JP2567827B2 - Graft copolymer of cellulose derivative - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention mainly relates to a graft copolymer of a fibrin derivative useful as a coating vehicle.

[Conventional technology]

Acrylic copolymers have been conventionally provided as paint vehicles. It is also possible to mix a fibrin derivative such as cellulose acetate butyrate (CAB) with the acrylic copolymer in order to improve the drying property, the hardness, and the metallic pigment dispersibility of the coating material using the acrylic copolymer as a vehicle. Has been done. Further, in order to improve the compatibility or solvent solubility between the acrylic copolymer and the fibrin derivative, grafting of the acrylic copolymer onto the fibrin derivative is also carried out (for example, JP-A-60- 58415, JP-A-61
-72072).

[Problems to be solved by the invention]

However, the above-mentioned conventional acrylic copolymer, acrylic copolymer-fibrin derivative mixture, or coating material using the acrylic copolymer-grafted fibrin derivative as a vehicle has flexibility when the coating hardness is increased. If it is insufficient, the coating film becomes brittle, and if it is given flexibility, the coating film hardness becomes insufficient, which is an antinomy problem.

[Means for Solving Problems] As a means for solving the above-mentioned conventional problems, the present invention provides a homopolymer chain of a vinyl monomer having a hydroxyl group or the vinyl monomer and another vinyl monomer. The present invention provides a graft copolymer of a fibrin derivative obtained by ring-opening polymerization of ε-caprolactone on the hydroxyl group of the fibrin derivative having a graft chain composed of a copolymer chain.

<Cellulose Derivatives> Cellulose derivatives used in the present invention include nitrocellulose (NC), cellulose acetate butyrate (CA).
B), cellulose acetate propionate (CAP), cellulose acetate (CA), ethyl cellulose (EC) and the like. The above nitrocellulose can be used all types that are classified in JIS K6703, particularly preferable nitrocellulose nitrogen content 11.5 to 12.2 wt%, viscosity 1/16 to 20 seconds H1 / 16, H1 / 8, H1 / 4, H1 / 2, H
2, H20, more preferably H1 / 16, H1 / 8, H1 / 4, H
There is 1/2. The above cellulose acetate butyrate can be used with various degrees of acetylation and butyrylization, but when it is used as a coating material, it is preferable that the degree of butyrylation is 30% or more from the viewpoint of meltability to the coating solvent. ,
As such CAB, Eastman Kodak Company's products CAB-551-0.01, CAB-551-0.2, CAB-531-
1, CAB-500-1, CAB-500-5, CAB-553-0.4, CAB
-451-1, CAB-381-0.1, CAB-381-0.5, CAB-381
-2 and CAB-20.

<Graft chain containing a hydroxyl group> The graft chain containing a hydroxyl group of the present invention means a homopolymer chain of a vinyl monomer containing a hydroxyl group or a vinyl monomer containing a hydroxyl group, and the hydroxyl group. It is composed of a copolymer chain of a vinyl monomer and another vinyl monomer copolymerizable therewith.

1. Vinyl monomer containing a hydroxyl group As the vinyl monomer containing a hydroxyl group used in the present invention, β-hydroxyethyl acrylate, β-
Examples include hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, allyl alcohol and the like.

2. Other vinyl-based monomers Other desirable vinyl-based monomers copolymerizable with the above-mentioned hydroxyl-containing vinyl-based monomers are methyl acrylate, ethyl acrylate, n-butyl acrylate, iso-butyl. Acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, iso
-Acrylic ester and / or methacrylic ester such as butyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate. However, for example, methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, iso-butyl vinyl ether, n-butyl vinyl ether, styrene, α-methyl styrene, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl chloride, vinylidene chloride, vinyl fluoride, fluorine. Vinylidene chloride,
Ethylene, propylene, isoprene, chloroprene, butadiene, methacrylic acid, itaconic acid, maleic acid, atropic acid, citraconic acid, crotonic acid, acrylic amide, methacrylic amide, diacetone acrylic amide, vinylpyrrolidone, vinylpyridine, vinylcarbazole, glycidyl acrylate , Glycidyl methacrylate, glycidyl allyl ether and the like.

The vinyl-based monomer containing the hydroxyl group and the other vinyl-based monomer may be used alone or in combination of two or more kinds.

Desirably for the graft copolymer of the present invention, 1 to 100% by weight of the vinyl monomer containing the hydroxyl group in the vinyl monomer mixture used for forming the graft chain, the acrylic ester and / or methacrylic ester. Is contained in an amount of 0 to 99% by weight.

<Method for Producing Graft Copolymer> The following method is used to produce the graft copolymer of the present invention, for example.

(1) A method in which an organic peroxide is used as a polymerization initiator in the presence of a fibrin derivative, or graft polymerization is performed using a C ₀ or Ce ⁺⁺⁺ salt (2) A fibrin derivative The polymerizable double bond is introduced into the fibrin derivative by binding an unsaturated fatty acid having a polymerizable double bond to the residual hydroxyl group of the above by an esterification reaction, and the polymerizable fibrin thus produced. The derivative and the vinyl monomer are copolymerized.

(3) A polymerizable double bond is introduced into the fibrin derivative by transesterification of an unsaturated fatty acid ester (mono or di) having a polymerizable double bond with the residual hydroxyl group of the fibrin derivative, The polymerizable fibrin derivative thus produced and the vinyl monomer are copolymerized.

(4) A copolymer comprising the above vinyl-based monomer having a hydroxyl group in the isocyanate group by introducing an isocyanate group into the fiber derivative by reacting a bifunctional isocyanate with the residual hydroxyl group of the fiber derivative. (5) The polymerizable double bond is introduced into the fibrin derivative by reacting the isocyanate of the isocyanate compound having a polymerizable double bond with the residual hydroxyl group of the fibrin derivative. The polymerizable fibrin derivative thus produced and the vinyl monomer are copolymerized.

Among the above methods, (1) does not have high grafting efficiency, (2) has a difficulty in esterification reaction, and as a result, cannot have high grafting efficiency, and (2) and (3) have the above unsaturated fatty acids. Mainly fumaric acid, maleic acid, or mono- or diesters of fumaric acid and maleic acid are used, so styrene is essential for copolymerizing vinyl-based monomers from the viewpoint of MRR. However, since (4) has a problem that the Grat's efficiency is lowered due to steric hindrance, high grafting efficiency can be obtained and the selection of vinyl monomers is not restricted (5) Is recommended.

Examples of the isocyanate compound having a polymerizable double bond used in the method (5) include β-isocyanatoethyl acrylate, β-isocyanatoethyl methacrylate, γ-isocyanatopropyl acrylate and γ-isocyanatopropyl methacrylate. −
Examples thereof include acrylic ester or methacrylic ester containing an isocyanate group, or vinyl isocyanate.

In the method (5), a urethane bond is formed by reacting a hydroxyl group remaining in the fibrous derivative with an isocyanate group of the isocyanate compound. In this way, a polymerizable double bond derived from the isocyanate compound is introduced into the cellulose derivative. The reaction in this case is usually benzene, toluene, xylene, ethyl acetate, n-butyl acetate, acetone, methyl ethyl ketone,
The reaction is carried out in an organic solvent having no active hydrogen such as methyl isobutyl ketone, and if desired, cobalt naphthenate, benzyltrimethylammonium hydroxide, stannous chloride, tetra-n-butyltin, stannic chloride, tri-n The reaction is carried out at room temperature to about 100 ° C. using a catalyst such as -butyltin acetate, n-butyltin trichloride, trimethyltin hydroxide, dimethyltin dichloride, dibutyltin dilaurate and the like. The mixing ratio of the above fibrin derivative and the above isocyanate compound is desirably equal to or less than the hydroxyl group remaining in the above fibrin derivative. What is more, when the isocyanate compound is added in an amount equal to or more than the hydroxyl group remaining in the cellulose derivative, the urethane bond formed is further reacted with the isocyanate group to form allophanate, resulting in too many graft active sites to be grafted. This is because gelation may occur at times.
The end point of the above reaction is judged by confirming the absence of the isocyanate group by infrared absorption spectrum (IR). The reaction time is usually about 5 to 15 hours.

In the present invention, the ratio of the fibrin derivative and the vinyl-based monomer to be graft-copolymerized is not particularly limited, but usually the fibrin derivative: the vinyl-based monomer has a weight ratio of 2: It is about 98 to 70:30.

<Ring-opening polymerization of ε-caprolactone> ε-caprolactone is subjected to ring-opening polymerization on the hydroxyl group of the fibrin derivative having a graft chain containing a hydroxyl group obtained as described above. The above ring-opening polymerization is represented by the following reaction formula.

The above reaction is carried out by heating at about 100 ° C. in the presence of an esterification catalyst such as tetrabutyl zirconate, tetrabutyl titanate, tetraoctyl titanate and zirconium naphthate, and the reaction time is about 5 to 15 hours. The degree of polymerization of the ε-caprolactone polymer chain is equivalent to ε-per one equivalent of the hydroxyl group in the fibrin derivative.
It depends on whether caprolactone is added and reacted.
Usually, 1 to 10 equivalents of ε-caprolactone is added per 1 equivalent of the above hydroxyl group and the reaction is carried out. In this case, n of the above formula is used.
Will be approximately 0-9.

<Use> The graft copolymer of the present invention may be used as it is as a vehicle for coating, but a polyvalent isocyanate, a melamine resin, a benzoguanamine resin, utilizing a hydroxyl group present at the terminal of the ε-caprolactone polymer chain, Urea resin,
It is desirable to add a cross-linking agent such as a phenol resin to obtain a room temperature curable type or a thermosetting type. The most preferable cross-linking agent is a polyvalent isocyanate, and examples of the polyvalent isocyanate include paraphenylene diisocyanate, 2-chloro-1,4-phenyl diisocyanate and 2,4.
-Toluene diisocyanate, 2,6-toluene diisocyanate, 1,4-naphthalene diisocyanate, hexamethylene diisocyanate, 4,4'-diphenyl diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-diphenyldiisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 3,3'-dimethoxy-4,4'-diphenyldiisocyanate , 1-chloro-2,4-phenylene diisocyanate, m-phenylene diisocyanate, p-
Phenylene diisocyanate, 2,2 ', 5,5'-tetramethyl-4,4'-biphenylene diisocyanate, m-xylylene diisocyanate, etc., or a burette of the polyvalent isocyanate, and the poly Examples include adducts with polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin and erythritol of divalent isocyanate.

[Action]

In the present invention, the ε-caprolactone polymer chain is present as a side chain of the graft chain of the fibrin derivative, and therefore the polymer chain of the present invention has a high hardness but exhibits desirable flexibility. . The weather resistance and solvent solubility are improved by the graft chain, and the dryness, solvent resistance, tightness, etc. are improved by the fibrin derivative.

〔The invention's effect〕

Therefore, when the fibrin derivative graft copolymer of the present invention is used, a coating material having high hardness and flexibility, good weather resistance, solvent resistance, good drying property, and providing a well-tight coating film can be obtained. can get.

Example 1 (Polymerizable fibrin derivative A) CAB5 was added to a reactor equipped with a stirrer, a thermometer and a condenser.
20 parts by weight of 51-0.2 (manufactured by Eastman Kodak Co.) and 50 parts by weight of toluene were added and heated to a reflux temperature while stirring and mixing to dissolve CAB and perform reflux dehydration. After dehydration under reflux, 1 part by weight of β-isocyanatoethyl methacrylate and 0.002 part by weight of dibutyltin dilaurate are added, stirred, and reacted at 80 ° C. for 10 hours. After confirming the end point of the reaction by IR, the mixture was cooled to room temperature to obtain a polymerizable cellulose derivative A.

Example 2 (Polymerizable fibrin derivative B) 20 parts by weight of NC (H1 / 4) and 60 parts by weight of xylene were placed in the same reactor as in Example 1 and heated to the reflux temperature while mixing and stirring. NC was dissolved and reflux dehydration was performed. Γ-isocyanatopropyl methacrylate after reflux dehydration
1.2 parts by weight and 0.005 parts by weight of dimethyltin dichloride are added, stirred, and reacted at 85 ° C. for 8 hours. End of reaction
After confirmation by IR, it was cooled to room temperature to obtain a polymerizable fibrin derivative B.

Example 3 (Polymerizable fibrin derivative C) 20 parts by weight of CAB551-0.2 (manufactured by Eastman Kodak Company) and 25 parts by weight of toluene were charged into a reactor similar to that of Example 1 and stirred and mixed until the reflux temperature. CAB was dissolved by heating. Then, 4 parts by weight of monobutyl maleate, 0.04 parts by weight of dibutyltin oxide and 5 parts by weight of toluene were charged,
The mixture was heated to the reflux temperature in a nitrogen gas atmosphere and stirred for reaction for 10 hours. Then, 20 parts by weight of toluene and 30 parts by weight of n-butyl acetate were added and cooled to room temperature to obtain a polymerizable fibrin derivative C.

Example 4 (Graft copolymer A) A vinyl monomer mixture having the following composition and a polymerization initiator were added to the solution of the cellulose derivative A obtained in Example 1.

Styrol 20.0 parts by weight Methyl methacrylate 15.0 〃 n-Butyl acrylate 10.0 〃 β-Hydroxyethyl methacrylate 14.0 〃 Azobisisobutyronitrile 2.0 〃 The above mixture was stirred at 90 ° C. for 8 hours in the same reactor as in Example 1. Graft copolymerization is performed. Then, after cooling to room temperature, 20 parts by weight of ε-caprolactone, 0.01 parts by weight of tetrabutyl titanate and 20 parts by weight of toluene were added, and 115 ° C.
After reacting for 8 hours at ε by gas chromatography
-After confirming that caprolactone does not remain, 50 parts by weight of n-butyl acetate is added to complete the reaction and then cooled.
Thus, the graft copolymer A is obtained.

Example 5 (Graft Copolymer B) A graft copolymer B is obtained in the same manner as in Example 4 except that the following composition is used instead of the vinyl-based monomer mixture of Example 4.

n-Butyl Methacrylate 30.0 parts by weight Ethyl Acrylate 13.5 〃 β- Hydroxypropyl Methacrylate 15.0 〃 Azobisisobutyronitrile 2.0 〃 Example 6 (Graft Copolymer C) Solution of the fibrin derivative B obtained in Example 2 A vinyl-based monomer mixture having the following composition and a polymerization initiator were added to.

Vinyl acetate 10.0 parts by weight Ethyl methacrylate 22.4 〃 iso-butyl acrylate 19.0 〃 β-Hydroxyethyl acrylate 12.4 〃 Azobisisobutyronitrile 2.0 〃 The above mixture was subjected to graft copolymerization in the same manner as in Example 4 and then cooled. Then, 15 parts by weight of ε-caprolactone, 0.01 part by weight of tetrabutyl zirconate and 15 parts by weight of toluene were added, and after reacting at 110 ° C. for 8 hours, it was confirmed by gas chromatography that ε-caprolactone did not remain. Add 40 parts by weight of methyl isobutyl ketone to complete the reaction and cool. Thus, the graft copolymer C is obtained.

Example 7 (Graft copolymer D) To the solution of the fibrin derivative C obtained in Example 3, a vinyl-based monomer mixture having the following composition and a polymerization initiator were added.

Styrol 30 parts by weight n-butyl acrylate 25 〃 iso-butyl vinyl ether 3.8 〃 allyl alcohol 6.2 〃 azobisisobutyronitrile 2 〃 Graft copolymerization of the above mixture was carried out in the same manner as in Example 4, and then ε-caprolactone was opened. Polymerization was performed and 20 parts by weight of n-butyl acetate was added to obtain a graft copolymer D.

Example 7 (Graft Copolymer E) In a reactor similar to Example 1, CAB551-0.2,20 parts by weight,
50 parts by weight of toluene was added and the mixture was stirred and heated to 90 ° C. to dissolve CAB. After that, stirring was continued while maintaining at 90 ° C., a vinyl-based monomer mixture having the same formulation as in Example 4 and 2 parts by weight of t-butylperoxy 2-ethylhexanoate were added, and the mixture was reacted for 8 hours and then brought to room temperature. After cooling, ring-opening polymerization of ε-caprolactone was carried out in the same manner as in Example 4, and then 50 parts by weight of n-butyl acetate was added to obtain a graft copolymer E.

Comparative Example 1 (Graft Copolymer F) A graft copolymer before ring-opening polymerization of ε-caprolactone in Example 4 was prepared, and this is designated as graft copolymer F.

Comparative Example 2 (Copolymer G) Polymerization was carried out by stirring the following composition at 90 ° C. for 8 hours in the same reactor as in Example 1 to obtain a copolymer GE.

Styrol 30.0 parts by weight Methyl methacrylate 35.0 〃 n-Butyl acrylate 17.0 〃 β-Hydroxyethyl methacrylate 18.0 〃 Graft copolymers A to E prepared according to the above Examples 4 to 8 and graft copolymer F prepared according to Comparative Example 1 The following coating film test is performed on the copolymer G prepared according to Comparative Example 2.

(1) Preparation of coated plate sample For each of the above copolymers, a burette of hexametallene diisocyanate was mixed at a ratio of OH / NCO = 1: 1, and the mixture was mixed with a 4 mil applicator into a glass plate and a tin plate. And coated on iron plate, 20 ℃, humidity 65% RH
The coated plate paints A to G were dried for 3 days.

(2) Coating film performance test Finishing: The appearance of the coating film is visually observed on the glass plate sample.

◯: Smooth, Δ: Slightly twisted, ×: Twisted pencil hardness: Perform on a glass plate sample according to JIS K5400.

Bending test: tin plate sample, temperature 20 ℃, humidity 65
For% RH, use a 3 mm diameter mandrel.

Impact test: The height of a steel plate sample when a coating film is cracked by a 1/4 ″ diameter × 500 g punch is measured using a DuPont impact tester.

Adhesion: For the tin plate sample, make vertical and horizontal cuts at 2 mm intervals on the coating film to make 100 scorings, press the cellophane tape and then peel it off to measure the scoring.

 The results of the coating film performance test are shown in Table 1.

As shown in Table 1, the graft copolymers A to E of the present invention
Has sufficient hardness, but shows satisfactory data on adhesion, bending test and impact test. On the other hand, the graft copolymer F, which does not undergo ring-opening polymerization of ε-caprolactone, has sufficient hardness, but satisfactory data cannot be obtained for adhesion, bending test and impact test, and the acrylic copolymer G is Hardness is not sufficient and excellent data cannot be obtained for impact test.

Continuation of front page (56) Reference JP-A-59-98135 (JP, A) JP-A-57-155231 (JP, A) JP-A-60-188401 (JP, A) JP-A-60-221476 (JP , A) JP 60-212422 (JP, A) JP 59-86621 (JP, A) JP 62-39656 (JP, A) JP 57-212278 (JP, A) JP 62-32142 (JP, A)

Claims (1)

(57) [Claims] 1. A hydroxyl group of a fibrin derivative having a homopolymer chain of a vinyl monomer having a hydroxyl group or a graft chain composed of a copolymer chain of the vinyl monomer and another vinyl monomer. Graft copolymer of fibrin derivative characterized by ring-opening polymerization of ε-caprolactone