阅读说明：本技术 一种新型非酚热敏显色剂及其制备方法 (Novel non-phenolic thermosensitive color developing agent and preparation method thereof ) 是由 文兆峰 范银彬 李海涛 开永平 鲁刚 柴宝红 于 2020-12-10 设计创作，主要内容包括：本发明属于热敏显色剂技术领域,涉及一种新型非酚热敏显色剂及其制备方法。所述的新型非酚热敏显色剂的结构如式5所示。利用本发明的新型非酚热敏显色剂及其制备方法,能够合成成本低廉的制备新型非酚热敏显色剂,制得热敏显色剂显色性能高、稳定性能好、环保安全。(The invention belongs to the technical field of thermosensitive color developing agents, and relates to a novel non-phenolic thermosensitive color developing agent and a preparation method thereof. The structure of the novel non-phenol heat-sensitive color developing agent is shown as a formula 5. The novel non-phenolic thermal color developing agent and the preparation method thereof can be used for synthesizing the novel non-phenolic thermal color developing agent with low cost, and the prepared thermal color developing agent has high color developing performance, good stability, environmental protection and safety.)

1. A novel non-phenolic thermosensitive color developing agent is characterized in that: the structure of the novel non-phenol heat-sensitive color developing agent is shown as a formula 5,

2. a method for preparing a novel non-phenolic heat-sensitive color developer according to claim 1, wherein the method comprises the following steps:

(1) reacting the compound of the formula 1 with the compound of the formula 2 to obtain a compound of a formula 3;

(2) reacting the compound of the formula 3 with the compound of the formula 4 to obtain a compound of a formula 5;

3. the method of claim 2, wherein: in the step (1) and the step (2), one or more of acetone, butanone and tetrahydrofuran are used as a solvent in the reaction.

4. The method of claim 2, wherein: in the step (1), the mass ratio of the compound of the formula 1 to the compound of the formula 2 in the reaction is 1:2-1:5, and the reaction temperature is 0-30 ℃.

5. The method of claim 2, wherein: in the step (2), the mass ratio of the compound of the formula 3 to the phenol compound of the formula 4 in the reaction is 1:2-1:10, and the reaction temperature is 50-60 ℃.

Technical Field

The invention belongs to the technical field of thermosensitive color developing agents, and relates to a novel non-phenolic thermosensitive color developing agent and a preparation method thereof.

Background

Thermal paper is also called thermal facsimile paper, thermal recording paper, thermal transfer paper, and thermal transfer paper in taiwan. Thermal paper is a processed paper produced by coating a layer of "heat-sensitive paint" (heat-sensitive color-developing layer) on a high-quality base paper. The thermosensitive paper is widely applied to the fields of logistics, lottery, medical treatment and ticket, and is a readable information recording material. The thermal paper is classified into a non-protective layer thermal paper and a protective layer thermal paper, distinguished from the field of use. The protective layer-free thermal sensitive paper is commonly used in fast consumption fields such as catering, cash register and the like, has poor protective performance, is easy to scrape and develop color, and is easy to fade when encountering ethanol, oil and even water. The thermosensitive paper with the protective layer is developed on the basis of the technology of the thermosensitive paper without the protective layer, and is widely applied to the welfare lottery industry, the logistics label industry, the ticket industry and the like because the thermosensitive paper has the advantages of being not easy to collide and scrape and good in water resistance, oil resistance and ethanol resistance. The structure composition of the thermosensitive paper with the protective layer is shown in fig. 3, wherein 1 is base paper, 2 is a base layer, 3 is a color development layer, and 4 is the protective layer.

The thermosensitive color developing agent applied to the color developing layer of the thermosensitive paper is a color developing agent used in color development of a color base of a thermosensitive dye, and has the function of releasing hydrogen ions (H +) when being heated and melted to develop the color of the color base of the thermosensitive dye.

The thermal-sensitive color developing agents which are used on the market in a large scale are mainly bisphenol A, bisphenol s and derivatives thereof. Most molecules of the compounds have polyphenol hydroxyl groups, although the compounds have strong color development capability, the compounds have lower melting points and are insoluble in water, and the compounds have the defects of easy oxidation, short storage time, lower color development sensitivity, high sensitivity requirement only by using a sensitizer and the like. Bisphenol a is a kind of estrogen, which can enter into body through skin, interfere and destroy endocrine system, and has definite carcinogenicity. At present, some countries such as the United states, Europe, Japan, etc. have limited the use of phenolic developers.

Therefore, the development significance of the non-phenolic thermosensitive color developing agent which is more environment-friendly, safer and stable in performance is important, and the non-phenolic thermosensitive color developing agent has important economic value and social significance for promoting the healthy development and the competitiveness improvement of the thermosensitive material industry in China.

Disclosure of Invention

The invention aims to provide a novel non-phenol heat-sensitive color developing agent which has the advantages of high color developing performance, good stability, strong ethanol resistance and the like.

To achieve the object, in a basic embodiment, the present invention provides a novel non-phenolic heat-sensitive color developing agent having a structure represented by formula 5,

the second purpose of the invention is to provide a preparation method of the novel non-phenolic thermal color developing agent, which has low synthesis cost and is environment-friendly and safe.

To achieve the object, in a basic embodiment, the present invention provides a method for preparing the above-mentioned novel non-phenolic heat-sensitive color developer, the method comprising the steps of:

(1) reacting the compound of the formula 1 with the compound of the formula 2 to obtain a compound of a formula 3;

(2) reacting the compound of the formula 3 with the compound of the formula 4 to obtain a compound of a formula 5;

in a preferred embodiment, the present invention provides a preparation method of the above-mentioned novel non-phenolic heat-sensitive color developing agent, wherein in the step (1) and the step (2), one or more of acetone, butanone and tetrahydrofuran are used as a solvent in the reaction.

In a preferred embodiment, the invention provides a preparation method of the novel non-phenolic heat-sensitive color developing agent, wherein in the step (1), the compound in the formula 1 and the compound in the formula 2 are mixed according to the mass ratio of 1:2-1:5, and the reaction temperature is 0-30 ℃.

In a preferred embodiment, the invention provides a preparation method of the novel non-phenolic heat-sensitive color developing agent, wherein in the step (2), the mass ratio of the compound in the formula 3 to the phenol in the compound in the formula 4 in the reaction is 1:2-1:10, and the reaction temperature is 50-60 ℃.

The novel non-phenol thermal color developing agent and the preparation method thereof have the advantages that the novel non-phenol thermal color developing agent with high ethanol aging retention rate can be synthesized at low cost, the thermal color developing agent has the advantages of high color developing performance, good stability, strong ethanol resistance and the like, and the preparation process is environment-friendly and safe.

Drawings

FIG. 1 is a High Performance Liquid Chromatography (HPLC) result chart of the novel non-phenolic thermal-sensitive color developing agent prepared in example 2.

FIG. 2 is a graph showing the results of nuclear magnetic hydrogen spectroscopy (H-NMR) measurement of the novel non-phenolic heat-sensitive color developing agent obtained in example 2.

Fig. 3 is a structural composition diagram of the thermal paper.

Detailed Description

The following description will further describe embodiments of the present invention with reference to the accompanying drawings. It will be understood that these examples are intended to illustrate the invention and are not intended to limit the scope of the invention in any way.

In the following examples, various procedures and methods not described in detail are conventional methods well known in the art. Materials, reagents, devices, instruments, apparatuses and the like used in the following examples are commercially available unless otherwise specified.

Example 1: synthesis of Compounds of formula 3

Washing and drying a 20L three-neck flask, putting 2100 g of a compound (TDI) shown in a formula 2 into the three-neck flask under the protection of nitrogen, adding 5L of acetone, dissolving 1000 g of a compound shown in a formula 1 into 5L of acetone, slowly dropwise adding, controlling the temperature to be 0-25 ℃, and stirring and reacting for 20 hours. Filtering, washing the obtained solid with petroleum ether for 2 times, filtering, drying to obtain 2020 g of the compound shown in the formula 3, and directly carrying out the next reaction without further purification.

Example 2: synthesis of Compounds of formula 5

A20L three-necked round-bottomed flask was washed and dried, and 2020 g of the compound of formula 3, 1600 g of phenol (i.e., the compound of formula 4), and 2 mL of dibutyltin dilaurate (DBTDL) were dissolved in 10L of acetone, heated to 55 ℃ and reacted with stirring for 5 hours. Pouring the reaction solution into toluene, stirring for 1-2 hours, filtering, washing the solid with toluene for 2 times, and drying to obtain a white solid compound 5 with 2100 g of formula 5, yield 79%, purity 97.9%, single impurity<1.0 percent, which shows that the compound has high effective purity, environmental protection and safety. The detection results of the high performance liquid chromatography and the nuclear magnetic hydrogen spectrum are respectively shown in the figures 1-2. The high performance liquid chromatography HPLC detection method comprises the following steps: agilent 1100, YMC ODS-AQ 3UM 120A 4.6 × 50MM, 220nm, ACN/H₂O/buffer solution; nuclear magnetic hydrogen spectrum H-NMR, 400MHz, DMSO-d₆。

Example 3: thermo-sensitive color development test of the Compound of formula 5

The compound of formula 5 obtained in example 2 was subjected to a thermal color development test in the following manner.

The preparation process of the thermal sensitive paper comprises the step of sequentially coating a base layer, a color development layer and a protective layer on a raw paper layer.

1. Preparation and application of primer layer (prior art)

50kg of calcined kaolin, 10kg of calcium carbonate, 20kg of polystyrene hollow sphere resin, 8kg of calcium stearate, 5kg of polyvinyl alcohol, 5kg of starch latex, 2kg of auxiliary agent and water are mixed according to a proportion to prepare the coating with the solid content of 40-50%. Coating with a doctor bladeCoating the coating on the heat-sensitive base paper containing chemimechanical pulp by a cloth machine, wherein the coating weight is 4-12g/m²And forming the heat-sensitive precoated paper by drying and calendering.

2. Preparation and coating of color-developing layer

The color development layer consists of leuco dye, color developing agent and other auxiliary materials, wherein 20kg of 3-isopentyl-amino-6-methyl-7-anilinofluorane is formed into stable crystal particles through grinding and heat treatment processes, and the particle size of the particles is controlled to be 0.2 mu m. Weighing 30kg of the compound shown in the formula 5, adding the compound, a polyvinyl alcohol solution and a dispersing agent into water according to the dry weight ratio of 90:9:1, and grinding the mixture by a grinder to obtain tiny particles with the particle size of less than 100 nm; the auxiliary materials comprise 12Kg of benzyl-2 naphthyl ether, 10Kg of modified polyvinyl alcohol, 10Kg of calcium carbonate, 10Kg of zinc stearate, 3Kg of cross-linking agent and 5Kg of starch cooking liquor, and the color development layer coating with the solid content of 20-40 percent is prepared by mixing and adding water. Coating the color development layer on the thermosensitive pre-coated paper by a scraper coater, wherein the coating weight is 4-5g/m²And drying and calendaring to obtain the heat-sensitive surface coating paper.

3. Preparation and application of protective layer

The protective layer comprises 20kg of light calcium carbonate, 23kg of silicon dioxide, 8kg of zinc stearate, 2kg of calcium stearate, 30kg of acrylic latex, 5kg of cross-linking agent, 10kg of polyvinyl alcohol and 2kg of auxiliary agent, the protective layer is prepared by mixing and adding water to prepare a protective layer coating with the solid content of 10-20%, the protective layer coating is coated on the heat-sensitive top-coated paper by a curtain type coating machine, and the coating weight is 1-2g/m²And drying and calendaring to obtain the thermal sensitive paper with the protective layer.

Performance testing

(1) Depth of color development

The samples were tested using a thermal printing apparatus (Xinbeiyang, TSC TTP-244pro), square developed patterns were printed one by one, and developed light density was measured with a densitometer.

The control sample was bis (3-allyl-4-hydroxyphenyl) sulfone (TGSA), which was manufactured by Shenyang sensitization chemical research institute and has the following chemical formula:

this data indicates that the compound of formula 5 has more excellent color development depth.

(2) Ethanol prevention Properties

Selecting experimental examples and control samples with the same area one by one, measuring the color development optical density of the samples by using the thermal printing device according to the national standard (GB/T28210-2011) of thermal paper, and calculating the retention rate (%) of the ethanol, wherein the retention rate (%) is as follows:

ethanol retention (%) of (Q1/Q0) × 100

Q1: color depth of color pattern after test

Q0: color development depth of color development pattern before test

This data demonstrates that the compound of formula 5 has very high retention in ethanol protection.

(3) Anti-aging Property (stability)

The experimental examples and the control samples with the same area are selected one by one, the thermal printing device is used, the color development optical density is measured according to the national standard (GB/T28210-2011) of thermal paper, and the aging retention rate (%) is calculated as follows:

aging retention (%) (Q1/Q0) × 100

Q1: color depth of color pattern after test

Q0: color development depth of color development pattern before test

This data shows that the compounds of formula 5 have a very high retention in terms of anti-aging properties.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include such modifications and variations. The foregoing examples or embodiments are merely illustrative of the present invention, which may be embodied in other specific forms or in other specific forms without departing from the spirit or essential characteristics thereof. The described embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. The scope of the invention should be indicated by the appended claims, and any changes that are equivalent to the intent and scope of the claims should be construed to be included therein.