JPH0580506B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a new and useful curable resin composition, and mainly to a resin composition that can be applied to paints or inks. [Prior art and problems to be solved by the invention] Conventionally, various polyols such as alkyd polyols, polyester polyols, or acrylic polyols have been combined with aminoformaldehyde resins (hereinafter abbreviated as aminoplasts). It is used for paints and inks by curing with heat or with an acid catalyst. However, such curable resin compositions mainly composed of polyol and aminoplast cannot be said to have sufficient coating film performance, mainly because the compatibility of these two components is insufficient. do not have. In other words, in addition to being excellent in luster and texture,
It provides a sufficiently high bridging density, but it is also strong and
The reality is that it is not possible to obtain a highly cured coating. In addition, a phenomenon called "repellency" was observed on the coated or printed material during coating or printing, making it difficult to obtain a smooth coating film. Currently, a method has been proposed in which polyol and aminoplast are subjected to a dealcoholization reaction during the resin preparation stage, resulting in a type of "modified polyol," but in this case, if the ratio of aminoplast used is small, On the other hand, when the ratio of aminoplast used is large, as long as various polyols such as those mentioned above, which are usually used for paints or inks, are used, As the reaction rate increases,
The drawback is that the resin becomes highly viscous during preparation, making it impossible to put it to practical use. [Means for Solving the Problems] However, as a result of intensive studies by the present inventors in order to eliminate the various drawbacks of the conventional techniques as described above, the inventors first prepared a compound having a triazine ring in the molecule. This ensures sufficient compatibility with the aminoplast, and then furthermore, by having an active hydrogen in the molecule, especially this active hydrogen and an alkoxyl group, a sufficient cross-linking reaction is ensured. It is possible to provide a curable resin composition that has physical properties of a coating film, especially high hardness, and further has an average degree of functionality of hydroxyl groups per molecule of 1.5 to 2.5.
By using a polyol within the above range, all of the drawbacks of the prior art as described above were overcome, and the present invention was completed by finding a curable resin composition having the desired properties as described above. I've come to the point where I can. That is, the present invention uses the general formula

〔Example〕

Next, the present invention will be explained in more detail with reference to Reference Examples, Examples, and Comparative Examples. In the following, all parts and percentages are based on weight unless otherwise specified. Reference Example 1 [Preparation example of active hydrogen-containing compound (A) having a triazine ring] Using 45.7 parts of neopentyl glycol, 25.6 parts of phthalic anhydride and 28.7 parts of isophthalic acid,
An esterification reaction was carried out at 240° C. according to a conventional method, and a polyol with n of 1000 was obtained.
Hereinafter, this will be abbreviated as polyol (a-1-1). Next, 62.6 of this polyol (a-1-1)
24.4 parts of Cymel 300, 13.1 parts of neopentyl glycol, and 8.0 parts of xylene were subjected to a dealcoholization reaction at 120°C for 1 hour, and then the reaction product was treated with ethyl acetate as a nonvolatile component (NV).
When the compound was prepared so that the viscosity was 70%, the target compound (A) having a Gardner viscosity (hereinafter the same) at 25°C of U-V, an acid value of 3.2, and a hydroxyl value of 109 was obtained. Hereinafter, this will be abbreviated as triazine polyol (A-1). Reference Example 2 (Same as above) A dealcoholization reaction was carried out at 110°C for about 1 hour using 45.7 parts of Cymel 300 and 26.8 parts of propylene glycol, and then a dealcoholization reaction was carried out at 110°C for about 1 hour.
After adding 0.1 part, the dealcoholization reaction was further carried out at 130°C for about 15 hours, and then the reaction product was adjusted to have an NV of 70% with a mixed solvent of toluene/cellosolve acetate = 8/2 (volume ratio). , the viscosity is N
-O and a target compound (A) with a hydroxyl value of 250.0
I got it. Hereinafter, this will be referred to as triazine polyol (A
-2). Reference example 3 (same as above) 771 parts of xylene was heated to 110℃, and β-
A polymerization reaction was carried out by dropping 105 parts of hydroxyethyl methacrylate and 695 parts of methyl methacrylate together with 72 parts of di-tert-butyl peroxide. Next, 170 parts of "Cymel 300" and 64 parts of propylene glycol were further added to the acrylic resin thus obtained, and solvent removal and alcohol dealing reactions were carried out at 110° C. for about 13 hours. A target compound (A) having an NV of 60%, a viscosity of _Z1 - _Z2 , and a hydroxyl value of 40 was obtained. Hereinafter, this will be abbreviated as triazine polyol (A-3). Examples 1 to 3 and Comparative Examples 1 and 2 A curable resin composition of the present invention and a control resin composition were prepared by mixing each component in a conventional manner in the proportions shown in Table 1. .

[Table] For each resin composition thus obtained, the physical properties of the paint and the physical properties of the coating film were compared and examined.
The results are summarized in Table 2. The evaluation method at this time is roughly as follows. First, the polyol and titanium oxide are kneaded together with a diluting solvent if necessary, and then the aminoplast and, if necessary, a curing catalyst are mixed to form a paint. Thereafter, each of the paints thus obtained was applied by air spray onto a wet-sanded tin plate so that the dry film thickness was approximately 40 μm. Next, each coated plate was set at 20°C for 20 minutes, and then heated and cured at 140°C for 20 minutes to obtain various cured coating films.

【table】

〔Effect of the invention〕

As is clear from the results in Table 2, the curable resin composition of the present invention has excellent paint properties such as pigment dispersibility and texture, as well as excellent paint film properties such as pencil hardness. I know this.

Claims (1)

[Claims] 1 (A) General formula: [However, in the formula, X is -H, -CH ₃ , -C ₂ H ₅ , -
shall represent _C3H7 , _{-C6H5 or -NH2 .} ] An active hydrogen-containing compound having a triazine ring obtained by co-condensing a triazine-based amino compound, formaldehyde and a polyol represented by the above with a monohydric alcohol, if necessary, and (B) an amino formaldehyde resin. A curable resin composition comprising both components (A) and (B) in a solid weight ratio of (A)/(B)=50/50 to 95/5. 2. The active hydrogen-containing compound (A) having a triazine ring described above has a hydroxyl value within the range of 20 to 400, and has two or more alkoxyl groups per molecule, A composition according to claim 1. 3. Claim 1, wherein the active hydrogen-containing compound (B) having a triazine ring has an acid value of 20 or less.
Compositions described in Section. 4. Claims 1 to 4, characterized in that the polyol described above has an average degree of functionality of hydroxyl groups per molecule in a range of 1.5 to 2.5.
Composition according to paragraph 3.