JP2813533B2 - Thick film coating composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition to be used as a base material for a thick film when a finish is applied to an object to be dressed or protected. It provides a smooth base that is suitable for the finish coating by covering irregularities and cracks, has good adhesion to both the object to be coated and the finish coating, and has excellent sealability due to its thick film properties and fine elasticity. The present invention relates to a thick film coating composition which forms a coating film having force and crack followability.

[0002]

2. Description of the Related Art Conventionally, finish coating has been performed for the protection and appearance of buildings, but these are generally applied after various treatments of a coating base as an object to be coated. .
The various treatments of these bases include: (1) forming a seal coating film on the surface of the object to be coated by applying a synthetic resin emulsion sealer or a synthetic resin solution-based sealer to prevent bleeding of Eflo and ac from the object to be coated; Conversely, it prevents water from entering the object to be coated from the outside and improves the adhesion to the finished coating film. (2) A synthetic resin putty that fills cracks and air holes on the surface of the object to be coated so that cracks, foams, and pinholes do not occur in the finished coating film when the finishing material is applied. (3) A cement-based, polymer-cement-based or the like base preparation material that repairs cracks, breakage, and floating of an object to be coated (concrete, mortar) and adjusts the pH and water content of the base. Etc., and the purpose and use of each are differentiated. In the treatment of these bases, the base treatment is performed singly or in combination depending on the condition of the object to be coated.

[0003]

However, (1)
The sealer cannot be used for the purpose of repairing irregularities on the surface of the object to be coated and forming a smooth surface, and when the suction of the substrate is large, a large amount of coating is required to form a seal coating film. . In the synthetic resin putty of (2),
Not only is workability inferior due to the need for filling with a special device or iron, but also the surface of the object to be coated after the base adjustment is difficult to be smooth.
Furthermore, the silicone-modified putty has insufficient adhesion to the finished coating film. Next, the cement-based, polymer-cement-based, etc. base conditioning material of (3) contains cement, causing efflorescence, and cannot be forcibly dried even in the case of factory coating. In addition, the surface of the article to be coated after the preparation of the base is not easily smoothed due to the cohesive force of the cement. Therefore, a combination of the advantages of the individual base adjustment materials, that is, filling of cracks on the object to be coated, concealment and repair of irregularities on the surface, sealing of Efro and scum from the object to be coated, and external water A coating that prevents intrusion.Provides a very smooth base for the subsequently applied finish coating, has excellent adhesion to the finish coating, and has an elasticity that follows the displacement of cracks on the workpiece. Nevertheless, none of the finished coating films satisfied the physical property of microelasticity without cracking with only one kind of base material. The problem to be solved by the present invention is to find a material which can attain the advantages of various kinds of base material at once with a single material.

[0004]

Means for Solving the Problems In order to solve such a problem, the present inventors have made intensive studies and as a result, have found that a specific dimer acid-modified epoxy resin used for the purpose of imparting flexibility to an epoxy resin. By mixing a specific epoxy resin and a dimer acid-modified epoxy resin with a composite having a specific oil absorption to obtain a specific pigment volume concentration (hereinafter referred to as PVC), the above-mentioned physical properties are obtained. Was obtained. That is, 1. Epoxy equivalent 600-800, molecular weight 1200-1
600 dimer acid-modified epoxy resin and 1 ′. Epoxy equivalent 400-1000, molecular weight 800-
1. 2000 bisphenol A type epoxy resins are mixed such that the dimer acid-modified epoxy resin is 50% or less in terms of solid content weight ratio, or the dimer acid-modified epoxy resin is used alone. Oil absorption 15-30ml / 100g and 40-60m
2. 1/100 g of powder has a weight ratio of 35 to 15: 65 to 85; Further, an amine-based curing agent is mixed to make the PVC 25-
50%, solid content is 45 to 50%, and it is cured by reaction to form a coating film. Here, 1 '. The specific bisphenol A type epoxy resin is produced by a condensation reaction of bisphenol A and epichlorohydrin, and the epoxy equivalent and molecular weight range in the present invention is usually a resin in a solid state. It is a varnish-type prepolymer dissolved in a system solvent. A typical example is Epicoat 1001 manufactured by Yuka Shell Epoxy Co., Ltd. Here, when the epoxy equivalent or the molecular weight exceeds the above-mentioned range, it is difficult to achieve high solidification, the suitability for thick coating is reduced, the crosslinking density is reduced, and the coating film strength is reduced. Conversely, if the ratio is below the above range, problems such as an increase in crosslink density and difficulty in imparting plasticity occur. 1. The dimer acid-modified epoxy resin is a polyglycidyl ester of a polymerized fatty acid, and is generally a dimer having 36 carbon atoms obtained by polymerizing a linoleic acid such as a tall oil fatty acid and an unsaturated fatty acid having a high linolenic acid content by a Diels-Alder reaction. It is based on a polymerized fatty acid containing an acid as a main component, and is represented by a structural formula as shown in Chemical formula 1.

Embedded image If the epoxy equivalent or molecular weight of the dimer acid-modified epoxy resin exceeds the above range, the desired properties of the coating film cannot be obtained. Conversely, if it is below the above range,
Problems such as a decrease in the flexibility of the coating film occur. 1. And 1 '. The solids content ratio can be appropriately selected as long as the physical properties of the thick film coating composition are not impaired. Is less than 50%, there arises a problem that flexibility cannot be obtained. 2. Oil absorption of 15 ~ 30ml / 100g and 40 ~
60 ml / 100 g powder is 20-30 ml / 100 g, and titanium dioxide, heavy calcium carbonate, and precipitated barium sulfate are 40-60 ml / 100 g, and talc, light calcium carbonate, calcined clay (silicic acid) Alumina) and kaolin clay (aluminum silicate). These were prepared by weight ratio of 35 to 15: 65 to 85, PV
C (pigment volume concentration) is blended so as to be 25 to 50%, but if it is out of this range, problems such as concealing property, alkali sealing property, thick film property, workability and the like arise. 3.
Examples of the amine-based curing agent include aliphatic polyamines such as chain aliphatic polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dipropylenediamine, and diethylaminopropylamine;
-Aminoethylpiperazine, mensendiamine, cycloaliphatic polyamines such as isophoronediamine, aliphatic aromatic diamines such as xylylenediamine, aromatic amines,
For example, metaphenylene diamine, diaminodiphenylmethane, diaminodiphenylsulfone, or the like, or a polyamideamine or a polyamine epoxy resin adduct can be used, but a polyamideamine-based curing agent having an active hydrogen equivalent of 150 to 500 is preferable. 1.1 '. 3.
The organic solvent solution may be used as the component, but in order to effectively exhibit various physical properties as the thick film coating composition of the present invention, the solid content of the coating composition is finally set to 45 to 80%. Is desirable. It is not clear how the effect of the present invention is exerted, but it is not clear whether a specific dimer acid-modified epoxy resin that imparts flexibility to the specific epoxy resin is blended or the specific dimer acid-modified epoxy resin alone has a specific oil absorption. It is presumed that an appropriate high elongation was able to be given by combining the powders.

[0005]

【Example】

(Example 1) 4.5 parts by weight of "Epicoat 1001-X-70" (bisphenol A type epoxy resin solution, solid content 70%) manufactured by Yuka Shell Epoxy Co., Ltd., "Epicoat 872-" manufactured by Yuka Shell Epoxy Co., Ltd. X-75 "(dimer acid-modified epoxy resin solution, solid content 75%) 12.
7 parts by weight, 40.9 parts by weight of xylene-methyl isobutyl ketone mixed solvent, 4 parts by weight of titanium dioxide, 2 parts by weight of heavy calcium carbonate, and sedimentable barium sulfate as a powder having an oil absorption of 15 to 30 ml / 100 g. 2 parts by weight total 8
16.5 parts by weight of talc was mixed as a powder having an oil absorption of 40 to 60 ml / 100 g by weight to prepare a thick film coating composition of the present invention. The thick film coating composition was mixed with 17.4 parts by weight of a polyamidoamine (active hydrogen equivalent: 400) as a curing agent, and the following test was carried out using a thick film which was cured by reaction. Table 2 shows the test results. As a result, it was found that the elongation and the strength were excellent in the high elongation, and further, the water permeability, the alkali sealing property, the adhesion to the substrate, the crack resistance and the mirror finish were excellent. (Test method) (1) Permeability test According to JIS K 5400 8.16 Permeability test method, apply a coating material of the formulation shown in Table 1 to prepare a test body with a dry film thickness of 150μ, and after 24 hours Was measured. (2) Test method for strength and elongation JIS K 5400 8.8 According to the test method for tensile strength and elongation, a coating material having the formulation shown in Table 1 was applied.
Specimens were prepared at 00 ± 10μ and tested at a tensile speed of 5 mm / min. The elongation and tensile strength were measured. (3) Alkali sealability test According to the water permeability test of (1), phenolphthalein was mixed with deionized water of a tester so as to have a concentration of 0.01 wt%, and the presence of dissolution of alkali was confirmed by discoloration. . At this time, a completely discolored state was evaluated as 1, and a non-discolored state was evaluated as 5, and evaluated in five steps. (4) Thick coating suitability test method A coating material having the composition shown in Table 1 was applied to a 30 cm square flexible board at a width of 15 cm, a length of 30 cm, and a wet film thickness of 400 μm. The flexible board is placed vertically so that is horizontal, and the degree of sagging of the coating material is visually observed. At this time, the state where there was no sag was set to 3, the case where there was a slight sag was set to 2, and the case where there was a large sag was set to 1. (5) Adhesion strength test method A coating material having the formulation shown in Table 1 was applied at a coating amount of 500 g / m ² , and JIS K 5400 8.7 was applied using a test piece prepared at a dry film thickness of 150 to 200 μm. The adhesion strength was measured according to the strength test method. (6) Mirror Finish The coating material having the formulation shown in Table 1 was sprayed onto a 30 × 30 cm flexible board with an HS gun at a coating amount of 500 g / m ² , and then dried at 20 ° C. for 16 hours. The surface of this test piece was polished with an electric sander to which a # 320 sandpaper was attached. At this time, the polished surface was smoothed.
, And those with unevenness were evaluated as x. Furthermore, after applying a general-purpose hard urethane paint to the polished surface and curing, JIS K 5400
7.6 Based on the specular gloss test, a gloss of 60 degrees was measured. (7) Crack resistance JIS A 6910 is applied to a flexible board of 30 × 30 cm.
After applying a waterproof type multi-layer coating material (middle coating is an acrylic rubber coating material, and top coating is an elastic urethane coating material) specified in (1), a coating material having a formulation shown in Table 1 is coated with an HS gun at a coating amount of 500 g / m 2. ^Two
And dried at 20 ° C. for 16 hours. Furthermore, apply a general-purpose hard urethane coating material as an overcoat, and after drying and curing,
The presence or absence of cracks on the surface of the hard urethane coating film after 50 cycles was confirmed according to JIS A 6910 5.9 hot and cold repetition test. (Example 2) A test was conducted in the same manner as in Example 1 except that the formulation was as shown in Table 1. The results are shown in Table 2. As a result, as in Example 1, the elongation and the strength were excellent in the high elongation, and the water permeability, alkali sealability, adhesion to the substrate, crack resistance and mirror finish were also excellent. I understand. (Example 3) The formulation was as shown in Table 1, and the bisphenol A type epoxy resin was not blended. The test method was the same as in Example 1, and the results are shown in Table 2. As a result, in Example 3, although the strength itself of the high elongation was slightly lowered, there was no problem, the flexibility was excellent, and the other physical properties were evaluated as good as Examples 1 and 2. (Comparative Example 1) The formulation was as shown in Table 1 and the oil absorption was 4
0-60 ml / 100 g of powder was not blended. The test method was the same as in Example 1, and the results are shown in Table 2. As a result, it was found that Comparative Example 1 had high water permeability, poor elongation at high elongation, and poor polishing properties. (Comparative Example 2) Bisphenol A type epoxy resin and dimer acid-modified epoxy resin were compounded at a solid content weight ratio of 55:45 as shown in Table 1. The test method was the same as in Example 1, and the results are shown in Table 2. As a result, it was found that Comparative Example 2 had a poor elongation at a high elongation and poor crack resistance. (Comparative Example 3) The formulation was as shown in Table 1 and PVC was 5
It was blended so as to be 0% or more. The test method was the same as in Example 1, and the results are shown in Table 2. As a result, it was found that Comparative Example 3 had high water permeability, poor elongation at high elongation, and poor alkali sealability, glossiness, and crack resistance. Although the adhesion strength is the same as that of the example, the adhesion performance is considered to be slightly inferior to that of the example because of the peeling off of the interface between the base material and the coating film. (Comparative Example 4) A test was performed in the same manner as in Example 1 using a general-purpose cement filler. The results are shown in Table 2. As a result, it was found that Comparative Example 4 had extremely high water permeability, could not be measured for elongation and elongation, and was inferior in alkali sealability, adhesion strength, abrasiveness, and crack resistance. . (Comparative Example 5) Example 1 using a general-purpose solvent-based sealer
The test was performed in the same manner as described above. The results are shown in Table 2. As a result, Comparative Example 5 had a very low elongation at high elongation,
It was found that the alkali sealability and adhesion strength were inferior. Furthermore, it was found that the suitability for thick coating was very poor and the crack resistance was also poor.

[0006]

The thick coating composition of the present invention is mixed with an appropriate active hydrogen equivalent of an amine-based curing agent and sprayed onto a substrate.
By applying the iron, fine cracks on the surface of the object are concealed and firmly adhered to the object. Furthermore, because it has excellent thick coating suitability and adhesion strength, if the cured coating is appropriately polished as necessary to make it a smooth surface, even if a finish coating is laminated, it will only give a design like mirror surface In addition, the flexibility of the coating film itself follows the shrinkage of the object to be coated and alleviates the shrinkage. Does not occur. Furthermore, when performing mirror finishing, a smooth surface can be easily formed due to its excellent polishing properties, and when coated with a hard finish coating material, a mirror surface having excellent gloss can be formed.

[Table 1]

[Table 2]

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C09D 163/00-163/10 C08G 59/12

Claims (2)

(57) [Claims] 1. 1. A dimer acid-modified epoxy resin having an epoxy equivalent of 600 to 800 and a molecular weight of 1200 to 1600. Oil absorption 15-30ml / 100g and 40-60m
2. 1/100 g of powder has a weight ratio of 35 to 15: 65 to 85; Furthermore, an amine-based curing agent is mixed, and PVC
(Pigment volume concentration) 25-50%, solid content 45-80
% Thick film coating composition. 2. A dimer acid-modified epoxy resin having an epoxy equivalent of 600 to 800 and a molecular weight of 1200 to 1600; 1 ′. Epoxy equivalent 400-1000, molecular weight 800-
1. A mixture of 2,000 bisphenol A type epoxy resins mixed with a dimer acid-modified epoxy resin at a solid content weight ratio of 50% or more; Oil absorption 15-30ml / 100g and 40-60m
2. 1/100 g of powder has a weight ratio of 35 to 15: 65 to 85; Furthermore, an amine-based curing agent is mixed, and PVC
(Pigment volume concentration) 25-50%, solid content 45-80
% Thick film coating composition.