A method of grafting and modifying thin films by electron beam curing

Abstract

The invention relates to a method for grafting modification of a film by electron beam curing. The method includes the step of performing grafting polymerization on the film and a grafting monomer or oligomer. The method has the advantages that the surface of the non-polar polymer film is treated by a grafting method and can be permanently changed, the polar performance of the surface of the film is kept when the film is placed for a long time, expensive photo-initiators are omitted by the aid of electron beam curing, formula product cost is reduced, unpleasant smell cannot be generated by residual photo-initiators and migration and volatilization of photodecomposition products, the aging resistance of materials is facilitated, the film can be applied to packaging materials for food, medicines and the like, and electron beams are strong in penetrating power, high in action speed and the like, so that the electron beams are uniform in distribution in non-polar substrate surface treatment.

Description

technical field

[0001] The invention relates to the technical field of film modification, in particular to a method for grafting and modifying films by electron beam curing. Background technique

[0002] Polypropylene and polyethylene are the most commonly used films in food packaging. The poor direct printing performance of these surface non-polar film materials has always been a problem that needs to be solved urgently in the packaging and printing industry. Most of them need surface treatment before printing. Traditional methods mainly include chemical treatment, solvent treatment, coating treatment, flame treatment, and corona treatment, among which corona treatment is the most commonly used at present.

[0003] Corona treatment is an electric shock treatment that results in a higher adhesion of the surface of the printed object. It uses high-frequency and high-voltage corona discharge on the surface of the treated plastic to generate low-temperature plasma. These ions...

Examples

Embodiment 1

[0035] Example 1: Polyethylene film electron beam curing grafted acrylic acid

[0036] The polyethylene film is placed in a quartz glass container filled with acrylic acid (containing 0.15% polymerization inhibitor) solution (the polyethylene film is 60 parts by weight, the acrylic acid is 30 parts by weight, and the solvent is 100 parts) , compacted with a glass sheet, open the nitrogen valve, fill the nitrogen for a period of time, then turn on the electron accelerator, and act for a certain period of time (5-60s) under the action of energy 100-300kev and power 20kw. After completion, wash with warm water, and then wash away unreacted acrylic acid monomers on the surface of the polymer with chloroform, and dry to constant weight. The polyethylene grafted acrylic acid was obtained, and the specific grafting rate is shown in Table 1. The surface tension shown in Table 1 is the result obtained by measuring the polyethylene grafted acrylic acid obtained under the action of ener...

Embodiment 2

[0039] Example 2: Electron Beam Curing of Low Density Polyethylene Grafted Vinyl Acetate

[0040] Take two low-density polyethylene films, inject 20% vinyl acetate solution (pre-filled with nitrogen to remove oxygen) into the middle of the two films with a micro-syringe, gently press the film to spread the reaction solution evenly, and place it on a quartz glass plate , use an electron beam accelerator at a predetermined temperature (10-50°C) to irradiate with a certain energy. After the reaction, take out the film, dry it to remove unreacted monomers, dry the film and weigh it. Obtained low-density polyethylene grafted vinyl acetate, the specific grafting rate is shown in Table 2, the surface tension shown in Table 2 is the result measured by polyethylene grafted acrylic acid obtained under the action of energy 300kev for 60s.

[0041] Table 2

[0042]

Embodiment 3

[0043] Example 3: Polypropylene electron beam curing grafted N-isopropylacrylamide

[0044] Between the two polypropylene films to be grafted, inject a certain concentration of N-isopropylacrylamide solution (pre-filled with nitrogen to remove oxygen) and inject it into the middle of the two films and lightly press the film to spread the reaction solution evenly. The quartz glass sheet is irradiated with an electron beam accelerator at a predetermined temperature and a certain energy. After the reaction is completed, the film is taken out, dried to remove unreacted monomers, and the film is dried and weighed. The polypropylene grafted N-isopropylacrylamide was obtained, and the specific grafting rate is shown in Table 3. The surface tension shown in Table 3 is the result obtained by measuring the polyethylene grafted acrylic acid under the action of energy 300kev for 60s.

[0045] table 3

[0046]

[0047] In summary, the grafting rate of the grafted film prepared in this ...

technical field

[0001] The invention relates to the technical field of film modification, in particular to a method for grafting and modifying films by electron beam curing. Background technique

[0002] Polypropylene and polyethylene are the most commonly used films in food packaging. The poor direct printing performance of these surface non-polar film materials has always been a problem that needs to be solved urgently in the packaging and printing industry. Most of them need surface treatment before printing. Traditional methods mainly include chemical treatment, solvent treatment, coating treatment, flame treatment, and corona treatment, among which corona treatment is the most commonly used at present.

[0003] Corona treatment is an electric shock treatment that results in a higher adhesion of the surface of the printed object. It uses high-frequency and high-voltage corona discharge on the surface of the treated plastic to generate low-temperature plasma. These ions...

Examples

Embodiment 1

[0035] Example 1: Polyethylene film electron beam curing grafted acrylic acid

[0036] The polyethylene film is placed in a quartz glass container filled with acrylic acid (containing 0.15% polymerization inhibitor) solution (the polyethylene film is 60 parts by weight, the acrylic acid is 30 parts by weight, and the solvent is 100 parts) , compacted with a glass sheet, open the nitrogen valve, fill the nitrogen for a period of time, then turn on the electron accelerator, and act for a certain period of time (5-60s) under the action of energy 100-300kev and power 20kw. After completion, wash with warm water, and then wash away unreacted acrylic acid monomers on the surface of the polymer with chloroform, and dry to constant weight. The polyethylene grafted acrylic acid was obtained, and the specific grafting rate is shown in Table 1. The surface tension shown in Table 1 is the result obtained by measuring the polyethylene grafted acrylic acid obtained under the action of ener...

Embodiment 2

[0039] Example 2: Electron Beam Curing of Low Density Polyethylene Grafted Vinyl Acetate

[0040] Take two low-density polyethylene films, inject 20% vinyl acetate solution (pre-filled with nitrogen to remove oxygen) into the middle of the two films with a micro-syringe, gently press the film to spread the reaction solution evenly, and place it on a quartz glass plate , use an electron beam accelerator at a predetermined temperature (10-50°C) to irradiate with a certain energy. After the reaction, take out the film, dry it to remove unreacted monomers, dry the film and weigh it. Obtained low-density polyethylene grafted vinyl acetate, the specific grafting rate is shown in Table 2, the surface tension shown in Table 2 is the result measured by polyethylene grafted acrylic acid obtained under the action of energy 300kev for 60s.

[0041] Table 2

[0042]

Embodiment 3

[0043] Example 3: Polypropylene electron beam curing grafted N-isopropylacrylamide

[0044] Between the two polypropylene films to be grafted, inject a certain concentration of N-isopropylacrylamide solution (pre-filled with nitrogen to remove oxygen) and inject it into the middle of the two films and lightly press the film to spread the reaction solution evenly. The quartz glass sheet is irradiated with an electron beam accelerator at a predetermined temperature and a certain energy. After the reaction is completed, the film is taken out, dried to remove unreacted monomers, and the film is dried and weighed. The polypropylene grafted N-isopropylacrylamide was obtained, and the specific grafting rate is shown in Table 3. The surface tension shown in Table 3 is the result obtained by measuring the polyethylene grafted acrylic acid under the action of energy 300kev for 60s.

[0045] table 3

[0046]

[0047] In summary, the grafting rate of the grafted film prepared in this ...

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