JPH02153982A - Coating composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coating composition that improves the surface conditions of plastics, wood products, metal products, etc., such as surface hardness, weather resistance, chemical resistance, and dyeing resistance.

Plastic molded products such as polycarbonate, polymethyl methacrylate, polystyrene, and polyvinyl chloride have excellent transparency, lightness, ease of processing, and impact resistance, but they have poor abrasion resistance and solvent resistance, and the surface The drawback is that it is easily damaged and is easily attacked by organic solvents.

Although methods of coating with various curable resins have been proposed as a method to improve these drawbacks, at present no fully satisfactory method has been obtained.

For example, trialkoxysilanes such as methyltrialkoxysilane and phenyltrialkoxysilane, combinations of these with tetraalkoxysilanes such as ethylsilicate and butylsilicate, or mixtures with other resin paints are known. Abrasion resistance, hot water resistance,
A product with good physical properties such as heat resistance, adhesion, and pot life of the paint has not been obtained, and JP-A-51-427
52, Japanese Patent Publications No. 52-13818 and No. 53-15743, BF3 and BF are added to epoxy group-containing alkoxysilanes.
:Lewis acid such as l etherate or its complex, lI
c7! , HBr, ! II,) INOs.

The use of Brønsted acids such as RoCI Os and HsPOa, and metal salts of organic acids such as cobalt naphthenate and zinc naphthenate as curing catalysts has been disclosed; It takes a long time and is not practical. JP-A-49-7529 discloses epoxy group-containing alkoxysilane, zinc borofluoride,
Compositions containing tin borofluoride or boron trifluoride amine complexes have been disclosed, but these do not provide sufficient hardness using the methods taught in the disclosure and suffer from loss of hardness after hot water testing.

JP-A No. 534-336 discloses that one or a mixture of two or more selected from compounds containing an epoxy group and/or a silanol and/or siloxane group;
Coating compositions containing silica particles of ~100 millimicrons and an aluminum chelate compound have been disclosed, but the hardness of these cured coatings is insufficient, and hardness decreases when immersed in boiling water, etc., and plastics, especially diethylene glycol Adhesion to bisallyl carbonate polymer (trade name CR-39) and bisphenol type polycarbonate is poor.

In addition, when applying these surface coating treatments to plastic eyeglass lenses, it is desirable that the coating film formed can be easily dyed. However, coating films with high surface hardness generally have poor dyeability, and are usually difficult to dye on fibers or other surfaces. The dyeing methods used for plastics and the like either do not dye at all, or even if they do dye, the harsh conditions during dyeing result in a decrease in coating film performance such as a decrease in the hardness of the coating.

U.S. Pat. No. 4,173,490 discloses that a siloxane having an active polar group to make it dyeable is used as a main component consisting of a cohydrolyzate of ethyl silicate and an alkyltrialkoxysilane and/or a dialkyldialkoxysilane. Alternatively, a coating composition containing a nonionic surfactant has been disclosed, but the cured coating film easily cracks and the degree of staining is low.

Based on the above, the present inventors removed such drawbacks and
The present invention was achieved as a result of repeated research into a coating composition that has good abrasion resistance, hot water resistance, adhesion, weather resistance, dyeability, etc., and has a long paint pot life.

The present invention is a coating composition containing the following (^), (B) and (C).

That is, (B) the present invention is (A) (B) - electrification type Ra Si
(OR”)4-m (1) (In the formula, R1 is 1 carbon number
-6 hydrocarbon group, vinyl group, methacryloxy group, amino group, mercapto group or chlorine-containing organic group, R2 is a hydrocarbon group having 1 to 5 carbon atoms, an alkoxyalkyl group or an acyl group having 1 to 4 carbon atoms, a is 0 to 3); and (0) a hydrolyzate of the above organosilicon compound; (B) colloidal silica (C) with a particle size of 1 to 100 millimicrons; ) A coating composition containing ammonium perchlorate.

Among the components (A,) used in the present invention, the organosilicon compounds represented by the general formula (B) include the following: trimethylmethoxysilane, dimethyldimethoxysilane, methyltrimethoxysilane, Tetraethoxysilane, phenyltrimethoxysilane, phenylmethyldimethoxysilane, vinyltriethoxysilane, vinyl-tris(β-methoxyethoxy)silane, vinyltriacetoxysilane, γ-methacryloxypropyltrimethoxysilane, T-aminopropyltriethoxy Silane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, Nbis(β-hydroxyethyl>-r-aminopropyltriethoxysilane, N
-β-(aminoethyl)-γ-aminopropyl(methyl)dimethoxysilane, γ-chloropropyltrimethoxysilane, T-mercaptopropyltrimethoxysilane, etc. These may be used alone or in combination of two or more. .

These organosilicon compounds may be used as they are, but
It is preferable to use it as a hydrolyzate.

A hydrolyzate of an organosilicon compound is one in which a part or all of the alkoxy group, alkoxyalkoxy group, or acyloxy group in the silicon compound is substituted with a hydroxyl group, and a hydrolyzate in which some of the substituted hydroxyl groups are naturally condensed with each other. contains things. These hydrolysates can be obtained by hydrolysis in a mixed solvent such as water and alcohol in the presence of an acid, as is known.

When using the organosilicon compound represented by the general formula (1) as a hydrolyzate, the hydrolyzate of the organosilicon compound prepared in advance may be mixed with colloidal silica as component (B) and used. B) Carrying out the hydrolysis of component (^) in the presence of B) often gives better results.

The component (B) colloidal silica having a particle size of 1 to 100 millimeters is a colloidal solution in which ultrafine particles of silicic anhydride having the above particle size are dispersed in a dispersion medium such as water or an alcohol-based dispersion medium, and is prepared by a well-known method. It is manufactured and commercially available.

By combining one or more components (A) with colloidal silica (B) and using ammonium perchlorate (described below) as a curing catalyst, the pot life of the paint is long, and the paint has excellent wear resistance and heat resistance. Water-based, adhesive, weather resistant,
A coating film with good dyeability is formed.

In the present invention, the preferred range of the mixing amount of component (A) and component (B) is 100 rbit parts (Sin
25 to 300 parts by weight of component (A) in total (calculated as solid content, based on the general formula (1
) The organosilicon compound represented by R--3i-O40-2
00 parts by weight. If the total amount of component (A) is less than 25 parts by weight, the effect of combined use will be reduced, causing problems with film forming properties, adhesion, hot water resistance, dyeing properties, etc., and if it exceeds 300 parts by weight, wear resistance will be reduced. properties, weather resistance, etc. tend to deteriorate.

Next, the curing catalyst for ammonium perchlorate, which is component (C) of the composition of the present invention, will be explained in detail.

That is, the following catalysts are well known as curing catalysts for epoxy groups and/or silanol groups. Namely, perchloric acid, hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid, sulfonic acid, para-toluenesulfonic acid, boron trifluoride and its electron donor and complex *5nCf4゜ZnC1,, FeC1
,,8I C1! ! , SbCj! s,TiCI!
Lewis acids such as a and their complexes, organic acid metal salts such as sodium acetate, zinc naphthenate, cobalt naphthenate, zinc octylate, and tin octylate. Borofluoride and other metal salts such as zinc borofluoride and tin borofluoride.

Boric acid organic esters such as ethyl borate and methyl borate. Alkali such as sodium hydroxide and potassium hydroxide.

Titanate esters such as tetrabutoxytitanium and tetraisopropoxytitanium. Metal acetylacetonates such as chromium acetylacetonate, titanyl acetylacetonate, aluminum acetylacetonate, cobalt acetylacetonate, and nickel acetylacetonate.

n-butylamine, di-n-butylamine, tri-n-
There are amines such as butylamine, guanidine, biguanide, imidazole, etc., but all of them have various drawbacks.

That is, since perchloric acid is an overt catalyst, the pot life of the coating liquid is extremely short. Further, the coloring of the cured coating film is also significant.

Brønsted acids such as hydrochloric acid, para-toluenesulfonic acid, boron trifluoride monoedylamine combresox, or their complexes with electron donors. SnCj! a*ZnC
Lewis acids such as lz. Metal salts of organic acids such as sodium acetate, zinc naphthenate, cobalt naphthenate, zinc octylate, tin octylate. Alkali such as sodium hydroxide and potassium hydroxide; titanate esters such as tetrabutoxytitanium and tetraisopropoxytitanium. Chromium acetylatonate. Amines such as n-butylamine, di-n-butylamine, tri-n-butylamine, and imidazole require heating at high temperatures for a long time to cause sufficient curing, making them impractical; Coatings using tin, etc., have insufficient water resistance and decrease in hardness when immersed in hot water, and aluminum acetylacetonate has insufficient hardness and poor adhesion to substrates. .

Based on the above points, the present inventors found that perchloric acid, a type of latent catalyst, has a long pot life for the coating liquid, can be cured sufficiently in a short time even at relatively low temperatures, and has good adhesion. We found that ammonium is optimal.

The amount of this curing catalyst added is based on the solid content of the composition (component (A)).
Ten Commandments (B)] is 0.05 to 10 parts by weight, more preferably 0.1 to 5 parts by weight.

Examples of solvents that may be included in the coating composition include alcohols, ketones, esters, ethers, cellosolves, halides, carboxylic acids, aromatic compounds, and one or two of these. It can be used as a mixed solvent of the above. Especially methanol,
Lower alcohols such as ethanol, propatool, impropatool, butanol. Cellosolves such as methyl cellosolve, ethyl cellosolve, butyl cellosolve.

Lower alkyl carboxylic acids such as formic acid, acetic acid, and propylene acid; aromatic compounds such as toluene and xylene.

It is preferable to use esters such as ethyl acetate and butyl acetate alone or as a mixed solvent.

Furthermore, if necessary, a flow control agent made of a block copolymer of alkylene oxide and dimethylsiloxane, such as NUC Silicone Y-7006 (trade name) manufactured by Nippon Unicar Co., Ltd., can be added to obtain a smooth coating film. The amount of these flow control agents added is sufficient in a small amount, and is 0.01 to 5 parts by weight, more preferably 0.03 to 3 parts by weight, based on the entire coating composition.

Further, small amounts of antioxidants, ultraviolet absorbers, etc. can also be added. Coating with the composition of the present invention is carried out by a commonly used coating method such as dipping, spraying, roller coating, or flow coating for 20 minutes at a temperature below the deformation temperature of the substrate (for example, 130°C). By baking and curing for up to 5 hours, a coating film with good abrasion resistance, hot water resistance, adhesion and weather resistance can be obtained.

The preferred thickness of this coating is 1 to 30 microns, more preferably 3 to 15 microns. If it is less than 1 micron, the wear resistance will not be sufficient, and if it is more than 30 microns, cracks will easily occur.

The composition of the present invention can be applied to plastic substrates such as polycarbonate, polymethyl methacrylate, polystyrene, and polyvinyl chloride. If adhesion is a particular problem, a primer treatment can provide a coating film with sufficiently effective adhesion.

The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited by these Examples.

In addition, parts 2% in Examples indicate parts by weight and parts by weight %, respectively.

The performance of the coating film was evaluated using the following method.

That is, abrasion resistance: The resistance to scratching was examined by rubbing with #0000 steel wool and judged as follows.

A: No damage occurs even if strongly rubbed.

B: Slight scratches occur when rubbed strongly.

C. If you rub it strongly, it will be seriously damaged.

D: Even weak friction causes scratches.

Adhesion: In the so-called cross-cut tape test, 100 squares were cross-cut by making parallel lines vertically and horizontally at 1 x 1 intervals on the surface of the paint film, and then adhesive cellophane tape was attached on top of the cross-cuts. After that, the tape was peeled off, and the number of squares that did not peel off among 100 squares was reported.

Hot water resistance: The state of the coating film was examined after being immersed in boiling water for 1 hour.

Heat resistance: The state of the coating film was examined after being stored in a hot air drying oven at 120°C for 100 hours.

Chemical resistance: The state of the coating film was examined after being immersed in the following chemicals at room temperature for 50 hours.

3% sulfuric acid, 1% sodium hydroxide, 95% ethanol,
Acetone, ethyl acetate, carbon tetrachloride, toluene, n-hebutane, 10% saline.

Staining; - Sumikaron B, an intramembrane disperse dye
1 part of lueE-FBL (manufactured by Sumitomo Chemical) and 1 part of dispersant Suwipon TF (manufactured by Sumitomo Chemical)
The dyeing process was carried out by immersion treatment at 90° C. for 20 minutes in a dye bath containing 300 parts of water and 300 parts of water.

The degree of staining of the dyed sample is measured by visible light transmittance, and if the value is 80% or less, it can be determined that the stainability is good. In addition, the light fastness is determined by the dyeing fastness test against carbon arc lighting (JIS L-0842-1971).
Judgment was made after 100 hours.

Examples 1 to 4 Comparative Examples 1 to 3 (Separate production of hydrolyzate of romethyltrimethoxysilane and colloidal silica (AB-1).

20 parts of 0.1N hydrochloric acid aqueous solution was gradually added to a mixture of 100 parts of methyltrimethoxysilane and 274 parts of colloidal silica (manufactured by Catalyst Kasei Kogyo ■, isopropyl alcohol colloidal silica, solid content 30%), and the mixture was stirred at room temperature to add water. Decomposition was performed, followed by aging at room temperature for more than 20 hours. The resulting solution contained 13% methyltrimethoxysilane hydrolyzate calculated as CH35iO1,s and 21% colloidal silica calculated as Sing.

(2) Preparation of a hydrolyzate of T-methacryloxypropyltrimethoxysilane and colloidal silica (AB-2).

γ-methacryloxypropyltrimethoxysilane 100
22 parts of a 0.1 N aqueous hydrochloric acid solution was added to a mixture of 361 parts of colloidal silica (isopropyl alcohol colloidal silica manufactured by Catalysts & Chemical Industry ■, solid content 30%),
Hydrolysis was carried out by refluxing at °C for 5 hours. The resulting solution contained 15% T-methacryloxypropyltrimethoxysilane hydrolyzate, calculated as CHgC(Chs) C00CsHiSiO+, s, and 22% colloidal silica, calculated as SiO□.

(3) Epoxy compound (A-2, A-3, A-5)
Those shown in Table 1 were used.

(4) 10% aqueous solution of curing catalyst ammonium perchlorate (C-1), 10% benzene solution of aluminum acetylacetonate (
C-2) and 10% aqueous solution of sodium acetate (C-3)
It was used.

(5) Preparation of paint Mix components (^), (B) and curing catalyst in the proportions shown in Table 2, add a small amount of flow control agent, and dilute with ethyl cellosolve so that the solid content is 20-40%. It was made into a paint. Note that no curing catalyst was added to the paint of Comparative Example 3.

(6) Painting The above paint was applied by dipping onto a pre-washed diethylene glycol bisallyl carbonate polymer (trade name: CR-39) flat plate and cured by heating at 130°C for 1 hour.

Further, staining was carried out using the method described above. The coating film performance before and after dyeing is summarized in Table 2.

Claims (1)

[Claims] (1) The following (A), (B) and (C) (A) (a) General formula R_a-Si-(OR^2)_4_
-_a(1) (in the formula, R^1 is a hydrocarbon group having 1 to 6 carbon atoms, a vinyl group, a methacryloxy group, an amino group, a mercapto group, or an organic group having chlorine; R^2 is a hydrocarbon group having 1 to 6 carbon atoms; Hydrocarbon group, alkoxyalkyl group or carbon number 1-4
(b) a hydrolyzate of the above organosilicon compound; (B) a particle size of 1 to 100 millimicrons; A coating composition containing colloidal silica (C) ammonium perchlorate.