JPH08134222A - Polyester-modified polyol resin and production thereof - Google Patents

Abstract

PURPOSE: To obtain a polyester-modified polyol resin by reacting a polyester resin with a polyol resin obtained by reacting bisphenol epoxy resins, a specific polyester resin, and compounds. CONSTITUTION: A bisphenol epoxy resin having an epoxy equivalent of 170-500 and a number-average mol.wt. (Mn ) of 350-1,200 is mixed with a bisphenol epoxy resin having an epoxy equivalent of 1,500-5,000 and an Mn of 2,000-5,000, a compound having active hydrogen, e.g. p-cumylphenol, bisphenol A, and a carboxyl-terminated polyester resin having an acid value of 20-70 and an Mn of 1,500-6,000 and containing two or more carboxyl groups, in a given proportion. The mixture is heated with stirring to give a homogeneous melt. A catalyst is added to the melt, and this mixture is reacted at about 100-200 deg.C for a given period to yield a polyol resin. A polyester resin having an acid value of 0-50 and an Mn of 1,500-6,000 is added thereto, and the resulting mixture is reacted at about 100-200 deg.C to obtain the objective resin having a softening point of about 70-180 deg.C, a glass transition temp. of about 50-90 deg.C, and an Mn of about 800-5,000.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester-modified polyol resin and a method for producing the same, and in particular, a cured coating film having excellent flexibility can be obtained by using it as a polyol component of a coating material, and further, it has high crosslinking reactivity. The present invention relates to a polyester-modified polyol resin that can be suitably used as a component of a baking paint and the like and a method for producing the same.

[0002]

2. Description of the Related Art A high molecular weight bisphenol type epoxy resin has a considerable amount of a secondary alcoholic hydroxyl group in the side chain of its molecular chain and can be considered as a kind of polyol resin. Therefore, a high molecular weight bisphenol type epoxy resin is used, for example, as a polyol component of a urethane paint.

[0003]

However, a cured coating film obtained by curing a urethane coating containing a bisphenol type epoxy resin as a polyol component has a drawback that it is brittle due to the rigidity of the bisphenol type epoxy resin itself. is there. Further, in order to save energy in the coating line, a coating composition having a short baking time, that is, a short curing time is required, and the appearance of a polyol component having higher reactivity than that of a conventional bisphenol epoxy resin or the like. Is desired.

Therefore, a first object of the present invention is to obtain a cured coating film having excellent flexibility by using a bisphenol type epoxy resin as a starting material and as a polyol component of a coating material, and further, having a high crosslinking reactivity. Therefore, it is an object of the present invention to provide a novel method for producing a polyester-modified polyol resin capable of obtaining a coating material having a short curing time.

A second object of the present invention is to provide a novel polyester-modified polyol resin obtained by the above method, which is suitable as a polyol component for baking paints and the like.

[0006]

Means for Solving the Problems The present inventors have conducted extensive studies in order to improve the drawbacks of the bisphenol type epoxy resin as such a polyol component. As a result, the bisphenol-type epoxy resin is reacted with bisphenols and a carboxylic acid-terminated polyester resin having an average of two or more carboxyl groups in the molecule to extend the chain length, and at the same time the epoxy groups at both ends of the bisphenol-type epoxy resin are After reacting a monovalent active hydrogen compound capable of reacting with substantially all of the epoxy groups present, and then further reacting with a polyester resin, the bisphenol type epoxy resin which is hard and brittle has an appropriate flexibility. The present invention has been found out that is added. When a carboxylic acid-terminated polyester resin having an average of two or more carboxyl groups in the molecule is used as the chain extender, the reactivity of the resulting polyol resin with the methylol group-containing compound and the isocyanate compound is improved, It has been found that time baking or lowering of the curing temperature is possible.

That is, according to the present invention, in the presence or absence of the bisphenol (C), (i) the epoxy group in the bisphenol type epoxy resin (A) and two or more carboxyl groups on average in the molecule. A step of reacting the carboxylic acid-terminated polyester resin (B) with, (ii) an epoxy group in the bisphenol type epoxy resin (A),
A step of reacting a compound (D) having one active hydrogen in the molecule to produce a polyol resin (F) which does not substantially contain an epoxy group, and then a polyol resin (F) and a polyester resin The present invention provides a method for producing a polyester-modified polyol resin having a step of reacting with (E).

The present invention also provides, as a novel polyester-modified polyol resin, an epoxy group in a bisphenol type epoxy resin (A) and a carboxyl group in the molecule in the presence or absence of a bisphenol (C). A carboxylic acid-terminated polyester resin (B) having an average of two or more and a compound (D) having one active hydrogen in the molecule are represented by the following formulas (1) and (2):

[0009]

(Equation 3)

[0010]

[Equation 4]

In the above formulas (1) and (2), w: amount of bisphenol (C) used (g) x: amount of compound (D) having one active hydrogen in the molecule (g) y: Amount of carboxylic acid terminated polyester resin (B) having an average of 2 or more carboxyl groups in the molecule (g) z ¹ : amount of epoxy resin (A1) (g) z ² : amount of epoxy resin (A2) used (G) α: Hydroxyl equivalent of bisphenol (C) (g / eq) β: Hydroxyl equivalent or carboxyl equivalent of compound (D) having one active hydrogen in the molecule (g / eq) γ: Polyester resin ( B) carboxyl group equivalent (g
/ Eq) δ ¹ : Epoxy equivalent of the epoxy resin (A1) (g / e
q) δ ² : Epoxy equivalent (g / e) of epoxy resin (A2)
q) Polyester modification obtained by reacting a polyester resin (E) with a polyol resin (F) having a carboxylic acid-terminated polyester resin (B) content of 1 to 30% by weight, which is reacted so as to satisfy A polyol resin,
A polyester-modified polyol resin satisfying the following formula (3): 10 ≦ polyester resin (E) / polyester-modified polyol resin ≦ 90 (formula 3) is provided.

Hereinafter, a method for producing the polyester-modified polyol resin of the present invention (hereinafter referred to as "method of the present invention"),
Further, the polyester-modified polyol resin obtained by the production method thereof will be described in detail.

The method of the present invention comprises bisphenols (C)
In the presence or absence of (i) the epoxy group in the bisphenol type epoxy resin (A) and the carboxylic acid-terminated polyester resin (B) having an average of two or more carboxyl groups in the molecule are reacted. Substantially no epoxy group-containing polyol, which comprises a step and (ii) a step of reacting the epoxy group in the bisphenol type epoxy resin (A) with a compound (D) having one active hydrogen in the molecule. It is a method having a step of producing a resin (F) and then reacting the polyol resin (F) with the polyester resin (E). In the present invention, the term "substantially free of epoxy group" means that the carboxylic acid-terminated polyester resin (B) and compound (D) with respect to the epoxy group have the formula 2
Means that the epoxy equivalent is approximately 1
Saying that it is over 10,000. In the method of the present invention,
The order of performing the step (i) and the step (ii) is not particularly limited, and the step (ii) may be performed after the step (i).
After performing i), step (i) may be performed, or
You may perform (i) and process (ii) simultaneously. Usually step (i)
And step (ii) can be performed simultaneously without any particular distinction. In addition, it is preferable to add the bisphenol type epoxy resin (A2) described below immediately before the both steps are completed, because side reactions such as branching reaction of alcoholic hydroxyl groups in the bisphenol type epoxy resin (A2) can be suppressed.

The bisphenol type epoxy resin (A) used in the step (i) and the step (ii) carried out by the method of the present invention is, for example, the following general formula:

[0015]

Embedded image

R ² is a hydrogen atom or a methyl group, and R 2
³ is a hydrogen atom, a methyl group or a halogen atom,
n is the number of repeating units and is an integer of 0 or more]

Examples include those represented by: This bisphenol type epoxy resin (A) is further reacted with the reaction of bisphenols with epichlorohydrin or β-methylepichlorohydrin, and optionally with bisphenols to extend the chain length. Can be obtained.

This bisphenol type epoxy resin (A)
As specific examples (when n = 0 in the general formula (I)), 2,2-bis (4-hydroxyphenyl) propane (commonly known as bisphenol A), bis (4-hydroxyphenyl) methane (commonly known as bisphenol F) ), 1,
Examples thereof include glycidyl ethers of bisphenols such as 1-bis (4-hydroxyphenyl) ethane (commonly called bisphenol AD) or β-methylglycidyl ethers. Among these bisphenol type epoxy resins (A), glycidyl ether of 2,2-bis (4-hydroxyphenyl) propane is particularly preferable.

In the method of the present invention, among the bisphenol type epoxy resins (A), the amount of hydrolyzable chlorine is 0.00 because the heat stability of the resin during production is good.
It is preferably from 1 to 1.0% by weight, particularly 0.01
It is preferably about 0.50% by weight.

In the method of the present invention, as the bisphenol type epoxy resin (A) represented by the general formula (I), two kinds of epoxy equivalents (A1) and (A2) having different epoxy equivalents and number average molecular weights are used. It is preferable to use it in combination. In particular, when the bisphenol type epoxy resin (A2) described below is added and reacted immediately before the completion of both the steps (i) and (ii), side reactions such as a branching reaction can be suppressed. preferable. As the bisphenol type epoxy resin (A), (A1) and (A2)
In the case of using two kinds of the bisphenol type epoxy resin (A1), the epoxy equivalent is usually 150 to 800.
It is of the order of magnitude, and particularly preferably 170 to 500. In particular, the step of coexisting with bisphenols (C)
When (i) or step (ii) is performed, the bisphenol type epoxy resin (A1) has an epoxy equivalent of 170 to 5
It is preferable to use the one of 00. The number average molecular weight (Mn) is usually 300 to 1500, and particularly 3
Those of 50 to 1200 are preferable.

The other bisphenol type epoxy resin (A2) has an epoxy equivalent of usually 1000 to
It is about 6000, and particularly preferably 1500 to 5000. The number average molecular weight (Mn) is usually 1500 to 8000, and particularly 2000 to 500.
0 is preferable.

The bisphenols (C) used in the method of the present invention may be the same as or different from the bisphenols constituting the skeleton of the bisphenol type epoxy resin (A). The bisphenols (C) may be used alone or in combination of two or more.

The carboxylic acid-terminated polyester resin (B) used in step (i) of the method of the present invention has an average of 2 or more, preferably 2 to 3, carboxyl groups in the molecule,
It is a linear polyester resin or a non-linear polyester resin having a carboxyl group at the molecular end. Examples of the linear polyester resin include those obtained by polycondensing dihydric alcohol and divalent carboxylic acid, and examples of the non-linear polyester resin include, for example, dihydric alcohol and divalent carboxylic acid, and Examples thereof include those obtained by polymerizing a polyhydric alcohol or a polyhydric carboxylic acid having a valency or more.

Examples of the dihydric alcohol include ethylene glycol, diethylene glycol, polyethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol and 1,4-butenediol. And diols such as 1,4-bis (hydroxymethyl) cyclohexane, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, polyoxypropyleneized bisphenol A, and other etherified bisphenols.

Examples of the divalent carboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid and naphthalenedicarboxylic acid, succinic acid, fumaric acid, adipic acid,
Maleic acid, sebacic acid, decamethylene dicarboxylic acid,
Aliphatic dicarboxylic acids such as mesaconic acid, citraconic acid, itaconic acid, glutaconic acid and maconic acid, alicyclic compounds such as 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, hexahydrophthalic acid and tetrahydrophthalic acid Examples thereof include dicarboxylic acids, acid anhydrides thereof, dimers of lower alkyl esters and linoleic acid, and the like.

Examples of trihydric or higher polyhydric alcohols include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, 1 , 2,4-butanetriol, 1,2,5-pentanetriol, glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol,
Trimethylol butane, trimethylol propane, 1,
3,5-trihydroxymethylbenzene etc. can be mentioned.

Examples of trivalent or higher polycarboxylic acids include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2,5-benzenetricarboxylic acid, 1,
2,4-cyclohexanetricarboxylic acid, 2,5,7-
Naphthalene tricarboxylic acid, 1,2,4-naphthalene tricarboxylic acid, 1,2,4-butane tricarboxylic acid,
1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxylic propane, tetra (methylenecarboxyl) methane, 1,
2,7,8-octane tetracarboxylic acid, acid anhydrides or lower alkyl esters thereof, and the like can be mentioned.

The carboxylic acid-terminated polyester resin (B) having these components may be used alone or in combination of two or more. In particular, in the method of the present invention, as the carboxylic acid-terminated polyester resin (B), terephthalic acid is used as the divalent carboxylic acid, ethylene glycol and neopentyl glycol are used as the divalent alcohol, and trimellitic acid or trimellitic anhydride is used as the polycarboxylic acid. Carboxylic acid-terminated polyester resins having a minimum of structural units are preferred.

The carboxylic acid-terminated polyester resin (B) preferably has an acid value (mgKOH / g) of 20 to.
70, and more preferably 25 to 40. The carboxylic acid terminated polyester resin (B) preferably has a number average molecular weight (Mn) of 1500 to 6000.

In the method of the present invention, as the compound (D) having one active hydrogen in the molecule used in the step (ii), monohydric phenols or monohydric carboxylic acids are usually used. Examples of monohydric phenols include phenol, cresol, isopropylphenol, amylphenol, nonylphenol, todecylphenol, xylenol, cumylphenol, octylphenol and the like. Among these, carbon number 6
-40 is preferable. The monovalent carboxylic acid, for example, acetic acid, propionic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, acrylic acid, oleic acid, arachidic acid, linoleic acid, castor oil fatty acid, tall oil fatty acid Etc. Among these, those having 6 to 25 carbon atoms are preferable.

In the present invention, the compound (D) comprising these components may be used alone or in combination of two or more. In particular, as the compound (D), monohydric phenols such as p-cumylphenol and p-octylphenol are preferable because the raw materials are easily available and the sublimation amount under the reaction conditions is small.

In the method of the present invention, the carboxylic acid terminated polyester resin (B) used in the step (i) and the compound (D) having one active hydrogen in the molecule used in the step (ii).
Are bisphenol type epoxy resins (A1) and (A2) used in both steps, and bisphenols (C) are
It is used in a usage amount that satisfies the following formulas (1) and (2).

[0033]

(Equation 5)

[0034]

(Equation 6)

In the above formulas (1) and (2), w: amount of bisphenol (C) used (g) x: amount of compound (D) having one active hydrogen in the molecule (g) y: Amount of carboxylic acid terminated polyester resin (B) having an average of 2 or more carboxyl groups in the molecule (g) z ¹ : amount of epoxy resin (A1) (g) z ² : amount of epoxy resin (A2) used (G) α: Hydroxyl equivalent of bisphenol (C) (g / eq) β: Hydroxyl equivalent or carboxyl equivalent of compound (D) having one active hydrogen in the molecule (g / eq) γ: Polyester resin ( B) carboxyl group equivalent (g
/ Eq) δ ¹ : Epoxy equivalent of the epoxy resin (A1) (g / e
q) δ ² : Epoxy equivalent (g / e) of epoxy resin (A2)
q)

In the method of the present invention, the bisphenol type epoxy resin (A2) is generally contained in the obtained polyol resin (F) in an amount of 0 to 25% by weight, preferably 5 to
It is preferable to adjust the amount used so as to contain 20% by weight and to add the polyester-modified polyol resin having a Tg of 60 ° C. or higher.

The content of the carboxylic acid terminated polyester resin (B) in the polyol resin (F) is 0 to 30.
%, Preferably 1 to 10% by weight.

Steps (i) and (ii) in the method of the present invention
In the presence or absence of the bisphenols (C), the reaction of the epoxy group of the bisphenol type epoxy resin (A) with the carboxylic acid terminated polyester resin (B) and the compound (D) is usually 50 to 250 ° C. And preferably at a temperature of 100 to 200 ° C.

In the method of the present invention, the reaction in the step (i) or (ii) can be carried out in the presence of a catalyst. Examples of the catalyst to be used include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide, alkali metal alcoholates such as sodium methylate, tertiary amines such as dimethylbenzylamine, triethylamine and pyridine, and tetraamines. Quaternary ammonium salts such as methylammonium chloride and benzyltrimethylammonium chloride, organic phosphorus compounds such as triphenylphosphine, triethylphosphine and triphenylphosphine, sodium carbonate, alkali metal salts such as lithium chloride, boron trifluoride, aluminum chloride, Tin tetrachloride,
A preferable example is a diethyl ether complex of Lewis acids such as boron trifluoride.

The amount of the catalyst used varies depending on the reaction temperature, but is usually 0.1 to 1000 wtppm, preferably 1 to 100 wt% based on the weight of the polyol resin (F) produced.
wt ppm.

The reaction in steps (i) and (ii) may be carried out without using a solvent or may be carried out using a solvent. When a solvent is used, a solvent having no active hydrogen such as hydrocarbons such as toluene and xylene, ketones such as methyl isobutyl ketone, methyl ethyl ketone and cyclohexanone can be used.

In the method of the present invention, the polyol resin (F) produced by the above steps (i) and (ii) is
Further, it is subjected to a step of reacting with the polyester resin (E).

In the method of the present invention, the polyester resin (E) to be reacted with the polyol resin (F) has an average of 3 or less carboxyl groups in the molecule, preferably 0 to 2
It is a linear or non-linear polyester resin having individual pieces.
Examples of the linear polyester resin include those obtained by polycondensing a dihydric alcohol and a divalent carboxylic acid.Examples of the non-linear polyester resin include, for example, a dihydric alcohol and a divalent carboxylic acid, and Examples thereof include those obtained by polymerizing a polyhydric alcohol or a polyhydric carboxylic acid having a valency or more.

The dihydric alcohol, dihydric carboxylic acid, trihydric or higher polyhydric alcohol and polyhydric carboxylic acid are the same as those exemplified for the carboxylic acid terminated polyester resin (B) used in the above step (i). Things can be used. Usually, terephthalic acid as a divalent carboxylic acid, ethylene glycol and neopentyl glycol as a dihydric alcohol, when using a polyester resin having a minimal constituent unit such as trimellitic acid or trimellitic anhydride as a polycarboxylic acid, preferable.

This polyester resin (E) has an acid value (m
Those in which gKOH / g) is 0 to 50 are preferable from the viewpoint of thermal stability of the polyester-modified polyol resin. Further, those having a number average molecular weight (Mn) of 1500 to 6000 are preferable.

When the polyol resin (F) and the polyester resin (E) are reacted, the polyester resin (E)
Is usually added to the resulting polyester-modified polyol resin in an amount of 10 to 90% by weight, preferably 25 to 75% by weight. The temperature in this reaction is usually about 100 to 200 ° C. Also,
This step may be performed without using a solvent or may be performed using a solvent. When using a solvent, toluene,
Solvents having no active hydrogen such as hydrocarbons such as xylene, ketones such as methyl isobutyl ketone, methyl ethyl ketone and cyclohexanone can be used.

Further, this reaction step is usually carried out without newly adding a catalyst, but it may be carried out in the presence of the catalyst by adding a catalyst. As the catalyst used,
For example, Group IIA or IIB such as Ca, Mg, Zn, Cd
Group metal compounds, Ti, Ge, Sn, Pb, Sb, M
Examples thereof include compounds of group IVA or group IVB or group Vb metal such as n. The addition amount of these catalysts is usually 5 to 5 with respect to the polyester-modified polyol resin obtained.
The amount is 00 wtppm.

The reaction between the polyol resin (F) and the polyester resin (E) is roughly divided into two types of reactions. The first reaction is an esterification reaction between an alcoholic hydroxyl group in the polyol resin (F) and a carboxyl group of the polyester resin (E) when a carboxyl group is present in the polyester resin (E), The reaction 2 is an ester exchange reaction between the ester bond in the molecular skeleton of the polyol resin (F) and the polyester resin (E) and the alcoholic hydroxyl group in the polyol resin (F). Further, this reaction is carried out at a reaction temperature of 100 to 200 ° C., preferably 130 to 170 ° C., if necessary under reduced pressure and dehydration.

The polyester-modified polyol resin of the present invention obtained by the above method satisfies the above formulas (1) and (2) obtained by the above method, and further has the following formula (3): 10 ≦ polyester resin (E) / Polyester-modified polyol resin ≦ 90 A polyester-modified polyol resin that substantially does not contain an epoxy group and that satisfies (Formula 3). Further, this polyester-modified polyol resin has a toughness (=) attributed to a rigid bisphenol skeleton and a flexible ether bond.
It is a novel polyol resin having both hardness and large breaking elongation, and at the same time excellent flexibility due to the polyester backbone coexisting in the resin main chain backbone and side chains.

The acid value of the polyester-modified polyol resin is usually about 1 to 20 mgKOH / g, and the hydroxyl value is usually about 150 to 300 KOHmg / g. The softening point is about 70 to 180 ° C. Furthermore, the glass transition temperature is about 50 to 90 ° C., and the number average molecular weight (Mn) is about 800 to 5000.

The polyester-modified polyol resin of the present invention is a baking coating in combination with a melamine resin, an amine resin such as a urea resin, a resin having a methylol group such as resole, or an isocyanate or a block isocyanate at room temperature. It can be used as a dry paint or a baking paint.

Further, the polyester-modified polyol resin of the present invention is blended with other polyol resins such as polyester polyol and acrylic polyol, polyethers such as polyethylene glycol and polypropylene glycol, polyester resin, acrylic resin and fibrin resin. And can be used as a modifier for these resins.

Since the polyester-modified polyol resin of the present invention has a Tg of 55 ° C. or higher, it shows good blocking resistance. Therefore, it also has the feature of exhibiting extremely good storage stability in applications where it is stored in a powder state for a long period of time.

When the polyester-modified polyol resin of the present invention is used for various purposes, talc, calcium carbonate, silica, carbon, petroleum resin,
Various vinyl compound polymers, inorganic or organic fillers such as tar and asphalt, and pigments can also be used in combination.

[0055]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples. The present invention is not limited to these examples. In addition, in the following Examples and Comparative Examples, the epoxy equivalent and the hydroxyl value were measured according to the following methods.

Epoxy equivalent 0.2 to 10 g of resin is precisely weighed, put in a 200 ml Erlenmeyer flask, and 25 ml of dioxane is added and dissolved. 1 /
After accurately adding 25 ml of a 5 N hydrochloric acid solution (dioxane solution), the mixture is tightly capped, sufficiently mixed, and then left to stand for 30 minutes. Next, after adding 50 ml of a toluene-ethanol (1: 1, volume ratio) mixed solution, the mixture is titrated with a 1/10 N sodium hydroxide solution using cresol red as an indicator.
Based on the titration result, the epoxy equivalent is calculated according to the following formula.

[0057]

(Equation 7)

W: Weight of sample (g) S: Titration of 1 / 10N sodium hydroxide solution (m
l) f: titer of 1/10 normal sodium hydroxide Q: titer of 1/10 normal sodium hydroxide solution in blank test (ml)

Hydroxyl value 1.5 to 2.0 g of resin is precisely weighed and put in a 25 ml volumetric flask, filtered with a molecular sieve 4A, and ethanol and purified chloroform from which water has been removed are added and dissolved.
After completely dissolving, add 25 ml of purified chloroform.
The sample solution was prepared by adjusting the marked line to l. Next, the sample solution is placed in a KBr solution cell (thickness: 0.2 mm), and the absorbance at a wavelength of 4000 to 3000 cm ^-1 is measured using purified chloroform as a control solution. The absorbances T ₁ and T ₂ of the _two absorption peaks appearing in the absorbance curve are determined with the absorbance of the control solution as the zero standard.

Next, based on the calibration curve prepared in advance according to the following method, T ₁ + T obtained above is calculated.
_The hydroxyl group concentration (eq / l) is calculated from the value of ₂ , and the hydroxyl value is calculated according to the following formula.

[0061]

(Equation 8)

Here, F = cell thickness correction coefficient, F = L ₁ / L ₂ L ₁ = cell thickness at the time of creating a calibration curve (mm) L ₂ = cell thickness used for absorbance measurement ( mm)

Preparation of calibration curve In each of the six 25 ml flasks, the molecular
Purified Diethylene Glycol filtered and dehydrated with a tube 4A
To 0.1, 0.2, 0.3, 0.4, 0.5 and
Collect 0.6 g, add purified chloroform and add 25 ml.
Adjusted to the marked lines, 0.075, 0.151, 0.
226, 0.301, 0.376 and 0.452eq
A standard solution having a hydroxyl equivalent of 1 / l is prepared. These standard solutions
Using a KBr liquid cell (0.2 mm).
Wavelength 4000-3000 cm with rum as control liquid^-1To
The absorbance curve is measured. The two that appear in the absorbance curve
Absorbance T of absorption peak₁And T₂Is the absorbance of the control solution
Is taken as the zero reference, and T₁+ T ₂Value and hydroxyl equivalent
Plot the relationship and use it as the calibration curve.

Number average molecular weight (Mn) Tetrahydrofuran as elution solvent, elution temperature 40 ° C,
It is measured by GPC using HSG20, 40, 50 and 60 manufactured by Shimadzu Corporation as a column. The number average molecular weight is calculated by using polystyrene having a known molecular weight as a standard substance.

Example 1 In a separable flask having an internal volume of 3 L equipped with a stirrer, a thermometer, an N ₂ inlet and a cooling tube, a bisphenol A type epoxy resin (solid content concentration:
74.7% by weight, xylene concentration: 25.3% by weight, resin equivalent epoxy equivalent: 467, hydrolyzable chlorine concentration:
0.003% by weight) 444.7 g, highly hydrolyzable chlorine-containing bisphenol A type epoxy resin (epoxy equivalent: 2
14, hydrolyzable chlorine concentration: 2.0% by weight) 22.7
g, bisphenol A 53.0 g, p-cumylphenol 81.1 g, and carboxylic acid terminated polyester resin [Nippon Yupica Co., Ltd., GV335, acid value: 30 mgK
OH / g, softening point: 135 ° C, number average molecular weight (Mn, G
PC): 3200] 30.0 g was charged and the mixture was melted and homogenized by stirring at a temperature of about 100 ° C. In addition, the two kinds of epoxy resins obtained above are referred to as "A-
1 ”.

Then, a lithium chloride aqueous solution (concentration: 5.
(0% by weight) was added, and the temperature was gradually increased.
In order to suppress heat generation during the reaction, xylene was distilled off under reduced pressure when the temperature of the reaction mixture reached about 130 ° C. Finally, the temperature of the reaction mixture was increased to 160
The mixture was kept at 0 ° C. and stirred for about 6 hours for reaction. Then 1
Bisphenol A type epoxy resin [epoxy equivalent: 2690, hydrolyzable chlorine concentration: 60 ° C] in the reaction mixture.
0.003% by weight, hereinafter referred to as "A-2"] 77.6
After adding g over about 15 minutes, the mixture was stirred at the same temperature for about 45 minutes to uniformly melt. Next, in a reaction mixture kept at a temperature of 160 ° C., a polyester resin [manufactured by Nippon Yupica Co., Ltd., GV335, acid value: 30 mgKOH / g, softening point: 135 ° C., number average molecular weight (Mn, GPC): 32]
00] 400 g was added over about 40 minutes, then the temperature of the reaction mixture was raised to 170 to 180 ° C., and mixed for about 3 hours while stirring. As a result of sampling and analyzing a part of the reaction mixture, the number average molecular weight (Mn) was 405.
0, softening point 123 ° C, DSC Tg 67 ° C, acid value 12 mgKOH / g or less, hydroxyl value 190 mgK
It was OH / g. At this time, the reaction mixture was immediately diluted with an equal volume mixed solvent of cyclohexanone and ethyl acetate to obtain a polyester-modified polyol resin solution having a solid content concentration of 40.1% by weight.

(Examples 2 to 5, Comparative Examples 1 to 3) Bisphenol A type epoxy resin (A
Examples 1) and (A2), bisphenols (B), compound (D) having one active hydrogen in the molecule, carboxylic acid terminated polyester resin (B), and polyester resin (E) were used. A polyester-modified polyol resin was produced in the same manner as in 1. With respect to the obtained polyester modified polyol resin, the properties of the solid polyester modified polyol resin before solvent dilution and the solid content concentration of the solution after solvent dilution were measured. The results are shown in Table 1.

[0068]

[Table 1]

[0069]

[Table 2]

[0070]

Next, Examples 1 to 5 and Comparative Examples 1 to 1
Polyester-modified polyol resin obtained by blending each of the polyester-modified polyol resins obtained in No. 3 with urethane resin (Takenate D-102 manufactured by Takeda Pharmaceutical Co., Ltd.) so that the NCO / OH equivalent ratio becomes 0.8. And a urethane resin mixture was prepared. This mixture of polyester-modified polyol resin and urethane resin was applied to a polished mild steel plate (SS41) sprayed with a release agent to form a semi-dried coating film having a film thickness of 400 μm. This coating film was left standing at room temperature for 33 hours and then heated at 60 ° C. for 24 hours to obtain a cured coating film. About this cured coating, according to the following method,
The tensile strength, tensile modulus and elongation were measured. Table 2 shows the results.

Tensile Strength, Tensile Modulus and Elongation of Hardened Coating Film After removing the cured coating film from the mild steel plate, JIS K-71
A No. 2 type test piece specified in No. 13 was cut out. Using this test piece, a tensile test was performed according to JIS K-7113 to measure the tensile strength, tensile elastic modulus and elongation. At this time, the crosshead speed of the tester Tensilon was set to 1 mm / min.

[0073]

The polyester-modified polyol resins obtained in Examples 1 to 6 and Comparative Examples 1 and 2 were subjected to a storage stability test according to the following method. The results are shown in Table 3.

Storage stability test The polyester modified polyol resin is finely pulverized using a sample mill. Next, use a vibrating sieving machine for 7 mesh.
(2.83 mm) to 150 mesh (0.105 mm)
The powder of is classified and collected. Next, in a glass container having a diameter of 5 cm and a height of 15 cm, 50 cm of the powder prepared above is added.
³ is charged, and a weight of 1000 g is applied to it by using a SUS weight having a diameter of 5 cm. After being left for 5 days in an atmosphere having a humidity of 60% RH and a temperature of 40 ° C., it is left at room temperature for 3 hours.
After the weight was removed, the ease of flow of the powder was visually observed when the glass container containing the powder was horizontally inverted. The results are shown in Table 3.

[0076] Note 1) No problem; powder does not block at all, and it easily flows out in a powder state when falling.

[0077]

According to the method of the present invention, a cured coating film having excellent flexibility can be obtained by using a bisphenol type epoxy resin as a starting material and used as a polyol component of a coating material, and further, it has a high crosslinking reactivity. Therefore, a novel polyester-modified polyol resin capable of obtaining a coating material having a short curing time can be produced.

Further, the polyester-modified polyol resin of the present invention can be used as a polyol component of a coating material to obtain a cured coating film having excellent flexibility. Further, since it has high crosslinking reactivity, a coating material having a short curing time can be prepared. It is useful as a component that can be obtained. Especially pre-coated metal (PC
M) When the polyol resin of the present invention is used as a main curing agent as a primer for a coating film and a thermosetting polyester-based resin is used as an overcoat layer, a good coating film that sufficiently withstands severe processing treatment is provided. be able to.

Claims (7)

[Claims] 1. A carboxylic acid terminal having (i) an epoxy group in a bisphenol type epoxy resin (A) and an average of two or more carboxyl groups in the molecule in the presence or absence of a bisphenol (C). The step of reacting with the polyester resin (B), and (ii) the step of reacting the epoxy group in the bisphenol type epoxy resin (A) with the compound (D) having one active hydrogen in the molecule are carried out. A method for producing a polyester-modified polyol resin, which comprises a step of producing a polyol resin (F) substantially containing no epoxy group, and then reacting the polyol resin (F) with the polyester resin (E). 2. The bisphenol type epoxy resin (A)
Is an epoxy equivalent (g / equivalent) of 170 to 500 and a number average molecular weight of 350 to 1200 and a bisphenol type epoxy resin (A1), and an epoxy equivalent (g / equivalent).
Is 1500 to 5000, and the number average molecular weight is 2000 to
5000 bisphenol type epoxy resin (A2)
And as a main component, and the content of hydrolyzable chlorine is 0.01 to
The method for producing a polyester-modified polyol resin according to claim 1, wherein the bisphenol-type epoxy resin is 0.50% by weight. 3. The polyester modification according to claim 1, wherein the carboxylic acid terminated polyester resin (B) has an acid value (mgKOH / g) of 20 to 70 and a number average molecular weight (Mn) of 1500 to 6000. Method for producing polyol resin. 4. In the step (i), the carboxylic acid-terminated polyester resin (B) is added at the start of the reaction so as to be 1 to 10% by weight based on the weight of the obtained polyol resin (F). Item 2. A method for producing the polyol resin according to Item 1. 5. The polyester resin (E) has an acid value (m).
gKOH / g) 0 to 50, and number average molecular weight (Mn) 1
The method for producing a polyester-modified polyol resin according to claim 1, which is 500 to 6000. 6. The polyester resin (E) is added in an amount of 25 to 25 with respect to the weight of the polyester modified polyol resin obtained.
The method for producing a polyester-modified polyol resin according to claim 1, wherein the polyester-modified polyol resin is added in an amount of 75% by weight. 7. A carboxylic acid-terminated polyester resin having an epoxy group in a bisphenol type epoxy resin (A) in the presence or absence of a bisphenol (C) and an average of two or more carboxyl groups in the molecule ( B) and the compound (D) having one active hydrogen in the molecule are represented by the following formulas (1) and (2): [Equation 2] In the above formulas (1) and (2), w: amount of bisphenol (C) used (g) x: amount of compound (D) having one active hydrogen in the molecule (g) y: in molecule Amount of carboxylic acid terminated polyester resin (B) having an average of two or more carboxyl groups (g) z ¹ : amount of epoxy resin (A1) (g) z ² : amount of epoxy resin (A2) (g) α: Hydroxyl equivalent of bisphenol (C) (g / eq) β: Hydroxyl equivalent or carboxyl equivalent of compound (D) having one active hydrogen in the molecule (g / eq) γ: Polyester resin (B) Carboxyl group equivalent (g
/ Eq) δ ¹ : Epoxy equivalent of the epoxy resin (A1) (g / e
q) δ ² : Epoxy equivalent (g / e) of epoxy resin (A2)
q) Polyester modification obtained by reacting a polyester resin (E) with a polyol resin (F) having a carboxylic acid-terminated polyester resin (B) content of 1 to 30% by weight, which is reacted so as to satisfy A polyol resin,
Polyester-modified polyol resin satisfying the following formula (3): 10 ≦ polyester resin (E) / polyester-modified polyol resin ≦ 90 (formula 3).