JPS6392658A - Radical polymerization method in the presence of dissolved air oxygen to modify surface of high-molecular material - Google Patents

Abstract

PURPOSE:To carry out modification of the surface of a high-molecular compd. by radical polymn. easily and inexpensively with a simple apparatus, by adding a photosensitizing dye or periodic acid, etc. and carrying out irradiation with light without removing oxygen dissolved in monomers or a monomer soln. CONSTITUTION:A radical polymn. reaction is allowed to proceed to modify the surface of a high-molecular compd. without removing oxygen dissolved in monomers or a soln. thereof or purging it with an inert gas. The radical polymn. is carried out by adding a photosensitizing dye (e.g., riboflavin, methylene blue, eosine, flocesine, etc.) or periodic acid or a peroxide such as hydrogen peroxide to the monomers or the soln. thereof and carrying out irradiation with light.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is directed to the use of jl'-r+1. This invention relates to a method for polymerizing without removing atmospheric oxygen dissolved in the monomer or monomer solution or replacing it with an inert gas.

[Conventional technology] Conventionally, in order to advance a radical polymerization reaction.

Adding an excess initiator, introducing radical initiator species by plasma treatment or radiation irradiation, and removing oxygen in a reaction system by replacing it with an inert 'A' form such as nitrogen gas, It was necessary to perform deaeration. If the total radical concentration that can be generated in the reaction system is higher than the concentration that can be captured by dissolved oxygen, the polymerization reaction is possible even if step h is omitted, but polymers may be synthesized or generated. When the total radical concentration is low, the dissolved rv! It is essential to remove as much of the element as possible.

Regarding polymer surface modification by graft polymerization.

Although many methods have already been proposed, the current situation is that the degassing step increases the size of the equipment and the reaction time becomes longer. Therefore, even if an excellent graft polymerization method is established, this is one of the reasons why surface modification cannot be performed at low cost.

[Problems and Means to be Solved by the Invention] The present inventors have discovered that Ir (even if the concentration of the initiating species is low).

As a result of intensive research aimed at surface modification of polymeric materials by surface graft polymerization without interference from dissolved oxygen, the present invention was completed.

According to the present invention, light irradiation is performed by adding a photosensitizing dye such as riboflavin, periodic acid, or a salt thereof.

The photosensitizing dye referred to in the present invention is not particularly limited, and includes riboflavin (vitamin B2), methylene blue,
Dyes commonly used in photosensitized polymerization such as furosecin (uracin), eosin, and erythrosin may be used.

As a light source used for light irradiation, a high pressure mercury lamp is generally used, but a low pressure mercury lamp, a xenon arc lamp, a hydrogen discharge lamp, etc. may also be used. There is no need to use a filter to specifically cut out specific wavelength ranges from these light sources.

The features of the present invention are listed below.

1. Since the step of removing dissolved oxygen can be omitted, the radical polymerization reaction can be easily carried out.

2. The photosensitizing dye and periodic acid added to carry out radical polymerization in the presence of dissolved oxygen are not toxic.

3. The device that performs light irradiation is inexpensive and easy to handle.

Examples will be described below.

Examples] Acrylamide (hereinafter abbreviated as AAm) and N, N-
The concentration of riboflavin was 0.5 in each 10% by weight aqueous solution of dimethylacrylamide (hereinafter abbreviated as DMAA).
Add to give a concentration of 400
W high pressure mercury lamp (UV L-4 manufactured by Riko Kagaku Sangyo Co., Ltd.)
00HA type).

Light irradiation was performed for 30 minutes. Ten minutes after starting light irradiation, the optical density of the solution at 445 nm decreased to one-fifth of that without irradiation, and the viscosity of the IK polymer solution increased, >
It was found that the R combination reaction was progressing. After 30 minutes, the optical density decreased to one-tenth or less, the yellow coloring of riboflavin that had not been irradiated disappeared, and the solution had no fluidity at all.

However, polymerization hardly progressed at the interface with air, where there was a large excess of dissolved oxygen. In addition, when riboflavin of the same concentration was added to the same 01M body solution and the same concentration of f(f) was performed, polymerization hardly proceeded even under light irradiation of 1:1j[I, but after 4 hours the dissolved 6 I according to the present invention found that polymerization proceeded in the same manner as in the presence of oxygen
In the rC combination method.

Radical polymerization can proceed more effectively in the presence of dissolved oxygen at an appropriate temperature of 1°C.

Example 2 A silicone film was used, and a voltage of 9 kv was applied to the film for 2 m.
After applying corona discharge treatment for 80 seconds between the structures of m, this pretreated film was immersed in an aqueous solution of A m and DMA at the same concentration as in Example 1 without removing dissolved oxygen. Light irradiation was performed under the same conditions. It was found that by irradiating with light for 20 minutes, graft polymerization progressed on the silicone film surface at the same time as homopolymer production. After removing the homopolymer attached to the surface of the grafted film, it was dried and the contact angle with water was measured. 18° and 19° when graft polymerized
It was found that the water wettability was improved by 1%, and the surface was made hydrophilic by grafting.

Comparative Example Graft polymerization onto a silicone film was attempted in the same manner as in Example 2 without the corona radiation treatment.

It was found by contact angle measurement that although a homopolymer was produced when either the ΔAm or DMΔA monomer was used, graft polymerization did not proceed.

Example 3 A polyethylene film was used instead of a silicone film using a Pelger type plasma polymerization apparatus at 5 Kllz for 10
After a second glow discharge treatment, graft polymerization was carried out in the same manner as in Example. The contact angle on the surface of the grafted film was reduced to 15 to 20° even when AAm, DMAΔ, II+, and mercury were used.

Example 4 Graft polymerization was performed in the same manner as in Example 1 without pretreating a polyethylene terephthalate (hereinafter abbreviated as '1') film 11 instead of the silicone film. After drying, the contact angle on the surface of the grafted film 11 was 706 for the untreated 11ET film, whereas it decreased to 15 to 20° when either ΔΔm or DMAA was graft-polymerized. .

It has been found that graft-R bonding can be achieved in PET films without plasma pretreatment.

Example 5 Using a PET film, a monomer aqueous solution was mixed with sodium styrene sulfonate (NaSS), 2-acrylamide-2-
Graft polymerization was carried out in the same manner as in Example 4, except that loWL% aqueous solutions of methylpropanesulfonic acid (ΔMps), dimethylaminopropylacrylamide (DMAPAA), and acrylic acid (AA) were used. The contact angle of the graph 1-formed film is N a S S ,
AMPS, 1. ) MΔI) AA, the angles were 15°, 20°, 21°, and 25°, respectively, indicating that graft polymerization progressed and the 9 surfaces were made hydrophilic.

Example 6 Grafting was carried out under the same conditions as in Examples 4 and 5 except that PET cloth was used.
As a result of measuring the charging characteristics of the ET cloth, we found that the SKV applied voltage decreased during the lapse of time, and the Jf rubbing voltage against the cotton cloth also showed AA m, ΔA, DMAA, Na5S, Δ compared with the untreated sample.
When graft polymerizing MI) S and DMAPAA, 1/10, 1/20, 1/10 and 1/20, respectively.
, 1/5, and 1/100, and it was found that the charging property was greatly improved by grafting on two surfaces.

Example 7 Graft polymerization of ΔΔm was carried out in the same manner as in Example 1 except that riboflavin solutions of various concentrations were used. Riboflavin concentration is 1. XlO"mol/liter, lXl0-'
The contact angles of the t:r filter t1 obtained by light irradiation for 1 hour at mol/liter and IXLO-'' mol/liter were 60'', 30°, and 55°, respectively, and the riboflavin concentration to be added It was found that there is an optimal value for .

Example 8 A polymerization reaction was carried out under the same conditions as in Example 1, except that 1.0 x 10 -) mol/liter of sodium periodate t1 was used in place of riboflavin.

AAm,l by 2 hours of light irradiation in the presence of dissolved oxygen
) MΔΔ, it was found that the radical 1rC combination reaction proceeded in both cases.

Example 9 Experiments similar to those performed in Examples 4-6 were conducted using various concentrations of sodium periodate solutions. The concentration of sodium periodate is 6,6X10-5 mol/liter,
The contact angles of the grafted samples obtained by irradiation for 1 hour at 6.6 x IO' mol/liter and 1.0 x IO' mol/liter were 60', 21', and 55'', respectively. It was found that an optimum value exists for the addition 1.j even in the case of a sodium chloride solution.

Example 10 Example 8 except that hydrogen peroxide was used in place of sodium periodate. As a result of conducting an experiment similar to that in Example 9, it was found that almost the same amount of grafting was obtained even when hydrogen peroxide was used, and the contact angle was also reduced.

Claims (1)

[Claims] 1. Modification of the surface of a polymer compound by proceeding radical polymerization without removing atmospheric oxygen dissolved in the monomer or monomer solution or replacing it with an inert gas. Characteristic radical polymerization method. 2. The radical polymerization method according to claim 1, wherein the radical polymerization is carried out by adding a photosensitizing dye to the monomer or monomer solution and irradiating it with light. 3. The radical polymerization method according to claims 1 and 2, characterized in that riboflavin is used as the photosensitizing dye. 4. The riboflavin concentration added to the monomer or monomer solution is 10^-^5 to 10^-^3 mol/liter, according to claims 1 to 3. Radical polymerization method. 5. Radical polymerization according to claim 1, characterized in that radical polymerization is carried out by adding a peroxide such as periodate ion or hydrogen peroxide to a monomer or a monomer solution and irradiating it with light. Polymerization method. 6. Claims 1 to 2, characterized in that the concentration of periodate ion added to the monomer or monomer solution is 10^-^4 to 10^-^1 mol/liter. Radical polymerization method described in section.