JPH0463881A - Paint resin for metal - Google Patents

Abstract

PURPOSE:To obtain the title resin which is excellent in adhesiveness to a metallic surface by coating the metallic surface with an acrylic resin which is obtained by copolymerizing a prescribed amount of 2-(meth)acryloxyalkyl succinate with comonomers. CONSTITUTION:The title paint resin for a metal comprises an acrylic resin obtained by copolymerising 0.5 to 15wt.% 2-(meth)acryloxyalkyl succinate, such as 2-methacryloyloxyethyl succinate, with comonomers. The acrylic resin is, for example, one obtained from 2-methacryloyloxyethyl succinate, styrene, methyl methacrylate and 2-ethylhexyl acrylate.

Description

DETAILED DESCRIPTION OF THE INVENTION r Industrial Field of Application The present invention relates to a paint resin for metals made of an acrylic resin that has excellent adhesion to metal materials, particularly iron materials, and has a rust-preventing effect.

[Prior Art] As conventional metal coating resins, alkyd resins, evoquino resins, phenol resins, acrylic resins, aminoalkyd resins, acrylic polyurethane resins, etc. have been used. However, when these resins are used for coating purposes, their adhesion to metal surfaces is usually improved by heat treatment and/or the combined use of a curing agent.

Among these, acrylic resins come in a wide variety of varieties, from those with high hardness and low elongation to those that are soft and sticky, depending on the acrylic moatsummer that makes up the resin, other copolymerized monomers, and the degree of polymerization of the resin. In addition to producing paint products, such acrylic resin paints have excellent weather resistance and yellowing resistance, making them highly practical.

[Problem to be solved by the invention] However, with acrylic resin paints, sufficient adhesion cannot be achieved simply by heat treatment, so it may be necessary to use a curing agent in combination with the resin. If it is a two-component type that is mixed with a hardening agent, a mixing operation is required before painting, resulting in poor workability.On the other hand, if it is a one-component type, in which the hardening agent is mixed with the resin in advance, the pot life will be shortened. , various issues arise. Therefore, there is currently a need for the development of an acrylic resin coating that exhibits sufficient adhesion to metal surfaces using a resin alone, even without the use of a curing agent.

[Means for solving the problem] Therefore, the present inventors conducted intensive research to solve the problem, and as a result, as a copolymer component of acrylic resin,
The inventors have discovered that the objective can be achieved by copolymerizing a special succinic acid monoester, and have completed the present invention.

That is, the present invention provides ``2-(meth)acryloquine alkylsuccinic acid with 0.5
A metal coating resin made of an acrylic resin copolymerized with ~15% by weight. ”.

The feature of the present invention is that, as described above, a specific amount of 2-(meth)acryloxyalkyl succinic acid is copolymerized as a copolymerization component of the acrylic resin.

Paint resins made of acrylic resins into which such special succinic acid monoalkyl esters are introduced have excellent adhesion to the surfaces of metal materials, especially iron materials, and have antirust effects.

The 2-(meth)acryloxyalkylsuccinic acid of the present invention includes, for example, 2-methacryloyl oxyneethylsuccinic acid,
These are 2-acryloyl oxinoethylsuccinic acid, 2-methacryloyl oxinopropylsuccinic acid, and 2-acryloyl oxinepropylsuccinic acid, and these may be used alone or in combination of two or more.

In the acrylic resin of the present invention, it is essential to copolymerize the above-mentioned 2-(meth)acryloquine alkylsuccinic acid in an amount of 05 to 15% by weight, preferably 1 to 5% by weight.

If the succinic acid monoalkyl ester is less than 0.5% by weight, it is difficult to obtain the effects of the present invention, and if it exceeds 15% by weight, the water resistance of the coating film tends to decrease and adhesion tends to be poor, which is not preferable. .

In the acrylic resin of the present invention, the constituent components other than the 2-(meth)acryloxyalkyl succinic acid component are not particularly limited, and include the same main monomer components and comonomer components as conventional acrylic paint resins, and further as necessary. Small amounts of functional group-containing monomer components may be mentioned.

Examples of the raw monomer components include alkyl groups having 2 to 2 carbon atoms, such as ethyl acrylate, n-butyl acrylate, 1so-butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, benzyl acrylate, and cyclohexyl acrylate. Acrylic acid alkyl ester of about 12, n-butyl methacrylate, methacrylic acid 1so-
Examples include methacrylic acid alkyl esters having an alkyl group of about 4 to 12 carbon atoms, such as butyl, 2-ethylhexyl methacrylate, lauryl methacrylate, henonol methacrylate, and cyclohexyl methacrylate. and methacrylic acid alkyl esters having an alkyl group of 1 to 3 carbon atoms such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, etc., aromatic polymerizable unsaturated carbonized materials such as styrene, vinyltoluene, α-methylstyrene, chlorostyrene, etc. Examples include hydrogens, vinyl acetate, vinyl chloride, vinylpyridine, acrylonitrile, methacrylonitrile, etc. The functional group-containing monomer components include acrylic acid, methacrylic acid, crotonic acid, itaconic acid (or its anhydride)
, maleic acid (or its anhydride), fumaric acid, and β-hydroquinoethyl acrylate, β-hydroquinepropyl acrylate, β-hydroxyethyl methacrylate,
Hydroquinoalkyl (meth)acrylates such as β-hydroquinepropyl methacrylate, as well as acrylamide, methacrylamide, N,N-trimethylacrylamide, diacetone acrylamide, N-(hydroquinomethyl)acrylamide, N,N- Examples include noethylaminoethyl methacrylate and glinodyl methacrylate.

The above components alone make the acrylate resin suitable for practical use as a paint resin for metals, but in order to provide stronger adhesion and better pigment dispersibility, it is necessary to further add dialkylaminoethyl (meth) as a copolymerization component. Acrylate 01
It is suitable to copolymerize up to 10% by weight, preferably 0.5 to 5% by weight.

When the content of this component is less than 0.1% by weight, it is difficult to obtain the desired effect, and when it exceeds 10% by weight, metal adhesion and pigment dispersibility are adversely reduced.

Examples of such dialkylaminoethyl (meth)acrylate include methylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, and the like.

The acrylic resin of the present invention is prepared by mixing the above-mentioned 2-(meth)acryloquine alkylsuccinic acid, noalkylaminoethyl (meth)acrylate, main monomer, comonomer, and optionally a functional group-containing monomer in an organic solvent. It is easily produced by methods well known to those skilled in the art, such as radical copolymerization.

Examples of the organic solvent used in the polymerization include aromatic hydrocarbons such as toluene and kiln, esters such as ethyl acetate and butyl acetate, n-propyl alcohol, and IS.

Examples include aliphatic alcohols such as propyl alcohol, ketones such as methyl edyl ketone, methyl isobutyl ketone, and noclohexanone.

The polymerization catalyst used in the radical polymerization includes azohisisobutyronitrile, which is a usual radical polymerization catalyst,
Specific examples include benzoyl peroxide, not-t-butyl peroxide, and cumene hydroperoxide.

The metal coating resin of the present invention is prepared into a coating by a conventional method. Typical pigments used include white pigments such as titanium white, subpencil, lithopone, and lead white; black pigments such as carphone black, graphite, and iron black;
Red pigments such as Bengara, fast yellow, anthraquinone yellow, henchinone yellow, yellow pigments such as yellow lead, yellow ocher, titanium yellow, green pigments such as phthalonoamine green, chrome clean, chromium oxide, phthalonoamine blue Examples of extender pigments include general extender pigments such as carbonic acid, talc, and clay palite powder, and special extender pigments such as calcined gypsum, silica powder, and elonol.

In addition, as rust-preventing pigments that have a particularly rust-preventing effect, we also use lead-based pigments such as red lead, lead white, lead zinc oxide, basic lead chromate, basic lead sulfate, calcium lead acid, lead noanamide, and non-fuchromate (ZTC). and ZTC type), chromate pigments such as strontium chromate and barium chromate, metal powder pigments such as aluminum powder, zinc powder, metal lead powder, copper powder, and bronze powder, mica-like iron oxide (MTO), glass flakes, mica By adding special anticorrosive pigments such as powder, the antirust effect is further improved.

In addition to these, ordinary curing agents such as amino resins, evoquino resins, noevoquino resins, dibasic acids, acid anhydrides, and melamine, plasticizers, anti-sagging agents, anti-settling agents, leveling agents, and erasers may be used as necessary. Foaming agents and the like are added as appropriate.

The metal paint obtained as described above is applied by a conventional coating method such as a brush or a spray roller.

[Function] 2-(meth)acryloxyalkyl succinic acid, which is a copolymer component of the acrylic resin of the present invention, has the effect of improving the adhesion of the resin to the metal surface.

[Example and control example] Hereinafter, the present invention will be explained in more detail with reference to Examples.

Resin production example 1 Styrene 280 parts by weight 11 L Methyl methacrylate 380 parts by weight, 2-ethylhexyl acrylate 320 parts, 2-methacryloyloxyethylsuccinic acid 20 parts by weight, xylene 900 parts by weight, azobisisobutyronitrile 1.0 parts by weight was placed in a flask equipped with a condenser, stirrer, and thermometer, heated to 90°C to polymerize, polymerized for 12 hours while adding azohisisobutyronitrile sequentially during polymerization, and then added a kiln to adjust the concentration. Resin solution (A) with a resin content of 452% by weight and a viscosity of 2000 cps/25°C
I got it.

The composition of the resulting resin (A) was 28% by weight of styrene, 38% by weight of methyl methacrylate, 320% by weight of 2-ethylhexyl acrylate, and 20% by weight of methacryloyl oxyneethylsuccinic acid.

Resin Production Examples 2 to 13 Copolymers were produced according to Production Example 1 using each copolymer component shown in Table 1. The copolymers obtained in Production Examples 2 to IO are respectively referred to as resins (B) to (4I),
The copolymers obtained in Production Examples 11 to 13 were designated as resins (a) to (c), respectively.

Example 1 250 m of 100 parts by weight of resin (A), 33 parts by weight of titanium oxide, 20 parts by weight of runner, and 100 parts by weight of glass beads
1! The mixture was placed in a glass container and dispersed with a paint conditioner for about 1 hour to obtain white enamel.

The resulting autoenamel was applied to a degreased cold-rolled steel plate by spraying to a dry coating thickness of 100 μm for 20 minutes.
CX was air-dried for 7 days to prepare a sample for a coating film test.

Using this sample, the adhesion was evaluated by the following measuring method, and the results are shown in Table 2.

○ Use a cutter knife on the adhesive coating film to measure the number of holes on the base that do not peel off in the cellophane tape peel test.

○ Adhesion after immersion in saline solution Number of base marks that do not peel off in cellophane tape peeling test by using a cutter knife to cut a base of 1 mm x I mm into a coating film immersed in a 5% by weight aqueous sodium chloride solution for 5 days.

○ After immersing in salt water, make cross cuts in the cross cut area coating film using a cutter knife, and add 5% by weight.
Bulge width (mm) of cut line after immersion in sodium chloride aqueous solution for 5 days.

Examples 2 to 10 and Control Examples 1 to 3 Paints were prepared and evaluated in the same manner as in Example 1 using resins B-J and a-c obtained in the above production examples, and the results are shown in Table 2. Indicated.

Table 2 Example II A white enamel was prepared in Example 1 using 100 parts by weight of resin (A), 27 parts by weight of titanium oxide, 5 parts by weight of aluminum phosphate, 20 parts by weight of thinner, and 100 parts by weight of glass beads. Samples for coating film testing were prepared in the same manner as in the spinning process, except that the coating was applied to a dry coating thickness of approximately 100p, and the evaluation results are shown in Table 3.

Examples 12 to 20 and Comparative Examples 4 to 6 Paints were prepared and evaluated in the same manner as in Example II using the resins B to, I, and a''-c obtained in the above production examples, and the third Shown in the table.

Table 1 [Effects] The acrylic resin produced by copolymerizing 2-(meth)acryloxyalkyl succinic acid of the present invention has significantly improved adhesion to metal surfaces, so it can be used industrially as a paint resin for metals. It is extremely useful.

Claims (1)

[Claims] 1,2-(meth)acryloxyalkyl succinic acid with 0.
A metal coating resin made of an acrylic resin copolymerized in an amount of 5 to 15% by weight. 2. The resin according to claim 1, further comprising 0.1 to 10% by weight of dialkylaminoethyl (meth)acrylate.