JPS62250017A - Silicone resin composition - Google Patents

Abstract

PURPOSE:The titled composition, consisting of a copolymer consisting essentially of an NCO group-containing monomer and a hydrolyzable silyl group-containing monomer, having an extremely high curing rate and capable of giving films having improved solvent resistance, adhesive property, etc., in the initial period of forming the films. CONSTITUTION:A composition obtained by copolymerizing (A) an NCO group- containing monomer, e.g. beta-isocyanatoethyl acrylate, etc., and (B) a hydrolyzable silyl group-containing monomer, e.g. gamma-methacryloxypropyltrimethoxysilane, etc., to give preferably 30-50pts.wt. component (A) and 10-20pts.wt. component (B).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a silicone resin composition particularly useful as a raw material for paint.

[Conventional technology]

Conventionally, paints made from copolymers of acrylic esters and methacrylic esters having a hydrolyzable silyl group, such as an alkoxysilyl group or a trihalosilyl group, have been provided. In a paint having such a hydrolyzable silyl group, the silyl group is hydrolyzed to become a silanol group during the process of forming a coating film, and the silanol group is further condensed to form a siloxane bond and cured.

The coating film has excellent chemical resistance, weather resistance, and adhesion to inorganic materials.

[Problem that the invention seeks to solve]

While the above-mentioned conventional paints having hydrolyzable silyl groups have the above advantages, they have poor adhesion to organic materials, and the intermolecular force of silicon itself is very small, so it easily swells in solvents and has poor solvent resistance. Also inferior.

Furthermore, the hydrolysis of silyl groups is carried out by taking in moisture from the outside air, so curing is slow, and the surface area that comes into contact with the outside air is selectively hardened, and it takes a long time for the hardening to progress to the inside, resulting in a coating film. There is a problem in that the solvent resistance at the initial stage of formation becomes even worse.

[Means for solving problems]

The present invention provides a silicone resin composition comprising a copolymer mainly composed of an isocyanate group-containing monomer and a hydrolyzable silyl group-containing monomer as a means to solve the above conventional problems. It is.

The incyanato group-containing monomer (hereinafter referred to as weight A) used in the present invention includes β-incyanatoethyl acrylate, β-isocyanatoethyl methacrylate, γ-isocyanatopropyl acrylate, γ-incyanatopropyl methacrylate, etc. The isocyanate group-containing acrylic ester mojikuha contains a polymerizable vinyl group and an isocyanate group in one molecule, such as methacrylic ester and vinyl isocyanate.

The hydrolyzable silyl group-containing monomer used in the present invention (hereinafter referred to as monomer B) is a monomer containing a polymerizable vinyl group and hydration, such as γ-methacryloxibu tetrapyltrimethoxysilane, vinyl acetoxysilane, vinyl trimethoxysilane, etc. It contains a decomposable silyl group in one molecule and does not contain a functional group having active hydrogen.

In addition to the above-mentioned monomers A and H, the silicone resin composition of the present invention further uses monomers that are copolymerizable with the above-mentioned monomers A and B and do not contain a functional group having active hydrogen (hereinafter referred to as monomers C), for example methyl acrylate, ethyl acrylate, n-butyl acrylate r 1so-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate.

ethyl methacrylate, n-butyl methacrylate) r
Acrylic ester or methacrylic ester such as 1so-butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate.

Styrene, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, vinyl fluoride.

Monomers such as vinylidene fluoride, methyl vinyl ether, ethyl vinyl ether, and vinyl acetate may be copolymerized.

The silicone resin composition of the present invention contains 20 to 60 monomers A.
Parts by weight, preferably 30 to 50 parts by weight, and 5 to 5 parts by weight of monomer B
25 parts by weight, preferably 10 to 20 parts by weight, are copolymerized.

The silicone resin composition of the present invention contains the above monomer A.

A mixed monomer obtained by mixing B and, if desired, the above monomer C therein with toluene, xylene, ethyl acetate, acetic acid n
-Butyl, methyl ethyl ketone, methyl isobutyl ketone, cellosolve acetate.

Oil-soluble initiators such as pesozoyl peroxide, lauryl peroxide, cumene hydroperoxide, azobisisobutyronitrile in organic solvents that do not contain functional groups with active hydrogen such as n-butyl cellosolve, mineral turpentine, and mineral spirits. However, the above-mentioned organic solvent is not essential, and the copolymer may be produced by bulk polymerization, suspension polymerization, etc.

Further, during the above polymerization, lauryl mercaptan, carbon tetrachloride, etc. may be added as a chain transfer agent.

The silicone resin composition of the present invention has an incyanate group and a hydrolyzable silyl group in one molecule, and the silicone resin composition alone can be used as a coating film forming material. polyhydroxy compounds such as propylene ether) polyol, poly(oxyethylene-propylene ether) polyol, acrylic polyol, hydroxyl group-containing styrene butadiene rubber, hydroxyl group-containing acrylonitrile butadiene rubber, castor oil derivatives, tall oil derivatives, carboxyl group-containing acrylic resins , carboxyl group-containing polymers such as carboxyl group-containing styrene butadiene rubber, carboxyl group-containing acrylonitrile butadiene rubber, glycidyl group-containing polymers,
When mixed with a polymer containing a functional group having active hydrogen, such as an amino group-containing polymer or a tertiary amine-containing polymer, it cures rapidly even at room temperature to form a coating film. If desired, a further catalyst such as an amine may be added to the above mixture.

[Effect]

The operation of the present invention is as follows.

When the silicone resin composition of the present invention is used alone or by mixing the silicone resin composition with a polymer containing a functional group having active hydrogen to form a coating film, the coating film combines the incyanato groups of the silicone resin composition with moisture from the outside world. or the reaction between the silicone composition and the functional group of the polymer, it cures rapidly even at room temperature and generates urea bonds and urethane bonds in the coating film, thereby increasing the cohesive strength of the coating film. enhance In the coating film formation process, the hydrolyzable silyl groups originating from the silicone resin composition are oriented at the coating film interface (front and back surfaces) due to the interfacial migration property of the silyl groups, and are oriented by the moisture present in the environment. The silyl group is hydrolyzed to form a silanol group, and the silyl groups are further condensed with each other to form a siloxane bond. Furthermore, on the back side of the coating film, that is, the surface in contact with the base material, if the base material is an inorganic material such as glass containing silanol groups, the silanol groups of the coating film will hydrogen bond with the silanol groups of the base material and/or siloxane. form a bond.

〔Effect of the invention〕

Therefore, in the present invention, the coating film is cured by the reaction between the isocyanate group and the functional group having active hydrogen before the siloxane bonds are formed, so the curing speed is extremely fast even at room temperature, and the initial coating strength and solvent resistance are improved. The physical properties of the coating film are good, and the presence of siloxane bonds on the coating film surface prevents the coating film from deteriorating due to ultraviolet rays and maintains good gloss over a long period of time. In addition, when the base material is inorganic, chemical bonds are formed between the paint film and the base material, resulting in extremely excellent adhesion of the paint film.Furthermore, the urethane bonds present in the paint film allow it to be bonded to organic materials. Adhesion is also improved.

Example 1 A mixture with the following composition was placed in a flask equipped with a stirrer, a thermometer, and a condenser, and heated at 90°C for 7 hours under a nitrogen atmosphere.
Allow time to react.

β-incyanatoethyl methacrylate 40 parts by weight r-methacryloxypropyltrimethoxysilane
10 parts by weight methyl methacrylate 25 parts by weight n-butyl methacrylate 2
5 parts by weight Toluene 66.7 parts by weight Azobisisobutyronitrile 2 parts by weight Lauryl mercaptan 2 parts by weight Thus, the amount of incyanate was 6.5% by weight, and the number average degree of polymerization was 5000 to 5.
500 silicone resin composition (1) is obtained.

Example 2 A mixture having the following composition was reacted in the same manner as in Example 1 to obtain an isocyanate amount of 6.8% by weight and a number average degree of polymerization of 5000 to 5.
500 silicone resin composition (2) is obtained.

γ-Isocyanate globil methacrylate 45 parts by weight vinyl acetoxysilane 10 parts by weight ethyl methacrylate 35 parts by weight ethyl acrylate)
10 parts by weight n-butyl acetate
66.7 parts by weight benzoyl peroxide 2
Parts by weight Lauryl mercaptan 2 Parts by weight Comparative Example A mixture having the following composition is reacted in the same manner as in Example 1 to obtain a silicone resin composition (3).

Styrene 20 parts by weight Methyl methacrylate 40 parts by weight n-butyl methacrylate 15 parts by weight n-butyl methacrylate 1
0 parts by weight γ-methacryloxypropyltrimethoxysilane 15 parts by weight azobisisobutyronitrile 2 parts by weight lauryl mercaptan 2 parts by weight xylene 6
6.7 parts by weight Example 3 The manure formulation was put into a flask equipped with a stirrer, a thermometer, and a condenser and stirred at 75°C for 15 hours to obtain 40% by weight of acrylic polyol.

Methyl methacrylate 20oM parts (n-butyl acrylate) 160 parts 2-hydroxyethyl acrylate 40 parts benzoyl peroxide 2 parts by weight Toluene
600 parts by weight Example 4 Coating film of a composition obtained by mixing 100 parts by weight of the silicone resin composition (1) of Example 1 and 100 parts by weight of poly(oxypropylene ether) polyol having a number average degree of polymerization of 3000. was formed on a predetermined substrate using a 4 mil doctor blade, and cured at 110'C for 2 hours to prepare sample 1.

Example 5 Sample 2 was prepared in the same manner as in Example 4 using silicone resin composition (2) instead of silicone resin composition (1).

Example 6 Sample 3 was prepared in the same manner as in Example 4 using silicone resin composition (3) instead of silicone resin composition (1).

Example 7 Sample 4 was prepared in the same manner as in Example 4 by mixing 60 parts by weight of silicone resin composition (1) and 100 parts by weight of the acrylic polyol prepared in Example 3.

Example 8 Sample 5 was prepared in the same manner as in Example 7 using silicone resin composition (2) instead of silicone resin composition (1).

Example 9 Sample 6 was prepared in the same manner as in Example 7 using silicone resin composition (3) instead of silicone resin composition (1).

Table 1 shows the coating film performance of Samples 1 to 6 prepared according to Examples 4 to 9 above.

Example 10 Sample 7 was prepared in the same manner as in Example 4 by adding and mixing 2 parts by weight of dibutyltin dilaurate (curing catalyst) to 100 parts by weight of silicone resin composition (1).

Example 11 Sample 8 was prepared in the same manner as in Example 10 using silicone resin composition (2) instead of silicone resin composition (1).

Example 12 Sample 9 was prepared in the same manner as in Example 10 using silicone resin composition (3) instead of silicone resin composition (1).

First surface adhesion 1: A thermosetting acrylic resin paint was applied to a 0.8 sa + thick annealed copper plate at a thickness of 4 mils at 150°C.

A painted board baked for 30 minutes is used as a base material. 10 squares vertically and horizontally at 1m intervals. Make a loss cut and tape it with sellotape. A peeled sample was conducted.

Adhesion 2: A glass plate is used as the base material.

Flexibility: A mandrel test with a predetermined diameter is performed using a 0.5 m thick tin plate as a base material.

Weather resistance: Using a glass plate as a base material, a weather resistance test is conducted for 1500 hours using a weather meter.

Gasoline resistance 2 Using a glass plate as the base material, it is resistant to gasoline.
Soaked for an hour.

Chemical resistance: 0.5N HCI using a glass plate as the base material
It was immersed in an aqueous solution for 5 hours.

Evaluation method Adhesion ○: No peeling at all B: 10-chi peeling Δ: 20% peeling x: 30% or more peeling Flexibility ○: No cracks occur at diameter IW+.

B: Cracks occur when the diameter is 1 sm, but no cracks occur when the diameter is 2 ms.

Δ: Longitudinal diameter 2s will not cause cracks.

×: Cracks occur with a diameter of 3 cm or more.

Weather resistance ○: No yellowing.

B: Almost no yellowing.

△: Slight yellowing ×: Significant yellowing Gasoline resistance ○: No change B: Slight swelling △: Swelling X: Swelling and partial dissolution Chemical resistance O: No change B: Slight swelling Δ: Swelling ×: Peeling

Claims (1)

[Claims] A silicone resin composition consisting of a copolymer mainly composed of an isocyanate group-containing monomer and a hydrolyzable silyl group-containing monomer