JPS5852365A - Coating agent composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which can be stored for a long period of time in the absence of moisture and cured at room temperature in the presence of moisture and exhibits gool adhesiveness, consisting of a silicone-modified epoxy resin contg. alkoxy groups attached to silicon atoms and an organotitanium compd. CONSTITUTION:A compsn. consists of 0.1-100pts.wt. organotitanium compd. and 100pts.wt. silicone-modified epoxy resin contg. alkoxy groups attached to silicon atoms obtd. by condensing a polysiloxane or silane (i) contg. at least two alkoxy groups to silicon atoms per molecule and having the formula (wherein R is a monovalent org. group; X is alkoxy; 0<=a<=2; 1<=b<=4; 1<=a+b<=4) with an epoxy resin (ii) contg. at least one epoxy group and hydroxyl group in the molecule under such conditions that the ratio of alkoxy eguivalents in component (ii) to hydroxyl equivalents in component (ii) is 1 or above.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coating composition. More specifically, the present invention relates to a coating composition that can be stored for a long period of time in the absence of moisture, cures at room temperature in the presence of moisture, and exhibits good adhesion to various substrates.

In general, silicone resins have excellent heat resistance and electrical insulation properties, and are therefore widely used as base resins for heat-resistant paints and as electrical insulation panels. However, silicone resin requires baking at high temperatures and for a long time to harden, and although it adheres well to metal plates such as mild steel plates and stainless steel plates, it does not adhere well to plastics. It has its drawbacks.

The inventors of the present invention have conducted intensive studies to improve the above-mentioned drawbacks of silicone resin, and have found that it can be stored for a long time in the absence of moisture, hardens at room temperature in the presence of moisture, and is compatible with various substrates such as metals and plastics. The present invention was achieved by discovering a coating agent that exhibits good adhesion to.

That is, the present invention has A (a) average unit formula Ra5iXb04-JL-b
(During the ceremony.

R is a monovalent organic group, and X is an alkoxy group.

a is a number such that O≦a≦2, bFil≦b≦4, and 1+b is 1≦a+b≦4. ) and having at least two silicon-bonded alkoxy groups in one molecule; and (b) an epoxy resin containing at least one epoxy group and one hydroxyl group in one molecule. , 100 parts by weight of a silicone-modified epoxy resin having a silicon atom-bonded alkoxy group obtained by condensation reaction under conditions such that the ratio of [hydroxyl group equivalent contained in component (B)] is 1 or more, and 0.1 parts by weight of B organic titanium compound. to 100 parts by weight.

This coating agent composition will be explained in detail below. Component A consists of a silicon atom-bonded alkoxy group in component (A) and (
It is a condensation reaction product with the hydroxyl group in component b), and is the main component of the composition of the present invention. Component (a) is a silane or polysiloxane having at least two silicon-bonded alkoxy groups in one molecule that can undergo a condensation reaction with the hydroxyl group in the epoxy resin, and R in the formula is a silicon-bonded monovalent organic group. , methyl group, ethyl group.

Alkyl groups such as propyl and octadecyl groups.

Alkenyl groups such as vinyl groups and allyl groups, phenyl groups,
Naryl groups such as naphthyl groups, and those in which some of the hydrogen atoms of these groups are substituted with -.rogen atoms, cyano groups, hydroxyl groups, mercapto groups, etc. Also, some of the hydrogen atoms of alkyl groups are methacryloxy groups, Examples include acrylyl substituted with a functional group such as a cy group, a glycidyl group, or a 14-epoxycyclohexyl group. X is a silicon atom-bonded alkoxy group, and is a methoxy group.

As shown in (a), it may not be present in the component. but,
The reason why a is 2 or less, b is 1 or more, and at least two silicon-bonded alkoxy groups are required in one molecule is because if there are too few alkoxy groups, the degree of condensation with the hydroxyl group in the component (b) will be low; In addition, the amount of silicon-bonded alkoxy groups in component (5) is small, resulting in insufficient curing.

From this point of view, it is preferable that at least three of them exist in the component.

Component (a) may be silane or boria silane, and in the case of polysiloxane, it is sufficient as long as the degree of polymerization is 2 or more. The molecular shape of polysiloxane may be linear, monobranched, or network-like, and contains a small amount of silicon-bonded hydroxyl groups, /%Rogge/
Specific examples of component 0 (a) which may contain an atom or a hydrogen atom include methyltrimethoxy7rane, methyltripropoxysilane, and dimethyljethoxysilane.

Ethyltriethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, phenylmethyljethoxysilane, vinyltrimethoxysilane, allyltripropoxysilane/.

Vinyltri(methoxyethoxy)silane, methylvinyljethoxysilane, tetramethoxysilane, tetraethoxysilane, γ-chloropropyltrimethoxysilane/,
r-chloropropylmethyldimethoxysilane, γ-glycidylglobiltrimethoxysilane, γ-glycidylpropylmethyljethoxysilane, β(14-epoxycyclohexyl)ethyltrimethoxysilane, r-methacryloxyglobiltrimethΦsisila/ , γ-methacryloxyglobylmethyldiethoxysilane, r-acryloyloxyglobyltrimethoxysilane, partially hydrolyzed condensates of one or more of these silanes, these silanes and other organosilanes, Examples include ethyl polysilicate, a partially hydrolyzed condensate with trimethylethoxysilane.

The component (b) is an epoxy resin having at least one epoxy group and hydroxyl group in one molecule, and may be bisphenol-based or novolac-based, but preferably has the following structural formula and a molecular weight of 300 to 6,000. .

As a commercially available product of such epoxy resin, for example, Ebiko (8) 815°820.8 manufactured by Shell Chemical Co., Ltd.
28,834,864.1001, 1004
.

1007 etc.　　　　　,.

Component A is a cone-modified epoxy resin that combines component (a) and component (b) as described above. However, if the above ratio is less than 1, the condensation reaction between component (a) and component (b) will occur during the condensation reaction. , it tends to gel, and even if it does not gel, it tends to gel when it is blended with the organic titanium compound of component B, which is a curing catalyst, and is storage stable. is not expressed. The larger the above ratio is, the less gelation occurs during the reaction, and the greater the storage stability when component B is blended.

The condensation reaction between component (a) and component (b) is preferably 8
This condensation reaction is carried out at 0 to 250°C by adding a small amount of a conventionally known catalyst, such as an organic titanate. However, it is desirable to carry out the reaction in a coated state.

Component B is a catalyst that makes component A curable at room temperature with humidity,
A specific example is methyl alcohol.

Ethyl alcohol, isopropyl alcohol.

Butyl alcohol, cyclohexyl alcohol.

Octyl alcohol, octadecyl alcohol.

titanate esters of -hydric alcohols such as ethylene glycol, fluoropylene gellicol, octylene glycol, diethylene glycol.

Titanate esters of dihydric alcohols such as triglobylene glycol and tetraethylene glycol, titanate esters of dihydric alcohols such as glycerin, diisogloboxy bis(acetyl acetonide) titanium, di-N-butoxy bis(triethanol) There are alkoxy7 titanium chelates such as aminato) titanium, and dihydro-bis(:)cutato) titanium.

If the amount of component B added is too small, curing will be slow and workability will be reduced, and if it is too large, the cured film will become brittle and cracks will easily occur. parts to 1001 parts. hardening,
Preferably from 5 to 9 in terms of adhesion to the base material and storage stability.
In order to obtain the coating agent composition of the present invention from 0 parts by weight of OA acid component B, it is sufficient to simply mix the two. However, in order to increase storage stability, mixing in the absence of moisture or mixing After degassing, it is preferred to store it in a moisture-impermeable container.

In the coating agent composition of the present invention, component (a) or component (b) or both may remain within a range that does not impair the object of the present invention, and additional components such as an organic solvent and an inorganic filler may be present. Agents, pigments, and heat-resistant agents may also be added. especially(
b) Organotrialkoxysilane, which is a type of component, may be actively added in an amount of 5 to 500 parts by weight per 100 parts by weight of component A. The organic group in this organotrialkoxysilane is The alkoxy group is the same as X described above. The coating composition of the present invention can be stored for a long time in the absence of moisture, and cures even at room temperature in the presence of moisture.
+W LtL Nose [hl-L It forms a ridge and firmly adheres to various metals, plastics, wood, and other base materials, so it is extremely useful as a protective coating for these base materials.

-Next, examples of the claimed invention are listed.
"" means parts by weight. -1 &, dry time to the touch,
Adhesion and lead wire hardness were measured under the following conditions.

Dry-to-touch time: After coating the base material, the coating surface becomes non-adhesive and the dry-to-touch time is defined as the time until the surface of the coating becomes non-adhesive and fingerprints do not stick to it.0 Pencil rating: JIS K 5400
0s measured according to. The number of remaining squares was written in the numerator □, the number of cut squares was written in the denominator, and 90 and methyltrimethoxysilane were subjected to a condensation reaction with the composition shown in Table 1. At this time, tetrabutyl titanate was added as a catalyst for promoting the condensation reaction, and toluene was used as a solvent. These raw materials were cooled using a reflux condenser, a temperature variable meter, and a stirring device to obtain a pale yellow transparent silicone-modified epoxy resin containing silicon-bonded methoxy groups.

When 2 parts of tetrabutyl titanate was added to these resin-added parts, gelation immediately occurred for sample NIh1, which had a ratio of methoxy group equivalent to hydroxyl group equivalent of less than 1. Sample N4 using Sample Electron 2 with the same ratio of 6.9 did not increase in viscosity by 4 g, and when stored in a glass bottle tightly sealed, it maintained a uniform liquid state even after 3 months. When the composition of sample l'11114 containing tetrabutyl titanate was applied to a stainless steel plate at room temperature, the coating surface became non-adhesive within 10 minutes and adhered well to the stainless steel plate.

Table 1. Raw material composition table of Silico-7 modified epoxy resin 2.
Composition of coating agent and evaluation results・）The coating surface is
Time until it becomes non-adhesive and does not leave fingerprints Example 2 0.1 part of Shell Chemical Co., Ltd. Sα Ebiko) 1001
The mixture was placed in a 2000-sized Mitsuro Frusts equipped with a stirring device. While stirring, gradually raise the temperature until it reaches 72 kg.

Since a reflux state was obtained at the angle of 0, 1,390 parts of this transparent silicone-modified epoxy resin I containing silicon-bonded methoxy groups was obtained. Based on the solid content calculation, the silicone-modified epoxy resin contains about 14% by weight of silicone. Note that the volatile matter in the reaction residue is the raw material methyltrimethoxysilane. This silicone-modified epoxy resin 1ift I, methyltrimethoxysilane, and tetrabutyl titanate were blended as shown in Table 3 to make five types of compositions.

The coating was applied to a methacrylic resin plate and a carbon-recarbonate resin plate, and the 0-touch drying time, the hammer time, the adhesion after curing (cross-cut test), and the pencil hardness were evaluated. The results are shown in Table 3. From this, it can be seen that when the amount of tetrabutyl titanate added is small, the film becomes thicker, more likely to crack, and the adhesion between the methacrylic resin plate and the stainless steel plate decreases. Recognize.

Table 1 Composition and Evaluation of Coating Agent Results Examples & Silicone Modified Ebony Resin I Solid Content of Example 2 100
260 parts of methyltrimethoxysilane and 26 parts of tetrabutyl titanate were added to the mixture to obtain a coating composition. This was coated on the various substrates shown in Drop 4 and left to cure at room temperature during the daylight hours, and then the adhesion to these substrates and coating hardness were examined, and the results are shown in Table 2.

Table 4 Adhesion to various substrates Note) Example t of liquid polyurethane resin paint for curtain walls manufactured by Dainippon Toyo Co., Ltd. (1) Synthesis of silicone-modified epoxy resin ■ Methyltrimethoxysilane is hydrated under an acid catalyst. After decomposition and condensation,
Viscosity centistokes at 25°C obtained by distilling off low-boiling substances, 144 parts of methylmethoxypolysiloxane containing methoxy groups*(9) by weight (methoxy group equivalent L3)
9) and Epicor (manufactured by Shell Chemical Co., Ltd.) 1001
576 parts (OH group equivalent: 1.84), 2 parts of tetrabutyl ditanate α, and 1080 parts of toluene were placed in a 92000-three-necked flask equipped with a stirring device, an R-flow condenser, and a thermometer. is. The temperature was gradually raised to 105° C., and stirring was continued while distilling off the methanol produced at this temperature, and the reaction was carried out until compatibility was obtained. (Compatibility is determined by taking a sample on a glass plate every hour and evaporating the solvent.) When the film becomes transparent, the compatibility h.
1 and a busy schedule.

°) After compatibility was obtained, low-boiling substances were distilled out at 300°C, and then the temperature was lowered to (capital) °C. When the temperature reached 100° C. or lower, 138 parts of methyltrimethoxysilane (methoxy group equivalent: 3.03) was charged. The ratio of total methoxy group equivalents to hydroxide group equivalents was 24.

The temperature of the mixture was gradually raised, and the reaction was carried out in a relaxed state for 6 hours. After the reaction, the temperature was lowered and a transparent liquid silicone-modified epoxy resin with zero non-volatile content was obtained.

12) Preparation of coating agent composition and adhesion to various substrates Silicone-modified epoxy resin 100 parts of solid content, 230 parts of methyltrimethoxyresilane, 24 parts of dibutyl titanate or diisopropoxytitanium bis(acetylacetonate) was blended. These compositions are left at room temperature for an hour to cure, and then the
Adhesion was examined using a bread test. All 100/
100, indicating good adhesion.

The coating agent composition did not increase in viscosity even when it was stored in a sealed glass bottle at room temperature for 3 months.

Claims (1)

[Claims] A (a) Average unit formula Ra5IXb04-, L-b(
During the ceremony. R is a monovalent organic group, and X is an alkoxy group. a tiO≦a≦2, b is 1≦b≦4, 1+b
is 1≦a+b≦4. ) polysiloxane and (b) Ebogi 7 resin containing at least one Eboki 7 group and hydroxyl group in one molecule, the ratio of [hydroxyl group equivalent contained in component (B)] to 1 or more. A coating agent composition comprising 100 parts by weight of a silicone-modified epoxy resin having a silicon atom-bonded alkoxy group obtained by condensation reaction under the following conditions and 1 to 100 parts by weight of an organic titanium compound α.