JPS58108285A - Antistatic agent - Google Patents

Abstract

PURPOSE:To obtain titled agent capable of exhibiting antistatic and fog-preventive effect for plastics, comprising a water-soluble acrylic resin, a polyoxyethylene sorbitan ester and/or a N-hydroxyethyl-N-hydroxy-alkylamine. CONSTITUTION:The objective composition can be obtained by dissolving in water (A) 10-90 (pref. 30-50)pts.wt. of a water-soluble acrylic resin and (B) 90-10 (pref. 70-50)pts.wt. of, pref., a 12-18C-polyoxyethylene sorbitan fatty acid ester and/or a 8-18C N-hydroxyethyl-N-hydroxyalkylamine[pref. of formula (n: 8-18)]. EFFECT:Improving wetting to plastic surface, thus leading to uniform coating in the form of a perfect aqueous solution.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface-coating type antistatic agent that is applied to the surface of plastic to prevent charging.

Plastic sheets, films, etc. are often used in the field of packaging containers, etc., and are generally desired to have antistatic ability and transparency. In particular, packaging for items containing water; the plastic used (if any, it is desirable to have transparency and the ability to prevent fogging. Antifogging agents and antifogging agents are applied.

However, water-soluble acrylic resin, which is known as a surface-applied antistatic agent, has a slow dissolution rate in water and requires a long time to prepare an aqueous solution. It is more poorly soluble than water, making it difficult to apply with a printing machine that requires a short drying time, and furthermore, after applying it to a sheet (= if this sheet is thermoformed by means such as vacuum forming, it will be charged). The disadvantage is that the antistatic ability decreases.Also, polyoxyethylene sorbitan fatty acid ester and N-hydroxyethyl-N-hydroxyalkylamine, which are also known as antistatic agents, can be used in plastics by making an aqueous solution of them. If applied to the surface, the surface will not be uniformly wetted and water droplets will aggregate, making it necessary to use a solvent such as alcohol, which will inevitably worsen the working environment, and require a large amount of money to recover the used solvent. The problem is that it requires capital investment.

In view of this, the inventors of the present invention have conducted extensive research into a coating-type antistatic agent that is completely water-soluble, easy to prepare and apply as an aqueous solution, and has an excellent antistatic effect. contains water-soluble acrylic resin, polyoxyethylene sorbitan fatty acid ester and/or N
-By blending with -hydroxyethyl-N-hydroxyalkylamine, the poor solubility of water-soluble acrylic resin in water is eliminated, and polyoxyethylene sorbitan fatty acid ester and N-hydroxyethyl-N-
The wetting of hydroxyalkylamine to the plastic surface has been improved, and it can be uniformly applied to the plastic surface by means such as a roll coater or spray in a completely aqueous solution without using any solvents such as alcohol, and The present invention was achieved based on the discovery that a good antistatic effect or an excellent antifogging effect can be exhibited even after thermoforming such as vacuum forming.

That is, the present invention provides a glue-type antistatic agent for plastics containing a water-soluble acrylic resin, a polyoxyethylene sorbitan fatty acid ester, and/or an N-hydroquine-N-hydroxyalkylamine.

In the present invention C, the water-soluble acrylic resin is polyacrylic acid obtained by hydrolyzing polymethyl acrylate with an alcoholic alkali, or by polymerizing hetamine acrylic acid, or its sodium salt or ammonium salt, or A monomer having an acid group such as acrylic acid, methacrylic acid, maleic anhydride, itaconic acid and an acrylic ester or methacrylic ester are mixed in a hydrophilic organic solvent such as a lower alcohol or dioxane in the presence of a conventional polymerization catalyst (
Examples include those obtained by double copolymerizing and neutralizing the acid groups in the polymer with a base. Further, the water-soluble acrylic resin may be of the amphoteric ion type or the positive ion type, but is preferably of the amphoteric ion type.

Examples of the water-soluble acrylic resin include amphoteric or positive ion type acrylic water-soluble resins that are commercially available as antistatic agents in the form of an aqueous solution (containing some alcohol) with a concentration of 10 to 40% by weight. be able to.

The polyoxyethylene sorbitan fatty acid ester used in the present invention is preferably an ester of a fatty acid having 12 to 18 carbon atoms, and N-hydroxyethyl-N
The -hydroxyalkylamine is preferably one represented by the following general formula, where n is 8 to 18.

Note that polyoxyethylene sorbitan fatty acid ester and N-hydroxyethyl-N-hydroxyalkylamine are usually commercially available in the form of a solution such as an aqueous solution, so it is advantageous to use this.

The blending ratio of polyoxyethylene sorbitan fatty acid ester and/or N-hydroxyethyl-N-hydroxyalkylamine to the water-soluble acrylic resin is preferably 90 to 10 parts by weight per 10 to 9011r parts of the water-soluble acrylic resin. is 30 to 60 parts by weight (2 to 70 parts by weight)
~50 parts by weight.

The antistatic agent of the present invention combines both polyoxyethylene/sorbitan fatty acid ester and N-hydroxyethyl-N-hydroxyalkylamine with a water-soluble acrylic resin, or polyoxyethylene/sorbitan fatty acid ester or N-hydroxyethyl-N-hydroxyalkylamine. - It can be obtained by stirring and mixing either one of the hydroxyalkylamines and the water-soluble acrylic resin with a predetermined amount of water. In this case, a small amount of alcohol or the like may be added as necessary to promote dissolution. In addition, other chemicals such as a stabilizer may also be present as required. In addition,
When a commercially available solution of water-soluble acrylic resin, polyoxyethylene sorbitan fatty acid ester, or N-hydroxyethyl-N-hydroxyalkylamine is used, the components contained therein are naturally present.

In this case, the concentration should be considered when determining the mixing ratio. Furthermore, the concentration of the antistatic agent of the present invention can be made higher than the concentration at the time of use, and the antistatic agent can be diluted at the time of use.
The total amount of water-soluble acrylic resin, polyoxyethylene sorbitan fatty acid ester and/or N-hydroxyethyl-N-hydroxyalkylamine calculated as pure product is 0.
．． It is appropriate to set the concentration to about 0.08 to 5.0 weight.

In addition, water-soluble acrylic resin, polyoxyethylene,
Sorbitan fatty acid ester and/or N-hydroxyethyl-N-hydroxyalkylamine can be diluted to a predetermined concentration and then mixed, but these alone are extremely difficult to dilute with water. Therefore,
Water-soluble acrylic resin and polyoxyethylene sorbitan fatty acid ester and/or N-hydroxyethyl-N
- It is preferable to dilute with water in the presence of hydroxyalkylamine.

The antistatic agent of the present invention thus obtained can be applied to the surface of plastic by conventionally known means. If necessary, it can be further diluted with water to form a dilute aqueous solution. , a printing machine, a roll coater, a spray, etc.

Examples of plastics that can be treated with the antistatic agent of the present invention include transparent synthetic resins such as general-purpose polystyrene, high-impact polystyrene, polyethylene, polypropylene, polyacrylonitrile, polyvinyl chloride, and polymethyl methacrylate. However, it is not limited to these. In addition, it is preferable to use a transparent film or sheet shape for the coating.

The antistatic agent according to the present invention not only can be uniformly applied to the surface of plastic molded products in the form of an aqueous solution without using a solvent such as alcohol, but also has an excellent antistatic effect on plastics. Shows excellent anti-fog effect. This effect persists even after thermoforming such as vacuum forming. Furthermore, when applied to a transparent film, it imparts an excellent antistatic effect or a submerged antifogging effect in addition to the antistatic effect without causing blocking or impairing transparency.

Hereinafter, the present invention will be specifically explained using examples.

Example L Commercially available amphoteric ionic water-soluble acrylic resin (product name: YUKA 5T-1000, manufactured by Mitsubishi Yuka Co., Ltd.) and commercially available polyoxyethylene sorbitan fatty acid ester having 12 to 18 carbon atoms (manufactured by Matsumoto Yushi Confectionery Co., Ltd.) Product name: TB
-109) were allowed to coexist in water and mixed by stirring.

The obtained antistatic agent was an aqueous solution containing water-soluble acrylic resin α3 by weight, polyoxyethylene sorbitan fatty acid ester α45 by weight, and trace amounts of alcohols derived from the raw materials.

Example 2 Water-soluble acrylic resin used in Example 1 and carbon 8~
18 N-hydroxyethyl-N-hydroxyalkylamine (manufactured by Miyoshi Yushi Co., Ltd., product name: Dasper-125
BS) were allowed to coexist in water and mixed by stirring.

The obtained antistatic agent is a water-soluble acrylic resin α3 weight -
It was an aqueous solution containing 1N-hydroxylether-N-hydroxyalkylamine α45 by weight and trace amounts of alcohols derived from the raw materials.

Test Example 1 A transparent high-impact polyprene, which is a styrene-butadiene block copolymer with a styrene content of 76 weight and a butadiene content of 25 weight, was molded into a sheet with a thickness of α6. Above Example 1 and Example 2 on the surface
antistatic agent, and the water-soluble acrylic resin aqueous solution used as a raw material in each of the above examples as a comparative example, carbon number 12
~18 polyoxyethylene sorbitan fatty acid ester and N-hydroxyethyl-N-hydroxyalkylamine having 8 to 18 carbon atoms were each diluted with water to give 0.75% by weight.
An aqueous solution was prepared and applied to the surface of the upper layer to a thickness of 20 μm using a bar coater. Use this sheet 13
It was vacuum formed into a cup shape at 0°C. The half-life of the obtained cup-shaped molded product was measured using a static honest meter (manufactured by Shishido Shokai) at two points on the side wall (point 1 and point b) and two points on the bottom wall (point 8 and point d). In addition to measuring the antistatic properties, pour 70°C hot water into a 100 mA beaker, cover the top of this beaker with the above molded product, and place at each point I of the above a% b, e, and d. We checked the degree of cloudiness. The results are shown in Table 1, and the antistatic agents of Examples 1 and 2 of the present invention were superior to the comparative example in both honest meter half-life and degree of cloudiness. It has been found that the anti-static effect and the anti-fogging effect are exhibited.

Test Example 2 The impact-resistant polystyrene used in Test Example 1 was used to
0% film was formed and 3% of each drug used in Test Example 1 was formed.
Weight: Apply the aqueous solution to a thickness of 6μ with a percoater, dry with hot air, and then lay the coated sides of the film together, 5
A load of 0 g/c- was applied and the sample was left at 28°C for U hours, and the state of blocking on the contact surface was examined. The results are shown in Table 2, and both the antistatic agent of Example 1 and the actual weaving example were coated uniformly and transparently, and the blocking was also V.
It did not fit.

Chapter 1 Table No. 1 Goose Table *10 mark There is no or slight nib locking.

There is X-mark Ni blocking.

*20 mark: Evenly and transparently applied.

Δ mark: Slight coating unevenness is observed.

×: There is uneven coating.

Claims (2)

[Claims] (1) Water-soluble acrylic resin and polyoxyethylene
A coating type antistatic agent for plastics, characterized in that it contains sorbitan fatty acid ester and/or N-hydroxyethyl-N-hydroxyalkylamine. (2) 10 to 90 parts by weight of water-soluble acrylic resin and polyoxyethylene sorbitan fatty acid ester having 12 to 18 carbon atoms and/or 904 to 10 lO of N-hydroquinethyl-N-hydroxyalkylamine having 8 to 18 carbon atoms The coating type antistatic agent for plastics according to claim 1, which is obtained by dissolving the antistatic agent in water.