JPS6317086B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in curable compositions containing (A) an active hydrogen-containing organic compound and (B) an organic polyisocyanate compound. Conventionally, so-called polyurethane resins, which are obtained by reacting organic polyisocyanate compounds with compounds containing at least two active hydrogen-containing functional groups, such as hydroxyl groups and carboxyl groups, in the molecule, have various desirable properties. For example, paints using this polyurethane resin have excellent physical properties such as impact resistance and abrasion resistance. However, on the other hand, these polyurethane resins having ether bonds or ester bonds in their polymer chains do not necessarily have sufficient chemical properties such as water resistance and alkali resistance, and their uses are therefore restricted. Several techniques have been proposed so far to improve these shortcomings. For example, Tokko Akira
No. 33-8994 discloses a method of reacting an organic polyisocyanate compound with a diene polymer having hydroxyl groups at both ends. However, although this method is effective in improving water resistance, it is insufficient in terms of the hardness of the resulting coating film or its adhesion to the object being coated. Also, Special Publication No. 16823 and Special Publication No. 16823 and Special Publication No. 16823
No. 42791 discloses 1,2- as an active hydrogen-containing compound with which an organic polyisocyanate compound is reacted.
It discloses the use of polybutadiene having 50% or more bonds and having hydroxyl groups at both ends. However, this method also uses auxiliary cross-linking of the double bonds in polybutadiene, and does not necessarily provide sufficient performance in terms of changes in the physical properties of the resulting coating film over time and the balance between hardness and flexibility. do not have. Moreover, polybutadiene having hydroxyl groups at both ends has low compatibility with industrially available organic polyisocyanate compounds, is not only inconvenient to handle, but also has a limited synthesis method, making it expensive. Furthermore, if a polybutadiene having a hydroxyl group at only one end is mixed into the polybutadiene, there is a drawback that the physical properties of the resulting cured product are significantly reduced. The object of the present invention is to have favorable performance in both physical properties such as impact resistance, abrasion resistance and flexibility, and chemical properties such as alkali resistance, acid resistance and water resistance, and to An object of the present invention is to provide a composition of an active hydrogen-containing organic compound and an organic polyisocyanate compound, which has excellent adhesion. The present inventors previously invented a new hydroxyl group-containing polybutadiene derivative obtained by reacting maleated polybutadiene with a monoalkanolamine, and reacted the isocyanate group of an acrylic double bond-containing organic isocyanate compound with the hydroxyl group of this derivative. They discovered that a compound in which an organic group containing an acrylic double bond is bonded to the side chain of a polymer via a urethane bond has extremely excellent performance as a raw material for thermosetting resins or paints. A patent application was filed as Japanese Patent Application No. 1972-972. The inventors have now further discovered that certain of the novel hydroxyl-containing polybutadiene derivatives react with a wide range of organic polyisocyanates to form cured films of excellent performance. That is, the present invention provides a curable composition containing (A) an active hydrogen-containing organic compound and (B) an organic polyisocyanate compound as essential components.
is obtained by reacting a monoalkanolamine with at least one maleated polybutadiene selected from the addition reaction product of a butadiene polymer and/or copolymer having a number average molecular weight of 300 to 5000 and maleic anhydride, and at least one type of hydroxyl group-containing polybutadiene derivative in which a hydroxyalkyl group is bonded to the polymer chain via a succinimide bond, and the content of component (A) and component (B) is within the range of the organic polyisocyanate compound. isocyanate group per equivalent of hydroxyl group in the hydroxyl group-containing polybutadiene derivative.
A curable composition characterized in that the proportion is between 0.5 and 3.0 equivalents. The butadiene polymer and/or copolymer (hereinafter referred to as polybutadiene) in the present invention is
It is a butadiene polymer, a copolymer, or a mixture thereof. The butadiene copolymer referred to herein is a copolymer of butadiene and a vinyl monomer such as styrene, or a copolymer of butadiene and a diolefin such as isoprene, and the butadiene units in the copolymer are 50 % or more. The number average molecular weight of polybutadiene is 300-5000,
Preferably it is 500-3000. If the molecular weight is lower than this range, the cured resin or coating film will not have the required strength, and performances such as heat resistance, water resistance, and chemical resistance will deteriorate. On the other hand, when the molecular weight is higher than this range, the viscosity becomes significantly high, workability decreases, and it becomes difficult to obtain a uniform cured product. There are no particular restrictions on the microstructure of polybutadiene, and polymers with many vinyl bonds and 1,
Any 4-bond rich polymer can be used. The above-mentioned various polybutadienes can be produced by, for example, a polymerization reaction in a hydrocarbon solvent using an alkali metal, such as lithium, sodium, or an organometallic compound thereof, or a polycyclic aromatic compound, such as naphthalene or anthracene, as an activator. It can be produced by a polymerization reaction using an alkali metal as a catalyst, a polymerization reaction using a coordination anion polymerization catalyst, or telomerization using a radical polymerization catalyst in a solvent, for example, tetrahydrofuran. The maleated polybutadiene referred to in the present invention is obtained by subjecting the polybutadiene to an addition reaction with maleic anhydride. Addition reaction is 100-300℃
Conventionally known methods, for example, Japanese Patent Application Laid-Open No. 1987-
This can be carried out by the method disclosed in No. 83795 or Japanese Patent Application Laid-Open No. 52-98793. At this time, gelation reaction can be prevented by adding a small amount of phenylene diamines, pyrogallols, naphthols, or the like. The amount of maleic anhydride in the addition reaction is 0.1 to 0.8 mol, preferably 0.15 to 0.6 mol, per 100 g of polybutadiene. The hydroxyl group-containing polybutadiene derivative (component (A)) referred to in the present invention is obtained by reacting the maleated polybutadiene with a monoalkanolamine, and a hydroxyl alkyl group is bonded to the polymer chain via a succinimide bond. It is characterized by the fact that The monoalkanolamine mentioned here is a saturated aliphatic hydrocarbon having 2 to 10 carbon atoms and having one hydroxyl group and one amino group, and includes monoethanolamine, monopropanolamine, monobutanolamine, etc. It is representative. This reaction is an imidization reaction in which a succinimide bond is formed by the succinic anhydride group and amino group in maleated polybutadiene, and maleated polybutadiene and monoalkanolamine are mixed in the presence or absence of a solvent such as xylene or diglyme. This is achieved by heating and mixing at 50-200°C, preferably 80-150°C. The amount of monoalkanolamine is usually 0.2 to 5.0 relative to the succinic anhydride group in the maleated polybutadiene.
The molar ratio is preferably 0.8 to 1.5 molar times, most preferably equimolar. In this case, it is possible to use less than the same mole of monoalkanolamine and leave unreacted succinic anhydride groups; on the other hand, when using an excess of monoalkanolamine, unreacted monoalkanolamine can be removed by distillation etc. after the imidization reaction. It is preferable to remove it. In the imidization reaction, when the succinic anhydride group and the hydroxyl group in the monoalkanolamine partially react to form an ester bond at the beginning of the reaction, or when the succinic anhydride group and the amino group in the monoalkanolamine react together, In some cases, an amide bond is formed through a partial reaction, but by continuing the reaction, this ester bond or amide bond further reacts to substantially form an imide bond. The imidization reaction generally proceeds smoothly as described above, but may be accompanied by a gelation reaction in some cases. In this case, the gelation reaction can be prevented by semi-esterifying the succinic anhydride groups in the maleated polybutadiene with alcohol prior to the imidization reaction. Alcohols that can be used in this half-esterification reaction are compounds that do not have any functional groups that substantially react with maleated polybutadiene other than hydroxyl groups, and specifically, alkanols or alcohol ethers having 1 to 20 carbon atoms, such as ethanol. ,
These include butanol, ethyl cellosolve, or butyl cellosolve. The half-esterification reaction is achieved by reacting the maleated polybutadiene and the alcohol at 50 to 200°C in the presence or absence of a solvent. After confirming that almost all of the succinic anhydride groups in the maleated polybutadiene have been half-esterified, the imidization reaction proceeds effectively by reacting this with a monoalkanolamine.
That is, the alcohol and water are separated by the half-esterified succinic anhydride group and the amino group to form a succinimide bond, and by performing this imidization reaction while removing the generated water, half-esterification is achieved. Succinic acid groups can be converted into succinimide bonds almost quantitatively. The conditions for the imidization reaction between the half-esterified maleated polybutadiene and the monoalkanolamine are similar to the conditions for the imidization reaction between the maleated polybutadiene and the monoalkanolamine described above. That is, the imidization reaction proceeds by heating and mixing at 50 to 200°C, preferably 80 to 150°C, in the presence or absence of a solvent.
When performing the imidization reaction in the presence of a solvent, the alcohol used in the half-esterification reaction can also be used, but in order to effectively perform the reaction with the organic polyisocyanate compound described later, alcohol, It is preferable to sufficiently remove monoethanolamine and the like by distillation or the like. The amount of monoalkanolamine is usually 0.2 to 5.0 times the mole of the half-esterified succinic anhydride group.
Preferably it is 0.8 to 1.5 times the mole, most preferably equimolar. In the present invention, it is also possible to use a polyfunctional organic compound containing active hydrogen in place of a part of the hydroxyl group-containing polybutadiene derivative (component (A)). Such compounds include low-molecular polyols such as glycerin and pentaerythritol, polyethers such as polyoxyalkylene polyols, polyesters having hydroxyl groups at the ends, such as aliphatic or aromatic dicarboxylic acids, and excess Examples include reaction products with diols or triols, polyamines such as ethylenediamine and diethylenetriamine, and mixtures of these various compounds.
The blending ratio of these active hydrogen-containing polyfunctional organic compounds is 50% by weight based on the total active hydrogen-containing compounds.
The content is preferably 30% by weight or less. The organic polyisocyanate compound (component (B)) in the present invention includes aliphatic or alicyclic polyisocyanates, specifically 2,2,4-trimethylhexamethylene diisocyanate, diisocyanate from dimer acid, methylcyclohexane- 2,4-diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, etc., or aromatic polyisocyanate, specifically 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate,
4,4'-diphenylmethane diisocyanate, m
Examples include -phenylene diisocyanate and 1,5-naphthalene diisocyanate. Furthermore, organic polyisocyanate compounds in which the isocyanate groups are blocked can also be used. In this case, the blocking agent is preferably phenol, methyl ethyl ketone oxime, ε-caprolactam or butanol. In the present invention, the hydroxyl group-containing polybutadiene derivative (component (A)) and the organic polyisocyanate compound (component (B)) can be simply mixed together immediately before use and then cured at the time of use, or it is possible to form a gel. It is also possible to react the two in advance under conditions that do not cause chemical reaction, and then use it as a polybutadiene derivative containing an isocyanate group. That is, the composition is cured by the urethane bond between the hydroxyl group in the hydroxyl group-containing polybutadiene derivative and the isocyanate group in the organic polyisocyanate compound. This reaction may proceed at room temperature depending on the type of hydroxyl group-containing polybutadiene derivative or organic polyisocyanate compound, but it proceeds extremely quickly by heating both to 40 to 80°C. In addition, when using blocked organic polyisocyanate compounds,
Preferably, it is heated to 100-250°C. It is also possible to use catalysts to accelerate these curing reactions. As a catalyst, tertiary amines such as triethylamine, dimethylbenzylamine,
Organometallic compounds such as tetramethylpropylene diamine, triethylene amine, N-alkylmorpholine, such as stannath octoate, dibutyltin dilaurate, tetrabutyl titanate, trialkylphosphine, trialkylantimony, cobalt naphthenate, lead naphthenate etc. can be used. The organic polyisocyanate compound contains 0.5 to 3.0 equivalents of isocyanate groups, preferably 0.7 equivalents of hydroxyl groups contained in the hydroxyl group-containing polybutadiene derivative or the mixture of the hydroxyl group-containing polybutadiene derivative and the active hydrogen-containing polyfunctional compound. It is preferable to use it in such a proportion that the amount becomes ~2.0 equivalents. Further, in the composition of the present invention, a solvent can be used if necessary. The solvent is preferably one that can dissolve the hydroxyl group-containing polybutadiene and is inert to isocyanate groups, specifically hydrocarbons such as benzene, toluene, xylene, cyclohexane, etc.
Examples include esters such as ethyl acetate and butyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, and cellosolve acetates such as ethylene glycol monoethyl ether acetate. Furthermore, pigments, fillers, antioxidants, ultraviolet inhibitors, and the like may be added as necessary. The present invention will be specifically explained below using synthesis examples, examples, and comparative examples. Synthesis Example 1 () Using benzyl sodium as an initiator and toluene as a chain transfer agent in a benzene solvent.
Polymerize butadiene at 40°C to determine the number average molecular weight.
700, a butadiene polymer having a 1,2-bond content of 60% was obtained. () Butadiene polymer obtained in () above 1000
g, maleic anhydride 390g, antigen 3C2g,
10 g of xylene was placed in a 3-separable flask equipped with a reflux condenser, and the flask was purged with nitrogen, followed by reaction at 195° C. for 5 hours. After the reaction, the solvent and unreacted substances were distilled off under reduced pressure, and the acid value was 160 mgKOH/g.
of maleated polybutadiene was obtained. () Maleated butadiene obtained in () above
Add 1000 g and 506 g of butyl cellosolve to a 3-separable flask equipped with a reflux condenser, and add 120 g of butyl cellosolve.
℃ and continued stirring at the same temperature for 4 hours. The temperature of the flask contents was then reduced to 80°C and 174.5
g of monoethanolamine was added dropwise over 30 minutes. Immediately after the completion of the dropwise addition, the temperature was raised to 150°C, and maintained at the same temperature for 5 hours while removing water that flowed out. Thereafter, the solvent, water generated by the reaction, and unreacted substances were distilled off under reduced pressure to obtain a hydroxyl group-containing polybutadiene derivative in which a hydroxyalkyl group was bonded to the polymer chain via a succinimide bond. . Synthesis Example 2 High cis-1,4 with a number average molecular weight of 900 obtained by coordination anionic polymerization using a nickel catalyst
1000g of liquid polybutadiene and maleic anhydride
From 356g, acid value 150mg was obtained using the same procedure as in Synthesis Example 1.
KOH/g of maleated polybutadiene was obtained. 506g of 1000g of the above maleated polybutadiene
was dissolved in butyl cellosolve and reacted with 174.5 g of monoethanolamine in the same manner as in Synthesis Example 1 to obtain a hydroxyl group-containing polybutadiene derivative in which a hydroxyalkyl group was bonded to the polymer chain via a succinimide bond. . Using the hydroxyl group-containing polybutadiene derivatives obtained in Synthesis Examples 1 and 2, the following Examples 1 to 2 were prepared.
A curable composition of No. 4 was produced. This was applied to a mild steel test panel to form a coating film, and the physical and chemical properties of the coating film were evaluated according to JIS K5400 "General Test Methods for Coatings." The results are shown in Table 1. Example 1 The hydroxyl group-containing polybutadiene derivative synthesized in Synthesis Example 1 was dissolved in butyl acetate, and 4,4'-diphenylmethane diisocyanate was added to this solution at a ratio of 1 equivalent of isocyanate group to 1 equivalent of hydroxyl group. Mix and add more butyl acetate.
A 40% by weight solution was prepared. This solution was applied using an applicator to a 150 x 70 x 0.7 mm mild steel test panel that had been thoroughly degreased and dried in advance, and was heated at 20℃ for 24 hours.
After leaving it for an hour, it was baked at 80°C for 1 hour to form a coating film. Example 2 A phenol-blocked product of 4,4'-diphenylmethane diisocyanate was mixed at a ratio of 1 equivalent of isocyanate group to 1 equivalent of hydroxyl group of the polybutadiene derivative containing hydroxyl group synthesized in Synthesis Example 1, and a trace amount of After adding dibutyltin dilaurate, a 40% by weight solution was prepared by diluting with butyl acetate. This solution was applied to mild steel test panels in the same manner as in Example 1 and then baked at 160°C for 30 minutes. Example 3 4,4'-diphenylmethane diisocyanate was mixed at a ratio of 1 equivalent of isocyanate group to 1 equivalent of hydroxyl group in the polybutadiene derivative containing hydroxyl group of Synthesis Example 2, and the same procedure as in Example 1 was carried out. A coating film was formed. Example 4 A caprolactam, methyl ethyl ketone oxime (4:6) blocked product of 4,4'-diphenylmethane diisocyanate was added at a ratio of 1 equivalent of isocyanate group to 1 equivalent of hydroxyl group in the hydroxyl group-containing polybutadiene derivative of Synthesis Example 2. were mixed. A 40% by weight solution was prepared by adding a trace amount of dibutyltin dilaurate and then diluting with butyl acetate. This solution was applied to mild steel test panels in the same manner as in Example 1 and then baked at 180°C for 30 minutes. As is clear from the results in Table 1, the compositions of Examples 1 to 4 all exhibit extremely excellent performance in both physical and chemical properties, and can be preferably used as curable compositions. Comparative Example 1 A phenol-blocked product of 4,4'-diphenylmethane diisocyanate was mixed in such a ratio that the isocyanate group was 1 equivalent to 1 equivalent of the hydroxyl group of a polyester polyol having a hydroxyl value of 205 to 221 (Desmophene 1100 manufactured by Bayer AG). A coating film was prepared in exactly the same manner as in Example 1 and baked at 160°C for 30 minutes. The performance of this coating film is shown in Table 1. This composition performed poorly in the Goban eye test and various chemical properties. Comparative Example 2 1,2- having hydroxyl groups at both ends with a hydroxyl value of 120
Mix a phenol-blocked product of 4,4'-diphenylmethane diisocyanate in a ratio of 1 equivalent of isocyanate group to 1 equivalent of hydroxyl group of polybutadiene (NISSO PB G-1000), and dilute with butyl acetate to make a 40% by weight solution. However, phase separation occurred and a homogeneous solution could not be obtained. A solution that had been stirred vigorously and suspended was applied with an applicator and baked, but a smooth coating film could not be obtained and physical properties could not be measured. Comparative Example 3 The maleated polybutadiene obtained in Synthesis Example 1 () was dissolved in butyl acetate, and 4,4'-diphenylmethane diisocyanate was mixed in an equimolar ratio to the acid anhydride groups in this solution. Then, butyl acetate was added to make a 40% by weight solution. When this solution was applied to a test panel and heated in the same manner as in Example 1, foaming occurred on the surface and inside of the coating film, the surface became uneven and a smooth coating film could not be obtained, and the physical properties could not be measured. It was possible. Furthermore, the adhesion to the test panel was poor, and the acid resistance and alkali resistance failed. 【table】

Claims (1)

[Scope of Claims] 1. In a curable composition containing as essential components (A) an active hydrogen-containing organic compound and (B) an organic polyisocyanate compound, component (A) has a number average molecular weight of 300 to 5000. It is obtained by reacting a monoalkanolamine with at least one maleated polybutadiene selected from the addition reaction product of a butadiene polymer and/or copolymer and maleic anhydride, and is attached to the polymer chain via a succinimide bond. is at least one kind of hydroxyl group-containing polybutadiene derivative in which a hydroxyalkyl group is bonded to the organic polyisocyanate compound, and the content of component (A) and component (B) is such that the isocyanate group in the organic polyisocyanate compound is at least one of the hydroxyl group-containing polybutadiene derivatives. 0.5 per equivalent of hydroxyl group in derivative
A curable composition characterized in that the proportion is such that the proportion is ~3.0 equivalents. 2. Part of the hydroxyl group-containing polybutadiene in component (A) is replaced with another active hydrogen-containing organic compound, and the amount of the other active hydrogen-containing organic compound is:
The composition according to claim 1, wherein the content of the total active hydrogen-containing organic compounds is 50% by weight or less.