JPH02252720A - Curable resin composition - Google Patents

Abstract

PURPOSE:To make it possible to form a curable resin composition having good adhesion to substrates and showing film properties including excellent weathering resistance and antifouling properties by adding a polyisocyanate compound to a specified unsaturated graft polymer. CONSTITUTION:A resin composition comprising a graft polymer (A) obtained by reacting an unsaturated isocyanate with a silicone resin having at least one active hydrogen atom in the molecule and a main chain of a polysiloxane structure to convert the silicone resin into another silicone resin at least part of which has unsaturated bonds, adding a monomer having an active hydrogen atom and optionally a copolymerizable monomer to the obtained silicone resin, and polymerizing the mixture and a polyisocyanate compound (B). The mixing ratio is desirably 1-15 pts.wt. component B per 100 pts.wt. component A, though it may vary according to the intended use.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to curable resin compositions.

In particular, the present invention utilizes the properties of a curable resin that has excellent weather resistance and low surface energy to exhibit excellent effects in shapeability and antifouling properties, and is useful in the field of antifouling surface treatment. This invention relates to a resin composition.

[Conventional technology and issues]

It is known to mix a curable silicone resin, mainly a rubber-based silicone resin, with a liquid having a releasing effect, such as silicone oil, to form a coating that has an antifouling effect, especially in seawater.

The same thing has been reported regarding thermoplastic silicone resins. For example, JP-A-Shobako 60-65076
No. 62-15 describes a reaction-curing silicone composition.
No. 6172 discloses a polymer of vinyl silicon,
JP-275132 discloses a copolymer of a polysiloxane macromer and a vinyl monomer.

However, existing coatings based on silicone resins tend to peel off due to poor adhesion to the base material under conditions where they are constantly exposed to waves, such as when immersed in seawater. It is difficult to maintain the antifouling effect over a long period of time.

The present invention eliminates these conventional drawbacks, forms a low-energy surface, exhibits an antifouling effect, has good adhesion to prone substrates, and sufficiently withstands repeated stresses such as those caused by waves, making it suitable for practical use. This invention relates to a coating composition that is difficult to peel off.

[Means to solve the problem]

That is, the present invention provides an antifouling paint composition containing the following components (A) and (B): (A) having at least one active hydrogen in one molecule; After reacting a silicone resin whose molecular main chain is a polysiloxane structure with an unsaturated isocyanate to convert it into a silicone resin having at least a portion of unsaturated bonds, this is co-coated with a monomer having active hydrogen as necessary. A graft polymer obtained by adding a polymerizable monomer and polymerizing it and (B) polyvalent isocyanate compound 8. In other words, an unsaturated isocyanate is reacted with a silicone resin having a polysiloxane structure having active hydrogen, and at least a silicone resin is obtained. After introducing an unsaturated bond into a portion, a monomer having active hydrogen and, if necessary, a monomer copolymerizable with these are added, and the resultant graft polymer, which has a silicone resin as a portion, is made into a polyvalent polymer. By using an isocyanate compound in combination, a curable resin composition is obtained which, after coating and curing, provides a coating film that is tough and has excellent durability and adhesion.

The final cured resin according to the present invention has a wide range depending on (i) the ratio of unsaturated silicone resin (i) the amount of monomer having active hydrogen (iii) the type of monomer (iv) the type and amount of polyvalent incyanate, etc. Its physical properties can be changed, making it suitable for a wide range of applications.

The curable resin composition of the present invention has excellent adhesion to metals such as iron and aluminum, concrete, inorganic building materials such as slate, wood, etc., and by curing it, it becomes strong and durable. (A) of the composition of the invention, which makes it possible to obtain a certain coating film.
The procedure for producing the components is illustrated below.

CHl Active hydrogen-containing silicone resin Unsaturated isocyanate (
Isocyanatoethyl methacrylate) CI (.

Unsaturated bond-introduced silicone resin (unsaturated bond-introduced silicone resin) 10 (vinyl monomer/
Active hydrogen-containing upper layer) The above formula shows an example in which styrene is used as the vinyl monomer and 2-hydroxyethyl methacrylate is used as the monomer having active hydrogen.

The hydroxyl groups of the graft copolymer described above are crosslinked with a polyvalent isocyanate.

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

(a) silicone resin having active hydrogen, (b) unsaturated isocyanate, (c) monomer having active hydrogen, and optionally, further (d) copolymerizable monomer (A> component of the composition of the present invention). The silicone resin (A) used for manufacturing has a main chain of the constituent molecules of the following formula (however, R,
R' has a polysiloxane structure (alkyl group, phenyl group), and contains at least one active hydrogen, typically a hydroxyl group, that can react with isocyanate in one molecule.
It is necessary to own it individually.

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

X-22-160A Hydroxy value 62 Molecular weight 1
800 X-22-160B Hydroxy value 35 Molecular weight 3
200 Compounds that share a saturated bond, b) 1 mole to 1 mole adduct of diisocyanate and unsaturated monoalcohol, etc.

Examples of unsaturated isocyanates include isocyanate ethyl methacrylate, methacryloyl isocyanate, and isocyanate ethyl isocyanate. , is suitable from the viewpoint of isocyanate reactivity.

The reaction product of diisocyanate and unsaturated alcohol is, for example, a 1 mole to 1 mole adduct (formula below) of 2,4-)lylene diisocyanate and 2-hydroxyethyl methacrylate.

In this case, it is advantageous for the diisocyanate to be of a type in which two isocyanate groups have different reactivities, such as 2,4-)lylene diisocyanate and inphorone diisocyanate.

The reaction ratio between active hydrogen of silicone resin and unsaturated isocyanate is 100 parts of silicone resin (parts by weight, same below)
The amount of unsaturated isocyanate is 0.01 part or more and 10 parts or less, preferably 0.1 part or more and 3 parts or less. In this case, it is not necessary to react all of the active hydrogen present. The degree varies depending on the type of monomers used in combination and the ratio of unsaturated silicone resin to hexamer.

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

The monomers to be used in combination as the copolymerizable monomer (d) may be any monomer as long as it is copolymerizable with this monomer, and commonly commercially available types are used. There are no particular restrictions on the type, but
Examples include styrene, vinyltoluene, acrylic esters, methacrylic esters, acrylonitrile, methacrylate trile, vinyl acetate, ethylene, and butadiene.

The blending ratio of the unsaturated bond-introduced silicone resin and the monomer can be changed freely, but depending on the amount and type of monomer, the surface energy may increase, and there is a risk that the antifouling effect and weather resistance will be insufficient.

Considering these, the proportion of the unsaturated bond-introduced silicone resin is 10 to 95% (by weight, the same hereinafter), preferably 20 to 80%.

The proportion of the active hydrogen-containing monomer (c) to be used is desirably about 1 to 30 mol % when the total monomer is taken as 100, with the remainder being the copolymerizable monomer (d).

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

2.4-tolylene diisocyanate, 2,6-tolylene diisocyanate, mixture of 2.4-)lylene diisocyanate and 2.6-)lylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, xylylene diisocyanate , hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, 1,5 naphthylene diisocyanate, polyisocyanates represented by the following general formula.

Adducts of these isocyanates and, for example, polyols, in which isocyanate groups remain, can also be used.

Further, the combined use of a so-called urethanization catalyst in the reaction between the isocyanate compound and the active hydrogen of the polymer is effective in bringing out 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 the amount of the polyvalent isocyanate compound (B) is 0.1 to 30 parts by weight per 100 parts by weight of the unsaturated graft polymer that is the component (A). parts, preferably 1 to 15 parts by weight, more preferably 2 to 10 parts by weight.

Of course, in the resin composition according to the present invention, reinforcing materials, fillers, colorants, waxes, etc. can be used in combination as necessary.

Next, the present invention will be further explained by examples.

2. In a 21 separable flask equipped with a stirrer, reflux condenser, thermometer, and gas introduction, silicone resin having a hydroxyl group (X-22-160B manufactured by Shin-Etsu Chemical Co., Ltd., hydroxyl value approximately 35) , molecular weight 3200), 0.8 parts of isocyanatoethyl methacrylate, and 0.2 parts of dibutyltin dilaurate, and reacted at 60 to 65°C for 4 hours. As a result of infrared analysis, it was observed that free isocyanate groups had disappeared.

To this, 40 parts of 2-hydroxypropyl methacrylate, 177 parts of styrene, 300 parts of toluene, 4 parts of azobisisobutyronitrile, and 2 parts of tert-butyldodecanethiol were added, and at 75 to 80°C, azobisisobutyronitrile was added. After adding 2 parts of lonitrile and polymerizing for 16 hours, 0.1 part of hydroquinone monomethyl ether was added. A slightly viscous and cloudy solution of the homogeneous graft polymer of component (A) was obtained.

To 100 parts of this (A) component polymer solution, 7 parts of isophorone diisocyanate, 0.3 parts of dibutyltin dilaurate, and 10 parts of toluene as components (B) are mixed, and the mixture is coated on a Bonderite steel plate to a thickness of 100μ. Apply as shown,
After being left overnight, it was heated at 120° C. for 30 minutes to complete curing.

The hardness of the cured coating film was F, and no adhesion was observed in the Sellotape peel test, and the peel strength was 0.1 >g/in or less.

In the paint film adhesion test using crosscut, no peeling of the paint film was observed.

The gloss reflectance of the system to which 0.5 part of Tinuvin P (Ciba) was added as an ultraviolet absorber was initially 90%, but after 1000 hours of irradiation with a DEW cycle type wet-ometer, the gloss reflectance decreased to 85%. There wasn't.

L Next Day 1 In Example 1, silicone resin having active hydrogen (manufactured by Shin-Etsu Chemical Co., Ltd.) X-22-160B was used instead of the silicone resin to which isocyanate ethyl methacrylate was added.
The reaction was carried out in the same manner as in Example 1, except that the compound was used as it was. The obtained polymer separated into two layers after standing and did not form a homogeneous solution.

In other words, it is presumed that it was not grafted.

E1 and -1 In a 21 separable flask equipped with a stirrer, reflux condenser, thermometer, and gas inlet tube, silicone resin having a hydroxyl group (Shin-Etsu Chemical Co., Ltd. X-22-160^, hydroxyl value 62, 200 parts of molecular weight 1800), 2.5 parts of a 1 mole to 1 mole adduct of isophorone diisocyanate and 2-hydroxypropyl methacrylate as an unsaturated isocyanate, and 0.2 parts of dibutyltin dilaurate.
of the mixture was added, and the mixture was reacted at 65 to 70°C for 3 hours. As a result of infrared analysis, it was observed that free isocyanate groups had disappeared.

To this were added 120 parts of methyl methacrylate, 84 parts of isobutyl methacrylate, 26 parts of 2-hydroxyethyl methacrylate, 2.5 parts of azobisisobutyronitrile, 300 parts of toluene, and 1.3 parts of lauryl mercaptan.
After polymerization at 5-70°C for 15 hours, 0.0% of hydroquinone was added.
1 part was added to stop the polymerization.

In this way, a cloudy syrup-like polymer (A> component) was obtained.

To 100 parts of this (A) component polymer, 10 parts of toluene,
2.4-) 4 parts of lylene diisocyanate was added and coated onto a Bonderite steel plate to a thickness of 100 μm.

After being left overnight, it was heated at 120° C. for 1 hour to complete curing.

The cured coating film is glossy, has a hardness of B, and in the cellophane tape peel test, it has no adhesive force at all, and its peel strength is 0.
, 1 kg/in or less. In the DEIII cycle type weather heater exposure test, the gloss reflectance before exposure was 89%, and after 1000 hours of exposure, the gloss was 86%, which showed almost no decline, although there was some yellowing.

〔Effect of the invention〕

Since the present invention is configured as described above, it is possible to provide a curable resin composition that has good adhesion to a substrate and exhibits coating film performance with excellent weather resistance and antifouling properties.

Patent applicant: Showa Kobunshi Co., Ltd.

Claims (1)

[Scope of Claims] A curable resin composition containing the following components (A) and (B): (A) having at least one active hydrogen in one molecule, the main chain of the constituent molecules being polyester; After reacting a silicone resin with a siloxane structure with an unsaturated isocyanate to convert it into a silicone resin having at least a portion of unsaturated bonds, a monomer having active hydrogen and, if necessary, a copolymerizable monomer are added to the silicone resin. In addition, a graft polymer obtained by polymerization; and (B) a polyvalent isocyanate compound.