JPS5879028A - Treatment for antistatic prevention - Google Patents

Abstract

PURPOSE:To provide a synthetic resin having an ester bond with antistatic properties, by immersing it successively in a solvent capable of swelling the surface of the resin, an ether bond-containing solution having a reducing agent such as LiAlH4, etc. and an aqueous solution of an inorganic acid. CONSTITUTION:A synthetic resin having an ester bond (e.g., polymethyl methacrylate, polycarbonate, etc.) is immersed in (A) a solvent to swell the surface of the resin[a mixed solvent of hexane, heptane, etc. preferably containing 5- 45vol% THF], (B) an ether bond containing solution containing preferably >=2wt% reducing agent such as LiAlH4, NaBH4/AlCl3, Ca(BH4)2 a mixed solution of preferably 15-35wt% THF, 75-60wt% ethyl ether, 10-5wt% toluene, etc.), and (C) an aqueous solution of an inorganic acid (e.g., diluted aqueous solution of hydrochloric acid, etc.) for 1-5min for each solution respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel antistatic treatment method by chemically treating the surface of a synthetic resin.

Since many synthetic resins do not have hydrophilic or ionic groups, they have the disadvantage of being easily charged and charged with static electricity. One of the methods used is to apply an antistatic agent to the However, performance is not satisfactory (things are
The reality is that it has not yet been achieved.

The present inventor is currently studying various methods of imparting antistatic properties to synthetic resins having ester bonds, such as polymethyl methacrylate and polycarbonate, by chemically treating the surface thereof.
It was discovered that the problem could be solved by the following method. That is, the gist of the present invention is that after immersing a synthetic resin having an ester bond in a solvent (Al) having the ability to swell the surface of the resin, Ll'4, Na
A solution having an ether bond in which at least one of B H4/ All 'as, Cm(BH,) is present (
B) K immersion followed by immersion in an inorganic acid aqueous solution.

The present invention will be specifically explained below.

The synthetic resin having an ester bond according to the present invention can be used as a film, sheet, plate, or molded product without any problem.

Solvents that have the ability to swell the surface of the synthetic resin used in the present invention (for example, Al can include chloroform, methylene chloride, acetone, toluene, tetrahydrofuran, etc., and these may be used alone, but more Preferably, a mixed solvent with a solvent that does not have the ability to swell the synthetic resin surface, such as hexane, heptane, cyclohexane, etc., is used.The reactivity with LiAlHa and the smoothness and transparency of the synthetic resin surface after treatment are used. (solvent body)
A mixed solvent of tetranohydrofuran and hexane, heptane, cyclohexane, etc. is preferable as a tetranohydrofuran.
The content of hydrofuran is preferably 5 to 45 volumes.

Solutions having ether bonds (specific examples of Bl include tetrahydrofuran, ethyl ether, ethylene glycol diethyl ether, etc., and these may be used alone, but tetrahydrofuran,
A ternary mixed solution of ethyl ether and toluene, hexane, cyclohexane, heptane, etc. is preferable, and the mixing ratio of each solvent is 7 liters of tetrahydro ~ 50 / ethyl ether 80 ~ 45 /) luene etc. 1 0 ~ 5 volumes - More preferably, the ratio is 15 to 35% of tetrahydro 7 run/75 to 60% of ethyl ether/10 to 5% of volume, such as toluene.

The present invention uses a solution (LIJH4, Na as a reducing agent for Bl).
BH4/AlCJ11. The method is characterized in that Cm(BH*)t is used and a mixed solution of a solution that swells the resin and a solution that does not swell the resin is used as a solvent.

The amount of the reducing agent such as L I Ni H4 in the mixed solution is 0.
It is desirable that the amount is 5% by weight or more, more preferably 2% by weight or more, and there is no problem with the presence of an excessive amount.

Although the reason why the present invention exhibits a remarkable antistatic effect is not clear, the ester bonds of the synthetic resin undergo reductive hydrolysis, and the ester bonds are reduced to alcohol (-CH, OH), which gives rise to the antistatic effect. This seems to indicate that

The temperature at which the synthetic resin is immersed in the solvent (Al and solution (B) is *
There is no limit to the temperature, and temperatures around room temperature are preferred.

The immersion time is 30 seconds to 10 minutes for solvent (4), preferably 1 to 5 minutes, and 30 seconds to 10 minutes for solution (Bl)
Preferably it is 1 to 5 minutes.

Following these immersion operations, immersion in an inorganic aqueous solution for 1 to 5 minutes is an essential requirement for ensuring the transparency of the synthetic resin.

As the inorganic acid, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, etc. are used, but a dilute aqueous solution of hydrochloric acid is more preferable. The reason why the transparency of the synthetic resin is ensured by this operation is thought to be because the hydroxides of Li and H2 on the resin surface are removed by the inorganic acid.

Hereinafter, the present invention will be explained in detail with reference to Examples.

In addition, the antistatic ability is measured using a static honest meter (
The test was carried out by forcibly applying static electricity to the test piece using an electric shock absorber (manufactured by Shishido Co., Ltd.) and measuring its half-life (seconds). The smaller the number of seconds, the greater the antistatic ability.

Example 1 Polymethacrylic ester resin sheet (Mitsubishi Rayo/
Manufactured by Co., Ltd., product name Noibet W) 150X150X
LNkl
Tetrahydroara/30 with pH 410 weight dispersed
/ethylA/ When the antistatic ability was measured after immersion in an IN hydrochloric acid aqueous solution for 2 minutes, then washing with water and drying, the half-life was 1 to 0 seconds.

For comparison, the antistatic ability of an untreated sheet was measured in the same manner, and the half-life was 180 seconds or more.

Example 2 An experiment was conducted using the same pressure as in Example 1, except that the sheet was changed to polycarbonate or polymethyl methacrylate. The results were as shown in Table 1.

Experiments were conducted by changing the compound shown in Table 1 from Li MJH to the compound shown in Table 2. The results are shown in Table 2.

Happy 2nd table

Claims (1)

[Claims] After immersing a synthetic resin having an ester bond in a solvent that has the ability to swell the surface of the resin, "MH" NaBH4/k
ljceB, Ca(BHa)* (1) At least 1
An antistatic treatment method with two characteristics.