OH functional value of 2 and a number-average molar mass in the range of 160 g / mol to 800 g / mol, or (III) Any combination of (I) and (II) A manufacturing method that includes this.

10. The method for producing the product according to claim 10, wherein the isocyanate-reactive compound B) does not contain a polyester polyol different from (II).

11. A coating composition comprising the prepolymer according to any one of claims 1 to 8.

12. A method for preparing a coating on a substrate, i) A step of applying the coating composition according to claim 11 to at least a portion of the substrate, and ii) A step of curing the coating composition of step i). Methods that include...

13. A substrate coated with a coating obtained by the method of claim 12.

14. Use of the coating composition according to claim 11 for coating a substrate.

15. The use according to claim 14, wherein the substrate is an aircraft, helicopter, automobile, rotor blade, ship propeller, parking lot, roof, balcony, infrastructure equipment, or pipe.

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