JPH028263A - Composition capable of forming water-repellent film - Google Patents

Abstract

PURPOSE:To obtain a composition capable of forming water repellent films having low surface by containing a specific silicon-containing copolymer and particulate substance as principal components. CONSTITUTION:The objective composition containing (A) a copolymer consisting of (i) 0.1-75wt.% silicon-containing polymerizable unsaturated monomer expressed by formula I [R2 is H or CH3; R3 is a group expressed by formula II (j is 0 or 1; k is 0-6; p is 1-5; q is 1-20; r is 0-2; s is 1.3 and r + s is 3)] and (ii) 25-99.9wt.% monomer copolymerizable with the component (i) and (B) a particulate substance having <=5mu average particle diameter (preferably silica particles having <=3mu particle diameter).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a composition capable of forming a water-repellent film containing a silicon-containing copolymer and granules as main components.

[Prior Art and Problems] Typical examples of water-repellent materials include hydrocarbon-based polymer materials such as polyethylene, fluororesin-based polymer materials such as polytetrafluoroethylene, and silicon-based polymers. The materials etc. are known.

Among them, polytetrafluoroethylene has a ``contact angle with water'', which is one measure of the degree of hydrophobicity, of approximately 1
It is about 20' and is a particularly highly hydrophobic material (low polar component p of surface tension).

However, even polytetrafluoroethylene has a problem in that its water repellency is still insufficient depending on the environmental conditions in which it is used, and there is a desire to develop a material with even higher water repellency.

[Disclosure of the Invention] Therefore, the present inventors conducted intensive research to satisfy these social needs, and as a result, they found that the "contact angle with water" is 140° or more and the "contact angle with paraffin" is 140° or more. The film exhibits a larger angle than the angle in polytetrafluoroethylene film (the dispersion component d of surface tension is lower than that of polytetrafluoroethylene) at the "angle", and can form a coating film with better water repellency than polytetrafluoroethylene film. We have developed a water-repellent composition.

That is, the present invention provides CH2=CR3(I) in the formula, R2 represents a hydrogen atom or a methyl group, R3 represents a group represented by the following formula, where " is an integer of 0 or l, and k is O is an integer of ~6, p is an integer of 1 to 5, and q
is an integer from 1 to 20, r is an integer from 0 to 2, and S
is an integer of 1 to 3, and r + s = 3, silicon-containing polymerizable unsaturated monomer 0°1 to 7
5% by weight and 25-99.9% by weight of an unsaturated monomer copolymerizable with the silicon-containing polymerizable unsaturated monomer, and (1) contains granules with an average particle diameter of 5 μm or less The present invention provides a composition capable of forming a water-repellent film characterized by the following.

The composition capable of forming a water-repellent film in the present invention has two main components: (1) and (2), where the (2) component is a silicon-containing polymerizable unsaturated monomer represented by the general formula (I) above. and a copolymer of said monomer and an unsaturated monomer that can be copolymerized.

■Fluoroalkyl group-containing (meth) used for polymerization of components
The acrylic monomer has the following general formula (DCH2-CRs
(I) In the formula, R2 represents a hydrogen atom or a methyl group, and R1 represents a group represented by the following formula (%), where " is an integer of 0 or l, and k is an integer of 0 to 6. , p is an integer from 1 to 5, and q
is an integer from 1 to 20, r is an integer from 0 to 2, and S
is an integer from 1 to 3, and r+s=3.
Monomers of formula (■)), such as vinyltrimethoxysilane, vinyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxyglopylmethyl Dimethoxysilane, vinylmethyldimethoxysilane, vinyldimethylmethoxysilane, γ
Typical examples include methacryloyloxypropyldimethylmethoxysilane, among which γ-methacryloyloxypropyltrimethoxysilane and γ-methacryloyloxypropylmethyldimethoxysilane are preferred.

Examples of unsaturated monomers (hereinafter referred to as "copolymers") copolymerizable with the monomer of formula (I) used in the production of the copolymer of component (1) in the present invention include acrylic acid. Methyl, ethyl acrylate, propyl acrylate, inglovir acrylate, buty/lz acrylate, hexyl acrylate, 2-ethylhexyl acrylate, octinoacrylate, lauryl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate,
Isopropyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate,
01-C1, alkyl esters of (meth)acrylic acid such as octyl methacrylate and lauryl methacrylate: glycidyl acrylate, glycidyl methacrylate; methoxybutyl acrylate, methoxybutyl methacrylate,
C8-1 of (meth)acrylic acid such as methoxyethyl acrylate, methoxyethyl methacrylate, ethoxybutyl acrylate, and ethoxybutyl methacrylate. Alkoxyalkyl ester; C2~ alkenyl ester of (meth)acrylic acid such as allyl acrylate and allyl methacrylate; C2~ of (meth)acrylic acid such as hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxyethyl acrylate. Aminoalkyl ester of (meth)acrylic acid such as hydroxyalkyl ester dimethylaminoethyl acrylate, diethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, acrylamide, methacrylamide; acrylic acid, methacrylic acid: formula [wherein R4 represents a methyl group or a hydrogen atom, and q is 1
(meth)acryloxyalkylpolymethylsilicone represented by .gamma.-(meth)acryloxypropylpolymethylsilicone;
Fluoroethers having a meth)acryloxy group;
(meth)acrylic unsaturated monomers such as styrene, styrene pentafluoride, α
- Unsaturated monomers other than acrylic unsaturated monomers such as methylstyrene, vinyltoluene, acrylonitrile, methacrylonitrile, acrolein, methacrolein, butadiene, and isoprene can be mentioned.

Among these comonomers, preferred are (meta)
Included are alkyl esters of acrylic acid and styrene.

■The proportion of the monomer of formula (1) and comonomer used in the production of the component is preferably 0.1 to 75% by weight of the monomer of formula (1), based on the total amount of both. is 0.1 to 40% by weight and comonomer 25 to 99.9% by weight, preferably 60% by weight.
-99.9% by weight, and if the amount of the monomer of formula (1) is less than 0.1% by weight, the curability will generally be poor and the dispersion of particulate matter will not be sufficient.
If it exceeds % by weight, many silanol groups will be formed due to hydrolysis of silylalkoxy groups, making it difficult to maintain hydrophobicity.

■Production of the component copolymer can be carried out using a polymerization method known per se, for example, a solution polymerization method similar to that used in the production of ordinary acrylic resins. Specifically, a small amount of alcohol is added to the polymerization solution. It is preferable to blend a system solvent and carry out the polymerization in the presence of a polymerization initiator such as a peroxide or an azo compound. In addition, the copolymer of component (2) generally has a molecular weight of about 400
0 to about 2oo, ooo, preferably about 8,000 to about 7
It can have a number average molecular weight within the range of 0°000.

Component (2) in the composition of the present invention has an average particle diameter of 5 μm or less, preferably 3 μm or less, more preferably l/7+1
1 or less, and the granules may be either organic fine particles or inorganic fine particles, but it is necessary that they exist as granules in the coating film after the coating film is formed.

Examples of such granular materials include fine silica powder, fine fluorocarbon powder, carbon black, etc. Among them, fine silica powder is preferable, and in particular, the surface is coated with silazane [(CH3)aSi -N -5i(CH3) 3
] Preferably, fine silica powder is hydrophobized.

Further, by blending true spherical fine particles such as true spherical fine silica particles, the smoothness of the surface of the resulting coating film can be improved.

If a particulate material having an average particle diameter of more than 5 μm is used as the component, when formed into a coating film, the microscopic surface irregularities of the coating film tend to increase and the water repellency tends to decrease.

In the present invention, the blending ratio of component (1) and component (2) is not particularly limited, but generally 20 to 600 parts by weight, preferably 50 to 200 parts by weight of component (2) to 100 parts by weight of component (solid content). It is preferable to mix in the following range from the viewpoint of water repellency and physical properties of the resulting coating film.

In addition to the two components (1) and (2), the composition of the present invention may optionally contain additives commonly used in paints, such as solvents, colorants such as pigments, and surfactants. I can do it.

The preparation capable of forming the water-repellent film of the present invention can be carried out by mixing the above-mentioned components (1) and (2) and, if necessary, the above-mentioned additives. As the mixing means, a commonly used stirring method or dispersion method can be adopted, and for example, a daysilver steel ball mill, a pebble mill, a sand mill, an attritor, etc. can be used.

The composition capable of forming a water-repellent film of the present invention can be directly applied to the surface of a base material such as metal, plastic, glass, or wood material, or can be applied to a coating film previously formed on these base materials. It is also possible to paint over it as a top coat. Further, the composition of the present invention can also be used as a molded article by laminating it on the surface of an object.

As a method for applying the water-repellent composition of the present invention onto the above-mentioned substrates, known coating means such as spray coating, brush coating, roller coating, etc. can be used.

Further, the composition of the present invention usually has a dry film thickness of 1 to 5.
A good coating film can be obtained by coating to a thickness of 0 μm, preferably within the range of 10 to 30 μm, and drying at a temperature within the range of room temperature to 130°C.

[Operations and Effects] The surface of the coating formed from the composition of the present invention shows irregularities on the order of microns when viewed in a microscopic photograph.
It has been found from SCA analysis that C--F bonds are very abundantly distributed on the surface.

Furthermore, the surface energy γ calculated from the contact angle is calculated by the following formula: % formula The energy γ is less than 4.2 mN/m, and Teflon (γ = about 21
mN/m). This is thought to suggest the relationship between surface shape and apparent contact angle proposed by Wenzel et al. On a surface having such a low surface energy, the amount of water droplets adhering to the surface is very small, and since the water droplets have a spherical shape, they quickly separate.

Since the surface of the coating formed from the composition of the present invention has the above-mentioned properties, the composition of the present invention can be used for waterproofing, snowproofing,
It is very useful in the fields of water deposition prevention and prevention of current short circuits caused by moisture.

[Example 1 Hereinafter, the present invention will be explained in more detail with reference to Examples.

Note that the scope of the present invention is not limited to the examples. In the following, "1 part" and "%" mean "part by weight" and "% by weight", respectively.

Production of silicon-containing copolymer Production Example 1 250 parts of 2-ethylhexyl acrylate, 150 parts of methyl methacrylate, 9.5 parts of styrene, 5 parts of γ-methacryloyloxypropyltrimethoxysilane, and the polymerization initiator bisazoisobutyro Accurately weigh 5 parts of nitrile,
The mixture was stirred, mixed, and dissolved, and this mixed solution was charged into the dropping funnel of IQ. Separately, 212 is equipped with a water cooling tube, thermometer, and stirrer.
A four-bottle flask was prepared, a mixed solvent of 200 parts of butyl acetate, 100 parts of xylene, and 33 parts of n-butyl alcohol was blended and heated to 105 to 110°C, and this temperature was maintained. Next, the dropping funnel containing the liquid mixture was loaded into the flask, and the liquid mixture was added dropwise over a period of 2 hours. Dripping completed 1
After an hour, a mixed solution of 1 part of the polymerization initiator bisazoisobutyaratrile and 167 parts of butyl acetate was added dropwise over 1 hour and 30 minutes. Then, the reaction temperature was raised to 110-115°C, maintained at this temperature for 1 hour and 30 minutes, and then cooled.
The reaction has ended. The obtained resin liquid was colorless and transparent, and had a Gardner viscosity S1 and nonvolatile content of 50.5%.

Production Example 2 400 parts of lauryl methacrylate, 75 parts of methyl methacrylate, γ-
Methacryloyloxypropyltrimethoxysilane 25
A mixture of 7.5 parts of azobisvaleronitrile, a polymerization initiator, and 100 parts of xylene was used, and a mixed solvent of 200 parts of butyl acetate and 33 parts of n-butyl alcohol was initially added to a 2Q four-bottle flask. The reaction was carried out in the same manner as in Example 1 except that a mixed solvent was used.

The obtained resin liquid was colorless and transparent, and had a Gardner viscosity M1 nonvolatile content of 48.5%.

Production Example 3 Methyl methacrylate 300ffi, Silapre-N FMO711 (
Note 1) Reaction was carried out in the same manner as in Production Example 1, except that a mixed solution of 100 parts of styrene, 50 parts of γ-methacryloyloxypropyltrimexysilane, and 7.5 parts of azobisisobutyronitrile as a polymerization initiator was used. I did it.

The resulting resin liquid was lukewarm and translucent, and had a Gardner viscosity of V1 and non-volatile content of 50.2%.

(Note 1) Silabrene FMO7, 1: manufactured by Chisso Corporation, vinyl group-containing reactive silicone, trade name, molecular weight approximately 1000, and has the following structure (in the formula, n is 11 on average).

Production Example 4 300 parts of methyl methacrylate and Silabrene FMO711 (above,
Note 1) The reaction was carried out in the same manner as in Production Example 1, except that a mixed solution of 100 parts of γ-methacryloyloxypropyldimethoxymethylsilane and 7.5 parts of azobisisobutyronitrile as a polymerization initiator was used.

The obtained resin liquid was slightly cloudy and translucent, and had a Gardner viscosity W.
1 nonvolatile content was 49.8%.

Production Example 5 200 parts of methyl methacrylate, 100 parts of Silabrene FMO711 (above, note 1), 200 parts of γ-methacryloyloxypropyltrimethoxysilane, and 7.0 parts of polymerization initiator azobisvaleronitrile were charged into a dropping funnel of 5. The reaction was carried out in the same manner as in Production Example 1 except that 5 parts of the mixed solution was used.

The resulting resin liquid was translucent, had a Gardner viscosity of M, and a nonvolatile content of 48.0%.

Production Example 6 300 parts of methyl methacrylate, 198 parts of n-butyl acrylate,
The reaction was carried out in the same manner as in Production Example 1, except that a mixed solution of 2 parts of vinyltrimethoxysilane and 5.0 parts of azobisisobutyronitrile as a polymerization initiator was used.

The obtained resin liquid was colorless and transparent, and had a Gardner viscosity of Z3,
The nonvolatile content was 51.2%.

Production Example 7 (Comparative Example) As a liquid mixture charged into the lQ dropping funnel, 400 parts of γ-methacryloyloxypropyltrimethoxysilane, 85 parts of lauryl methacrylate, and 15 parts of methyl methacrylate were added.
The reaction was carried out in the same manner as in Production Example 2, except that a mixed solution of 7.5 parts of polymerization initiator azobisvaleronitrile and 100 parts of n-butyl alcohol was used.

The resulting resin liquid was colorless and transparent, had a Gardner viscosity of F, and a nonvolatile content of 47.7%.

Example 1 200 parts of silicon-containing copolymer resin liquid obtained in Production Example [
600 parts of butyl acetate, 400 parts of xylene, 200 parts of n-butyl alcohol, and 20 parts of hydrophobic silica A (Note 2) were blended and dispersed in a shaker to obtain a composition.

(Note 2) Hydrophobic silica A: Hydrophobic silica fine powder with an average particle size of approximately 0.1 μm, manufactured by Talco, Inc. in the United States, trade name “Talnox-”
500".

Examples 2 to 10 and Comparative Example 1.2 Example 2 to 10 and Comparative Example 1 were applied to an aluminum plate treated with chromium phosphate, treated in the same manner as in Example 1 except for the formulation shown in Table 1 below. The compositions obtained in Comparative Examples 1 to 11 and Comparative Examples 1 and 2 each had a dry coating amount of about 30 g/
After applying air spray coating to a thickness of m2, the test plate was left to dry at room temperature for 24 hours to obtain a test plate.

Tests were conducted on each test plate. The test results are shown in Table 1 below.

Comparative Example 3 Comparative Example 3 was prepared by laminating a polytetrafluoroethylene film onto an aluminum plate.

The test results are shown in Table 1 below.

and 2 compositions were obtained.

Notes in Table 1 are as follows.

(*l) Hydrophobic silica B: True spherical hydrophobic silica fine powder with an average particle size of about 2.0 μm, manufactured by Toshiba Silicone Co., Ltd., trade name “Tospearl”.

(Book 2) Untreated Silica C: Untreated silica fine powder with an average particle size of about 0.1 μm that has not been subjected to hydrophobization treatment.

(*3) Fluorocarbon: Fluorocarbon fine powder with an average particle size of approximately 0.3 μm.

(*4) Carbon black: Fine carbon black powder with an average particle size of approximately 0.3 μm.

(Book 5) Untreated silica D = Untreated silica fine powder with an average particle size of about 7 μm and not subjected to hydrophobization treatment, manufactured by Fuji Devison Co., Ltd., trade name “Syroid 308”.

(Persimmon) Contact angle with water: Drop 0.03 cc of deionized Honsuri as a water droplet with a syringe onto the painted surface of a horizontal test plate, and drop 1
The contact angle between the water droplet and the coated surface after a minute elapsed was measured using a contact angle gel meter manufactured by Kyowa Kaimen Kagaku Co., Ltd.

(*7) Contact angle with paraffin: In the above (*5) contact angle with water, use liquid paraffin instead of deionized water, and the contact angle between liquid paraffin and the coated surface after 4 minutes of dropping. Measurements were made in the same manner except that .

(Thursday 8) Sliding property of water droplets: 0°0 with a syringe on the test coated plate
3 cc of deionized water was added dropwise to create water droplets. Next, the coated plate was tilted, and the angle of inclination of the coated plate at which water droplets slid down was read.

Evaluation criteria O: Falling below 20° ■: Falling from 20″ to less than 40″ △: Falling at 40°~60e' ×: Does not fall even at 60°

Claims (1)

[Claims] 1. [a] The following general formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) In the formula, R_2 represents a hydrogen atom or a methyl group, and R_3
represents a group represented by the following formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼, where j is an integer of 0 or 1, k is an integer of 0 to 6, and p is an integer of 1 to 5. Yes, q
is an integer from 1 to 20, r is an integer from 0 to 2, and s
is an integer of 1 to 3, and r+s=3, silicon-containing polymerizable unsaturated monomer 0.1 to 7
5% by weight and 25 to 99.9% by weight of an unsaturated monomer copolymerizable with the silicon-containing polymerizable unsaturated monomer, and [b] granules with an average particle diameter of 5 μm or less. 1. A composition capable of forming a water-repellent film, comprising: 2. The composition according to claim 1, wherein the granules are fine silica particles having an average particle diameter of 3 μm or less. 3. The composition according to claim 1 or 2, which contains 20 to 600 parts by weight of the granular material of component [b] per 100 parts by weight of the copolymer of component [a].