CN107236367B - Temperature-sensitive reversible color-changing UV ink for PVC and preparation method and use method - Google Patents

Abstract

The invention provides a temperature-sensitive reversible color-changing UV ink for PVC, a preparation method and a use method, and relates to the technical field of printing inks. The raw materials include: prepolymer 30%-54%, monomer 30%-51%, photoinitiator 5%-9%, accelerator 3%-7%, dispersant 0.5%-2%, defoamer 1 %‑2%, thermochromic pigment 2%‑6%. This UV ink is prepared by using specific raw materials and dosages. It has the function of temperature-sensing and reversible discoloration, and can be used in packaging anti-counterfeiting printing. It has strong adhesion, simple curing, good strength and good resistance to resistance. The present invention also relates to the manufacturing process and using method of the UV ink. Pre-mixing the prepolymer, monomer, accelerator and defoamer to obtain a mixture, and then adding a thermochromic pigment, a photoinitiator and a dispersant to the mixture, and stirring. The preparation method is simple and easy to operate. At the same time, the use of UV ink is simple and has broad application prospects.

Description

Temperature-sensitive reversible color-changing UV ink for PVC and preparation method and use method

technical field

The invention relates to the technical field of printing inks, and particularly relates to a temperature-sensitive reversible color-changing UV ink for PVC, a preparation method and a use method.

Background technique

UV ink, also known as UV-curable ink, refers to the use of UV light of different wavelengths and energies to polymerize the monomers in the ink binder into polymers under the irradiation of ultraviolet rays, so that the ink is formed into a film and dried. UV ink not only has bright colors, good printability, suitable curing and drying rate, good adhesion, abrasion resistance, corrosion resistance, weather resistance, etc., but also has fast curing speed, high printing quality, no VOC emissions Etc. UV ink is an economical and efficient ink that has covered all printing fields. At present, the most important markets for UV inks in the world are: Europe, America, China, and Japan. The market for UV inks currently required in China is gradually expanding.

Reversible temperature-change color ink is a kind of special anti-counterfeiting ink that changes the color of the material when it reaches a certain temperature range, and returns to the original color when the temperature returns to the original temperature. The reversible temperature-change color-changing ink has the advantages of convenient, fast and accurate detection, and does not require additional auxiliary equipment, and has broad application prospects in packaging anti-counterfeiting printing. However, due to the high price of the ink, it is generally used in high-end printing, which is limited. At present, although there are many studies on thermochromic materials, there are few studies on thermochromic reversible thermochromic UV ink systems and their temperature control during heating and cooling.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a temperature-sensitive reversible color-changing UV ink for PVC, which has the advantages of convenient detection, simple curing, and good adhesion.

Another object of the present invention is to provide a preparation method of temperature-sensitive reversible color-changing UV ink for PVC, which is simple, easy to operate, and easy to control various parameters.

The third object of the present invention is to provide a method for using temperature-sensitive reversible color-changing UV ink for PVC, which is convenient to use and has good performance.

The present invention solves its technical problems by adopting the following technical solutions.

The invention proposes a temperature-sensitive reversible color-changing UV ink for PVC. According to the weight percentage, the raw materials are composed of the following components: prepolymer 30%-54%, monomer 30%-51%, photoinitiator 5% %-9%, accelerator 3%-7%, dispersant 0.5%-2%, defoamer 1%-2%, thermochromic pigment 2%-6%.

The present invention proposes a preparation method of temperature-sensitive reversible discoloration UV ink for PVC, which comprises the following steps:

Pre-mixing: Mix the prepolymer, monomer, accelerator and defoamer, and stir at 60-85°C to obtain a mixture;

Pigment dispersion: Then add thermochromic pigment, photoinitiator and dispersant to the mixture and stir.

The invention provides a method for using temperature-sensitive reversible color-changing UV ink for PVC. The temperature-sensitive and reversible color-changing UV ink for PVC is filtered with a silk screen, then coated on the PVC, and irradiated with ultraviolet light for 8-20 minutes.

The beneficial effects of the temperature-sensitive reversible color-changing UV ink for PVC, the preparation method and the use method of the embodiment of the present invention are:

The temperature-sensitive reversible discoloration UV ink of the invention is prepared by using specific raw materials and dosages, has the function of temperature-sensitive reversible discoloration, and can be applied to packaging anti-counterfeiting printing. It has the advantages of convenient, fast and accurate detection, and does not require additional auxiliary equipment, and has a broad market prospect. It has strong adhesion, simple curing, fast speed, no cracking, scratch resistance, and no ink diffusion on the material, and has sufficient strength and resistance to ethanol, acid, alkali, water and other properties. excellent.

The temperature-sensitive reversible color-changing UV ink is cured under ultraviolet light irradiation, which can reduce the interference of external temperature on the color-changing system, and has excellent adhesion on paper, plastic, metal and other substrates, and can greatly expand the Application of temperature-changing color-changing materials in packaging anti-counterfeiting printing.

In addition, the preparation method of the temperature-sensitive reversible color-changing UV ink is simple. The prepolymer, monomer, accelerator and defoamer are pre-mixed to obtain a mixture, and then a temperature-sensitive color-changing pigment is introduced into the mixture. , photoinitiator and dispersant to ensure good dispersion of pigments in ink, ensure effective mixing of various raw materials, and avoid premature introduction of thermochromic pigments and reduce product quality. The preparation method is simple, the operation is convenient, and it is suitable for industrialized large-scale production.

Detailed ways

In order to make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not indicated in the examples, it is carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments used without the manufacturer's indication are conventional products that can be purchased from the market.

A kind of temperature-sensitive reversible color-changing UV ink for PVC according to the embodiment of the present invention will be specifically described below.

The temperature-sensitive reversible color-changing UV ink for PVC provided by the embodiment of the present invention, in terms of weight percentage, the raw material is composed of the following components: prepolymer 30%-54%, monomer 30%-51%, light Initiator 5%-9%, accelerator 3%-7%, dispersant 0.5%-2%, defoamer 1%-2%, thermochromic pigment 2%-6%.

Further, in a preferred embodiment of the present invention, in terms of weight percentage, the raw materials of the temperature-sensitive reversible color-changing UV ink for PVC are: prepolymer 31.25%-50.11%, monomer 45.35%-50%, light Initiator 6.02%-8.04%, accelerator 3.74%-5.07%, dispersant 0.7%-1.25%, defoamer 1%-1.25%, thermochromic pigment 5%-5.26%.

By using a specific raw material composition and a specific dosage ratio, and using a thermochromic pigment, the product has the function of temperature-sensitive reversible color change, which can be used in packaging anti-counterfeiting printing.

Further, in a preferred embodiment of the present invention, the thermochromic pigment is thermochromic powder. The thermochromic powder in the embodiment of the present invention is prepared from an electron transfer organic compound system. Electron transfer organic compounds are a class of organic chromophoric systems with special chemical structures. At a specific temperature, the molecular structure of the organic matter changes due to electron transfer, thereby achieving color transformation. This color-changing substance is not only bright in color, but also can realize the color change from "colored-colorless" state, which is not available in heavy metal double salt complex type and liquid crystal type reversible thermochromic substances.

Further, the particle size of the thermochromic powder is preferably 200-800 mesh. The thermochromic powder with this particle size can be well dispersed in the product to ensure the uniformity of product quality.

Further, in a preferred embodiment of the present invention, the prepolymer is selected from one of epoxy acrylic resin, polyurethane acrylic resin, polyester acrylic resin, polyether acrylic resin, polypropyl acrylate, and unsaturated polyester resin. species or multiple species. More preferably, the prepolymer is selected from epoxy acrylic resins.

The choice of prepolymer has a great influence on the curing speed, hardness, sensitivity, stability and printability of UV ink. In addition, the dispersibility and resistance of the prepolymer to the pigment all have an effect on the discoloration temperature. In the embodiment of the present invention, epoxy acrylic resin is selected as the prepolymer, so that the thermochromic pigment can form a good dispersion in the product, and has good adhesion, and after reaching the expected temperature, a relatively conspicuous color change occurs.

Further, in a preferred embodiment of the present invention, the monomer is selected from ethylene glycol diacrylate, ethoxyethoxyethyl acrylate, diethylene glycol diacrylate phthalate, dipropylene glycol diacrylate One or more of ester and tripropylene glycol dipropylene ester.

Further, the monomer is preferably HDDA (ethylene glycol diacrylate). Using the monomer, the source of raw materials is convenient, the cost is low, and the solubility and viscosity reduction performance of the UV ink can be effectively adjusted, and the adhesion of the cured product can be adjusted.

Further, in a preferred embodiment of the present invention, the photoinitiator is selected from one or more of trimethylbenzoyl diphenyl phosphine oxide, bisbenzoyl phenyl phosphine oxide, and diphenyl ethyl ketone .

Photoinitiator is a compound that is easily excited by light. After absorbing light, it is excited into free radicals, and the energy is transferred to photosensitive molecules, so that the UV ink can be cured. In the embodiment of the present invention, the photoinitiator is preferably trimethylbenzoyldiphenylphosphine oxide (I1). The photoinitiator is very sensitive to light and greatly promotes the polymerization and crosslinking of monomers.

Further, in a preferred embodiment of the present invention, the accelerator is an active amine. Specifically, an active amine product consisting of TMPTA trimethylolpropane triacrylate, diethylamine, and a polymerization inhibitor is selected. Active amines are industrial products, and the raw materials are readily available. Reactive amines can promote the curing of resins, increase the light curing speed of products, and improve the hardness of products after curing.

Further, in a preferred embodiment of the present invention, the defoamer is a silicone oil defoamer (F810). The defoamer is used to improve the leveling of the ink layer, prevent the generation of shrinkage cavities, make the surface of the ink film smooth, and also increase the gloss of the ink printing. The defoamer is chemically inert, suitable for a wide temperature range, and has outstanding heat resistance, cold resistance, weather resistance and aging resistance. And only need less dosage to get better effect.

Further, in a preferred embodiment of the present invention, the dispersant is an active content polymer type dispersant (D-265). The dispersant can make the pigment and resin in the ink low wetting, make the pigment have good dispersibility in the ink, and prevent the agglomeration and precipitation of the ink particles. The dispersant contains more adsorption groups, which is conducive to the stirring and dispersion of the pigment, and ensures that the pigment can achieve good dispersion at a low stirring speed.

The present invention proposes a preparation method of temperature-sensitive reversible discoloration UV ink for PVC, which comprises the following steps:

Pre-mixing: Mix the prepolymer, monomer, accelerator and defoamer, and stir at 60-85°C to obtain a mixture;

Pigment dispersion: Then add thermochromic pigment, photoinitiator and dispersant to the mixture and stir.

First, through the pre-mixing process, pre-mix the prepolymer, monomer, accelerator and defoamer at a certain temperature. In this process, the temperature is relatively high to ensure that each material can be effectively mixed. In addition, preliminary stirring and mixing of the above-mentioned raw materials can form a uniform and stable mixture, which is more convenient for the subsequent addition of pigments. In addition, the pre-mixing process can avoid premature addition of pigments, photoinitiators, etc., which will be greatly affected in the subsequent operation process and affect product quality.

Further, in a preferred embodiment of the present invention, in the pre-mixing step, the stirring speed is 100-150 rpm, and the stirring time is 10-18 minutes.

Further, in a preferred embodiment of the present invention, in the pigment dispersion step, the stirring speed is 30-50 rpm, and the stirring time is 3-5 minutes.

In the pre-mixing process and the pigment dispersion process, a low speed is used for stirring, so as to avoid too fast speed, which may lead to the formation of polymerization of some raw materials. And the premixing process uses relatively high speed stirring for a relatively long time, while the pigment dispersion process uses relatively low speed stirring for a relatively short time, resulting in the best quality product.

The invention provides a method for using temperature-sensitive reversible color-changing UV ink for PVC. The temperature-sensitive and reversible color-changing UV ink for PVC is filtered with a silk screen, then coated on the PVC, and irradiated with ultraviolet light for 8-20 minutes. Further, the ultraviolet irradiation time is 10-18 min.

The features and performances of the present invention will be further described in detail below in conjunction with the embodiments.

Example 1

The temperature-sensitive reversible color-changing UV ink for PVC provided in this embodiment, in terms of weight percentage, its raw materials include the following components: epoxy acrylic resin 37.41%, hexanediol diacrylate 45.35%, trimethylbenzene Formyldiphenylphosphine oxide 6.02%, active amine 3.74%, active content polymer type dispersant 1.2%, silicone oil defoamer 1.02%, thermochromic powder 5.26%.

The above raw materials are all analytically pure.

The temperature-sensitive reversible color-changing UV ink for PVC is prepared according to the following steps:

a. Preparation: combine epoxy acrylic resin, hexanediol diacrylate, trimethylbenzoyl diphenylphosphine oxide (I1), active amine, silicone oil defoamer, active content polymer dispersant and The thermochromic powder is weighed one by one according to the composition of the above-mentioned raw materials, and the photoinitiator is prepared after step b.

b. Premixing: The prepolymer, monomer, accelerator, and defoamer prepared in step a are weighed and stirred in a water bath at a constant temperature of 75°C at a low speed of 150 rpm , stir for 18 minutes;

c. Pigment dispersion: add the thermochromic pigment, photoinitiator and dispersant to the mixture heated and stirred uniformly in step b, and stir it at a low speed with a glass rod at a low speed of 50 rpm for 5 minutes. In this embodiment, the basic temperature of the thermochromic powder is 31°C.

Example 2

The temperature-sensitive reversible color-changing UV ink for PVC provided in this embodiment, in terms of weight percentage, the raw materials include the following components: epoxy acrylic resin 50.11%, hexanediol diacrylate 30.04%, trimethylbenzene Formyldiphenylphosphine oxide 8.04%, active amine 5.07%, active content polymer dispersant 0.7%, silicone oil defoamer 1.04%, thermochromic powder 5%.

The above raw materials are all analytically pure.

The temperature-sensitive reversible color-changing UV ink for PVC is prepared according to the following steps:

a. Preparation: combine epoxy acrylic resin, hexanediol diacrylate, trimethylbenzoyl diphenylphosphine oxide (I1), active amine, silicone oil defoamer, active content polymer dispersant and The thermochromic powder is weighed one by one according to the composition of the above-mentioned raw materials, and the photoinitiator is prepared after step b.

b. Premixing: The prepolymer, monomer, accelerator, and defoamer prepared in step a are weighed and stirred in a water bath at a constant temperature of 65°C at a low speed of 100 rpm , stir for 15 minutes;

c. Pigment dispersion: add the thermochromic pigment, photoinitiator and dispersant to the mixture heated and stirred evenly in step b, and stir it at a low speed with a glass rod at a low speed of 40 rpm for 5 minutes. In this embodiment, the basic temperature of the thermochromic powder is 31°C.

Example 3

The temperature-sensitive reversible color-changing UV ink for PVC provided in this embodiment, in terms of weight percentage, its raw materials include the following components: epoxy acrylic resin 50%, hexanediol diacrylate 30%-51%, three Methylbenzoyl diphenylphosphine oxide 6.25%, active amine 5%, active content polymer type dispersant 1.25%, silicone oil defoamer 1.25%, thermochromic powder 5%.

The above raw materials are all analytically pure.

The temperature-sensitive reversible color-changing UV ink for PVC is prepared according to the following steps:

a. Preparation: combine epoxy acrylic resin, hexanediol diacrylate, trimethylbenzoyl diphenylphosphine oxide (I1), active amine, silicone oil defoamer, active content polymer dispersant and The thermochromic powder is weighed one by one according to the composition of the above-mentioned raw materials, and the photoinitiator is prepared after step b.

b. Premixing: The prepolymer, monomer, accelerator, and defoamer prepared in step a are weighed and stirred in a water bath at a constant temperature of 70°C at a low speed of 100 rpm , stir for 10 minutes;

c. Pigment dispersion: add the thermochromic pigment, photoinitiator and dispersant to the mixture heated and stirred uniformly in step b, and stir it at a low speed with a glass rod at a low speed of 30 rpm for 5 minutes. In this embodiment, the basic temperature of the thermochromic powder is 31°C.

Example 4

The temperature-sensitive reversible color-changing UV ink for PVC provided by this embodiment, in terms of weight percentage, its raw materials include the following components: 30% of polyurethane acrylic resin, 44% of diethylene glycol diacrylate phthalate, Diphenyl ethyl ketone 9%, active amine 7%, active content polymer type dispersant 2%, silicone oil defoamer 2%, thermochromic powder 6%.

The above raw materials are all analytically pure.

The temperature-sensitive reversible color-changing UV ink for PVC is prepared according to the following steps:

a. Preparation of materials: the prepolymer, monomer, accelerator, defoamer, dispersant, and thermochromic pigment are weighed one by one according to the composition of the above-mentioned raw materials, and the photoinitiator is prepared after step b.

b. Premixing: The prepolymer, monomer, accelerator, and defoamer prepared in step a are weighed and stirred in a water bath at a constant temperature of 60°C at a low speed of 150 rpm , stir for 10 minutes;

c. Pigment dispersion: add the thermochromic pigment, photoinitiator and dispersant to the mixture heated and stirred uniformly in step b, and stir it at a low speed with a glass rod at a low speed of 30 rpm for 5 minutes. In this embodiment, the basic temperature of the thermochromic powder is 39°C.

Example 5

The temperature-sensitive reversible color-changing UV ink for PVC provided in this embodiment, in terms of weight percentage, its raw materials include the following components: 54% diethylene glycol diacrylate phthalate, hexanediol diacrylate 34.5%, trimethylbenzoyl diphenylphosphine oxide 5%, active amine 3%, active content polymer type dispersant 0.5%, silicone oil defoamer 1%, thermochromic powder 2%.

The above raw materials are all analytically pure.

The temperature-sensitive reversible color-changing UV ink for PVC is prepared according to the following steps:

a. Preparation of materials: the prepolymer, monomer, accelerator, defoamer, dispersant, and thermochromic pigment are weighed one by one according to the composition of the above-mentioned raw materials, and the photoinitiator is prepared after step b.

b. Premixing: The prepolymer, monomer, accelerator, and defoamer prepared in step a are weighed and stirred in a water bath at a constant temperature of 85°C at a low speed of 100 rpm , stir for 18 minutes;

c. Pigment dispersion: add the thermochromic pigment, photoinitiator and dispersant to the mixture heated and stirred evenly in step b, and stir it at a low speed with a glass rod at a low speed of 50 rpm for 3 minutes. In this embodiment, the basic temperature of the thermochromic powder is 35°C.

Test Example 1

The temperature-sensitive reversible color-changing UV inks for PVC in Examples 1 to 5 were tested for hue, consistency and solid content, respectively. After passing the test, they were filtered with a wire mesh and evenly coated on the PVC. Then, put the ink coated on the PVC into an ultraviolet light irradiation box, and take it out after irradiating for 15 minutes to obtain samples 1 to 5, respectively.

The above samples were tested for performance.

The main performance test method in the test example of the present invention is as follows:

1) Inspection of light-fixing speed

Level 1: No stickiness. Touch the ink, no sticky feeling.

Level 2: No stickiness with thumb twist. With a downward pressure of about 5kg, rotate and twist the ink film with the thumb, and the ink film does not break.

Level 3: No scratch cure. The ink film is scratched with a fingernail without breaking.

2) Inspection of adhesion

Use a needle to scribe an X shape on the ink film, then stick cellophane tape to the notch, and pull to see if the ink film is pulled away from the glass substrate.

Level 0 (poor): The ink film with scratches can basically be pulled off;

Level 1 (moderate) has a small amount of ink film pulled off;

Level 2 (good) Very few ink films are pulled off;

Level 3 (excellent) did not come off at all.

3) Detection of resistance performance

The test method of ethanol resistance, acid resistance, alkali resistance and water resistance - soaking method is adopted, referring to the standard QB568-1983. Inspection principle: The dried ink samples are soaked in 1% sodium hydroxide solution, 1% hydrochloric acid solution, 95% ethanol solution and water, respectively, and the samples are taken out after soaking for 24 hours. The evaluation grades are as shown in Table 1. Show.

Table 1 Rating table of anti-resistance performance

The test results are shown in Table 2 below. The results show that the UV ink prepared in the embodiment of the present invention can be directly cured under ultraviolet light, has excellent curing effect, and has excellent adhesion. In addition, the obtained sample has excellent resistance to resistance, acid resistance, alkali resistance, ethanol resistance, water resistance, good quality, long service life, and has broad market application prospects.

Table 2 Performance Results Table

To sum up, the temperature-sensitive reversible color-changing UV ink for PVC in the embodiment of the present invention uses epoxy acrylic resin as a prepolymer, and temperature-sensitive color-changing powder as a pigment. High-quality temperature-sensitive reversible color-changing UV ink. It has the function of temperature-sensing and reversible discoloration, and has a wide range of raw material sources and low cost. It can be used in packaging anti-counterfeiting printing. It has the advantages of convenient, fast and accurate detection, and does not require additional auxiliary equipment. It has a wide range of packaging anti-counterfeiting printing. application prospects. The preparation method is simple, easy to operate, convenient to use, and short curing time. The obtained product has good curing performance, strong adhesion, acid and alkali resistance, water resistance and organic solvent resistance, and has broad application prospects.

The above-described embodiments are some, but not all, embodiments of the present invention. The detailed descriptions of the embodiments of the invention are not intended to limit the scope of the invention as claimed, but are merely representative of selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Claims (1)

1. A temperature-sensitive reversible color-changing UV ink for PVC, in percentage by weight, its raw material is made up of the following components: epoxy acrylic resin 37.41%, hexanediol diacrylate 45.35%, trimethylbenzoyl Diphenylphosphine oxide 6.02%, active amine 3.74%, active content polymer dispersant 1.2%, silicone oil defoamer 1.02%, thermochromic powder 5.26%; The temperature-sensitive reversible color-changing UV ink for PVC is prepared according to the following steps: a. Preparation of materials: the epoxy acrylic resin, hexanediol diacrylate, active amine, silicone oil defoamer, active content polymer type dispersant and temperature-sensitive color-changing powder are weighed one by one according to the above-mentioned raw material composition for use. b, take trimethylbenzoyl diphenyl phosphine oxide as a backup; the active amine is composed of trimethylolpropane triacrylate, diethylamine, and a polymerization inhibitor; b. Pre-mixing: The epoxy acrylic resin, hexanediol diacrylate, active amine, and silicone oil defoamer prepared in step a were weighed and prepared in a water bath at a constant temperature of 75°C for 150 rpm. Stir it at a low speed of /min for 18 minutes; c. Pigment dispersion: add the temperature-sensitive color-changing powder, trimethylbenzoyl diphenylphosphine oxide, and active content polymer type dispersant to the mixture heated and stirred uniformly in step b, and use a glass rod at 50 rev/min. Mix it evenly on low speed for 5 minutes.