JPS5915360B2 - alkaline cleaning agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In order to remove dirt from the surfaces of hard objects such as glass, metals, and plastics, cleaning with an alkaline cleaning agent is widely practiced.

These alkaline cleaning agents usually contain a surfactant to improve their cleaning performance. However, these surfactants are foaming, and the large amount of foam they generate often causes problems in the cleaning process or necessitates changing the cleaning conditions. Therefore, silicone-based antifoaming agents and mineral oil (including surfactant)-based antifoaming agents have been used for antifoaming and foaming purposes, but silicones are expensive and difficult to use as antifoaming agents for alkaline cleaning. It also has the drawback of not being sufficiently effective, and especially lacking in sustainability. Mineral oil-based antifoaming agents have the disadvantage that they are not sufficiently effective, but there is also a concern that they may contaminate the objects to be cleaned, so they cannot be used at all for cleaning food and beverage containers, etc. An object of the present invention is to provide an antifoaming agent for use in known alkaline detergents containing foaming surfactants.

``0'' The present invention relates to a known alkaline detergent containing a foaming surfactant, which has a molecular weight of 1000 or more and is obtained by random or block addition polymerization of ethylene oxide and propylene oxide to a compound having 2 to 8 active hydrogen groups. is a polyether polyol in which the proportion of ethylene oxide in the molecule is 3 to 3 by weight.
10p of the polyether polyol which is 0'11o
The present invention relates to an alkaline cleaning agent characterized in that it contains an antifoaming agent of .mu.m or more.

”0 The above-mentioned known alkaline detergents containing foaming surfactants are not only used when they contain a surfactant added in advance as a component, but also because they saponify fats and oils adhering to the object to be cleaned on the spot. This also includes the production of soap.

5 The polyether polyol used as an antifoaming agent in the present invention contains ethylene oxide in the molecule with a
0%, preferably 10 to 20%, if the proportion of ethylene oxide is less than 3Qlo, or 3
If the amount is more than 0%, sufficient quenching:0 foaming effect cannot be obtained.

Further, the polyether polyol should have a molecular weight of 1,000 or more, and those with a molecular weight of less than 1,000 have little antifoaming effect.

In addition, the amount added is determined when the concentration in the alkaline cleaning solution is j510.
The ratio must be such that the concentration in the cleaning solution is 10 pμm or more, preferably 100 ppIn or more.
When it is less than 100%, the antifoaming effect will not be practical.

;q-These polyether polyols can be produced by random or blocked addition polymerization of ethylene oxide and propylene oxide to a compound having 2 to 8 active hydrogen groups by a known method.

Examples of compounds having 2 to 8 active hydrogen groups include ethylene glycol, propylene glycol, neopentyl glycol, 1,6-hexanediol, tetramethylene glycol, diethylene glycol, glycerin,
These include trimethylolpropane, pentaerythritol, diglycerin, atonite, arabitol, sorbitol, and sucrose. The antifoaming agent used in the present invention is added to a known cleaning agent or cleaning solution used for alkaline cleaning such as electrolytic cleaning of metals, spray cleaning, immersion cleaning, and ultrasonic cleaning of hard surfaces such as metals, glass, ceramics, and plastics. By doing so, it exhibits an effective and stable antifoaming effect over a long period of time.

In addition to defoaming foaming caused by surfactants, it also actively defoams foaming caused by surfactants added to soaps and oils that are generated from saponifiable components developed in the washing process. EXAMPLE Polyether polyols shown in Table 1 were synthesized by addition polymerizing ethylene oxide and propylene oxide to a compound having an active hydrogen group according to a known method.

The antifoaming properties of the polyether polyols shown in Table 1 were tested.

20 parts of sodium hydroxide was used as an alkaline cleaning solution, an antifoaming agent was added to it at the concentration shown in Table 2 (PP [11), 50ml was collected in a 100ml tube, and the mixture was heated at 50℃
and shaken at 80°C for 30 times/10 seconds, immediately and once.
The amount of foam (TI) was measured after minutes.

Furthermore, in Table 3, one part of a saponifiable substance (contaminant) consisting of 80 parts of Mobil oil and 20 parts of beef tallow was added to the alkaline cleaning solution, and the effect was observed. However, the nonionic surfactant used in the alkaline cleaning solution was a polyoxyethylene alkyl ether type nonionic surfactant HCB=14 (Neugen ET-143 manufactured by Daiichi Kogyo Seiyaku was used).

Next, some of the cleaning agents were selected and electrolytic cleaning was performed using the above-mentioned alkaline cleaning solution.

The results are shown in Table 4. The foamability test was conducted in the same manner as in Tables 2 and 3.

For electrolytic cleaning, a commercially available test piece was used as an iron plate to be cleaned, and paper sheets impregnated with 80 parts of Mobil oil and 20 parts of beef tallow were alternately stacked on top of each other, and treated under a pressure of 100°C and 100k9/0d for 3 hours (the amount of attached oil was 100η/7rI~200
η/M2) was polar cathodized. The electrolysis conditions are as follows. Electrolysis time: 2 seconds Current density: 4A/DTI Amount of alkaline cleaning agent used: 309/l Cleaning temperature: 80°C or higher The results show that all the products of the present invention are excellent in terms of defoaming and cleaning properties.

On the other hand, the comparative products partially affected the detergency and showed that there was a major problem with the foaming properties.

There is a noticeable difference especially when using alkaline cleaning solution!
It can be seen that VJΔ-VVUl-1-R' (0 occurs (foaming property with oil).

Claims (1)

[Claims] 1. In known alkaline cleaning agents containing foaming surfactants, antifoaming agents with a molecular weight of 1000 or more obtained by random or block addition polymerization of ethylene oxide and propylene oxide to a compound having 2 to 8 active hydrogen groups are used. polyether polyol with a proportion of ethylene oxide in the molecule of 3 to 30% by weight
An alkaline cleaning agent characterized by containing 10 ppm or more of the polyether polyol.