JP2017186448A - Resin composition for coatings - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for coatings of which a coated film is hardly peeled off even in severe contact or rubbing between metals and which is suitable for the coatings used in coating various metal materials, hardly causes clogging even through a narrow nozzle of a printing device as the viscosity is low, is also suitable for the coatings used in marking various metal materials as the printing hardly disappears, and has less load on human bodies or the environment.SOLUTION: There is provided a resin composition for coatings by dissolving a crosslinkable acryl resin of 5 to 7.5 wt.% and an ethanol soluble resin of 5 to 15 wt.% in a solvent containing ethanol of 0.8 to 1.2 based on 1 of dimethyl glycol.SELECTED DRAWING: None

Description

  The present invention relates to a coating resin composition. Specifically, since the coating resin composition is in close contact with the metal surface, the coating film is very difficult to peel off even during intense contact or rubbing between metals, and is therefore suitable for coatings used for coating various metal materials, In addition, since the viscosity is low, clogging does not easily occur even through the thin nozzles of the printing device, and printing is difficult to erase. Therefore, it can be used suitably for paints used for marking various metal materials and has a heavy impact on the human body and the environment. The present invention relates to a small resin composition for paint.

Metal materials such as metal plates and metal pipes may come into contact with each other or rub against each other during the manufacturing process or transportation.
Therefore, the coating material used for coating or marking of a metal material is required to have adhesion with a metal surface so as not to be peeled off even by intense contact or rubbing.

  As a paint vehicle capable of obtaining adhesion to a metal surface, one containing a crosslinkable acrylic resin is known.

  The crosslinkable acrylic resin is soluble in a solvent having high solubility such as acetone, toluene, xylene, dimethyl glycol (1,2-dimethoxyethane, hereinafter referred to as “DMG”), but in a solvent having low solubility such as alcohol. Does not dissolve.

  However, solvents with high solubility, such as acetone, have a heavy impact on the human body and the environment, so they are subject to the PRTR (Pollutant Release and Transfer Register) system and need to submit SDS (Safety Data Sheet). In addition, the usage is limited by other rules.

  On the other hand, solvents such as alcohols are not subject to the PRTR system and organic solvent poisoning prevention regulations because they have a small burden on the human body and the environment, but have low solubility and cannot dissolve crosslinkable acrylic resins.

  In addition, if the viscosity of the coating material used for marking becomes too high, the fine nozzles of the printing apparatus may be clogged.

  Therefore, it is necessary to produce a coating material in which the cross-linkable acrylic resin is dissolved and in close contact with the metal surface, can be used for a printing device with a thin nozzle without excessively increasing the viscosity, and has a low impact on the human body and the environment. Development of a resin composition for paints that can be used is desired.

JP 5-117574

  Patent Document 1 discloses a hydroxyl group-containing vinyl copolymer (component A), a chlorinated polyolefin resin (component B), and a hydroxyl group composed of isobornyl (meth) acrylate and an α, β-unsaturated monomer copolymerizable therewith. A coating resin composition containing a crosslinkable resin (component C) capable of reacting is disclosed.

  However, the resin composition is soluble only in a highly soluble solvent such as thinner of xylene and butyl acetate, and since the solvent contains VOC (volatile organic solvent), the load on the human body and the environment is large. It is also subject to regulations in the organic solvent poisoning prevention regulations. Therefore, there is a problem that sellers and purchasers need to pay attention to handling.

  Therefore, the present inventors made it a technical problem to solve the above-mentioned problems, and as a result of repeated trial and error trial production and experiment, as a result, a solvent containing 0.8 to 1.2 ethanol with respect to dimethyl glycol 1 was obtained. If it is a resin composition for coating formed by dissolving 5 to 7.5% by weight of a crosslinkable acrylic resin and 5 to 15% by weight of an ethanol-soluble resin, it is in close contact with the metal surface, and the viscosity does not increase excessively, The present invention has been completed by obtaining the remarkable knowledge that the resin composition for coatings has little load on the human body and the environment.

  The technical problem can be solved by the present invention as follows.

  The present invention is a coating resin composition in which 5 to 7.5% by weight of a crosslinkable acrylic resin and 5 to 15% by weight of an ethanol-soluble resin are dissolved in a solvent containing 0.8 to 1.2 ethanol with respect to dimethyl glycol 1. (Claim 1).

  Further, the present invention is the coating resin composition according to claim 1, wherein the ethanol-soluble resin is an ethanol-soluble acrylic resin (claim 2).

  The present invention also provides a paint in which a pigment is dispersed in the paint resin composition according to claim 1 or 2 (claim 3).

The present invention also provides a metal material to which the paint according to claim 3 is applied (claim 4).

  The present invention is the metal material according to claim 4, wherein the metal is carbon steel (claim 5).

  Since the resin composition for coatings according to the present invention contains an ethanol-soluble resin in addition to the cross-linkable acrylic resin, the cross-linkable acrylic resin aggregates even in a solvent containing 0.8 to 1.2 ethanol with respect to DMG1. Therefore, the coating film is hardly peeled off even when intense contact or rubbing between metal materials occurs.

  In addition, since the solvent according to the present invention contains 0.8 to 1.2 ethanol that is highly safe with respect to DMG1, the load on the human body and the environment is small. Also, the viscosity does not become too high.

  Accordingly, a paint in which a pigment is dispersed in the resin composition for paint according to the present invention is suitable for coating a metal material, and it is difficult to cause clogging even through a thin nozzle of a printing apparatus, and printing is difficult to disappear. It can also be suitably used for various markings of metal materials.

  Further, if an ethanol-soluble acrylic resin is dissolved in the crosslinkable acrylic resin, the resins are mixed well, so that better adhesion can be realized.

  Moreover, the resin composition for coatings which concerns on this invention shows the adhesiveness which was more excellent with respect to carbon steel.

The present inventors presume that the reason why the resin composition for coating according to the present invention is in close contact with the metal surface is as follows.
That is, since the crosslinkable acrylic resin is dissolved in DMG but not in ethanol, in the resin composition in which only the crosslinkable acrylic resin is dissolved in the solvent according to the present invention, the highly volatile DMG is volatilized first. When the solubility of the solvent is weakened, the crosslinkable acrylic resins are aggregated and their characteristics are impaired.
However, since the resin composition for coatings according to the present invention also contains an ethanol-soluble resin, even if the solubility of the solvent is weakened, there is a dissolved resin around the crosslinkable acrylic resin, and the crosslinkable acrylic resins In order to prevent agglomeration, the property of the crosslinkable acrylic resin that it adheres to the metal surface after all the ethanol is volatilized can be maintained.

It is a schematic diagram which shows the measuring method of adhesiveness.

  The crosslinkable acrylic resin in the present invention is not particularly limited, but a crosslinkable acrylic resin having an average molecular weight of 30,000 to 100,000, a theoretical oxidation value (mgKOH / g) of 3 to 20, and a glass transition temperature of 40 to 100 ° C. is preferable. .

  Preferred examples of the crosslinkable acrylic resin include Dianal (registered trademark) BR116 (average molecular weight 45,000, theoretical oxidation value 7, glass transition point 50 ° C./manufactured by Mitsubishi Rayon Co., Ltd.).

The content of the crosslinkable acrylic resin in the coating resin composition is preferably 5 to 7.5% by weight.
If the content is lower than 5% by weight, the ratio of the cross-linkable acrylic resin is not sufficient, and if it exceeds 7.5% by weight, it will not be dissolved sufficiently and undissolved will occur and both will be in contact with the metal surface. This is because the adhesion is weakened.

  The ethanol-soluble resin in the present invention is not particularly limited as long as it is a resin that dissolves in ethanol, but an average molecular weight of 1,000 to 5,000, a theoretical oxidation value of 10 to 300, and a glass transition point of 40 to 100 ° C. are preferable.

  Preferred ethanol-soluble resins include Joncryl (registered trademark) 682 (acrylic resin, average molecular weight 1,750, theoretical oxidation value 238, glass transition point 57 ° C./BASF Corporation), Marquide (registered trademark) No. 32 (maleic resin) Softening point 130-140 ° C, theoretical oxidation value 140 or less / Arakawa Chemical Industries, Ltd., Harimac 145P (rosin-modified maleic resin, softening point 135-145 ° C, theoretical oxidation value 20-30 / Halima Chemical Group Co., Ltd.) ).

  In particular, an ethanol-soluble acrylic resin is preferable because it is well mixed with a cross-linkable acrylic resin and becomes a coating resin composition exhibiting better adhesion to a metal surface.

The content of the ethanol-soluble resin in the coating resin composition is 5 to 15% by weight, more preferably 7.5 to 15% by weight.
If it is lower than 5% by weight, aggregation of the crosslinkable acrylic resin cannot be sufficiently suppressed, and if it exceeds 15% by weight, it becomes difficult to show the characteristics of the crosslinkable acrylic resin. This is because the adhesion to the metal surface is weakened.

  The solvent in the present invention contains 0.8 to 1.2 ethanol with respect to DMG1. If the proportion of ethanol is less than 0.8, a part of the crosslinkable acrylic resin will aggregate as DMG volatilizes, and if it exceeds 1.2, the crosslinkable acrylic resin will not dissolve sufficiently, resulting in undissolved parts. This is because the adhesion to the metal surface is weakened.

  The pigment to be dispersed in the coating resin composition according to the present invention is not particularly limited, white pigments such as titanium dioxide, calcium carbonate, and barium sulfate, black pigments such as carbon black, organic coloring pigments, metal powders, fluorescent Pigments can be used.

  The content of the pigment in the coating resin composition is preferably 5 to 15% by weight.

  The resin composition for coatings in the present invention can contain an appropriate amount of a stabilizer and an antirust agent as required.

  The coating resin composition according to the present invention can be produced by mixing DMG and ethanol with stirring, then adding a crosslinkable acrylic resin and ethanol-soluble resin, and stirring to dissolve the resin.

  After the resin is dissolved, the pigment can be added and stirred. If necessary, a stabilizer or the like can be added and further stirred, and then filtered through a filter to produce a paint.

  Examples and Comparative Examples of the present invention are shown below, but the present invention is not limited thereto.

  After mixing and stirring in amounts as shown in Tables 1 to 4, the resin compositions for paints or paints (hereinafter referred to as “paints etc.”) of each Example and Comparative Example were filtered through a 10 μm filter. did.

  As a cross-linkable acrylic resin, Dianal BR-116 was used, and as an ethanol-soluble resin, Joncryl 682 (acrylic resin) and Marquide No. 32 (maleic resin) were used.

  As the white pigment, AWB-CP001A (manufactured by Nihongo Bix Co., Ltd.) and TXP (manufactured by Daihachi Chemical Industry Co., Ltd.) and / or Efka (registered trademark) SL 3031 (manufactured by BASF Corporation) were used as stabilizers.

  Those in which the resin did not dissolve or remained undissolved were evaluated as “insoluble”.

<Measurement of adhesion>
The measurement was performed according to the adhesion test (pull-off method) prescribed in JIS K 5600 5-7.

  On the surface of the metal plate (2a) polished with paper # 240, 4 μL of each of the paints of Examples and Comparative Examples accurately weighed with a microsyringe is dropped (1). A cylindrical metal (2b) that is the same metal as the metal plate (2a) is gently placed on the dropped paint (1) and adhered. As it is, it is dried at room temperature all day and night to cure the coating film.

  A metal plate (2a) to which a cylindrical metal (2b) is bonded with each paint, etc. (1) is fixed to a workbench (5) with a vise (Shakoman) (4), and a force gauge (3) (Iko Engineering Co., Ltd.) The force gauge value (N: Newton) when the cylindrical metal (2b) was peeled off the metal plate (2a) was carefully pulled so that the tension was evenly applied to the entire bonding surface. The adhesion was measured by reading.

  Tables 1 to 3 show adhesion to carbon steel (S45C), and Table 4 shows adhesion to aluminum alloy (AC4C).

  Note that if the adhesion measured by this measurement method is 160 N or less, peeling may occur when the metals come into intense contact with each other.

  From Tables 1 to 4, it was proved that the paints and the like according to the present invention have an adhesion of 180 N or more with respect to both carbon steel and aluminum alloy, and are very difficult to peel off even in intense contact between metals. .

If the resin composition for paints according to the present invention is used, the paint using the resin composition for paints is suitable for coating metal materials because the coating film is very difficult to peel off even in the case of intense contact or rubbing between metals. In addition, since the coating material has a low viscosity, it is difficult to cause clogging even with a thin nozzle of a printing apparatus, and printing is difficult to disappear. Therefore, it can be suitably used for marking various metal materials. Moreover, since the solvent of the resin composition for coatings concerning this invention has a high ratio of highly safe ethanol, there is little load given to a human body and an environment.
Therefore, the present invention has high industrial applicability.

1 Resin composition for paint or paint 2a Metal plate 2b Cylindrical metal 3 Force gauge 40 Vise (Shakoman)
5 Working table

Claims (5)

A resin composition for coatings comprising 5 to 7.5% by weight of a crosslinkable acrylic resin and 5 to 15% by weight of an ethanol-soluble resin in a solvent containing 0.8 to 1.2 ethanol relative to dimethyl glycol 1. 2. The coating resin composition according to claim 1, wherein the ethanol-soluble resin is an ethanol-soluble acrylic resin. 3. A paint in which a pigment is dispersed in the paint resin composition according to claim 1 or 2. A metal material coated with the paint according to claim 3. 5. The metal material according to claim 4, wherein the metal is carbon steel.

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