JPH07688B2 - Curable resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a curable resin composition.
In particular, the present invention utilizes a property of a curable resin having excellent weather resistance and low surface energy, and exerts an effect of excellent releasability and antifouling property, which is a curable resin suitable for surface coating. It relates to a composition.

[Conventional technology and problems]

It is known to mix a curable silicone resin, mainly a rubber silicone resin, with a liquid having a releasing action such as silicone oil to form a coating having an antifouling effect particularly in seawater.

The same is said for thermoplastic type silicone resins. For example, JP-A No. 60-65076 discloses a reaction-curable silicone composition, JP-A No. 62-156172 discloses a polymer of vinyl silicon, and JP-A No. 62-275132 discloses a polysiloxane macromer. Copolymers with vinyl monomers are disclosed.

However, existing coatings based on these silicone resins are easily peeled off because of poor adhesion to the substrate under conditions of constant exposure to waves, such as when immersed in seawater. It is difficult to maintain the antifouling effect for a long period of time.

The present invention eliminates these conventional drawbacks, forms a low energy surface to exhibit an antifouling effect, has good adhesion to the substrate, and can withstand repeated stress such as waves sufficiently, and is practically used. The present invention relates to a resin composition for a paint that is difficult to peel off.

[Means for Solving the Problems]

That is, the present invention provides a curable resin composition containing the following components (A) and (B): (A) Having at least one active hydrogen in one molecule,
After the unsaturated isocyanate is reacted with the silicone resin whose main chain of the constituent molecule is a polysiloxane structure to convert it into a silicone resin having at least a portion having an unsaturated bond,
A graft polymer obtained by adding thereto a monomer having active hydrogen, a fluorine-containing (meth) acrylate, and a copolymerizable monomer as required, and (B) a polyvalent isocyanate compound.

Thus, after introducing an unsaturated bond by reacting an unsaturated isocyanate with a silicone resin having active hydrogen, a monomer having active hydrogen and a fluorine-containing monomer copolymerizable therewith are added and polymerized. By using a polyvalent isocyanate compound as a crosslinking component in combination with the resulting graft polymer, a curable resin composition is obtained which, after coating and curing, provides a coating film that is tough and has excellent durability and adhesion. It is a thing.

The final cured resin according to the present invention comprises: (i) ratio of unsaturated silicone resin (ii) amount of monomer having active hydrogen (iii) type and amount of fluorine-containing (meth) acrylate (iv) type and amount of polyvalent isocyanate As a result, the physical properties can be changed in a wide range, and it can be used in various fields.

The coating composition according to the present invention has excellent adhesion with metals such as iron and aluminum, concrete, inorganic building materials such as slate, wood, etc., and by curing this, a tough and durable coating film. Can be obtained.

In order to facilitate the understanding of the present invention, (A) of the composition of the present invention
The procedure for making the components is illustrated below.

The above formula shows an example in which 1,1,1,3,3,3-hexafluoroisopropylmethacrylate is used as the fluorine-containing monomer and 2-hydroxyethylmethacrylate is used as the monomer having active hydrogen.

The raw materials used for producing the component (A) of the composition of the present invention are classified into the following types.

(A) Silicone resin having active hydrogen, (b) unsaturated isocyanate, (c) monomer having active hydrogen, (d) fluorine-containing (meth) acrylate and, optionally, (e) copolymerizable monomer.

The silicone resin (a) used for the production of the component (A) of the composition of the present invention has a main chain of constituent molecules represented by the following formula: (Wherein R and R'are alkyl groups and phenyl groups) and has a polysiloxane structure, and at least one active hydrogen capable of reacting with an isocyanate, typically a hydroxyl group, should be possessed in one molecule. is necessary.

As such a silicone resin, dimethylpolysiloxane having a hydroxyl group at the terminal is suitable, and examples of commercially available products include the following types manufactured by Shin-Etsu Chemical Co., Ltd.

The unsaturated isocyanate (b) for introducing an unsaturated bond into these hydroxyl group-containing silicone resins includes a) a compound which shares an unsaturated bond with an isocyanate group in one molecule, and b) a diisocyanate. With unsaturated monoalcohol
And 1 mole of adduct, and the like.

Examples of unsaturated isocyanates include, for example, isocyanate ethyl methacrylate, methacryloyl isocyanate, m-isopropenyl-α, α dimethylbenzyl isocyanate, generally isocyanate ethyl methacrylate (the following formula) Is preferable from the viewpoints of handleability and reactivity of isocyanate.

The reaction product of diisocyanate and unsaturated alcohol is, for example, an adduct of 2,4-tolylene diisocyanate and 2-hydroxyethyl methacrylate in an amount of 1 mol to 1 mol (the following formula).

In this case, diisocyanate includes 2,2-tolylene diisocyanate, isophorone diisocyanate, and the like.
Preference is given to different types of reactivity of the individual isocyanate groups.

The reaction ratio between the active hydrogen of the silicone resin and the unsaturated isocyanate is 0.01 part or more and 10 parts or less, preferably 0.1 part or more and 3 parts, with respect to 100 parts (weight part, the same below) of the silicone resin. It is the following. In this case, it is not necessary to react all the active hydrogen present. The degree depends on the types of monomers used together and the ratio of the unsaturated silicone resin to the monomers.

Examples of the monomer (c) having active hydrogen include 2-
Examples thereof include hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate and phenoxyethyl methacrylate.

The fluorine-containing (meth) acrylate (d) used in the present invention is an acrylic acid ester or methacrylic acid ester of an alcohol having a fluorinated alkyl group and / or alkylene group, and is a hydrogen atom of an alkyl group or an alkylene group. Acrylic ester or methacrylic acid ester of alcohol whose part or all is substituted by fluorine, and the total number of carbon atoms of alkyl group, alkylene group or both groups in one molecule is 1 to 30, Is a compound such as: (However, m = 0 to 18, n = 0 to 18, R = H or CH ₃ C
O, X = H or CH _3, R '= H or CH ₃ (CH ₂₎ a n).

The monomer used in combination as the copolymerizable monomer (e) may be any monomer as long as it can be copolymerized with the monomer, and generally commercially available types are used. There are no particular restrictions on the type,
Examples thereof include styrene, vinyltoluene, acrylic acid esters, methacrylic acid esters, acrylonitrile, methacrylonitrile, vinyl acetate, ethylene and butadiene.

The ratio of the unsaturated bond-introduced silicone resin and the fluorine-containing (meth) acrylate can be freely changed, but normally, the unsaturated bond-introduced silicone resin is 10 to 95% (wt%, the same applies hereinafter),
It is preferably 20 to 80%.

The use ratios of the monomer (c) having active hydrogen, the fluorine-containing (meth) acrylate (d) and the copolymerizable monomer (e) are 1 to 30, 1 to 70 and 0, respectively, when the total monomer is 100. It is desirable that the content is ˜69 mol%.

Added to the graft polymer (A) having active hydrogen,
Examples of the polyvalent isocyanate compound (B) for reacting with this to cure the resin include the following types.

2,4-Tolylene diisocyanate, 2,6-Tolylene diisocyanate, Mixture of 2,4-Tolylene diisocyanate and 2,6-Tolylene diisocyanate, Diphenylmethane diisocyanate, Isophorone diisocyanate, Xylylene diisocyanate , Hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, 1,5 naphthylene diisocyanate, and polyisocyanates represented by the following general formula.

Adducts of these isocyanates with, for example, polyols in which the isocyanate groups remain can be used as well.

Further, the combined use of a so-called urethane-forming catalyst in the reaction between the isocyanate compound and the active hydrogen of the polymer is effective in demonstrating the physical properties of the coating film at an early stage.

The mixing ratio of each component of the composition of the present invention varies depending on the purpose of use, but it is the unsaturated graft polymer which is the component (A).
0.1 parts of (B) polyvalent isocyanate compound per 100 parts by weight.
-30 parts by weight, preferably 1-20 parts by weight, more preferably 2-20 parts by weight.

It goes without saying that the curable resin composition according to the present invention may further contain a reinforcing material, a filler, a coloring agent, a wax and the like, if necessary.

Next, the present invention will be further described with reference to examples.

Example 1 In a one-separable flask equipped with a stirrer, a reflux condenser, a thermometer, and a gas inlet tube, a silicone resin having a hydroxyl group (X-22-160B, manufactured by Shin-Etsu Chemical Co., Ltd., hydroxyl number about 35, molecular weight 3200). ) 200 parts (parts by weight, the same applies hereinafter), 1.0 part of isocyanate ethyl methacrylate,
Charge 0.2 parts of dibutyltin dilaurate, 4 at 60-65 ℃
Reacted for hours. As a result of infrared analysis, it was confirmed that the free isocyanate group disappeared.

29 parts of 2-hydroxypropyl methacrylate,
Fluoroacrylate represented by the following formula 150 parts of toluene, 320 parts of toluene, and 2 parts of azobisisobutyronitrile were added, and after polymerization in a nitrogen stream at 65 to 70 ° C. for 8 hours,
Polymerization was stopped by adding 0.1 part of hydroquinone.

The obtained graft resin (A) (toluene solution) was a cloudy thixotropic liquid.

To 100 parts of this solution of the component (A) polymer, 6 parts of isophorone diisocyanate as the component (B) was added and coated on a Bonderite steel plate to a thickness of 100 μm.
The coating that was left standing overnight and cured at 120 ° C for 1 hour was glossy, had a hardness of 2B, and did not adhere at all in the cellophane tape peel test.
The peel strength was 0.1 kg / in or less. The gloss reflectance of the coating film was 90%, and it was 88% even after 1000 hours irradiation with a DEW cycle weatherometer, showing almost no change.

Example 2 A 2 l separable flask equipped with a stirrer, a reflux condenser, a thermometer, and a gas introduction tube was charged with a silicone resin having a hydroxyl group (Shin-Etsu Chemical Co., Ltd. X-22-160A, hydroxyl number 62, molecular weight 1800). 200 parts, 1 mol to 1 mol of an adduct of isophorone diisocyanate and 2-hydroxypropyl methacrylate as unsaturated isocyanate 2
And 0.2 part of dibutyltin dilaurate were added, and the mixture was reacted at 65 to 70 ° C. for 3 hours. As a result of infrared analysis, it was confirmed that the free isocyanate group disappeared.

Then 1,1,1,3,3,3-hexafluoroisopropylmethacrylate (the following formula) 220 parts, 2-hydroxypropyl methacrylate 30
Parts, 1 part of azobisisobutyronitrile, and 450 parts of toluene were added, and the mixture was polymerized in a nitrogen stream at 65 to 70 ° C. for 16 hours, and then 0.1 g of hydroquinone was added to terminate the polymerization.

Thus, a cloudy thixotropic liquid polymer as the component (A) was obtained.

To 100 parts of this component (A) polymer, 4 g of 2,4-tolylene diisocyanate was added and coated on a Bonderite steel plate to a thickness of 100 μm.

The coating film, which had been left to stand overnight and then cured at 120 ° C. for 1 hour, was glossy and had a hardness of B. In the cellophane peel test, no adhesion was observed and the peel strength was 0.1 kg / in or less. The gloss reflectance of the coating film is 89%, and it is 1 with the DEW cycle weatherometer.
Even after irradiation for 000 hours, it was 85%, which was almost unchanged.

〔The invention's effect〕

Since the present invention is configured as described above, the adhesion to the substrate is good, even when immersed in seawater, weather resistance,
It is possible to provide a curable resin composition exhibiting excellent coating performance with antifouling properties.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-58-63717 (JP, A) JP-A-2-252720 (JP, A) JP-A-2-252773 (JP, A) JP-A-2- 252774 (JP, A)

Claims (1)

[Claims] 1. A curable resin composition containing the following components (A) and (B): (A) At least one active hydrogen atom in one molecule, and the main chain of the constituent molecules is polysiloxane. After reacting the structure of the silicone resin with an unsaturated isocyanate to convert it into a silicone resin having at least a portion having an unsaturated bond, a monomer having active hydrogen, a fluorine-containing (meth) acrylate and, if necessary, a A graft polymer obtained by adding a polymerizable monomer and polymerizing it; and (B) a polyvalent isocyanate compound.