JPS60248777A - Coating composition - Google Patents

Abstract

PURPOSE:To provide the titled composition containing a cellulose graft polymer obtained by introducing a radically polymerizable unsaturated group to a graft polymer, having excellent compatibility, giving a transparent and glossy coating film, and suitable for the coating of metal, glass, plastic, etc. CONSTITUTION:(A) a graft polymer prepared by adding (i) a catalyst to (ii) a cyclic ester (e.g., epsilon-caprolactone) in the presence of (iii) a hydroxyl-containing cellulose derivative (e.g. cellulose acetate), is subjected to the esterification reaction with (B) a monomer having radically polymerizable group (e.g. acrylic acid), at room temperature - 200 deg.C, and the obtained cellulose graft polymer is copolymerized with a radically polymerizable monomer to obtain the objective composition. USE:Binder for paper-processing paint and printing ink.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to coating compositions containing novel cellulose gelabut polymers having radically polymerizable unsaturated groups.

Traditionally, coating compositions commonly used as lacquers include cellulose derivatives, natural or synthetic resins,
It has been manufactured by adding plasticizers, solvents, etc., and then mixing and dispersing pigments, etc. A coating film of a coating composition containing a cellulose derivative generally has excellent gasoline resistance, abrasiveness, blocking resistance, and high hardness.

However, since the cellulose derivatives used in these materials and natural or synthetic resins have essentially different structures, their compatibility is often insufficient, and their use as coating compositions is severely restricted. In addition, because cellulose derivatives have a relatively rigid molecular structure, they are often used in coating compositions in combination with plasticizers such as phthalate esters, and the plasticizers are lost from the coating film over time. This impairs the flexibility of the coating film, making coating defects such as cracks and chili-king more likely to occur.

In order to solve such problems, Japanese Patent Application Laid-Open No. 50-4803
In Publication No. 2, a polymerizable monomer is graft-polymerized using cellulose acetate butyrate or nitrocellulose, which has a copolymerizable unsaturated group or a functional group consisting of a sub-hydrogen bond from which hydrogen can be extracted by a radical. The patent discloses that the compatibility of the coating composition can be improved by using a coating composition.

However, carbon atoms that can extract hydrogen due to unsaturated bonds and radicals introduced into this cellulose derivative.
Functional groups formed by hydrogen bonds are located relatively close to the cellulose skeleton, and bulky butyryl groups may be present near these functional groups, so they do not necessarily serve as effective grafting points and may not be sufficient. In order to obtain a graft polymer with improved compatibility, it is difficult to obtain a graft polymer with sufficient probability.

In order to solve these problems, the present inventors conducted intensive studies and, as a result, introduced an unsaturated group capable of radical polymerization into a graft polymer obtained by ring-opening reaction of a cyclic ester in the presence of a cellulose derivative. The present invention was completed based on the discovery that the polymer was sufficiently copolymerized with the radically polymerizable monomer, and the compatibility of this copolymer was significantly improved compared to the cellulose derivative used. .

That is, the present invention relates to a cellulose graft polymer in which a radically polymerizable unsaturated group is introduced into a graft polymer obtained by carrying out a cyclic ester ring-opening reaction in the presence of a cellulose derivative having a hydroxyl group.

- provides a coating composition characterized by containing the following.

The cellulose derivative used in the present invention may be any cellulose derivative having a hydroxyl group in its molecule,
For example, cellulose acetate, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate tarley 1-. Cellulose ethers such as cellulose sulfate, cellulose nitrate, ethyl cellulose, and benzyl cellulose are mentioned. Among these cellulose derivatives, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, etc., which are industrially available, easy to handle, and have excellent weather resistance, are preferred. Note that these cellulose derivatives can be used alone or in combination of two or more.

The cyclic esters used in the present invention may be those that can be polymerized by a ring-opening reaction by a known method, such as propiolactone, β-butyrolactone, α, -α
-bischloromethylgropiolactone, α,α-dimethyl-β-propiolactone, δ-valerolactone, β-
Ethyl-δ-valerolactone, 3.4.5-trimethquine-δ-valerolactone, 1.4-dioxane-2-
on, glycolide, trimethylene carbonate, neopentyl carbonate, ethylene oxalate, propylene oxalate, α-methyl-ε-caprolactone, β
-Methyl-epsilon-caprolactone, gamma-methyl-epsilon-caprolactone, epsilon-caprolactone, 4-methyl-7-inpropyl-epsilon-caprolactone, 3,3.5-trimethyl-epsilon-caprolactone, Nsudisalinlide, Trisalicilide etc.

Among these cyclic esters, it is advantageous to use cellulose estertones, which are industrially easily available and easy to handle, such as cellulose acetate butyrate, cellulose acetate clobionate, and cellulose acetate.

In the present invention, a graft polymer obtained by ring-opening reaction of a cyclic ester in the presence of a cellulose derivative having a hydroxyl group can be obtained by the following method. That is, in the presence of at least one of the above cellulose derivatives, a catalyst used for the ring-opening reaction of a cyclic ester, such as organic acids, inorganic acids, organic tin compounds, organic acid tin salts, alkali metals, and organic compounds of alkali metals. Catalysts such as alkylaluminiums, organic compounds of titanium, halides such as tin chloride (catalysts used in the ring-opening reaction of cyclic esters are listed in Takeo Saegusa's [Lecture on Polymerization Reactions 7.
Ring-opening polymerization (ll) JP104-P128 (■ Chemical doujin 1
(published in 1973). ), adding an organic solvent such as xylene as necessary, generally 120
It can be obtained by a method of reacting at a temperature of ~230° C. for about 0.1 to 96 hours, that is, a method disclosed in Japanese Patent Application No. 197333/1983 by the present applicant.

The graft polymer has a graft chain consisting of a cyclic lactone with a primary hydroxyl group at the end, and since this graft chain is relatively flexible, the graft polymer has the rigidity that is a feature of cellulose derivatives. It has both flexibility and flexibility due to grafted chains. Moreover, since the graft polymer has a primary hydroxyl group that is more reactive than other alcoholic hydroxyl groups and is located away from the cellulose skeleton, the hydroxyl group is more reactive than the hydroxyl group that is directly bonded to the cellulose skeleton. Other functional groups, such as conjugate groups, acid halides,
Easily reacts with acid anhydrides, epoxy groups, isocyanate groups, N-alkoxyamide groups, etc.

The cellulose graft polymer of the present invention is obtained by introducing a radically polymerizable unsaturated group into the above-mentioned Graph 1 polymer, and there is no particular restriction on the method of introduction, but for example, (
1) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, or their acid anhydrides and acid halides;
Carboxyl group, acid anhydride or acid halide and radical l in one molecule, such as maleic anhydride and anthraconic anhydride.
An organic compound having a polymerizable unsaturated group and the above-mentioned graft polymer are combined in the absence of a solvent or in the presence of a solvent, and if necessary, acetic anhydride, anhydrous TRIFF! In the presence of leoloacetic acid or the like, without a catalyst or using a known esterification catalyst such as sulfuric acid, chloroacetic acid, triethylamine, sodium hydroxide, potassium acetate, zinc chloride, etc., at a temperature of room temperature to 200°C. A method of introducing an unsaturated group that can be radically polymerized into the graft polymer by carrying out an esterification reaction, (2) Grindyl allyl glycidyl methacrylate! An organic compound having an epoxy group and a radically polymerizable unsaturated group in one molecule, such as J y s' vs = -w, and the above graft polymer are mixed in the absence of a solvent or in the presence of a solvent, and if necessary, For example, bases (e.g. triethylamine, NN-dimethylbenzylamine,
room temperature to
A method of conducting a reaction at a temperature of 200°C and introducing an unsaturated group capable of radical polymerization into the graft polymer, +31
Polymerizable monomers having one unsaturated group and one hydroxyl group in one molecule (e.g., 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate,
Boria methacrylate A/◆≠ medium-sized chicken glycol hepta-diester, (meth)acrylic acid poly(ε-caprolactone) monoester), diisocyanates (e.g., hegisamethylene diisocyanate, 2.4-1-lylene diisocyanate, quinrylene diisocyanate) There is a method of introducing an unsaturated group capable of radical polymerization into the graft polymer by a three-way addition reaction of isocyanate, isophorone diiso/anate, etc.) and the graft polymer. Among the diisocyanates in the method (3), those having a difference in reactivity between the two isocyanate groups, such as 2,4-tolylene diisocyanate and diisophorone diisocyanate, are preferred because they are less likely to produce divinyl compounds; A polymerizable monomer having one unsaturated group and one hydroxyl group in one molecule of A preferred method is to react the graft polymer with a reactant having one unsaturated group and one isocyanate group in one molecule in advance. These reactions in (3) are carried out without a catalyst or in the presence of a solvent, using a base (e.g., triethylamine, N,N-dimethylbenzylamine, etc.), a metal compound (e.g., diptyltin dilaurate, tin chloride, etc.), and a well-known reaction. The addition reaction may be carried out at a temperature of room temperature to 130°C using a catalyst. In addition, when carrying out the above reactions), (2), or (3), a small amount of a polymerization inhibitor such as hydroquinone or hydrogynone monomethyl ether may be used as necessary.

The cellulose graft polymer of the present invention has excellent coating film properties and improved compatibility by copolymerizing the introduced radically polymerizable unsaturated group with the radically polymerizable monomer fIl that is copolymerizable. The recoating composition is a suitable cellulose derivative.

Here, the radically polymerizable monomer +11 is, for example, (a) an ester group of acrylic acid or methacrylic acid or a methyl group, and is an alkyl group of 01 to 2°, a cycloapkyl group of %A. , methoxybutyl group, ethoxybutyl group, phenyl group, benzyl group, allyl group, dicyclopentynyl group, C, hydroxyalkyl group,
These include polyethylene glycol group, poly-ε-caprolactone group, and the like.

ρ) The vinyl aromatic compound is a methyl group, and X is hydrogen, a methyl group, a halogen group, a nitro group, an amino group, -N (alkyl 9 groups, etc.).

Radically polymerizable unsaturated monomers with C1 functional group: glycidyl methacrylate, grindyl acrylate, allyl glycidyl ether, acrylic chloride, methacryloyl chloride, methacrylic acid, acrylic acid, maleic anhydride, crotonic acid, itaconic acid, N-methylol Acrylamide, N-butoxymethylo-ρ acrylamide, and the like.

) Other polymerizable unsaturated monomers include vinyl acetate, getadiene, chloroprene, isoprene, acrylonitrile, methacryloyl, vinyl chloride, ethylene, vinyl carboxylate esters, and the like.

The copolymerization of the cellulose graft polymer of the present invention and the radically polymerizable monomer fIl can be carried out using peroxides such as benzoyl peroxide and lauroyl peroxide, azo compounds such as α,α′-azobisisobutyronitrip, By radical polymerization methods such as bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization, using a radical polymerization initiator such as potassium persulfate, and adding a chain transfer agent such as mercaptan as necessary. ,
Generally, the temperature may be from room temperature to 200°C, preferably from 60 to 150°C. The cellulose graft polymer of the present invention and the radically polymerizable monomer fi+ used in the copolymerization
Although the ratio is not particularly limited, the copolymerization is preferably carried out in a weight ratio of graft cellulose polymer/radically polymerizable monomer: -5 to 70/95 to 3.

In order to use the resulting copolymer containing the cellulose graft polymer as a coating composition, powder, solution,
Alternatively, it may be dispersed and dispersed, and generally, ketones such as a7tone and methyl ethyl ketone, esters such as methyl cellosolve acetate, cellosolve acetate, ethyl acetate, and butyl acetate, and cyclic aezo) such as dioxane and tetrahydrofuran, etc. It can be used by dissolving it in an organic solvent, and in a solution of these organic solvents, aromatic hydrogen ash such as toluene and xylene, aliphatic hydrocarbons such as heptane, octane, and mineral spirits, ethanol, isopropanol, etc. It may be used by adding a small amount of alcohol.

Additives usually added to the coating agent of the coating composition of the present invention obtained by coating, such as a diluent such as a coating agent, an agent for controlling the drying rate of the coating film, a plasticizer such as a phthalate ester, a leveling agent, or a melamine compound. , polyisocyanates, crosslinking agents such as epoxy compounds, thickeners,
Appropriate amounts of dyes, pigments, etc. may be added.

The coating composition of the present invention can be applied to the objects to be coated, such as metal, wood, paper, ceramics, concrete, glass, mortar, glass paint, etc., by a known method such as brush coating, spray coating, roll coating, curtain flow coating, or dipping coating. Can be painted. It is also useful as a binder for paper processing coatings and printing inks.

In addition, since the cellulose graft polymer of the present invention has radically polymerizable unsaturated groups and flexible graft ti14, it can be used in combination with polyfunctional acrylates, unsaturated polyesters, sensitizers, etc. to form photocurable coatings. It can also be used as a component of electron beam-curable coating agents together with polyfunctional and monofunctional acrylates.

Next, further explanation will be given in synthesis examples and examples.

Synthesis Example 1 A 1e glass flask equipped with a stirrer, a reflux condenser, and a thermometer was prepared. ε-Caglolactone 1502 containing 200 ppm of tetrabutyl titanate and cellulose acetate sufficiently dried in advance (1LL-10 manufactured by Daicel Chemical Industries, Ltd.)
1502 is charged, heated to 120°C, and sufficiently stirred under a nitrogen atmosphere to dissolve. After that, the temperature was raised to 160℃ and 16
The reaction was carried out for a period of time to obtain a pale yellow graft polymer.

Synthesis Example 2 In Synthesis Example 1, cellulose acetate butyrate (manufactured by Eastman Chemical Co., CA) was used instead of cellulose acetate.
The reaction was carried out in the same manner as in Synthesis Example 1 except that B-551-α2)1502 was used to obtain a pale yellow graft polymer.

Example 1 A 1e glass flask equipped with a stirrer, a reflux condenser, a thermometer, and a dropping funnel contained the graft polymer 30F obtained in Synthesis Example 1 and 0.5% of N-dimethylpenzylamine. and methyl ethyl ketone 3002, heated to 78°C and dissolved. p-te to this thing
Grindge methacrylic acid/L151F containing 0.2% rt-butylcatechol was added and the reaction was carried out at 78°C for 3 hours.

Next, a radically polymerizable monomer solution of ethyl acrylate 102, methacrylate (methacrylate) V50t, methacrylic acid n-guti #50p, nutylene 20t and acrylic acid 10'i was added to the solution, and benzylic acid peroxide/I10.82 and A solution of toluene 192 is added dropwise in each case over a period of 3 hours under a nitrogen atmosphere. The reaction is further continued at 78-80°C for 5 hours. Thus, the solid content is 35.7% and the viscosity is 3260CP.
A coating composition containing a cellulose graft polymer of S was obtained.

When the coating composition was applied to a mild steel plate using a &40 bar coater and dried, a transparent and glossy coating film was obtained. Table 1 shows the results of evaluating the performance of this coating film.

Example 2 A 2e glass flask equipped with a stirrer, a reflux condenser, a thermometer, and a dropping funnel was charged with the graft polymer 182 obtained in Synthesis Example 2, methyl ethyl ketone 200j', maleic anhydride 3.62, and pyridine toy. , heat to 80° C. with stirring. Once the solution is homogeneous,
The reaction was carried out at 80°C for 5 hours, and then styrene 28.8
f, methyl methacrylate 602, acrylic acid 12y
and benzoyl peroxide LOP are added dropwise over a period of 1 hour under nitrogen atmosphere. Thereafter, polymerization is carried out at 80° C. for 2 hours. Then methyl methacrylate 68,4 F
, ethyl acrylate 60t, butylene acrylate/l 154
2. A mixture of 182 t of 2-hydroxyethyl methacrylate, 15.6 t of acrylic acid, 12F benzoyl peroxide and 1402 methyl ethyl ketone was added dropwise over 1 hour. Thereafter, a polymerization reaction is carried out at 80° C. for 4 hours.

To the thus obtained pale yellow polymer solution was added triethylamine 16.811. After adding 23.4 t of Butyl Cellosorg and 277.6 f of water and stirring thoroughly, the solid content was reduced to 3.
A coating composition was obtained containing a cellulose graft polymer which was an opalescent aqueous dispersion of 3.8%, viscosity 5430 CP S, pH 7.2.

When the coating composition was applied to a mild steel plate using an A40 bar coater and dried, a transparent and glossy coating film was obtained. Table 1 shows the results of evaluating the performance of this coating film.

Example 3 The coating composition 1002 obtained in Example 2 was added with a water-soluble epoxy compound, glycerol polygrindyl ether (Zidenacol EX-313, manufactured by Nagashio Sangyo Co., Ltd.) 2
F was added, thoroughly stirred, and applied to a mild steel plate using an AjO bar coater, and dried at 100° C. for 30 minutes to obtain a transparent and glossy coating. Table 1 shows the results of evaluating the performance of this coating film.

Example 4 2.4-Tolylene diisocyanate 17411 is charged into a 1e glass flask equipped with a stirrer, reflux condenser, temperature needle and dropping funnel and maintained at 50°C. 2-Hydroxyethyl methacrylate/I/130F containing 01% hydroquinone was added dropwise to this mixture over a period of 4 hours. then 5
After maintaining the temperature at 0°C and stirring for 5 hours, the mixture was sealed and left overnight. A white wax-like isocyanate group-containing methacrylic ester is obtained.

The graft polymer obtained in Synthesis Example 2 (hydroxyl value: 43, 2 (KOHmy/y)) 1 was placed in a glass flask 1e equipped with a stirrer, a reflux condenser, a thermometer, and a dropping funnel.
00 y, the above white wax-like isocyanate group-containing methacrylic acid ester/' 23.1 j' and methyl ethyl ketone 2002 were charged and heated at 60°C with stirring.
Increase the temperature to. Thereafter, a reaction was carried out at 60° C. for 6 hours to obtain a grafted cellulose polymer solution with a solid content of 38.1%.

This grafted cellulose polymer solution 52.52, oligoester acrylate (Toagosei Kagaku Kogyo ■ I-Atainisoku M-6300) 252, trimethylolpropane triacrylate 102, 2-ethylhexyl acrylate 301! , 2-hydroxyethyl methacrylate lo
t, benzophenone 2.51! and dimethylaminoethanol 25'i were mixed with stirring to obtain a coating composition. This material was applied to a mild steel plate using a 30°C percoater, set at 50°C for 10 minutes, and then placed vertically under a 25mm high-pressure mercury lamp (manufactured by Iwasaki Electric) for 10 minutes.
It should move horizontally at a speed of 31n/rnln.
1/) and cured to obtain a coating film.

Table 1 shows the results of evaluating the performance of this coating film.

As shown in Table 1, the coating films obtained in Examples 1 to 4 are all coating films with excellent practicality, and it is clear that the coating compositions of the present invention are extremely useful. It is.

Table 1 Transparency It was applied to a glass plate and its transparency was judged visually.

Coating film hardness: Conducted according to JISK-5400 pencil scratch test.

Adhesion Eleven lines were cut vertically and horizontally at 1fi intervals on the painted surface, cellophane adhesive tape was pressed on each of the lines, and the state of peeling of each line was evaluated after the tape was peeled off.

Water resistance: The state of the coating film was examined after 3 hours of immersion in water at 20°C.

Rubbing resistance: The condition was examined after rubbing the painted surface 100 times with absorbent cotton containing gasoline.

Claims (1)

[Claims] A coating composition characterized by containing a cellulose gelabut polymer in which a graft polymer obtained by ring-opening a cyclic ester in the presence of a cellulose derivative having a hydroxyl group and a polymerizable unsaturated group introduced therein. thing.