JPH08109236A - Composition for preparation of polyurethane - Google Patents

Abstract

PURPOSE: To obtain a compsn. which can offer a polyurethane having excellent water resistance and tensile strength and suitable for a coating material, a film, an adhesive, and various moldings. CONSTITUTION: A compsn., for preparation of a polyurethane, comprising: (a) a polyester polyol comprising acid units constituted by 5 to 50wt.% dimer acid residue, 50 to 95wt.% 6-8C aliph. or arom. dicarboxylic acid residue, and 0 to 45wt.% 5C or less aliph. dicarboxylic acid residue and diol units constituted by 5 to 50wt.% dimer diol residue, 50 to 95wt.% 5-9C aliph. or alicyclic diol residue, and 0 to 45wt.% 4 or less C aliph. diol residue; (b) polyisocyanate; and (c) a chain extender.

Description

Detailed Description of the Invention

[0001]

[Industrial field of application] With recent industrial development, air pollution caused by released organic solvents, exhaust gas, and soot has become serious, and while quantitative control of these emissions is being considered, it is used outdoors. It has been considered to impart durability to the above-mentioned discharged materials. In particular,
Research and development for changing organic solvent-based materials to solvent-free or water-based materials, as well as research and development of sulfur dioxide, nox, acid rain-resistant molding materials, paint coating materials, etc. are being actively conducted. Since many outdoor pollutants are water-soluble or hydrophilic substances, the industry strongly desires materials having excellent weather resistance, water resistance, and stain resistance.

The present invention relates to a polyurethane film, a polyurethane foam, various molding materials and adhesives having excellent weather resistance, water resistance and stain resistance, and a composition containing a polyester polyol as a main component, which is suitable for polyurethane paints and the like. . Furthermore, the composition for producing polyurethane of the present invention is also used for an aqueous polyurethane coating having excellent evaporation and drying properties of water.

[0003]

2. Description of the Related Art Conventionally, a raw material having a carbon number of about 2 to 6, which is a decomposition product of a fossil raw material such as petroleum, for example, a polyethylene adipate-based polyol obtained from adipic acid or ethylene glycol has been used. Generally used for polyurethanes. However, since it uses a raw material that does not exist in nature, it has a drawback that it is weak against a natural phenomenon, specifically, it has no water resistance and therefore has poor weather resistance.

Therefore, recently, natural products, particularly natural fats and oils materials have been reviewed and applied. Specifically, JP-A-64-045477 and JP-A-02-1
As disclosed in Japanese Patent Application Laid-Open No. 89375 and Japanese Patent Application Laid-Open No. 03-068677, a method for synthesizing a polyester polyol containing dimer acid as a component, which is obtained by hydrolyzing a natural fat and oil and thermally polymerizing the same, and the polyester polyol and a chain extender. JP-A-02-064174, in which a dimer diol and a polyisocyanate are combined, has been proposed as a method for synthesizing polyurethane (hereinafter referred to as DA method).

Further, Japanese Patent Laid-Open No. 03-277680
JP-A-04-130124 and JP-A-06-128
As disclosed in Japanese Patent No. 363, a method of hydrogenating and reducing the above dimer acid to synthesize a diol having a carbon number of 36, and then obtaining a polyester polyol using the diol (hereinafter referred to as D
There is also a proposal of (D method).

[0006]

However, the DA method and the DD method described in the above patent publication are disclosed in Japanese Patent Laid-Open No.
As disclosed in Japanese Patent Publication No. 045477, it is necessary to contain 50% by weight or more of a higher dicarboxylic acid or a higher diol in order to impart water resistance. When polycondensation of such a component having a large molecular weight is carried out using 50% by weight or more, the resulting polyester polyol has an extremely large molecular weight distribution, and there is a drawback that the tensile strength of the polyurethane obtained from it becomes small.

[0007]

The inventors of the present invention have conducted extensive studies to solve the above-mentioned problems, and as a result, the water resistance of polyurethane is proportional to the weight concentration of higher dicarboxylic acid or higher diol in the polyester polyol, and It was found that the tensile strength is greatly influenced by the molecular weight distribution of the polyester polyol, and as a result of diligent studies on the balance between water resistance and strength, the present invention has been completed. That is, in the present invention, the constitution of the (a) acid unit is a dimer acid residue; 5 to 50% by weight, an aliphatic or aromatic dicarboxylic acid residue having 6 to 8 carbon atoms; 50 to 95% by weight and a carbon number. 5 or less aliphatic dicarboxylic acid residue; 0 to 45% by weight, the composition of the diol unit is dimer diol residue; 5 to 50% by weight, residual aliphatic or alicyclic diol having 5 to 9 carbon atoms A composition for producing a polyurethane, comprising a polyester polyol having a group of 50 to 95% by weight and an aliphatic diol residue having 4 or less carbon atoms; 0 to 45% by weight, (b) polyisocyanate and (c) a chain extender. .

Repeated polycondensation in which the carboxylic acid and diol constituting the polyester polyol are a pair of dimer acid (molecular weight: 560) and a lower diol, or a pair of dimer diol (molecular weight: 532) and a lower dicarboxylic acid. Since the unit has a molecular weight of about 600 or more, even if the degree of condensation is different by one, the problem that the molecular weight is different by at least 600 is solved in the present invention.
This was solved by allowing a repeating unit having a molecular weight of about 250 composed of a lower dicarboxylic acid and a lower diol to coexist in the polyester polyol to obtain a polyester polyol having a narrow molecular weight distribution. The polyester polyol is a polyester having a hydroxyl group at the molecular end,
It basically has at least 2 or more hydroxyl groups in one molecule, and in the case of a branched polyester, it has 3 or more hydroxyl groups.

The present invention will be described in more detail below. The dimer acid in the present invention is an unsaturated fatty acid such as linoleic acid, oleic acid and linolenic acid, a carboxylic acid having 18 carbon atoms such as a dry oil fatty acid or a semi-dry oil fatty acid obtained from tall oil, cottonseed oil, soybean oil and the like. It is thermally polymerized and then purified by distillation. The main component is a dicarboxylic acid having 36 carbon atoms and usually contains a tricarboxylic acid having 54 carbon atoms in an amount of about 20% or less. Dimer acid obtained by hydrogenating the above-mentioned dimer acid to reduce the internal olefin bond may be distinguished as high-purity hydrogenated dimer acid,
The dimer acid in the present invention also includes such highly pure hydrogenated dimer acid.

For applications in which the demand for weather resistance is higher, it is preferable to use high-purity hydrogenated dimer acid.
Specific examples of the dimer acid include PRIPOL manufactured by Unichema International.
-1009, PRIPOL-1008, etc. are mentioned.
The amount of the units based on dimer acid in the polyester polyol, that is, the amount of dimer acid residues is 5 to 5 based on the total carboxylic acid residues constituting the polyester polyol.
0% by weight. When the amount of the dimer acid residue exceeds 50% by weight, the molecular weight distribution becomes broad, so that there is a drawback that the tensile strength does not appear. On the other hand, when it is less than 5% by weight, the water resistance becomes insufficient.

Examples of the aliphatic or aromatic dicarboxylic acid having 6 to 8 carbon atoms which is used in combination with the above-mentioned dimer acid include adipic acid, terephthalic acid and isophthalic acid. 5 based on the total amount
It is 0 to 95% by weight. With the dimer acid and an aliphatic or aromatic dicarboxylic acid having 6 to 8 carbon atoms,
An aliphatic dicarboxylic acid having 5 or less carbon atoms can be used in an amount of 0 to 45% by weight, and examples of such a dicarboxylic acid include succinic acid and glutaric acid.

In the present invention, the total amount of the aliphatic or aromatic dicarboxylic acid residue having 6 to 8 carbon atoms and the dimer acid residue is preferably 90% by weight or more of the total carboxylic acid residues. When the total amount is less than 90% by weight, the resulting polyurethane tends to have insufficient water resistance.

The dimer diol is an aliphatic diol having 36 carbon atoms, which is obtained by completely hydrogenating the dimer acid, and is obtained as a mixture of geometric isomers of the dimer diol having a branched structure or a cyclohexane ring. In addition, the product name PRIPOL manufactured by Unichema International
A commercial product such as -2033 can also be used. The amount of dimer diol residues in the polyester polyol is 5 to 50% by weight based on the total amount of all diol residues constituting the polyester polyol. If the amount of the dimer diol residue exceeds 50% by weight, the molecular weight distribution becomes broad and the tensile strength is poor, while if it is less than 5% by weight, the water resistance becomes insufficient.

5 to 9 carbon atoms used in combination with dimer diol
Specific examples of the aliphatic or alicyclic diol include neopentyl glycol, hexanediol, octanediol, nonanediol and cyclohexanedimethanol, and the amount thereof is based on the total amount of all diol residues. It is 50 to 95% by weight. With the dimer diol and the aliphatic or alicyclic diol having 5 to 9 carbon atoms, 0 to 45% by weight of an aliphatic diol having 4 or less carbon atoms can be used. Examples of such diol include ethylene glycol and butane diol. Can be mentioned.

In the present invention, the total amount of the aliphatic or alicyclic diol residue having 5 to 9 carbon atoms and the dimer diol residue is preferably 90% by weight or more of the total diol residues. When the total amount is less than 90% by weight, the resulting polyurethane tends to have insufficient water resistance.

A more preferred polyester polyol in the present invention has a total amount of dimer acid residues and dimer diol residues of 25 to 7 based on the total amount of all constituent units.
It is a polyester polyol of 5% by weight.

Examples of the method for synthesizing the polyester polyol include the methods disclosed in the above-mentioned patent publications cited as prior art. Depending on the application and equipment, there are a method of azeotropic dehydration in a high boiling point solvent such as xylene, a method of dehydrating in a solventless system, and in that case, a method of using no catalyst or a small amount of catalyst. An excess of diol is charged with respect to the acid in order to make the molecular terminal into a hydroxyl group, but in order to increase the polymerization degree of the obtained polyester polyol, it is preferable to carry out the dediol reaction at high vacuum and high temperature after completion of the esterification reaction. preferable. The molecular weight of the polyester polyol in the present invention is preferably 1,000 to 4,000, more preferably 1,000 to 2,000, in terms of polystyrene equivalent number average molecular weight by GPC analysis.

The polyurethane composition of the present invention is a composition obtained by blending the above polyester polyol with polyisocyanate as a curing agent and a chain extender, and as the polyisocyanate, diphenylmethane diisocyanate or 2,4-tolylene diisocyanate is used. Aromatic diisocyanates such as 2,6-tolylene diisocyanate, phenylene diisocyanate, 1,5-naphthalene diisocyanate and xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, hydrogenation Examples thereof include aliphatic or alicyclic diisocyanates such as xylylene diisocyanate and tetramethyl xylene diisocyanate. Preferred polyisocyanates are diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate.

As the chain extender, ethylene glycol,
The carbon number of butanediol, neopentyl glycol, cyclohexanedimethanol, nonanediol, etc. is 2 to 9
Individual diols can be used. From the viewpoint of compatibility with the polyester polyol, a diol having 6 to 9 carbon atoms is more preferable. A dihydroxycarboxylic acid such as dimethylolpropionic acid is preferable as the chain extender for obtaining the resin for water-based polyurethane coatings.

Regarding the use ratio of the polyester polyol, the chain extender and the polyisocyanate, the ratio of the polyester polyol and the chain extender is preferably 1 to 4 mol of the chain extender per 1 mol of the polyester polyol, and the polyester polyol and the chain extender. The equivalent ratio of the total amount of active hydrogen contained in the extender to the isocyanate group is preferably 1: 0.5 to 1: 2, and more preferably 1: 0.8 to 1: 1.2.

The method for obtaining polyurethane from the composition of the present invention includes (1) a method in which all of the polyester polyol, polyisocyanate and chain extender are reacted at once, and (2) after the polyester polyol and polyisocyanate are reacted. , A method of adding a chain extender to polymerize, (3) a method of reacting the total amount of each of the polyester polyol and the chain extender and a part of the polyisocyanate, and then adding the remaining polyisocyanate and further reacting Can be mentioned.

The polyurethane-forming reaction can be carried out in the presence or absence of a solvent inert to the isocyanate group. When a solvent is used, an amide solvent such as dimethylformamide, a sulfoxide solvent such as dimethyl sulfoxide, an ether solvent such as dioxane, a ketone solvent such as methyl ethyl ketone, an ester solvent such as ethyl acetate, and an aromatic solvent such as toluene. Group hydrocarbon solvents are preferred.

When the polyurethane-forming reaction is carried out in a solvent,
Usually, a high molecular weight polyurethane is obtained, and the obtained polyurethane solution can be used as it is as a paint, an adhesive or the like. The preferable reaction temperature in this case is 20 to 100 ° C. On the other hand, when carrying out the polyurethane reaction without solvent,
The preferred reaction temperature is 80-150 ° C. and the resulting polyurethane is a low molecular weight prepolymer. The prepolymer is heated to have a high molecular weight and then put into practical use.

In order to accelerate the above reaction, an amine-based catalyst (triethylamine, N-ethylmorpholine, triethylenediamine, etc.) or a tin-based catalyst (trimethyltin laurate, dibutyltin dilaurate) used in a usual urethanization reaction, if necessary. Etc.) may be used. Further, if necessary, a colorant and various stabilizers for improving weather resistance and heat resistance may be added to the reaction system.

The polyurethane obtained from the present invention has excellent mechanical strength and water resistance and is suitable for paints, adhesives, artificial leather, synthetic leather, fibers, foams, rubbers and the like.

The present invention will be described more specifically with reference to Examples, Reference Examples and Comparative Examples. <Reference Examples 1 to 3 and Comparative Reference Examples 1 and 2> (Production of Polyester Polyol) In a reactor, dimer acid (PRIPOL-1009, manufactured by Unichema International Co., Ltd.), dicarboxylic acid, dimer, in the proportions shown in Table 1. Diol (Unichema International,
PRIPOL-2033) and a diol were charged, and the temperature was raised from room temperature to 180 ° C. over 1 hour and 30 minutes in a nitrogen atmosphere, and then reacted at 180 ° C. for 30 minutes. 2 more
The reaction was carried out at 20 ° C. for 4 hours to distill the produced water, and then the pressure was reduced to 12 mmHg to distill the excess diol for 5 hours. As a result, polyester polyols having hydroxyl groups at both ends as shown in Table 1 were obtained.

In the above reaction, in order to increase the esterification reaction rate, the charge ratio is OH moles / C.
The low-boiling diol is charged in excess so that the number of OOH moles is 2.5. Since dimer acid, other dicarboxylic acids and dimer diol have high boiling points, the ratio of the charged weights is incorporated in the polyester almost as it is.

[0028]

Examples 1 to 3 0.14 mol of the polyester polyols obtained in Reference Examples 1 to 3 and diphenylmethane diisocyanate (0.43 mol) were placed in a 500 ml flask, and stirred and reacted at 80 ° C. for 2 hours under a nitrogen atmosphere. . Next, 0.29 of butanediol was used as a chain extender.
mol and added, and stirred for 30 seconds. The reaction solution was slightly yellow and transparent. By heating this reaction liquid at 100 ° C. for 24 hours, a translucent polyurethane cured product was obtained. JIS K7
In accordance with 113, the tensile strength (kgf / cm ² ) and water resistance of a dumbbell made from a polyurethane cured product were measured. The results are shown in Table 1.

[0029]

[Comparative Examples 1 and 2] Comparative procedures except that the polyester polyols obtained in Reference Examples 1 and 2 were used to obtain polyurethane cured products in the same manner as in the above Examples, and then dumbbells were prepared to obtain the physical properties thereof. It was measured.

[0030]

[Table 1]

[0031]

INDUSTRIAL APPLICABILITY The polyurethane obtained from the polyester polyol having the specific constitution of the present invention is excellent in both water resistance and tensile strength, which are the disadvantages of the conventional polyester polyol type polyurethane, and is excellent in coating materials, sheets and various moldings. It is preferably used for products.

Claims (1)

[Claims] 1. The composition of the (a) acid unit comprises a dimer acid residue; 5 to 50% by weight, an aliphatic or aromatic dicarboxylic acid residue having 6 to 8 carbon atoms; 50 to 95% by weight, and a carbon number. 5 or less aliphatic dicarboxylic acid residue; 0 to 45% by weight, and the constitution of the diol unit is dimer diol residue;
A polyester polyol having 50 to 95% by weight, an aliphatic or alicyclic diol residue having 5 to 9 carbon atoms; 50 to 95% by weight and an aliphatic diol residue having 4 or less carbon atoms; b) polyisocyanate and (c)
A composition for producing polyurethane, which comprises a chain extender.