阅读说明：本技术 一种彩色相纸用水溶性色稳定剂及其制备方法 (Water-soluble color stabilizer for color photographic paper and preparation method thereof ) 是由 胡占宗 于 2019-10-25 设计创作，主要内容包括：本发明涉及彩色相纸用水溶性色稳定剂及其制备方法,具体提出了共聚物,该共聚物具有式(I)所示结构,其中：m为1～5之间的整数；n为3～25之间的整数；l为3～30之间的整数；x为1、2、3、4或5；y为1、2、3、4或5；各R～1独立地为H、D、F、Cl、Br、I、OH、NO-2、CN或C-(1-6)烷基；各R～2独立地为H、D、F、Cl、Br、I、OH、NO-2、CN或C-(1-6)烷基；所述共聚物的分子量为2000～6000。该共聚物水溶性好,可以很好地应用于水溶性乳剂中,环保、无污染；且作为色稳定剂时,彩色相纸中品红染料影像密度褪色率小,色稳定效果好,可以使品染料影像密度下降率由85％降到11％以内。(The invention relates to a water-soluble color stabilizer for color photographic paper and a preparation method thereof, and particularly provides a copolymer, which has a structure shown in a formula (I), wherein: m is an integer between 1 and 5; n is an integer of 3-25; l is an integer of 3-30; x is 1, 2,3, 4 or 5; y is 1, 2,3, 4 or 5; each R 1 Independently H, D, F, Cl, Br, I, OH, NO 2 CN or C 1‑6 An alkyl group; each R 2 Independent of each otherGround is H, D, F, Cl, Br, I, OH, NO 2 CN or C 1‑6 An alkyl group; the molecular weight of the copolymer is 2000-6000. The copolymer has good water solubility, can be well applied to water-soluble emulsion, and is environment-friendly and pollution-free; and when the dye is used as a color stabilizer, the rate of fading of the image density of the magenta dye in the color photographic paper is small, the color stabilization effect is good, and the rate of decreasing the image density of the magenta dye can be reduced from 85% to 11%.)

1. A copolymer is characterized by having a structure shown in a formula (I),

wherein:

m is an integer between 1 and 5;

n is an integer of 3-25;

l is an integer of 3-30;

x is 1, 2,3, 4 or 5;

y is 1, 2,3, 4 or 5;

each R¹Independently H, D, F, Cl, Br, I, OH, NO₂CN or C_1-6An alkyl group;

each R²Independently H, D, F, Cl, Br, I, OH, NO₂CN or C_1-6An alkyl group;

the molecular weight of the copolymer is 2000-6000.

2. The copolymer of claim 1, wherein each R is¹Independently of each otherIs H, D, F, Cl, Br, I, OH, NO₂CN or C_1-4An alkyl group; each R²Independently H, D, F, Cl, Br, I, OH, NO₂CN or C_1-4An alkyl group;

optionally, each R¹Independently H, D, F, Cl, Br, I, OH, NO₂CN, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or tert-butyl; each R²Independently H, D, F, Cl, Br, I, OH, NO₂CN, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl.

3. The copolymer of claim 1, having a structure of formula (II),

wherein:

each M is independently NH₄ ⁺、K⁺Or Na⁺。

4. A method of making a copolymer, comprising:

1) carrying out first mixing treatment on an initiator and preheated maleic anhydride;

2) will be provided withCarrying out second mixing treatment with the first mixed treatment product;

3) distilling the second mixed treatment product;

4) carrying out third mixing treatment on the distillation treatment product and an alkalinity regulator;

5) subjecting the third mixed treatment product to a filtration treatment to obtain a filtrate, the filtrate comprising the copolymer;

wherein:

the above-mentionedAnd the above-mentionedThe ratio of the amounts of substances of (a) to (b) is 1: 3-1: 12,

the above-mentionedThe ratio of the amount of maleic anhydride to the amount of maleic anhydride is 1: 2-1: 13,

x is 1, 2,3, 4 or 5,

y is 1, 2,3, 4 or 5,

each R¹Independently H, D, F, Cl, Br, I, OH, NO₂CN or C_1-6An alkyl group, a carboxyl group,

each R²Independently H, D, F, Cl, Br, I, OH, NO₂CN or C_1-6An alkyl group.

5. The method of claim 4, wherein each R is¹Independently H, D, F, Cl, Br, I, OH, NO₂CN or C_1-4An alkyl group; each R²Independently H, D, F, Cl, Br, I, OH, NO₂CN or C_1-4An alkyl group;

optionally, each R¹Independently H, D, F, Cl, Br, I, OH, NO₂CN, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or tert-butyl; each R²Independently H, D, F, Cl, Br, I, OH, NO₂CN, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl.

6. The method of claim 4, wherein the maleic anhydride is provided in the form of a solution of maleic anhydride, the maleic anhydride being pre-dissolved in a first organic solvent;

optionally, the temperature of the preheated maleic anhydride is 60-80 ℃;

optionally, the temperature of the first mixed treatment product is 60 ℃ to 80 ℃;

optionally, the second mixing treatment is carried out at a temperature of 65 ℃ to 80 ℃.

7. The method of claim 4, wherein the third mixed treatment product has a pH of 6 to 9.

8. The method according to claim 4, wherein step 2) is performed by:

will be provided withThe mixture is dripped into the first mixed treatment product and then second mixed treatment is carried out;

optionally, the dropping time is 1-4 h, preferably 2-3 h;

optionally, the dropwise addition treatment is carried out at a temperature of 65 ℃ to 80 ℃;

optionally, the time of the second mixing treatment is 2-8 h;

optionally, theIs prepared by mixingDissolved in a second organic solvent;

optionally, the first organic solvent and/or the second organic solvent comprises at least one selected from toluene, xylene, ethyl acetate, butyl acetate, isoamyl acetate, n-amyl acetate, ethyl butyrate, acetone, methyl ethyl ketone, methyl isobutyl ketone, n-hexane, or cyclohexane.

9. The method of claim 4, wherein the initiator comprises at least one selected from the group consisting of benzoyl peroxide, lauroyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxypivalate, cumene hydroperoxide, tert-butyl hydroperoxide, di-tert-butyl peroxide, and azobisisobutyronitrile;

optionally, the mass of the initiator is the maleic anhydride,1-5% of the total mass of (A);

optionally, the total volume of the first organic solvent and the second organic solvent is the same as the maleic anhydride, The ratio of the total mass of (3-8)/1 mL/g;

optionally, the distillation treatment is distillation under reduced pressure;

optionally, the alkalinity regulator is aqueous ammonia, aqueous sodium hydroxide solution or aqueous potassium hydroxide solution.

10. Use of a copolymer according to any one of claims 1 to 3 or obtained by the preparation process according to any one of claims 4 to 9 as a color stabilizer;

optionally, the color stabilizer is used to prevent color fading of the color paper.

Technical Field

The invention relates to the field of photosensitive materials, in particular to a water-soluble color stabilizer for color photographic paper and a preparation method thereof.

Background

A vivid color photograph often fades or discolors partially over time. This is because the dyes on the color photograph are composed of three dyes of different colors, yellow, magenta and cyan. Most of the dyes are organic molecules with more complex structures, which are active compared with some common pigments. Firstly, color images such as color photographic paper are subjected to high temperature, sun exposure, ultraviolet irradiation and the like, so that colored parts on a picture fade; secondly, some photographs are partially discolored in addition to fading. For example, the leaves of a photograph that are originally green, slowly change to cyan or blue over time, a color change known as color cast. The reason for the color cast is that the three dyes added differ in the rate of photobleaching, with the magenta dye having the fastest rate of photobleaching. Therefore, in order to maintain the color balance of the image, it is necessary to improve the light (color) stability of the magenta dye.

At present, the methods for improving the color stability of color dyes mainly comprise: (1) adding an ultraviolet absorber into the emulsion layer; (2) adding human color stabilizer or combination of several color stabilizers into the emulsion layer; (3) selecting a novel color former; (4) changing the arrangement sequence of the coating; (5) using a plastic-coated paper base with an oxygen barrier layer and special treatment; (6) storing the photo after processing the color paper, and the like. Among them, the most effective method is to add a color stabilizer, which is effective for preventing the discoloration of the dye due to the presence of active oxygen, to the emulsion.

However, a color stabilizer which is excellent in fading prevention effect and is environmentally friendly has yet to be further studied.

Disclosure of Invention

The present application is based on the discovery and recognition by the inventors of the following facts and problems:

the color stabilizers which are disclosed at present and can be used in color photographic paper are divided into the following types in terms of chemical structure:

1. chromans of the color class

Monohedral, which represents compounds such as:

the bis-spirochroman class, which represents compounds such as:

dichroman, which represents compounds such as:

2. the bis spiro-tetralin class, which represents compounds such as:

3. phenols and bisphenols

Phenols, which represent compounds such as:

bisphenols, which represent compounds such as:

4. aryl ethers, which represent compounds such as:

5. corrins, which represent compounds such as:

6. organophosphorus and organosilicon, which represent compounds such as:

7. amines and nitrogen heterocycles, which represent compounds such as:

8. metal chelating groups, which represent compounds such as:

9. benzoic acid esters

10. Liquid paraffin

The color stabilizer with the structure has the following problems in practical application:

(1) chromans: the color fading inhibitor is usually used as a fading resistant agent on color photos, and can reduce the fading rate from 86 percent to 25 percent at most; the color stabilizer has the effect lower than that of fading prevention, and can reduce the image density reduction rate of the finished dye from 67.5% to 26%.

Aromatic ethers: the aromatic ether compound is mainly used for preventing the photo-fading and the thermal-fading of dye images, can effectively inhibit the photo-fading and the thermal-fading, and can reduce the reduction rate of the image density of finished dyes from 45 percent to about 15 percent.

Phenols and bisphenols: when they are used as color stabilizers, they sometimes affect image quality, produce fog, and have poor dispersion stability; the decrease rate of the image density of the dye product is reduced from 45% to about 30%, and the color stability is not high.

Corr ton: they are mainly used in green-and red-sensitive emulsion layers to prevent fading and yellow staining of magenta dyes, but the color-stabilizing effect is exerted only at the late stage of the storage of colored materials, and the reduction rate of the image density of magenta dyes is small.

Amines and nitrogen heterocycles: the amine is easy to generate color pollution, so that the application of the amine in photosensitive materials is limited; and nitrogen heterocycles are generally used as antifading agents.

Organophosphorus and organosilicon: as a color stabilizer, the dispersion and solubility are good, fogging is not generated, and the developability of the color former can be improved. However, synthesis of the organic phosphoric acid and the organosilicon color stabilizer is difficult, and it is not easy to obtain a high-purity product, and the cost is high.

Metal chelate compounds: in particular, the chelate compounds of Co, Ni, Pd and Pt, which are transition metal elements, have the properties of quenching singlet oxygen, decomposing peroxide, capturing free radicals and the like, and can be used as color stabilizers. But the maximum absorption peak is in the range of 300-800 nm except heavy metal pollution, can absorb partial visible light and is easy to bring in mottle.

(2) The color stabilizers are oil-soluble and are suitable for oil-soluble emulsion; generally not applied to more environmentally friendly water-soluble color paper emulsions.

(3) When the color stabilizer is applied to the oil-soluble emulsion, a proper emulsifier needs to be added, and the color stabilizer needs to be dispersed under high-speed stirring, so that the use is inconvenient.

(4) The color stabilizer is added into the water-soluble emulsion, a film is easily formed on the surface of the emulsion, and the material added during coating is easily adhered to the wall of a pot, is not easy to clean, can block a filter core and influences the operation and use.

(5) Most of the compounds have complex preparation process, easily cause environmental pollution in preparation and have higher cost.

Based on the problems, the inventor provides a novel copolymer and a preparation method thereof through a great amount of experimental exploration, on one hand, the copolymer has good water solubility, can be well applied to water-soluble emulsion, is safe and environment-friendly, and has no pollution; on the other hand, when the copolymer is used as a color stabilizer, the image density fading rate of the magenta dye in the color photographic paper is small, the color stabilizing effect is good, and the image density reduction rate of the magenta dye can be reduced from 85% to within 11%.

To this end, in a first aspect of the invention, a copolymer is proposed. According to an embodiment of the present invention, the copolymer has a structure represented by formula (I),

wherein:

m is an integer between 1 and 5, such as 1, 2,3, 4 or 5;

n is an integer between 3 and 25, such as 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23 or 25;

l is an integer between 3 and 30, such as 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29 or 30;

x is 1, 2,3, 4 or 5;

y is 1, 2,3, 4 or 5;

each R¹Independently H, D, F, Cl, Br, I, OH, NO₂CN or C_1-6An alkyl group;

each R²Independently H, D, F, Cl, Br, I, OH, NO₂CN or C_1-6An alkyl group;

the molecular weight of the copolymer is 2000-6000, such as 2500, 3000, 3500, 4000, 4500, 5000 or 5500.

The copolymer disclosed by the embodiment of the invention has good water solubility, can be well applied to a water-soluble emulsion, and is safe, environment-friendly and pollution-free; and when the dye is used as a color stabilizer, the magenta dye in the color photographic paper has small image density fading rate and good color stabilization effect.

According to an embodiment of the present invention, the above-mentioned copolymer may further comprise at least one of the following additional technical features:

according to an embodiment of the invention, each R¹Independently H, D, F, Cl, Br, I, OH, NO₂CN or C_1-4An alkyl group; each R²Independently H, D, F, Cl, Br, I, OH, NO₂CN or C_1-4An alkyl group.

According to an embodiment of the invention, each R¹Independently H, D, F, Cl, Br, I, OH, NO₂CN, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or tert-butyl; each R²Independently H, D, F, Cl, Br, I, OH, NO₂CN, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl.

According to an embodiment of the present invention, the copolymer has a structure represented by formula (II),

wherein:

each M is independently NH4⁺、K⁺Or Na⁺。

In a second aspect of the invention, a method of making a copolymer is provided. According to an embodiment of the invention, the method comprises: 1) carrying out first mixing treatment on an initiator and preheated maleic anhydride; 2) will be provided with Carrying out second mixing treatment with the first mixed treatment product; 3) distilling the second mixed treatment product; 4) carrying out third mixing treatment on the distillation treatment product and an alkalinity regulator; 5) subjecting the third mixed treatment product to a filtration treatment to obtain a filtrate, the filtrate comprising the copolymer;

wherein:

the above-mentionedAnd the above-mentionedThe ratio of the amounts of substances of (a) to (b) is 1: 3-1: 12, e.g. are1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, or 1: 12; the above-mentionedThe ratio of the amount of maleic anhydride to the amount of maleic anhydride is 1: 2-1: 13, such as 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, or 1: 12;

x is 1, 2,3, 4 or 5,

y is 1, 2,3, 4 or 5,

each R¹Independently H, D, F, Cl, Br, I, OH, NO₂CN or C_1-6An alkyl group, a carboxyl group,

each R²Independently H, D, F, Cl, Br, I, OH, NO₂CN or C_1-6An alkyl group.

It should be noted that the filtrate obtained finally contains the copolymer, but the copolymer does not need to be separated from the filtrate, and the filtrate can be used directly as a product in industrial production. The inventors found that the aboveWhen the amount of (B) is too large or too small, the color-stabilizing effect of the copolymer produced is remarkably reduced. The method provided by the embodiment of the invention has the advantages of simple synthesis process steps, simple post-treatment process and low cost, and is suitable for industrial mass production; the copolymer prepared by the method disclosed by the embodiment of the invention is suitable for water-soluble color paper emulsion, has good compatibility with the emulsion, is pollution-free, safe and environment-friendly, and has small fading rate of magenta dye image density and good color stabilization effect in color photographic paper when being used as a color stabilizer.

According to an embodiment of the present invention, the method may further include at least one of the following additional technical features:

according to an embodiment of the invention, each R¹Independently H, D, F, Cl, Br, I, OH, NO₂CN or C_1-4An alkyl group; each R²Independently H, D, F, Cl, Br, I, OH, NO₂CN or C_1-4An alkyl group.

According to embodiments of the present inventionEach R¹Independently H, D, F, Cl, Br, I, OH, NO₂CN, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or tert-butyl; each R²Independently H, D, F, Cl, Br, I, OH, NO₂CN, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl.

According to an embodiment of the invention, the maleic anhydride is provided in the form of a solution of maleic anhydride, which is pre-dissolved in a first organic solvent.

According to an embodiment of the invention, the temperature of the preheated maleic anhydride is 60 ℃ to 80 ℃, such as 63, 65, 67, 70, 73, 75, 77 or 80 ℃. Therefore, the initiator in the subsequent first mixing treatment is favorable for generating primary free radicals so as to generate an initiating reaction with the maleic anhydride.

According to embodiments of the invention, the temperature of the first mixed process product is 60 ℃ to 80 ℃, such as 63, 65, 67, 70, 73, 75, 77, or 80 ℃. In the first mixing treatment, the initiator and the monomer maleic anhydride release heat to cause temperature increase when initiating reaction. The inventor finds that when the temperature of the first mixed treatment product is stabilized at 60-80 ℃, the subsequent polymerization reaction is facilitated, and when the prepared copolymer is used as a color stabilizer, the image density fading rate of magenta dye is smaller, and the color stabilizing effect is better.

According to an embodiment of the invention, the second mixing process is carried out at a temperature of 65 ℃ to 80 ℃, such as 65, 67, 70, 73, 75, 77 or 80 ℃. In the second mixing treatment, the three monomers are polymerized by the initiator. The inventors found that the second mixing treatment at a temperature of 65 ℃ to 80 ℃ is advantageous for the polymerization reaction, and that the obtained copolymer has a lower image density fading rate and a better color stabilization effect when used as a color stabilizer.

According to an embodiment of the invention, the third mixed treatment product has a pH of 6 to 9, such as 6.2, 6.4, 6.6, 6.8, 7.0, 7.2, 7.4, 7.6, 7.8, 8.0, 8.2, 8.4, 8.6, 8.8 or 9.0. In the third mixing treatment, the distillation treatment product is changed from the free acid to the basic salt by an alkalinity adjusting agent such as aqueous ammonia. The inventor finds that when the pH value of the third mixed treatment product is 6-9, the prepared copolymer has better water solubility, better compatibility with a water-soluble emulsion, and is safer and more environment-friendly.

According to an embodiment of the invention, step 2) is performed by: will be provided withThe mixture of (1) is added dropwise to the first mixed-processed product and then subjected to a second mixing process. Therefore, the reaction is more sufficient, and when the prepared copolymer is used as a color stabilizer, the magenta dye has smaller image density fading rate and better color stabilization effect.

According to the embodiment of the invention, the dropping time is 1-4 h, such as 1.5, 2, 2.5, 3, 3.5 or 4 h. Therefore, the reaction is more sufficient, the reaction efficiency is higher, and when the prepared copolymer is used as a color stabilizer, the image density fading rate of the magenta dye is lower, and the color stabilization effect is better. In some embodiments, the dropping time is 2 to 3 hours.

According to an embodiment of the present invention, the dropping treatment is carried out at a temperature of 65 ℃ to 80 ℃, such as 65, 67, 70, 73, 75, 77 or 80 ℃. Therefore, the reaction is more sufficient, and when the prepared copolymer is used as a color stabilizer, the magenta dye has smaller image density fading rate and better color stabilization effect.

According to an embodiment of the invention, the time of the second mixing treatment is 2-8 h, such as 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5 or 8 h. The inventor finds that the reaction can be more complete and sufficient through further heat preservation reaction, and when the prepared copolymer is used as a color stabilizer, the image density fading rate of magenta dye is lower, and the color stabilizing effect is better.

According to an embodiment of the present invention, theIs prepared by mixing Dissolved in a second organic solvent.

According to an embodiment of the present invention, the first organic solvent and/or the second organic solvent comprises at least one selected from toluene, xylene, ethyl acetate, butyl acetate, isoamyl acetate, n-amyl acetate, ethyl butyrate, acetone, methyl ethyl ketone, methyl isobutyl ketone, n-hexane or cyclohexane.

According to an embodiment of the present invention, the initiator includes at least one selected from the group consisting of benzoyl peroxide, lauroyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxypivalate, cumene hydroperoxide, tert-butyl hydroperoxide, di-tert-butyl peroxide or azobisisobutyronitrile.

According to an embodiment of the invention, the mass of the initiator is the maleic anhydride, 1 to 5% of the total mass of (a), such as 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0, 4.2, 4.4, 4.6, 4.8 or 5.0%, whereby the polymerization reaction can be efficiently initiated while avoiding side reactions which would cause the initiator to lose its initiating activity and affect the polymerization degree of the copolymer. The inventors found that when the amount of the initiator is within the above range, the color stabilizing effect is more excellent when the copolymer prepared according to the method of the embodiment of the present invention is used as a color stabilizer.

According to an embodiment of the present invention, the total volume of the first organic solvent and the second organic solvent is equal to the total volume of the maleic anhydride,The ratio of the total mass of (3-8)/1 mL/g is, for example, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 7.5:1 or 8: 1.

According to an embodiment of the invention, the distillation process is a distillation under reduced pressure, so as to distill the solvent clean.

According to an embodiment of the present invention, the alkalinity regulator is ammonia water, an aqueous sodium hydroxide solution, or an aqueous potassium hydroxide solution.

In a third aspect of the invention, the present invention proposes the use of the copolymers described above or the copolymers obtained by the process described above as colour stabilizers. In some embodiments, the color stabilizer is used to prevent color fading of color photographic paper.

Detailed Description

The following detailed description of embodiments of the invention is intended to be illustrative, and not to be construed as limiting the invention.

It should be noted that, unless otherwise explicitly indicated, the descriptions of the present invention that "… is independently" and "… is independently" and "… is independently" are interchangeable, and should be understood in a broad sense to mean that the specific items expressed between the same symbols do not affect each other in different groups, or that the specific items expressed between the same symbols do not affect each other in the same groups.

In the various parts of this specification, substituents of the disclosed compounds are disclosed in terms of group type or range. It is specifically intended that the invention includes each and every independent subcombination of the various members of these groups and ranges. For example, the term "C_1-6Alkyl "means in particular independently disclosed methyl, ethyl, C₃Alkyl radical, C₄Alkyl radical, C₅Alkyl and C₆An alkyl group. For another example, "m is an integer of 1 to 5" means 1, 2,3, 4 or 5 which are independently disclosed, and "n is an integer of 3 to 25" and "l is an integer of 3 to 30" have the same meaning.

The term "alkyl" or "alkyl group", as used herein, denotes a saturated straight or branched chain monovalent hydrocarbon group. Unless otherwise specified, alkyl groups contain 1-6 carbon atoms; in another embodiment, the alkyl group contains 1 to 4 carbon atoms.

Examples of alkyl groups include, but are not limited to, methyl (Me, -CH)₃) Ethyl group (Et, -CH)₂CH₃) N-propyl (n-Pr, -CH)₂CH₂CH₃) Isopropyl group (i-Pr, -CH (CH)₃)₂) N-butyl (n-Bu, -CH)₂CH₂CH₂CH₃) Isobutyl (i-Bu, -CH)₂CH(CH₃)₂) Sec-butyl (s-Bu, -CH (CH)₃)CH₂CH₃) Tert-butyl (t-Bu, -C (CH)₃)₃) N-pentyl (-CH)₂CH₂CH₂CH₂CH₃) 2-pentyl (-CH (CH)₃)CH₂CH₂CH₃) 3-pentyl (-CH (CH)₂CH₃)₂) 2-methyl-2-butyl (-C (CH)₃)₂CH₂CH₃) 3-methyl-2-butyl (-CH (CH)₃)CH(CH₃)₂) 3-methyl-1-butyl (-CH)₂CH₂CH(CH₃)₂) 2-methyl-1-butyl (-CH)₂CH(CH₃)CH₂CH₃) N-hexyl (-CH)₂CH₂CH₂CH₂CH₂CH₃) 2-hexyl (-CH (CH)₃)CH₂CH₂CH₂CH₃) 3-hexyl (-CH (CH)₂CH₃)(CH₂CH₂CH₃) 2-methyl-2-pentyl (-C (CH))₃)₂CH₂CH₂CH₃) 3-methyl-2-pentyl (-CH (CH)₃)CH(CH₃)CH₂CH₃) 4-methyl-2-pentyl (-CH (CH)₃)CH₂CH(CH₃)₂) 3-methyl-3-pentyl (-C (CH)₃)(CH₂CH₃)₂) 2-methyl-3-pentyl (-CH (CH)₂CH₃)CH(CH₃)₂) 2, 3-dimethyl-2-butyl (-C (CH)₃)₂CH(CH₃)₂) 3, 3-dimethyl-2-butyl (-CH (CH)₃)C(CH₃)₃) And so on.

As described herein, a ring system formed on a ring wherein a substituent is bonded to the center (as shown in formula b) represents that the substituent may be substituted at any substitutable position on the ring. For example, the substituent R represented by the formula b may be mono-or polysubstituted at any possible substituted position on the C ring, as shown in the formulae C1 to C17.

The copolymer of the formula (I) according to the invention isSalts with suitable bases including, but not limited to, alkali metals, alkaline earth metals, ammonium and N⁺(C1-4 alkyl)₄A salt. The present invention also contemplates quaternary ammonium salts formed from compounds containing groups of N. Alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like. Suitable bases are, for example, ammonia, sodium hydroxide, potassium hydroxide, lithium hydroxide and the like.

The invention discloses a preparation method of a water-soluble color stabilizer for color photographic paper, which comprises the following steps:

(1) adding a certain amount of solvent into a reaction vessel, and adding a certain amount of maleic anhydride while stirring. After heating to 60-80 ℃, initiator is added. (2) After the temperature was stabilized, dropwise addition of a solution containing a mixed monomer of styrene and α -methylstyrene was started. The dripping time is 1 h-4 h, and the temperature is controlled at 65 ℃ to 80 ℃; and then keeping for 2-8 h. (3) After the reaction, the solvent was distilled under reduced pressure. After distillation, deionized water and inorganic base are added, stirred to dissolve and the pH is adjusted to 6-9. Filtering to obtain a light yellow transparent liquid product. The method has simple synthesis process steps, is suitable for water-soluble color paper emulsion, has good compatibility with the emulsion, and is pollution-free, safe and environment-friendly. The magenta dye in the color photographic paper has small image density fading rate and good color stability effect. The post-treatment process is simple, the cost is low, and the method is suitable for industrial mass production.

The technical scheme of the invention is as follows:

a water-soluble fading resistant agent for color photographic paper has the following structure:

m is NH₄Or Na or K.

m is 1 to 5, n is 3 to 25, and l is 3 to 30.

Molecular weight: 2000- - -6000.

A preparation method of a water-soluble color stabilizer for color photographic paper comprises the following steps:

(1) adding a certain amount of solvent into a reaction vessel, adding maleic anhydride while stirring, heating to 60-80 ℃, and adding an initiator.

(2) After the temperature is stabilized at 60-80 ℃, the mixed solution of monomer styrene and monomer alpha-methyl styrene is dripped. The dropping time is 1 h-4 h, the temperature is controlled at 65 ℃ to 80 ℃, and the temperature is kept for 2 h-8 h.

(3) And after the reaction is finished, distilling the solvent under reduced pressure, adding deionized water and inorganic base, stirring to dissolve, adjusting the pH value to be 6-9, and filtering (filtering impurities) to obtain light yellow transparent liquid.

In the above scheme, the solvent in step (1) is at least one of toluene, xylene, ethyl acetate, butyl acetate, isoamyl acetate, n-amyl acetate, ethyl butyrate, acetone, methyl ethyl ketone, methyl isobutyl ketone, n-hexane, and cyclohexane.

In the above scheme, the initiator in step (1) is at least one of benzoyl peroxide, lauroyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxypivalate, cumene hydroperoxide, tert-butyl hydroperoxide, di-tert-butyl peroxide, and azobisisobutyronitrile.

In the scheme, the amount of the initiator used in the step (1) is 1 to 5 percent of the total mass of the monomers.

In the above scheme, the mass ratio of the substances is: styrene: alpha-methylstyrene is 1: 3-1: 12; styrene: maleic anhydride 1: 2-1: 13.

in the above scheme, the ratio of the total volume of the solvent used in the step (1) and the step (2) to the total mass of the monomers is: (3-8): 1(V/W mL/g).

In the above scheme, the time for dripping the monomer in the step (2) is 1h to 4h, preferably 2h to 3 h.

In the above scheme, the distillation solvent in the step (3) is vacuum distillation.

In the above scheme, the inorganic base in step (3) may be ammonia water, sodium hydroxide solution and potassium hydroxide solution.

The reaction formula is as follows:

compared with the prior art, the invention has the following advantages:

1. the water-soluble color stabilizer for the color photographic paper comprises the following components: terpolymers of styrene, alpha-methylstyrene and maleic anhydride; is a nontoxic, harmless and more environment-friendly product.

2. The polymer reaction adopts the one-time dropwise addition of the mixed monomer of styrene and alpha-methylstyrene, the operation is simple, the polymerization degree is easy to control, and the molecular weight distribution range is narrow.

3. The water-soluble color stabilizer for the color photographic paper is mutually soluble with water in any proportion, is suitable for water-soluble color paper emulsion, and does not have the defects that a film is easily formed on the surface of the emulsion during emulsion preparation, the material is easily bonded on the wall of a pot during coating, the cleaning is difficult, a filter core is blocked and the like.

4. Because the product is aqueous solution, the product has no toxicity or low toxicity, and the defects of environmental pollution and the like do not exist in the operation.

5. The product has simple synthesis process and low cost.

6. The water-soluble color stabilizer for the color photographic paper enables the fading rate of the image density of the dye in the color photographic paper to be reduced from 85% to 11%.

It should be noted that, in the following examples, the individual temperature or pH was finally stabilized in a range during the actual production process, and the specific value could not be ensured.

The present invention is further illustrated by the following specific examples.

Example 1

In a 250mL flask, 80.0mL of ethyl acetate was added, 4.0g of maleic anhydride was added with stirring, the flask was heated in a water bath to 65 ℃ and 0.3g of benzoyl peroxide was added, and when the temperature stabilized at 65 ℃ to-70 ℃, the dropwise addition of the mixed monomer solution (2.3mL of styrene, 15.6mL of α -methylstyrene dissolved in 20.0mL of ethyl acetate) was started. The dropping time is 2 hours, and the temperature is stabilized at 65 ℃ to-70 ℃. The reaction was then incubated for 8 hours.

Then, ethyl acetate is distilled under reduced pressure and is steamed; deionized water (80.0 mL) and 25% ammonia were added to adjust the pH to 6.5-7, and the mixture was dissolved with stirring and filtered to obtain a color stabilizer, and 105.5g was weighed.

The molecular weight of the product is as follows: 3580; the product appearance is as follows: a light yellow transparent liquid; the solid content is 19.5%. The decrease rate of the image density of the dye is reduced from 85% to 10.5%.

Example 2

In a 250mL flask, 80.0mL of methyl ethyl ketone was added, 4.0g of maleic anhydride was added with stirring, the flask was heated to 65 ℃ in a water bath, 0.3g of benzoyl peroxide was added, and the mixed monomer solution (2.3mL of styrene, 15.6mL of α -methylstyrene dissolved in 20.0mL of methyl ethyl ketone) was started dropwise when the temperature stabilized at 65 ℃ to-70 ℃. The dropping time is 2 hours, and the temperature is stabilized at 65 ℃ to-70 ℃. The reaction was then incubated for 8 hours.

Then distilling the methyl ethyl ketone under reduced pressure, and completely distilling; deionized water (80.0 mL) and 25% ammonia were added to adjust the pH to 6.5-7, and the mixture was dissolved with stirring and filtered to obtain a color stabilizer, and 105.5g was weighed.

The molecular weight of the product is as follows: 3720 and (b); the product appearance is as follows: a light yellow transparent liquid; the solid content is 19.5%. The decrease rate of the image density of the dye is reduced from 85% to 10.2%.

Example 3

In a 250mL flask, 80.0mL of methyl ethyl ketone was added, 9.80g of maleic anhydride was added with stirring, the flask was heated in a water bath to 65 ℃ and 0.5g of benzoyl peroxide was added, and when the temperature stabilized at 75 ℃ to 80 ℃, the dropwise addition of the mixed monomer solution (2.3mL of styrene, 20mL of α -methylstyrene dissolved in 20.0mL of methyl ethyl ketone) was started. The dropping time is 2 hours, and the temperature is stabilized at 65 ℃ to 80 ℃. The reaction was then incubated for 6 hours.

Then distilling the methyl ethyl ketone under reduced pressure, and completely distilling; 120.0mL of deionized water and 25% aqueous ammonia were added to adjust the pH to 6.5-7, and the mixture was dissolved with stirring and filtered to obtain a color stabilizer, and 155.5g of the color stabilizer was weighed.

The molecular weight of the product is as follows: 3085; the product appearance is as follows: a light yellow transparent liquid; the solid content is 19.5%. The decrease rate of the image density of the dye is reduced from 85% to 10.2%.

Example 4

In a 250mL flask, 80.0mL of methyl ethyl ketone was added, 4.0g of maleic anhydride was added with stirring, the flask was heated in a water bath to 65 ℃ and 0.3g of azobisisobutyronitrile was added, and when the temperature stabilized at 75 ℃ to 80 ℃, dropwise addition of the mixed monomer solution (2.3mL of styrene, 15.6mL of α -methylstyrene dissolved in 20.0mL of methyl ethyl ketone) was started. The dropping time is 2 hours, and the temperature is stabilized at 65 ℃ to 80 ℃. The reaction was then incubated for 6 hours.

Then distilling the methyl ethyl ketone under reduced pressure, and completely distilling; deionized water (80.0 mL) and 25% ammonia were added to adjust the pH to 6.5-7, and the mixture was dissolved with stirring and filtered to obtain a color stabilizer, and 105.5g was weighed.

The molecular weight of the product is as follows: 3395; the product appearance is as follows: a light yellow transparent liquid; the solid content is 19.5%. The decrease rate of the image density of the dye is reduced from 85% to 10.6%.

Example 5

In a 250mL flask, 50.0mL of methyl ethyl ketone and 30mL of cyclohexane were added, 4.0g of maleic anhydride was added with stirring, the flask was heated to 65 ℃ in a water bath, 0.3g of benzoyl peroxide was added, and the drop wise addition of the mixed monomer solution was started when the temperature stabilized at 65 ℃ to 70 ℃ (2.3mL of styrene, 15.6mL of α -methylstyrene dissolved in 15.0mL of methyl ethyl ketone and 5mL of cyclohexane). The dropping time is 2 hours, and the temperature is stabilized at 65 ℃ to-70 ℃. The reaction was then incubated for 8 hours.

Then distilling the solvent under reduced pressure, and completely distilling; deionized water (80.0 mL) and 25% ammonia were added to adjust the pH to 6.5-7, and the mixture was dissolved with stirring and filtered to obtain a color stabilizer, and 105.5g was weighed.

The molecular weight of the product is as follows: 3860; the product appearance is as follows: a light yellow transparent liquid; the solid content is 19.5%. The decrease rate of the image density of the dye is reduced from 85% to 10.8%.

Example 6

In a 250mL flask, 50.0mL of toluene was added, 4.0g of maleic anhydride was added with stirring, the flask was heated to 65 ℃ in a water bath, 0.3g of t-butyl peroxybenzoate was added, and when the temperature stabilized at 75 ℃ to 80 ℃, dropwise addition of the mixed monomer solution (2.3mL of styrene, 15.6mL of α -methylstyrene dissolved in 20mL of toluene solution) was started. The dropping time is 2 hours, and the temperature is stabilized at 75 ℃ to 80 ℃. The reaction was then incubated for 8 hours.

Then, carrying out reduced pressure distillation on the toluene, and completely distilling; deionized water (80.0 mL) and 25% ammonia were added to adjust the pH to 6.5-7, and the mixture was dissolved with stirring and filtered to obtain a color stabilizer, and 105.5g was weighed.

The molecular weight of the product is as follows: 4120; the product appearance is as follows: a light yellow transparent liquid; the solid content is 19.5%. The decrease rate of the image density of the dye is reduced from 85% to 10.6%.

Note: the fading rate of the dye image density was measured according to the method of the GBT 12682-1990 contrast test for color stability of color photographic images.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.