JP2603602B2 - Silylated cellulose derivatives - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a silylated cellulose derivative which is mainly used as a vehicle for a coating material alone or as a mixture with an acrylic synthetic resin or the like.

[Conventional technology]

Conventionally, cellulose derivatives such as cellulose acetate butyrate, cellulose acetate propionate, cellulose acetate butylate, nitrocellulose, and mixtures of such cellulose derivatives with acrylic synthetic resins have been widely used as vehicles for coatings. . The cellulose derivative has excellent drying properties and weather resistance, and is useful as a vehicle for coating or as a modifier such as an acrylic synthetic resin.

(Object of the present invention)

An object of the present invention is to further improve the features of the conventional cellulose derivative as described above.

[Means for achieving the purpose]

According to the present invention, as a means for achieving the above object, a compound having a functional group capable of reacting with the OH group and a hydrolyzable silyl group is reacted with the OH group remaining in the cellulose derivative.

<Cellulose Derivative> Cellulose derivatives used in the present invention include cellulose derivatives such as nitrocellulose (NC), cellulose acetate butyrate (CAB), cellulose acetate propionate (CAP), cellulose acetate (CA),
Ethyl cellulose (EC) and the like.

As the above nitrocellulose, all types classified according to JIS K6703 can be used. Particularly preferred nitrocellulose is H1 / 16 having a nitrogen content of 11.5 to 12.2% by weight and a viscosity of 1/16 to 20 seconds. , H1 / 8, H1 / 4, H1 / 2, H2, H20,
More desirable are H1 / 16, H1 / 8, H1 / 4 and H1 / 2. As the above cellulose acetate butyrate, those having various degrees of acetylation and butyrylation can be used, but when used as a coating material, those having a degree of butyrylation of 30% or more are desirable from the viewpoint of solubility in a coating solvent. Such a CAB is a product of Eastman Kodak Company, CAB
-551-0.01, CAB-551-0.2, CAB-531-1, CAB-500
-1, CAB-500-5, CAB-553-0.4, CAB-451-1, C
AB-381-0.1, CAB-381-0.5, CAB-381-2, CAB-20
Etc.

<Silyl group-containing compound> The silyl group-containing compound used in the present invention has a functional group capable of reacting with the remaining OH group of the cellulose derivative and a hydrolyzable silyl group, and has the following structure: Have

In the formula, R ₁ is a divalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group, R ₂ is an organic residue having a polymerizable double bond, and X is a hydrolyzable group. , N
Is an integer of 1,2,3, and A is a functional group capable of reacting with an OH group.

It said X The example -OCH _3, alkoxyl groups such as -OC ₂ H _5, -Cl, there are halogen such as -Br, As A example -Cl, halogen such as -Br, -NH _2, -SH, there is -NCO and the like.

The above silyl group-containing compound will be described more specifically below.

ClC ₃ H ₆ Si (OCH ₃ ) ₃ , ClC ₃ H ₆ Si (OC ₂ H ₅ ) ₃ H ₂ NC ₂ H ₄ NHC ₃ H ₆ Si (OCH ₃ ) ₃ , _{H 2 NC 3 H 6 Si (} OC 2 H 5) 3, HSC 3 H 6 Si (OCH 3) 3, <Production of Silylated Fiber Derivative> By reacting A of the silyl group-containing compound with an OH group remaining in the above fibrin derivative, a hydrolyzable silyl group is derived into the above fibrin derivative. The most desirable A for the above reaction is -NCO. Since -NCO reacts efficiently with the OH group remaining in the cellulose derivative in a short time at a low temperature, it is possible to prevent an undesired side reaction such as hydrolysis of a silyl group during the reaction. A is -NCO
If desired, the reaction between the fibrous derivative and the silyl group-containing compound may be carried out, if desired, with triethylamine, cobalt naphthenate, benzyltrimethylammonium hydroxide, stannous chloride, tetra-n-butyltin, stannic chloride, tristannic chloride. A catalyst such as n-butyltin acetate, n-butyltin trichloride, trimethyltin hydroxide, dimethyltin dichloride, dibutyltin dilaurate, etc.
% By weight, and usually heated to about 70-90 ° C and
Let react for about an hour. The reaction end point is usually measured by confirming the disappearance of -NCO by infrared absorption spectrum (IR).

It is not always necessary to cause the silyl group-containing compound to react with 100% of the OH groups remaining in the cellulose derivative, but in order for the effects of the present invention to be remarkably exhibited, at least 30% of the OH groups are required. % Or more is desirably reacted with the silyl group-containing compound. After the above reaction, OH
If the group remains, a cross-linking agent having two or more OH-reactive functional groups such as a diisocyanate compound and a melamine resin can be used.

(Operation)

When a solution of the silylated cellulose derivative of the present invention alone or a mixture of the silylated cellulose derivative and an acrylic synthetic resin or the like is applied to a surface to be coated and dried, hydrolyzation contained in the silylated cellulose derivative is possible. The silyl group is hydrolyzed into silanol groups by contact with external moisture, and the silanol groups are condensed to form siloxane bonds and crosslink. In order to accelerate the crosslinking reaction, a catalyst such as dibutyltin dilaurate is added. Further, a stabilizer such as methyl orthoformate may be further added to prevent the pot life of the solution or the paint using the solution from being shortened by adding the catalyst.

〔effect〕

Since the silylated cellulose derivative of the present invention has a hydrolyzable silyl group, it provides a coating film excellent in hardness, chemical resistance, etc. by the above crosslinking, and at the same time, weather resistance, water resistance, adhesion, etc. by siloxane bond. Is greatly improved. Therefore, the silylated cellulose derivative of the present invention can be used alone or in combination with an acrylic synthetic resin to provide an excellent paint vehicle.

Example 1 (Cellulose derivative A) 100 g of CAB-551-0.2 and 280 g of toluene were charged into a reactor equipped with a stirrer, a thermometer and a condenser, and heated and stirred at a reflux temperature to reflux the toluene.
After sufficiently removing the water contained in B, 20 g of OCNC ₃ H ₆ Si (OC ₂ H ₅ ) ₃ and 0.01 g of dibutyltin dioctate were added, and the mixture was reacted by heating and stirring at 80 ° C. for 10 hours. The reaction was terminated by cooling to room temperature. The reaction end point was measured by confirming the disappearance of -NCO by IR. The thus obtained fibrous derivative A has a non-volatile content.
It was a clear solution of 30% by weight and viscosity W (Gardner Holtz).

Example 2 (Cellulose Derivative B) 95 g of NC (H1 / 4), toluene
After 280 g was charged and the water contained in the NC was sufficiently removed in the same manner as in Example 1, 25 g, tetraoctyl titanate 0.05 g and added at 80 ° C.
For 15 hours, and then cooled to room temperature to complete the reaction. Measurement of reaction end point by IR Was performed by confirming the disappearance. The cellulose derivative B thus obtained has a nonvolatile content of 30% by weight and a viscosity T
(Gardner Holtz) was a clear solution.

Example 3 (Cellulose derivative C) 100 g of EC and 280 g of toluene were charged in the same reactor as in Example 1, 20 g of HSC ₃ H ₆ Si (OCH ₃ ) _{3 and} 0.05 g of zirconium naphthenate were added, and the mixture was heated to reflux temperature. The reaction is carried out by heating and stirring to reflux toluene, and water generated by the reaction is removed from the system. After the above reaction was continued for 15 hours, disappearance of -SH was confirmed by IR, and the reaction was cooled to room temperature to terminate the reaction. The cellulose derivative C thus obtained was a (Gardner-Holtz) transparent solution having a nonvolatile content of 30% by weight and a viscosity Q.

Example 4 (Acrylic Synthetic Resin D) In a reactor similar to that of Example 1, 50 g of toluene and 50 g of n-butyl acetate were charged and heated and stirred at 90 ° C., and then 5 g of styrene, 40 g of methyl methacrylate, and 2-hydroxyethyl methacrylate. A mixed solution prepared by dissolving 1 g of benzoyl peroxide in a mixed monomer of 23 g and 32 g of n-butyl acrylate is added dropwise over 2 hours. The temperature is maintained at 90 ° C. even under the mixed droplets, and after maintaining at 90 ° C. for further 3 hours after the dropwise addition, the mixture is cooled to room temperature, and has a viscosity W (Gardner Holtz), a nonvolatile content of 50% by weight, a hydroxyl value of 50 mg / KOH.
Acrylic synthetic resin D was obtained.

Example 5 (Silicon Acrylic Synthetic Resin E) A mixed monomer of 5 g of styrene, 12 g of γ-methacryloxypropyltrimethoxysilane, 45 g of methyl methacrylate and 38 g of n-butyl acrylate was used instead of the mixed monomer of Example 4. Polymerization was carried out in the same manner as in Example 4 using a mixed solution obtained by dissolving 1 g of azobisisobutyronitrile in the same manner as in Example 4 to obtain a silicone acrylic synthetic resin E having a viscosity X (Gardner-Holtz) and a nonvolatile content of 50% by weight. .

Test 1. Preparation of Samples Using the cellulose derivatives of Examples 1 to 5 and a resin sample of an acrylic synthetic resin, samples were prepared according to the recipe shown in Table 1 below.

2. Test (1) Preparation of test plate Each of the above samples 1 to 7 was flow-coated so as to have a thickness of 30 μm of a galvanized steel plate, and then dried at room temperature for one week to prepare a test plate.

(2) Paint film performance test Pencil hardness: Performed based on JISK5400.

Adhesion: The coating film is cut vertically and horizontally at intervals of 2 m / m, a cellophane tape is pressed as 100 squares, and then peeled off.

Weather resistance: 3000 hours longer than the weatherometer ○: no change, □: extremely slight yellowing △: yellowing, ×: remarkable yellowing Water resistance: coating after immersion in water at 40 ° C for 1 month Observe changes in the film.

：: no change, □: very slight whitening △: whitening, ×: whitening and blistering Chemical resistance: dipped in a 5% NaOH aqueous solution and a 5% H ₂ SO ₄ aqueous solution at 20 ° C. for 24 hours, and then coated. Observe changes.

：: no change, × ₁ : blister in NaOH, × ₂ : blister in H ₂ SO ₄ The results of the above test are shown in Table 2.

As shown in Table 2, all of the samples 1 to 5 using the cellulose derivatives A, B, and C of the present invention were compared with the samples 6 and 7 relating to the acrylic synthetic resin D or the silicone acrylic synthetic resin E. See better results in items. As can be seen from Samples 4 and 5, the acrylic synthetic resin D and the silicone acrylic synthetic resin E are significantly improved by using the cellulose derivative of the present invention.

Claims (1)

(57) [Claims] 1. A silylated cellulose derivative, comprising reacting a residual OH group of the cellulose derivative with a compound having a functional group capable of reacting with the OH group and a hydrolyzable silyl group.