JPH0120163B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a novel graft-modified starch having a reactive anthranilic acid ester in the graft side chain. Previous attempts to introduce anthranilic acid esters into starches include, for example, isatoic anhydride (2H-3,1-benzoxazine-2,4(1H)-
It is known to make anthranilic acid esterified starch by using a combination of dione and dione), but isatoic anhydride easily decomposes in the presence of moisture, so no method has been found to efficiently esterify starch. .
Furthermore, it is difficult to obtain starches with a high degree of substitution in which a large amount of anthranilic acid ester is introduced into starch. The graft-modified starch of the present invention has the formula: [In the formula, R ₁ is hydrogen or methyl, R ₂ and R ₃
means hydrogen, methyl or hydroxy. ] Characterized by introducing a side chain polymer by homopolymerizing an acrylic monomer represented by or copolymerizing an ethylenically unsaturated monomer copolymerizable with this acrylic monomer,
It is a graft-modified starch with a molecular weight of 1000 or more calculated as GPC dextran and a graft ratio of 0.01 to 300%, preferably 0.01 to 200%, and has an aromatic amino group introduced therein, and can be modified to an azo dye. The graft-modified starch of the present invention itself emits fluorescence in the presence of ultraviolet light, so it can be used in laundry starches and the like.
Furthermore, due to its cationic properties, it can be widely used as a flocculant, a thickener for shampoo, a sizing agent for paper manufacturing, etc. The term "grafting ratio" as used herein means the ratio (%) of the weight of all graft side chains graft-copolymerized to the starch to the weight of the starch, which is the backbone polymer. The starch that becomes the trunk polymer may be any commonly used starch, such as potato starch, sweet potato starch, corn starch, waxy corn starch, high amylose corn starch, wheat starch,
Natural starches such as rice starch, tapioca starch, sago starch, and their decomposition products, amylose, amylopectin fractions, cross-linked starch, etherified starch, esterified starch, oxidized starch, acid-treated starch, enzyme-modified starch, roasted starch Examples include various modified starches, such as wheat flour, corn flour, dried sweet potato, and other starch-containing materials. Monomers [] include hydroxyethyl acrylate, hydroxyethyl methacrylate,
Monomer [] can be obtained in high yield by using isatoic anhydride with a hydroxyl group-containing acrylic acid or methacrylic ester such as hydroxypropyl acrylate or hydroxypropyl methacrylate in the presence of a base catalyst. for example, etc. In addition, the graft-modified starch of the present invention can be introduced as a side chain polymer by graft copolymerizing an ethylenically unsaturated monomer copolymerizable with the monomer [] above. Examples include the following: Hydroxyl group-containing acrylic or methacrylic esters such as hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxypropyl methacrylate; polyethylenes such as diethylene glycol acrylate, diethylene glycol methacrylate, triethylene glycol acrylate, and triethylene glycol methacrylate; Glycol acrylic or methacrylic esters or those with methyl or ethyl ether terminals, dipropylene glycol acrylate, dipropylene glycol methacrylate,
Acrylic or methacrylic acid esters of polypropylene glycol such as tripropylene glycol acrylate, tripropylene glycol methacrylate, or those whose terminals are methyl or ethyl etherified, acrylic acid, methacrylic acid, acrylic acid or methacrylic acid having 1 to 5 carbon atoms Examples include acid esters, aminoalkyl acrylates, aminoalkyl methacrylates, quaternary aminoalkyl acrylates, quaternary aminoalkyl methacrylates, acrylamide, methylolacrylamide, acrylonitrile, vinyl acetate, styrene, and the like. By copolymerizing these monomers with the monomer of formula [], solubility can be improved or stronger cationic properties can be imparted. In the graft-modified starch of the present invention, all the graft side chains graft-copolymerized to the starch powder are homopolymers of monomers of formula [], block or random copolymers of two or more monomers of formula [], respectively. or block or random copolymers of one or more monomers of [ ] and ethylenically unsaturated monomers other than the monomers of [ ], and the bonds of each monomer are head-to-head, head-to-tail, Either tail or tail is fine. The graft-modified starch of the present invention can be produced according to a known method. For example, raw starch and monomers are dispersed or dissolved in an organic solvent such as methanol, ethanol, propanol, or acetone, water, or a mixed solvent thereof to form a ceric salt, persulfate, persulfate-sulfite, or persulfate. salt-
Using common graft polymerization initiators such as Mohr's salt, hydrogen peroxide - Mohr's salt, hydrogen peroxide, etc.,
℃ Preferably graft copolymerization at 15-75℃,
The reaction product is purified and isolated according to conventional methods to obtain the desired graft-modified starch. Alternatively, after graft-copolymerizing raw material starch with acrylic acid or methacrylic ester containing a hydroxyl group, isatoic anhydride is applied to convert the graft side chains and the hydroxyl groups of the starch of the backbone polymer into anthranilic acid ester. Next, the present invention will be explained in more detail with reference to Examples. Examples 1-3 Oxidized starch (viscosity of 15% aqueous solution at 50°C
158cps) 3Kg was dispersed in 10W of water, followed by 100g of monomers of various formulas shown in Table 1 below.
Ceric ammonium nitrate 20g, 63% nitric acid 2m
was added, and a graft copolymerization reaction was carried out at 40 to 50°C for 5 hours. After the reaction, the mixture was neutralized to pH 4.0, thoroughly washed with water, and dried to obtain a graft-modified starch having the physical properties shown in Table 1 below.

【table】

[Table] Example 4 500g of corn starch was dispersed in 10ml of water,
After heating and gelatinizing at 85°C to 95°C for 30 minutes, it was cooled to 25°C, and 500g of the monomer used in Example 1, 20g of ceric ammonium nitrate, and 2m of 63% nitric acid were added.
A graft copolymerization reaction was carried out at 40 to 50°C for 5 hours. After the reaction, the reaction mixture was neutralized to pH 7.0, thoroughly washed with a water-methanol mixed solvent, and then the homopolymer was extracted in the order of DMF and acetone. As a result of nitrogen analysis of this graft-modified starch, it was found that the grafting rate was 68%. Furthermore, the molecular weight determined by GPC method was 1.3×10 ⁵ . This graft-modified starch was analyzed by the method shown below. Detection of aromatic amines: A small amount of 2N-sodium carbonate in a 1% sodium nitroprusside solution was added to one drop of a sample solution of graft-modified starch dissolved in dimethyl sulfoxide at a concentration of 5%, and the mixture was irradiated with ultraviolet light for 15 minutes. When one drop of the reagent and one drop of 2N sodium carbonate were added, the mixture immediately turned blue-green, confirming that it contained an aromatic amine. Infrared analysis As a result of infrared analysis of the graft-modified starch, strong carbonyl absorption due to the ester of the graft side chain was observed at 1720 cm ^-1 , and absorption due to the glucopyranone ring of starch was observed at 930, 855, and 760 cm ^-1 . Example 5 500g of oxidized starch used in Examples 1 to 3 was added to 10% of water.
After heating and gelatinizing at 85-95°C for 30 minutes, cooling to 25°C, the monomer used in Example 2
500 g of methyl ester of triethylene glycol methacrylate, 20 g of ceric ammonium nitrate, and 2 m of 63% nitric acid were added and a graft copolymerization reaction was carried out at 40 to 50°C for 5 hours.
7.0, washed with acetone and then DMF, and extracted the homopolymer. Next, as a result of nitrogen analysis and measuring the content of ester bonds to determine the grafting rate, the grafting rate of the methyl ester of triethylene glycol methacrylate was 78%, and the grafting rate of the monomer used in Example 2 was 73%. I got it. Furthermore, the molecular weight determined by GPC method was 3.8×10 ⁴ . Example 6 Same as Example 5 except that hydroxypropyl acrylate was used instead of methyl ester of triethylene glycol methacrylate,
Grafting rate of hydroxypropyl acrylate 80
%, grafting rate of monomer used in Example 2 75%
Graft modified starch was obtained. Furthermore, the molecular weight determined by GPC method was 4.1×10 ⁴ . Example 7 Dipropylene glycol methacrylate was used instead of the methyl ester of triethylene glycol methacrylate, and dipropylene glycol methacrylate was used in the same manner as in Example 5, except that the monomer used in Example 3 was used instead of the monomer used in Example 2. Grafting rate of propylene glycol methacrylate 75%, Example 3
A graft-modified starch with a grafting rate of 71% of the monomer used in was obtained. The molecular weight determined by GPC method was 3.6×10 ⁴ .

Claims (1)

[Claims] 1. Using starch as the backbone polymer, formula: [In the formula, R ₁ is hydrogen or methyl, R ₂ and R ₃
means hydrogen, methyl or hydroxy, respectively. ] Characterized by introducing a side chain polymer by homopolymerizing an acrylic monomer represented by or copolymerizing an ethylenically unsaturated monomer copolymerizable with this acrylic monomer,
A method for producing graft-modified starch having a molecular weight of 1000 or more as calculated by GPC dextran and a graft ratio of 0.01 to 300%.