JP4783276B2 - Polyester urethane resin. - Google Patents

Description

  The present invention relates to a polyester urethane resin having a carbodiimide bond (a).

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 polyester-type urethane resin excellent in hydrolysis resistance.

As a result of intensive studies, the present inventors have completed the present invention.
That is, the present invention relates to a slush molding polyester urethane resin (B) having a carbodiimide bond (a) represented by the general formula (1) in the molecule, and the polyester urethane resin (B) is generally used as a diisocyanate component. Using the diisocyanate containing the hexamethylene diisocyanate carbodiimidized dimer (A) represented by the formula (2), and reacting using a polyester diol as the polymer diol component , the hexamethylene diisocyanate carbodiimidized 2 A slush-molding polyester-based urethane resin (B) obtained by using 0.5 to 20% by weight of the monomer (A) based on the weight of the polyester-based urethane resin (B).

The polyester urethane resin of the present invention is excellent in hydrolysis resistance.

一般式（１）で示されるカルボジイミド結合（ａ）としては、一般式（３）〜（５）で示される結合等が挙げられる。

Since the polyester urethane resin of the present invention has a carbodiimide bond (a) represented by the general formula (1) in the molecule, it is excellent in hydrolysis resistance.

Examples of the carbodiimide bond (a) represented by the general formula (1) include bonds represented by the general formulas (3) to (5).

The polyester-based urethane resin of the present invention uses a diisocyanate containing the hexamethylene diisocyanate carbodiimidized dimer (A) represented by the general formula (2) as a diisocyanate component, and uses a polyester-based diol as a polymer diol component. It will be.

(A) is preferably contained in an amount of 0.5% by weight or more based on the weight of the polyester-based urethane resin from the viewpoint of hydrolysis resistance, and contained in an amount of 20% by weight or less from the viewpoint of the mechanical strength of the polyester-based urethane resin. It is preferred that More preferably, it is contained in an amount of 1 to 15% by weight, more preferably 2 to 10% by weight.

The hexamethylene diisocyanate carbodiimidization dimer (A) can be produced by adding a carbodiimidization catalyst to hexamethylene diisocyanate and heating.

1 and 2 show the infrared absorption spectrum and nuclear magnetic resonance spectrum of the hexamethylene diisocyanate carbodiimidized dimer.

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.

As the diisocyanate component, the diisocyanate component (F) other than (A) is not particularly limited as long as it is a diisocyanate used in a urethane resin, but isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4′-diisocyanate (hydrogenated) It is preferable to use alicyclic diisocyanates such as MDI), aliphatic diisocyanates such as hexamethylene diisocyanate (HDI), or a mixture of two or more.
The content mol% of (A) in the mixed diisocyanate of (A) and (F) is preferably 0.1 to 100 mol%, more preferably 1 to 50 mol%.

The polyester-based diol is, for example, (1) a product obtained by condensation polymerization of a low-molecular diol and a dicarboxylic acid or an ester-forming derivative thereof [an acid anhydride, a lower alkyl (1 to 4 carbon atoms) ester, an acid halide, etc.]; ) A 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.

The polyester-based urethane resin of the present invention can be produced using a known urethane polyaddition technique. That is, the polyester-based diol obtained above and, if necessary, a low molecular compound (chain extender) having two or more active hydrogen atoms are uniformly mixed and preheated, and then the number of active hydrogen atoms in these mixtures And a diisocyanate composed of a mixture of hexamethylene diisocyanate carbodiimidized dimer (A) and diisocyanate component (F) in an amount of 0.95 to 1.05 in molar ratio to the isocyanate group. It can be obtained by adding.

Also, a polyester-based diol, hexamethylene diisocyanate carbodiimidized dimer (A) and, if necessary, a diisocyanate composed of a mixture of diisocyanate components (F) are reacted in advance and obtained via a prepolymer of a terminal isocyanate group. You can also. These reactions are usually carried out without solvent, but can also be carried out in a solvent such as dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, toluene, ethyl acetate.
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 of the present invention is, as necessary, added with an additive (D) as a polyester-based urethane resin composition (C), as a material for extrusion molding such as hoses, tubes, films, sheets, belts, rolls, It is useful as a packing material such as packing materials, injection molding materials such as machine parts and automobile parts, slush molding materials, paints and coating vehicles.

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 urethane resin composition (C).
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.

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

The average particle diameter of the polyester-based urethane resin particles (E) of the present invention is 1 to 400 μm, preferably 5 to 300 μm.
A powder fluidity modifier, an antiblocking agent, and the like can be added to the polyester-based urethane resin particles (E).

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.

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

Production Example 1
Synthesis of hexamethylene diisocyanate carbodiimidized dimer (A) A 3 liter separable flask was equipped with a condenser, thermometer and stirrer, 300 parts of hexamethylene diisocyanate, 3-methyl-1-phenyl-2-phospholene 3 parts of oxide was charged, heated to 120 ° C. over 1 hour, and then reacted for 1.5 hours without changing the temperature, thereby synthesizing hexamethylene diisocyanate carbodiimidized dimer (A). The isocyanate group content was 27%.

Production Example 2
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 (92.1 parts), hexamethylene diisocyanate carbodiimidized dimer (A) (57.3 parts), tetrahydrofuran (250 parts), 2- ( 2H-benzotriazol-2-yl) -6- (straight and side chain dodecyl) -4-methylphenol [manufactured by Ciba Specialty Chemicals, Inc .; Tinuvin 571] (2.22 parts), 6 at 85 ° C. A prepolymer solution was obtained by reacting for a period of time. The NCO content of this prepolymer was 0.83%.

Production Example 3
Production of MEK ketimine product of diamine Hexamethylenediamine and excess 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 1
Production of polyurethane resin particles Into a reaction vessel, the prepolymer solution obtained in Production Example 2 (100 parts) and the MEK ketimine compound obtained in Production Example 3 (2.3 parts) were added, and diisobutylene, maleic acid and 340 parts by weight of an aqueous solution in which a dispersing agent (Sansper Chemical PS-8 manufactured by Sanyo Chemical Industries Co., Ltd.) (1.3 parts by weight) containing a Na salt of the copolymer is added, and Ultradis manufactured by Yamato Scientific Co., Ltd. is added. Using a parser, mixing was performed at 9000 rpm for 1 minute. 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 particles (E-1). When the volume average particle diameter (laser diffraction scattering method) was measured with a Nikkiso Co., Ltd. Microtrac particle size distribution analyzer HRA, the volume average particle diameter of (E-1) was 55 μm. The number average molecular weight was measured by gel permeation chromatography (GPC). Mn of (E-1) was 25,000. The weight of the hexamethylene diisocyanate carbodiimidized dimer (A) relative to the weight of the polyurethane resin was 6.5% by weight. The results are shown in Table 1. The same applies to the following embodiments.

Example 2
A prepolymer was synthesized in the same manner as in Example 1 except that Example 1 was changed to 122 parts of hexamethylene diisocyanate and 51 parts of hexamethylene diisocyanate carbodiimidized dimer (A). The NCO content of this prepolymer was 1.75%. Furthermore, a polyurethane resin powder (E-2) was produced in the same manner as in Example 1 except that the amount of MEK ketimine compound added in Example 1 was changed to 4.9 parts. Mn of (E-2) was 25,000, and the volume average particle diameter was 59 μm.

Example 3
A prepolymer was synthesized in the same manner as in Example 1 except that 149 parts of hexamethylene diisocyanate and 57 parts of hexamethylene diisocyanate carbodiimidized dimer (A) in Production Example 2 were changed in Example 1. The NCO content of this prepolymer was 2.84%. Furthermore, a polyurethane resin powder (E-3) was produced in the same manner as in Example 1 except that the amount of MEK ketimine compound added in Example 1 was changed to 7.9 parts. Mn of (E-3) was 25,000, and the volume average particle size was 64 μm.

Example 4
A prepolymer solution was obtained in the same manner as in Production Example 2 except that isophorone diisocyanate (135 parts) was used instead of hexamethylene diisocyanate (92.1 parts) in Production Example 2. The NCO content of this prepolymer was 0.72%. Furthermore, a polyurethane resin powder (E-4) was produced in the same manner as in Example 1 except that the amount of MEK ketimine compound added in Example 1 was changed to 2.0 parts. Mn of (E-4) was 25,000, and the volume average particle diameter was 48 μm.

Comparative Example 1
A prepolymer was synthesized in the same manner as in Example 1 except that the hexamethylene diisocyanate carbodiimidized dimer (A) of Production Example 2 was added in Example 1 and 153.4 parts of hexamethylene diisocyanate was used. did. The NCO content of this prepolymer was 1.75%. Furthermore, a polyurethane resin powder (E-5 ′) was produced in the same manner as in Example 1 except that the amount of MEK ketimine compound added in Example 1 was changed to 4.9 parts. Mn of (E-5 ′) was 25,000, and the volume average particle diameter was 55 μm.

Comparative Example 2
A prepolymer was synthesized in the same manner as in Example 4 except that 225 parts of isophorone diisocyanate was used in Example 4 without adding the hexamethylene diisocyanate carbodiimidized dimer (A) of Production Example 2. The prepolymer had an NCO content of 0.64%. Furthermore, a polyurethane resin powder (E-6 ′) was produced in the same manner as in Example 1 except that the amount of MEK ketimine compound added in Example 1 was changed to 1.8 parts. Mn of (E-6 ′) was 26,000, and the volume average particle diameter was 60 μm.

Comparative Example 3
Polycarbodiimide manufactured by Nisshinbo Co., Ltd. without adding the hexamethylene diisocyanate carbodiimidized dimer (A) of Production Example 2 in Example 1; Carbodilite V-03 (chemical name: 4,4-dicyclohexyl) A prepolymer was synthesized in the same manner as in Example 1 except that 57 parts of methanediisocyanate polycarbodiimide) was added. The NCO content of this prepolymer was 0.80%. Furthermore, a polyurethane resin powder (E-7 ′) was produced in the same manner as in Example 1 except that the amount of the MEK ketimine compound added in Production Example 4 was changed to 2.3 parts. Mn of (E-7 ′) was 27,000, and the volume average particle size was 54 μm.

Comparative Example 4
In Example 1, except that the hexamethylene diisocyanate carbodiimidized dimer (A) of Production Example 2 was not added, but the same as Example 1 except that 57 parts of polycarbodiimide; A polymer was synthesized. The NCO content of this prepolymer was 0.80%. Furthermore, a polyurethane resin powder (E-8 ′) was produced in the same manner as in Example 1 except that the amount of MEK ketimine compound added in Production Example 4 was changed to 2.3 parts. Mn of (E-8 ′) was 27,000, and the volume average particle diameter was 55 μm.

The polyurethane resin particles (E-1) to (E-4) of Examples 1 to 4 and the polyurethane resin particles (E-5 ′) to (E-8 ′) of Comparative Examples are classified by a sonic classifier. Then, fine powder having a volume average particle diameter of 20 μm or less and coarse powder having a volume average particle diameter 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 adjusted to 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 1.

Example 5
Production of polyurethane resin solution In a reaction vessel, the prepolymer solution (100 parts) obtained in Production Example 2 was dissolved in N, N-dimethylformamide (100 parts), and hexamethylenediamine (1.1 parts) was added. A polyurethane resin solution was prepared by mixing.

Example 6
The prepolymer solution (100 parts) of Example 2 was dissolved in N, N-dimethylformamide (100 parts), and hexamethylenediamine (2.3 parts) was added and mixed to prepare a polyurethane resin solution. .

Example 7
The prepolymer solution (100 parts) of Example 3 was dissolved in N, N-dimethylformamide (100 parts), and hexamethylenediamine (3.8 parts) was added and mixed to prepare a polyurethane resin solution. .

Example 8
The prepolymer solution (100 parts) of Example 4 was dissolved in N, N-dimethylformamide (100 parts), and hexamethylene diamine (1.0 part) was added and mixed to prepare a polyurethane resin solution. .

Comparative Example 5
The prepolymer solution (100 parts) obtained in Comparative Example 1 was dissolved in N, N-dimethylformamide (100 parts), and hexamethylenediamine (2.3 parts) was added and mixed to obtain a polyurethane resin solution. Produced.

Comparative Example 6
The prepolymer solution (100 parts) obtained in Comparative Example 2 was dissolved in N, N-dimethylformamide (100 parts), and hexamethylenediamine (0.8 parts) was added and mixed to obtain a polyurethane resin solution. Produced.

Comparative Example 7
The prepolymer solution (100 parts) obtained in Comparative Example 3 was dissolved in N, N-dimethylformamide (100 parts), and hexamethylenediamine (1.1 parts) was added and mixed to obtain a polyurethane resin solution. Produced.

Comparative Example 8
The prepolymer solution (100 parts) obtained in Comparative Example 4 was dissolved in N, N-dimethylformamide (100 parts), and hexamethylenediamine (1.1 parts) was added and mixed to obtain a polyurethane resin solution. Produced.

Using a commercially available spray gun on a zinc phosphate treated steel plate standard plate (manufactured by Nippon Test Panel Co., Ltd.) coated with Sumimold FF (manufactured by Sumitomo Lubricant) using these as a mold release agent, the film pressure becomes 80 to 120 μm. Each coating film was obtained by painting 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 Tables 1 and 2, it can be seen that Examples 1 to 8 to which hexamethylene diisocyanate carbodiimidized dimer is added have higher tear strength retention than Comparative Examples 1 to 8. Since the tear strength retention rate is high, the hydrolysis resistance is improved.

The polyester-based urethane resin composition containing the polyester-based urethane resin of the present invention is used for injection molding of extrusion materials such as hoses, tubes, films, sheets, belts, rolls, packing materials, machine 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 particles of the present invention are useful as a powder coating material, a powder adhesive, a slush molding material, and the like.

Hexamethylene diisocyanate carbodiimidized dimer, infrared absorption spectrum Hexamethylene diisocyanate carbodiimidized dimer, nuclear magnetic resonance spectrum Nuclide: ¹ H Solvent: CDCl ₃

Claims (3)

A slush-molding polyester-based urethane resin (B) having a carbodiimide bond (a) represented by the general formula (1) in the molecule, wherein the polyester-based urethane resin (B) is represented by the general formula (2) as a diisocyanate component. Using the diisocyanate containing the hexamethylene diisocyanate carbodiimidized dimer (A) shown, and reacting using a polyester diol as the polymer diol component , the hexamethylene diisocyanate carbodiimidized dimer (A) Slush molding polyester-based urethane resin (B), which is used in an amount of 0.5 to 20% by weight based on the weight of the polyester-based urethane resin (B).

Claim 1 The polyester-type urethane resin composition (C) for slush molding containing the polyester-type urethane resin (B) of description. A polyester urethane resin particle for slush molding (E) comprising the polyester urethane resin composition for slush molding (C) according to claim 2 .

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