JP2008156506A - Polycarbodiimide and polyester urethane resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester urethane resin composition having excellent hydrolysis resistance. <P>SOLUTION: The invention provides a polyester urethane resin composition containing a copolymerized polycarbodiimide of hexamethylene diisocyanate and isophorone diisocyanate and preferably having a copolymerized mol% of the hexamethylene diisocyanate of 10-80 mol% and a number-average molecular weight of 300-10,000 and a polyester urethane resin, and a polyester urethane resin powder containing the composition. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a copolymerized polycarbodiimide and a polyester-based urethane resin composition containing the copolymerized polycarbodiimide.

The polyester-based urethane resin is produced by reacting a polyester polyol and a polyisocyanate in the presence of a low-molecular diol, diamine or the like, if necessary. Polyurethanes using polyester polyols are excellent in mechanical properties, oil resistance (solvent) properties, etc., but have a problem that they are inferior in hydrolysis resistance because they have ester bonds that are susceptible to hydrolysis.
In particular, a coating film obtained by applying a polyester-based urethane resin paint to an article used outdoors has a problem that it is etched by heat, water, light or the like, and a stain is generated on the coating film.
To solve these problems, a urethane resin having a specific ether structure (see Patent Document 1), a resin composition for powder coating made of a urethane resin having a specific reactive group (see Patent Document 2), etc. are proposed. However, the hydrolysis resistance may still not be sufficient.
WO96 / 09334 JP 2001-192609 A

  The subject of this invention is providing the coating film, molded article, etc. which consist of a polyester-type urethane resin composition excellent in hydrolysis resistance.

The present invention includes a copolymerized polycarbodiimide (A) of hexamethylene diisocyanate and isophorone diisocyanate, a polyester-based urethane resin composition containing the copolymerized polycarbodiimide (A), and the polyester-based urethane resin composition. Polyester urethane resin powder.

A coating film, a molded product, etc. made of the polyester-based urethane resin composition of the present invention are excellent in hydrolysis resistance.

The copolymerized polycarbodiimide (A) of the present invention is a copolymerized polycarbodiimide of hexamethylene diisocyanate (hereinafter sometimes referred to as HDI) and isophorone diisocyanate (hereinafter sometimes referred to as IPDI). It is. The copolymerization mol% of the hexamethylene diisocyanate is preferably 10 mol% or more from the viewpoint of mechanical strength of the urethane resin, preferably 80 mol% or less from the viewpoint of handling properties as a liquid, more preferably 20 to 75 mol%, 30-70 mol% is further more preferable, and 45-70 mol% is especially preferable.

The number average molecular weight of the copolymerized polycarbodiimide (A) is preferably 300 or more from the viewpoint of carbodiimide group content, preferably 10,000 or less, more preferably 500 to 5000, and more preferably 1500 to 4000 from the viewpoint of solubility in the polyester-based urethane resin. Is more preferable. The number average molecular weight can be determined by calculation from the measured value of the isocyanate group content (JIS K7301).

The terminal group of (A) is an isocyanate group, alkyl group (methyl group, ethyl group, isopropyl group, 2-ethylhexyl group, etc.) alkoxy group (methoxy group, ethoxy group, etc.), PEG (polyoxyethylene group), etc. It is done. Among these, a 2-ethylhexyl group is preferable from the viewpoint of the stability of the polycarbodiimide (A) and the water resistance of the urethane resin composition to which (A) is added.

1-4 show the infrared absorption spectrum and nuclear magnetic resonance spectrum of polycarbodiimide.

The polycarbodiimide (A) of the present invention can be produced by adding a carbodiimidization catalyst to diisocyanate mixed at a predetermined ratio and heating. When the end of the polycarbodiimide is a terminal group other than an isocyanate group, a functional group that reacts with isocyanate, preferably a monofunctional compound, may be added and reacted before or after carbodiimidization. it can. Preferred monofunctional compounds include di-n-butylamine, di-n-butyl isocyanate, isopropyl alcohol, 2-ethylhexanol and the like.
The reaction temperature is preferably 40 to 150 ° C, more preferably 50 to 140 ° C. A reaction temperature of 40 ° C. or higher is practical because the reaction time is short. Further, when the reaction temperature is 150 ° C. or lower, the selection of the solvent becomes easy.

The carbodiimidization reaction can also be carried out in a solvent, and the diisocyanate monomer concentration in the reaction solution is preferably 20 to 100% by weight (hereinafter simply referred to as%). When the monomer concentration is 20% or more, the carbodiimidization reaction is completed in a shorter time, which is practical.
Solvents used for the reaction of polycarbodiimide and organic solvents used for the polycarbodiimide solution are preferably halogenated hydrocarbons such as tetrachloroethylene, 1,2-dichloroethane, chloroform, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone. And ketone solvents such as, cyclic ether solvents such as tetrahydrofuran and dioxane, and aromatic hydrocarbon solvents such as toluene and xylene. These solvents may be used alone or in combination of two or more.

Also, as the catalyst used for carbodiimidization, any known phosphorus catalyst is preferably used. For example, 1-phenyl-2-phospholene-1-oxide, 3-methyl-2-phospholene-1-oxide, 1- Examples include phospholene oxides such as ethyl-2-phospholene-1-oxide, 3-methyl-1-phenyl-2-phospholene-1-oxide, and 3-phospholene isomers thereof.

The polyester-based urethane resin composition (B) of the present invention contains a polyester-based urethane resin (C), a copolymerized polycarbodiimide (A), and, if necessary, an additive (D).

From the viewpoint of hydrolysis resistance, the polyester-based urethane resin composition (B) has a copolymer polycarbodiimide (A) content of 0.1% by weight or more based on the weight of the polyester-based urethane resin (C). It is preferably 1% by weight or more. Further, from the viewpoint of excellent mechanical strength of the urethane resin, the content of (A) is preferably 10% by weight or less, and more preferably 5% by weight or less.

The polyester urethane resin (C) can be produced by reacting a polyester polyol and a polyisocyanate.
Polyester polyols are, for example, those obtained by condensation polymerization of (1) a low molecular diol and a dicarboxylic acid or an ester-forming derivative thereof [an acid anhydride, a lower alkyl (carbon number of 1 to 4) ester, acid halide, etc.]; Examples thereof include ring-opening polymerization of a lactone monomer using a low molecular diol as an initiator; and a mixture of two or more of these.

Specific examples of the low molecular diol include aliphatic diols [linear diols (ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol. ) Having a branched chain (propylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2-diethyl-1,3-propanediol, 1,2-, 1,3- or 2,3-butanediol and the like]; diols having a cyclic group [for example, those described in JP-B No. 45-1474; diols containing aliphatic cyclic groups (1,4-bis (hydroxymethyl) cyclohexane, hydrogenated) Bisphenol A and the like, aromatic cyclic group-containing diol (m- and p-xylylene glycol) Alkylene oxide adduct of bisphenol A, alkylene oxide adduct of bisphenol S, alkylene oxide adduct of bisphenol F, alkylene oxide adduct of dihydroxynaphthalene, bis (2-hydroxyethyl) terephthalate, etc.)] and two or more of these A mixture is mentioned. Among these, preferred are aliphatic diols and diols having a cyclic group.

Specific examples of the dicarboxylic acid or ester-forming derivative thereof include aliphatic dicarboxylic acids having 4 to 15 carbon atoms [succinic acid, adipic acid, sebacic acid, glutaric acid, azelaic acid, maleic acid, fumaric acid, etc.] C8-12 aromatic dicarboxylic acids [terephthalic acid, isophthalic acid, etc.], ester-forming derivatives thereof [acid anhydrides, lower alkyl esters (dimethyl esters, diethyl esters, etc.), acid halides (acid chlorides, etc.), etc. And a mixture of two or more thereof.

Examples of the lactone monomer include γ-butyrolactone, ε-caprolactone, γ-barrel lactone, and a mixture of two or more thereof.

Examples of the polyisocyanate include aromatic diisocyanates such as diphenylmethane diisocyanate and 2,4-tolylene diisocyanate, alicyclic diisocyanates such as isophorone diisocyanate (IPDI) and dicyclohexylmethane-4,4′-diisocyanate (hydrogenated MDI), hexa Aliphatic diisocyanates such as methylene diisocyanate (HDI) are used alone or in admixture of two or more.

The polyester-based urethane resin (C) can be produced using a known urethanization polyaddition technique, and is not particularly limited. For example, after the polyester polyol obtained above and a low molecular compound (chain extender) having two or more active hydrogen atoms are uniformly mixed and preheated, the number of active hydrogen atoms and isocyanate groups in the mixture are mixed. It can be obtained by adding polyisocyanate in an amount such that the molar ratio is from 0.95 to 1: 1.05, and randomly adding polyisocyanates while stirring.

Alternatively, the polyester polyol and the polyisocyanate can be reacted in advance and obtained via a prepolymer of a terminal isocyanate group. These reactions are usually carried out without a solvent, but can also be carried out in a solvent such as dimethylformamide, dimethyl sulfoxide, tetrahydrofuran or toluene.
As the chain extender, diols such as ethylene glycol, propylene glycol, 1,4-butylene glycol and 1,6-hexanediol, diamines such as propylene diamine, and the like are used singly or in combination. Furthermore, if necessary, monovalent low molecular alcohols such as methanol and ethanol, monovalent low molecular amines such as methylamine and ethylamine, and the like can be added as a modifier.
The number average molecular weight of the polyurethane is preferably 10,000 to 200,000, more preferably 15,000 to 100,000.

The polyester-based urethane resin powder (E) of the present invention can be obtained by pulverizing the polyester-based urethane resin composition (B) by the following production method.
Although it does not specifically limit as this manufacturing method, For example, the following method can be illustrated.
(1) A method of obtaining a powder of (B) by pulverizing block or pellet (B) by a method such as freeze pulverization or freeze pulverization.
(2) A non-aqueous dispersion of (B) is formed in an organic solvent (n-hexane, cyclohexane, n-heptane, etc.) that does not dissolve (B), and (B) is separated and dried from the non-aqueous dispersion. A method for obtaining the powder of (B) (for example, a method described in JP-A No. 04-255755).
(3) A method of forming an aqueous dispersion of (B) in water containing a dispersant, separating and drying (B) from the aqueous dispersion, and obtaining a powder of (B) (for example, JP-A-07-133423) And the method described in JP-A-08-120041.
Among these, the method (3) is preferable because a powder having a desired particle size can be easily obtained without using a large amount of an organic solvent.

The method of adding the copolymerized polycarbodiimide (A) to the polyester-based urethane resin (C) is the method of adding to the raw material polyisocyanate or polyester polyol, the method of adding to the prepolymer, the urethane resin after polymerization (C). And the like. When the urethane resin is polymerized by the prepolymer method, a method of adding to the prepolymer is preferable.

The method of adding (A) to the polyester-based urethane resin powder (E) is as follows: (1) After adding to the polyester-based urethane resin (C) by the above method, pulverizing by the above method, (2) ( A method of adding to the polyester-based urethane resin powder (E) by a method such as dry blending or impregnation after powdering by the above method without adding to B) can be taken.

The polyester-based urethane resin composition (B) of the present invention includes extrusion molding materials such as hoses, tubes, films, sheets, belts and rolls, packing molding materials, injection molding materials such as machine parts and automobile parts, and slush molding. It is useful as a coating material such as a coating material, a paint, and a coating vehicle.
The polyester-based urethane resin powder (E) of the present invention is useful as a powder coating material, a powder adhesive, a slush molding material, and the like.

The additive (D) is preferably contained in an amount of 0 to 50% by weight, more preferably 5 to 30% by weight, based on the weight of the polyester-based urethane resin composition (B).
As an additive (D), it can be made to contain arbitrarily according to said each use.
Examples include pigments, fillers, curing agents, curing catalysts, coating surface preparation agents, surfactants, dispersants, plasticizers, ultraviolet absorbers, antioxidants, mold release agents, flame retardants, and the like.
Moreover, the fluidity modifier of powder, an antiblocking agent, etc. can also be added to the polyester-type urethane resin powder (E).

The average particle diameter of the polyester-based urethane resin powder (E) of the present invention is 1 to 400 μm, preferably 5 to 300 μm.

Hereinafter, although an example and a comparative example explain the present invention, the present invention is not limited to this. Hereinafter, unless otherwise specified, “part” means “part by weight” and% means wt%.

Example 1
A 3 liter separable flask was set with a condenser, a thermometer, and a stirrer, and charged with 138 parts of hexamethylene diisocyanate, 1644 parts of isophorone diisocyanate, and 20 parts of 3-methyl-1-phenyl-2-phospholene oxide. The temperature was raised to 120 ° C. over time, and then the copolymer polycarbodiimide (A-1) was synthesized by performing the reaction for 48 hours without changing the temperature. The isocyanate group content was 2.7%. The HDI copolymer molar ratio of (A-1) was calculated from the amount charged and listed in Table 1. (The same applies to the following examples.) The number average molecular weight of (A-1) is calculated from the charged amount and the isocyanate group content and listed in Table 1. (The same applies to the following examples.)

Example 2
Polycarbodiimide (A-2) was synthesized in the same manner as in Synthesis Example 1 except that 668 parts of hexamethylene diisocyanate and 883 parts of isophorone diisocyanate were used. The isocyanate group content was 3.1%.

Example 3
Polycarbodiimide (A-3) was synthesized in the same manner as in Synthesis Example 1 except that 1173 parts of hexamethylene diisocyanate and 388 parts of isophorone diisocyanate were used. The isocyanate group content was 2.4%.

Example 4
A polycarbodiimide (A-4) was synthesized in the same manner as in Synthesis Example 1 except that 937 parts of hexamethylene diisocyanate and 619 parts of isophorone diisocyanate were used. The isocyanate group content was 2.7%.

Example 5
Polycarbodiimide (A-5) was synthesized in the same manner as in Synthesis Example 1 except that the reaction time was changed to 937 parts of hexamethylene diisocyanate and 619 parts of isophorone diisocyanate and the reaction time was changed to 2 hours. The isocyanate group content was 28%.

Example 6
A polycarbodiimide (A-6) was synthesized in the same manner as in Synthesis Example 4 except that the reaction time was changed to 72 hours. The isocyanate group content was 0.8%.

Example 7
Polycarbodiimide (A-7) was synthesized in the same manner as in Example 1 except that 1078 parts of hexamethylene diisocyanate and 712 parts of isophorone diisocyanate were added and 210 parts of 2-ethylhexanol was added at the start of the reaction. The isocyanate group content was 0%.

Example 8
Polycarbodiimide (A-8) was synthesized in the same manner as in Example 1 except that 1078 parts of hexamethylene diisocyanate and 712 parts of isophorone diisocyanate were added and 210 parts of di-n-butyl isocyanate was added at the start of the reaction. The isocyanate group content was 0%.

According to the following manufacture example, the said copolymer polycarbodiimide was added to the polyester-type urethane resin (C), and was formed into particles, and the polyester-type urethane resin powder (E) was produced.

Production Example 1
Production of prepolymer solution In a reaction vessel equipped with a thermometer, a stirrer and a nitrogen blowing tube, polybutylene adipate (497.9 parts) having a number average molecular weight (hereinafter referred to as Mn) of 1000 and poly having a Mn of 900 Hexamethylene isophthalate (124.5 parts), pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] [manufactured by Ciba Specialty Chemicals, Inc .; Irganox 1010] (1.12 parts), kaolin (90.7 parts) having a volume average particle size of 9.2 μm were charged, and after substitution with nitrogen, the mixture was heated to 110 ° C. with stirring and melted, and cooled to 60 ° C. Subsequently, 1-octanol (9.7 parts), hexamethylene diisocyanate (153.4 parts), tetrahydrofuran (250 parts), 2- (2H-benzotriazol-2-yl) -6- (linear and side chain dodecyl) ) -4-methylphenol [manufactured by Ciba Specialty Chemicals; Tinuvin 571] (2.22 parts), reacted at 85 ° C. for 6 hours to obtain a prepolymer solution. The NCO content of this prepolymer was 2.05%.

Production Example 2
Production of MEK ketimine product of diamine Hexamethylenediamine and excess methyl ethyl ketone (hereinafter referred to as MEK, 4 times molar amount with respect to diamine) were refluxed at 80 ° C. for 24 hours, and the generated water was removed out of the system. Thereafter, unreacted MEK was removed under reduced pressure to obtain a MEK ketiminate.

Example 9
Preparation of polyurethane resin powder In a reaction vessel, the prepolymer solution obtained in Production Example 1 (100 parts), the MEK ketimine compound obtained in Production Example 2 (5.6 parts), and the polycarbodiimide (A- 1) (3 parts) was charged, and a dispersant containing a sodium salt of a copolymer of diisobutylene and maleic acid (Sansupar PS-8 manufactured by Sanyo Chemical Industries, Ltd.) (1.3 parts by weight) 340 parts by weight of an aqueous solution in which was dissolved was added and mixed for 1 minute at a rotation speed of 9000 rpm using an ultradisperser manufactured by Yamato Scientific Co. This mixture was transferred to a reaction vessel equipped with a thermometer, a stirrer and a nitrogen blowing tube, purged with nitrogen, and then reacted at 50 ° C. for 10 hours with stirring. After completion of the reaction, filtration and drying were performed to produce polyurethane resin powder (E-1). The volume average particle size (laser diffraction scattering method) of (E-1) was 55 μm as measured by Nikkiso Co., Ltd. Microtrac particle size distribution analyzer HRA. The gel permeation chromatography (GPC) of (E-1) was measured, and Mn of the polyurethane resin portion was 25,000. Table 1 shows the weight average particle diameter of (E-1), the Mn of the polyurethane resin, and the weight of the copolymerized polycarbodiimide (A-1) with respect to the weight of the urethane resin. (The same applies to the following examples.)

Examples 10-16
In Example 9, instead of the polycarbodiimide (A-1) (3 parts) produced in Example 1, each 3 parts of polycarbodiimide (A-2) to (A-8) produced in Examples 2-8 The polyester urethane resin powders (E-2) to (E-8) were produced in the same manner as the others.

Comparative Example 1
According to Production Examples 1 and 2, a prepolymer solution and a diamine MEK ketimine product were produced, and polyester urethane resin powder (E-9) was produced in the same manner as in Example 9 except that polycarbodiimide was not added in Example 9. ') Manufactured.
Comparative Example 2
A prepolymer solution and a MEK ketimine product of a diamine were prepared according to Production Examples 1 and 2, and the polycarbodiimide used in Example 9 was manufactured by Nisshinbo Co., Ltd .; Carbolite V-03 (chemical name: 4,4- Polyester urethane resin powder (E-10 ′) was produced in the same manner as in Example 9, except that dicyclohexylmethane diisocyanate polycarbodiimide) was used.

Comparative Example 3
According to Production Examples 1 and 2, a MEK ketimine product of a prepolymer, a solution, and a diamine was prepared, and the polycarbodiimide used in Example 9 was manufactured by Bayer; in the same manner as in Example 9 except that Stavaxol P was used. A polyester urethane resin powder (E-11 ′) was prepared.

The urethane resin powders (E-1) to (E-8) of Examples 9 to 16 and the urethane resin powders (E-9 ′) to (E-11 ′) of Comparative Examples 1 to 3 were classified into a sonic classifier. And fine powder having a volume average particle size of 20 μm or less and coarse powder having a particle size of 60 μm or more were removed.
Using a commercially available corona charging spray gun on a zinc phosphate-treated steel plate standard plate (manufactured by Nippon Test Panel Co., Ltd.) coated with Sumimold FF (manufactured by Sumiko Lubricant) using this as a mold release agent, the film pressure is 40-60 μm Electrostatic coating was performed, and baking was performed at 180 ° C. for 20 minutes to obtain respective coating films. About the coating film obtained by peeling off these coating films from the standard plate, the following items were tested, and the evaluation results are shown in Table 2.

Example 17
Production of polyurethane resin solution In a reaction vessel, the prepolymer solution (100 parts) obtained in Production Example 1 was dissolved in N, N-dimethylformamide (100 parts), and hexamethylenediamine (2.8 parts) and Example 1 were dissolved. A polyurethane resin solution was prepared by adding the polycarbodiimide (A-1) (3 parts) produced in 1.

Examples 18-24
In Example 17, instead of the polycarbodiimide (A-1) (3 parts) produced in Example 1, 3 parts each of the polycarbodiimides (A-2) to (A-8) produced in Examples 2-8 A polyurethane resin solution was prepared in the same manner as the others.

Comparative Example 4
A polyurethane resin solution was prepared in the same manner as in Example 17 except that polycarbodiimide was not added in Example 17.

Comparative Example 5
A polyurethane resin solution was prepared in the same manner as in Example 17 except that the polycarbodiimide added in Example 17 was changed to Nisshinbo Co., Ltd .; Carbolite V-03.

Comparative Example 6
A polyurethane resin solution was prepared in the same manner as in Example 17, except that the polycarbodiimide added in Example 17 was changed to Bayer Co .;

The polyurethane resin solutions of Examples 17 to 24 and Comparative Examples 4 to 6 are commercially available on zinc phosphate-treated steel sheet standard plates (manufactured by Nippon Test Panel Co., Ltd.) coated with Sumimold FF (manufactured by Sumiko Lubricant) as a release agent. Each coating film was obtained by coating with a spray gun so that the film pressure was 80 to 120 μm and drying at 100 ° C. for 20 minutes. About the coating film obtained by peeling off these coating films from the standard plate, the following items were tested, and the evaluation results are shown in Table 2.

<Moist heat aging test>
The molded skin was treated in a constant temperature and humidity machine at a temperature of 80 ° C. and a humidity of 95% RH for 400 hours. After the test, the tear strength of the epidermis was measured and compared with the initial strength.
The tear strength retention after the wet heat aging test was calculated by the following formula (1).

・ Tear strength Three pieces of JIS K 6301 (1995) tear test specimen dumbbell No. B are punched from the skin sample. The plate thickness takes the minimum value at five locations in the vicinity of the bent location. This is attached to an autograph, pulled at a speed of 200 mm / min, and the maximum strength at which the test piece breaks is calculated.

  From Table 2, it turns out that Examples 9-24 which added copolymer polycarbodiimide of Examples 1-8 have high tear strength retention compared with Comparative Example 1 (carbodiimide addition-free) -6. . Since the tear strength retention rate is high, the hydrolysis resistance is improved.

  The polyester-based urethane resin composition containing the copolymerized polycarbodiimide of the present invention is used for injection molding materials such as hoses, tubes, films, sheets, belts, rolls, packing materials, mechanical parts, automobile parts, etc. It is useful as a coating material for materials, slush molding materials, paints, coating vehicles and the like. The polyester urethane resin powder of the present invention is useful as a powder coating material, a powder adhesive, a slush molding material, and the like.

HDI, IPDI copolymer polycarbodiimide (HDI copolymer molar ratio 67 mol%, terminal isocyanate group) infrared absorption spectrum HDI, IPDI copolymerized polycarbodiimide (HDI copolymer molar ratio 67 mol%, terminal isocyanate group) nuclear magnetic resonance spectrum Nuclide: ¹ H Solvent: CDCl ₃ HDI, IPDI copolymerized polycarbodiimide (HDI copolymer molar ratio 67 mol%, terminal 2-ethylhexanol capped) infrared absorption spectrum HDI, IPDI copolymerized polycarbodiimide (HDI copolymer molar ratio 67 mol%, terminal 2-ethylhexanol capped) Nuclear magnetic resonance spectrum Nuclide: ¹ H Solvent: CDCl ₃

Claims (8)

Copolymer polycarbodiimide (A) of hexamethylene diisocyanate and isophorone diisocyanate. The copolymerized polycarbodiimide (A) according to claim 1, wherein the copolymerization mol% of hexamethylene diisocyanate is 10 to 80 mol%. The copolymerized polycarbodiimide (A) according to claim 1 or 2, which has a number average molecular weight of 300 to 10,000. The polyester-type urethane resin composition (B) containing the copolymer polycarbodiimide (A) of any one of Claims 1-3, and a polyester-type urethane resin (C). The polyester-based urethane resin composition (B) according to claim 4, wherein the content of the copolymerized polycarbodiimide (A) is 0.1 to 10% by weight based on the weight of the polyester-based urethane resin (C). The polyester-type urethane resin composition for coatings containing the polyester-type urethane resin composition (B) of Claim 4 or 5. A polyester urethane resin powder (E) comprising the polyester urethane resin composition (B) according to claim 4 or 5. The polyester-type urethane resin composition for powder coatings containing the polyester-type urethane resin powder (E) of Claim 7.

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