JP6222462B2 - Paint composition - Google Patents

Description

The present invention relates to a coating composition capable of thick coating.

In coating compositions, it is known to add a tackifier or the like that is an adhesion-imparting agent to an elastomer or the like. As in the invention described in Patent Document 1, an elastomer component and an adhesion-imparting agent component are added. It is described that they are integrated by copolymerization. It is described that a coating using such a copolymer can be applied to a thickness of about 30 μm in a wet manner, and can be formed as a single layer with a thickness that conventionally required overcoating. Yes. However, the characteristics may change due to variations in the copolymerization process.

JP 2004-182844 A

When a conventional coating composition is thickly coated, a solvent is likely to remain inside, and a uniform coating cannot be formed. The coating is resistant to salt water (95% in a 35 ° C. atmosphere using a 5 mass% sodium chloride solution). It was difficult to withstand the endurance test (such as RH).

As a result of intensive studies to achieve the above object, the present inventors have completed the present invention relating to a coating composition having good salt water resistance.

The gist of the present invention will be described next. The first embodiment of the present invention is a non-reactive coating composition containing components (A) to (D).
(A) Component: Acrylic polymer (B) component having a weight average molecular weight of 120,000 or less and a glass transition point of 70 ° C. or less: Polymer (C) component polymerized from a monomer containing α-methylstyrene: Plasticizer (D) component: aromatic solvent having 7 to 12 carbon atoms

2nd embodiment of this invention is a coating composition as described in 1st embodiment whose softening point of (B) component is 120 degrees C or less.

A third embodiment of the present invention is the coating composition according to either the first or second embodiment used for a vehicle chassis.

A fourth embodiment of the present invention is a rust preventive paint comprising the paint composition according to any one of the first to third embodiments.

In the present invention, even if it is thickly coated, it is difficult for the solvent to remain inside, and a uniform coating film can be formed. to enable.

Details of the present invention will be described below. The component (A) that can be used in the present invention is an acrylic polymer having a weight average molecular weight of 120,000 or less and a glass transition point of 70 ° C. or less. Here, the polymer includes a homopolymer obtained by polymerizing one kind of acrylic monomer and a copolymer obtained by polymerizing a plurality of kinds of acrylic monomers. The component (A) is an acrylic polymer having a specific weight average molecular weight and a glass transition point and having no reactive functional group. As the component (A), one kind or a mixture of plural kinds may be used.

Particularly preferably, the weight average molecular weight is 5,000 or more and 120,000 or less, and the glass transition point is 50 ° C. or more and 70 ° C. or less. It is presumed that the lower the molecular weight, the higher the solubility in a solvent, and the lower the glass transition point, the higher the flexibility.

The products corresponding to the component (A) include EVONIK's DEGALAN PM602, P28N, 64/12, LP63 / 11, LP65 / 11, LP64 / 11, LP65 / 12, LP64 / 12, PM381N, N742N, and 64 / 12N. , 66 / 02N, etc., but is not limited thereto.

The component (B) that can be used in the present invention is a polymer that is polymerized from a monomer containing α-methylstyrene. Any polymer consisting of α-methylstyrene alone or a copolymer used in part can be used. Although it is positioned as one type of so-called tackifier, saltwater resistance is reduced in tackifiers other than the component (B). As the component (B), one type may be used, or a plurality of types may be mixed and used. From the viewpoint of solubility, the softening point of the component (B) is preferably 120 ° C. or lower. The softening point refers to a temperature at which a solid substance begins to soften and become deformed.

Specific products of the component (B) include, but are not limited to, YS Resin SX100 manufactured by Yasuhara Chemical Co., Ltd., Sylvares SA85, SA100 manufactured by Arizona Chemical Co., etc.

It is preferable that 20-80 mass parts of (B) component is added with respect to 100 mass parts of (A) component. Especially preferably, it is 30-70 mass parts. When there are more (B) components than 20 mass parts, the adhesiveness with respect to a to-be-adhered body can be maintained. On the other hand, when the component (B) is less than 80 parts by mass, the flexibility of the coating film can be maintained.

The component (C) that can be used in the present invention is a plasticizer. In consideration of not volatilizing from the coating film, the boiling point is preferably 300 ° C. or higher. Specific examples of the component (C) include dioctyl phthalate, diisononyl phthalate, dioctyl phthalate, diisononyl phthalate, diisodecyl phthalate, butyl benzyl phthalate, alkylaryl phthalate, dibenzyl phthalate, diaryl phthalate, and adipic acid Examples thereof include, but are not limited to, dibutyl and 1,2-cyclohexanedicarboxylic acid diisononyl ester. As the component (C), one type may be used, or a plurality of types may be mixed and used.

It is preferable that 1-60 mass parts of (C) component is added with respect to 100 mass parts of (A) component. Especially preferably, it is 10-50 mass parts. When there are more (B) components than 10 mass parts, the flexibility of a coating film can be maintained. On the other hand, when the component (B) is less than 60 parts by mass, a coating film having a smooth surface can be formed.

The component (D) that can be used in the present invention is an aromatic solvent having 7 to 12 carbon atoms. Here, the “carbon number” refers to all carbons contained in one molecule. Specific products include toluene (7 carbon atoms), xylene (8 carbon atoms), Ipsol No. 100 (9 carbon atoms), Ipsol No. 150 (10 carbon atoms), etc. It is not limited to.

As a solvent other than the component (D), diacetone alcohol having a high polarity such as isohexane and naphthenic solvent having a low polarity are known. However, these have low solubility of the component (A) and are volatile. There is a problem that the coating film surface is not smooth because it is high, and it cannot be used alone. However, it can be appropriately used in combination with the component (D).

The present invention includes inorganic fillers such as calcium carbonate, talc, silica, alumina, and aluminum hydroxide, organic fillers such as acrylic particles, flame retardants, antioxidants, and antifoaming agents as long as the characteristics of the present invention are not impaired. Additives such as coupling agents, leveling agents, and rheology control agents may be blended in appropriate amounts. By adding these, a coating film excellent in resin strength, adhesive strength, workability, storage stability and the like can be obtained.

As an application of the present invention, it can be used for general antirust applications. Since the present invention has good salt water resistance and is difficult to peel off from an adherend even in a harsh environment, it is suitable for a vehicle application, and can be used for a specific application such as a chassis.

EXAMPLES Next, although an Example is given and this invention is demonstrated further in detail, this invention is not limited only to these Examples. (Hereinafter, the coating composition is simply referred to as a composition.)

In order to prepare the composition, the following components were prepared.
Component (A): Acrylic polymer having a weight average molecular weight of 120,000 or less and a glass transition point of 70 ° C. or less. Acrylic polymer having a weight average molecular weight of 60000 and a glass transition point of 63 ° C. (DEGALAN 64/12 EVONIK (Made by company)
Weight average molecular weight: 110000, glass transition point: 61 ° C. acrylic polymer (DEGALAN P28N EVONIK)
Component (A ′): Acrylic polymer other than component (A). Weight average molecular weight: 160000, glass transition point: acrylic polymer with a temperature of 50 ° C. (manufactured by DEGALAN MB319 EVONIK)
Weight average molecular weight: 180,000, Glass transition point: 104 ° C. acrylic polymer (DEGALAN M345 EVONIK)
Component (B): Polymer polymerized from monomer containing α-methylstyrene / α-methylstyrene polymer having a softening point of 100 ° C. (YS Resin SX100, manufactured by Yasuhara Chemical Co., Ltd.)
Α-methylstyrene polymer having a softening point of 85 ° C. (Sylvares SA85, manufactured by Arizona Chemical Co., Ltd.)
Α-methylstyrene polymer having a softening point of 100 ° C. (Sylvares SA100, manufactured by Arizona Chemical Co., Ltd.)
Component (B ′): Polymer other than component (B) / terpenephenol copolymer having a softening point of 80 ° C. (YS Polystar T80, manufactured by Yasuhara Chemical Co., Ltd.)
-Terpene phenol copolymer with softening point of 100 ° C (YS Polystar T100 Yasuhara Chemical Co., Ltd.)
-Terpene phenol copolymer with a softening point of 125 ° C (YS Polystar G125 Yasuhara Chemical Co., Ltd.)
-Terpene phenol copolymer with softening point of 125 ° C (YS Polystar N125 Yasuhara Chemical Co., Ltd.)
・ Aromatically modified terpene polymer having a softening point of 85 ° C. (YS Resin TO85 manufactured by Yasuhara Chemical Co., Ltd.)
-Terpene resin with a softening point of 80 ° C (YS Resin PX800 manufactured by Yasuhara Chemical Co., Ltd.)
・ Aliphatic saturated hydrocarbon resin with a softening point of 90 ° C (Alcon P-90, Arakawa Chemical Industries, Ltd.)
-Aliphatic saturated hydrocarbon resin with a softening point of 100 ° C (Alcon P-100, manufactured by Arakawa Chemical Industries, Ltd.)
-Aliphatic saturated hydrocarbon resin with a softening point of 125 ° C (Alcon P-125, Arakawa Chemical Industries, Ltd.)
-Aliphatic saturated hydrocarbon resin with a softening point of 140 ° C (Alcon P-140, Arakawa Chemical Industries, Ltd.)
-Polyethylene resin with a softening point of 98 ° C (S-394 N1 manufactured by Shamrock)
-Terpene phenol resin with a softening point of 95 ° C (Sylvares TP96, manufactured by Arizona Chemical Co., Ltd.)
(C) Ingredient: Plasticizer / Plasticizer 1: Dioctyl phthalate (DOP Co., Ltd. manufactured by J Plus)
・ Plasticizer 2: Diisononyl phthalate (DINP CG Esther)
Plasticizer 3: 1,2-cyclohexanedicarboxylic acid diisononyl ester (manufactured by HEXAMOL DINCH BASF Japan Ltd.)
(D) component: C7-C12 aromatic solvent, C9 aromatic hydrocarbon (Ipsol No. 100, manufactured by Idemitsu Kosan Co., Ltd.)
・ Toluene (C7 aromatic hydrocarbon) (Toluene made by Nippon Alcohol Sales Co., Ltd.)
Component (D ′): Solvent other than component (D), isohexane (Kyowasol C-600M manufactured by KH Neochem Co., Ltd.)
・ Naphthenic solvents (Exsol D40 manufactured by ExxonMobil Chemical)
・ Diacetone alcohol (Diacetone alcohol KH Neochem Co., Ltd.)

In order to prepare References 1 to 20, the above acrylic polymer and solvent are weighed in a beaker and stirred at 25 ° C. for 24 hours. Detailed preparation amounts follow Table 1, and all numerical values are expressed in parts by mass. For References 1 to 20, compatibility confirmation and thick film formation confirmation were performed. The results are also summarized in Table 1.

[Compatibility check]
The prepared composition is put into a glass container and left at 25 ° C. for 1 day. Visually confirm with the following evaluation criteria to be “compatible (no unit)”.
Evaluation criteria ○: All raw materials are dissolved ×: Some or all are not dissolved, or separated after standing

[Confirmation of thick film formation]
On the steel plate (SPCC-SB), the composition is applied so that the dry film thickness is 30 μm. Then, it dries at 25 degreeC and produces a test piece. The surface of the test piece is visually confirmed and judged according to the following evaluation criteria, and is defined as “thick film formability (no unit)”. If unconfirmed, write "-".
Evaluation criteria ○: The surface is smooth ×: The surface is not smooth

Both compatibility and thick film formation are “◯” in Reference Examples 1, 2, 7, 12, and 17, and the acrylic polymer is dissolved in an aromatic solvent having 7 to 12 carbon atoms. It was.

Examples 1 to 7 and Comparative Examples 1 to 15 as coating compositions were prepared. The component (D) (component (D ′) in the comparative example) is weighed and charged into a stirring vessel, and the component (A) (component (A ′) in the comparative example) and component (B) (in the comparative example (B ′) ) Component) and solvent are weighed in a beaker and stirred at 25 ° C. for 24 hours. Finally, the component (C) is weighed and stirred at 25 ° C. for 1 hour. Detailed preparation amounts follow Table 2, and all numerical values are expressed in parts by mass.

For Examples 1 to 7 and Comparative Examples 1 to 15, compatibility confirmation, thick film formation confirmation, initial adhesion confirmation, and salt water resistance test were performed. The results are summarized in Table 3. The compatibility check and the thick film curability check are the same tests as described above.

[Initial adhesion confirmation]
On the steel plate (SPCC-SB), the composition is applied so that the dry film thickness is 30 μm. Then, it dries at 25 degreeC and produces a test piece. Make a 1 mm square notch cut on the surface of the coating. Thereafter, the surface of the coating film is peeled off with an adhesive tape and visually confirmed according to the following evaluation criteria to obtain “initial adhesion”. The detailed test method follows JIS G3141.
Evaluation criteria ○: 100/100 ×: Not 100/100

[Saline test]
On the steel plate (SPCC-SB), the composition is applied so that the dry film thickness is 30 μm. Then, it dries at 25 degreeC and produces a test piece. In accordance with the following test conditions, the test piece is put into a salt spray tester. At each time, the test piece is removed from the tester, and a cross-cut test is performed while cooling to room temperature. When the grid time is maintained at 240/360 hours and 480 hours and 100/100 for the grid, the 600, 700, and 800 hours are continuously confirmed. Time (unit: time) ". The detailed test method follows JIS Z2371. The durability time is preferably 500 hours or more.
Test conditions Salt solution: 5% by mass sodium chloride solution Temperature: 35 ° C.
Humidity: 95% RH

Although Examples 1-7 using the polymer polymerized from the monomer containing α-methylstyrene as the component (B) have a durability time of 500 hours or more, tackifiers other than the component (B) are used. The comparative examples 1 to 12 and the comparative examples 13 and 14 which do not contain the component (B) have a durability time of less than 500 hours. Further, in Comparative Example 15 using an acrylic polymer having a weight average molecular weight of 120,000 or less and a glass transition point of 70 ° C. or less, the durability time is reduced.

In recent years, switching to a paint such as an aqueous emulsion has been attempted for environmental considerations. However, it is difficult to exceed solvent-based paints as a strong coating film that can withstand harsh environments. The present invention is a coating composition suitable for a specific application such as a vehicle chassis because it has good salt water resistance and is difficult to peel off from an adherend even in a harsh environment.

Claims (4)

A non-reactive coating composition containing the components (A) to (D).
(A) Component: Acrylic polymer (B) component having a weight average molecular weight of 120,000 or less and a glass transition point of 70 ° C. or less: Polymer (C) component polymerized from a monomer containing α-methylstyrene: Plasticizer (D) component: aromatic solvent having 7 to 12 carbon atoms (B) The coating composition of Claim 1 whose softening point of a component is 120 degrees C or less. The coating composition according to claim 1, which is used for a vehicle chassis. A rust preventive paint comprising the paint composition according to claim 1.