CLEANING AGENT FOR AIR-CONDITIONER RADIATOR

CLEANING AGENT FOR AIR-CONDITIONER RADIATOR

Technical Field

The invention pertains to the field of cleaning agents, and particularly, relates to a cleaning agent for an air-conditioner radiator.

Background Art

The air-conditioner radiator (also known as condenser) is generally placed outdoors or in front of the vehicle and thus stained by dusts, flying insects' bodies and fallen leaves and the like. The fins of the radiator have reduced heat dissipation ability after been stained or fouled, which results in that the air-conditioner has an inferior refrigerating effect. Thus, the cleaning of the air-conditioner radiator has become an important aspect of air conditioner maintenance.

The radiator fins are generally made of light-gauge aluminum which is easy to be corroded by a cleaning agent. The mildly alkaline cleaning agent provides good protection for aluminum, but has a poor cleaning performance. The acidic cleaning agent can offer excellent cleaning property, but needs a large number of corrosion inhibiting additives added to protect aluminum and other metal parts.

Thus, it is significant to develop a cleaning agent for an air-conditioner radiator which can effectively remove the contamination on the air-conditioner radiator while preventing the metallic surface of the fins from being corroded and providing a long-term protection.

Disclosure of the Invention

The invention has been made for the above purposes, and the present inventors have made an intensive research and found that the efficiency of a cleaning agent for removing dusts and greases on fins can be greatly improved and aluminum fins of the radiator and steel parts of the vehicle body can be protected, by using a specific combination of specific amounts of a fatty alcohol polyoxyethylene ether, an organic acid and a passivating agent. Therefore, the invention has been achieved. Therefore, according to an aspect of the invention, a cleaning agent for an air-conditioner radiator is provided, comprising: from 1 to 90 % by weight of a fatty alcohol polyoxyethylene ether; from 1 to 20 % by weight of an organic acid; from 0.1 to 10 % by weight of a quaternary ammonium type passivating agent; from 0 to 50 % by weight of a wetting agent; and deionized water for adjusting the total amount of the cleaning agent for the air-conditioner radiator to 100 % by weight.

As compared with the prior arts, the cleaning agent for an air-conditioner radiator according to the invention has the following advantages:

1. The specific combination of a fatty alcohol polyoxyethylene ether, an organic acid and a passivating agent can greatly improve the efficiency of the cleaning agent for removing dusts and greases on the fins; and

2. The specific quaternary ammonium type passivating agent has excellent corrosion resistance to metallic iron and aluminum and can protect aluminum fins of the radiator and steel parts of the vehicle body.

Description of the Drawings

Fig. 1 shows the temperature -time curves obtained when the cleaning agent composition F2 is used for a real car test.

Best Modes for Carrying out the Invention

The invention provides a cleaning agent for an air-conditioner radiator which can effectively remove dusts, greases and metal oxides on the air-conditioner radiator while preventing the metallic surface of the fins from being corroded and providing a long-term protection.

Specifically, the invention provides a cleaning agent for an air-conditioner radiator comprising: from 1 to 90 % by weight of a fatty alcohol polyoxyethylene ether; from 1 to 20 % by weight of an organic acid; from 0.1 to 10 % by weight of a quaternary ammonium type passivating agent; from 0 to 50 % by weight of a wetting agent; and deionized water for adjusting the total amount of the cleaning agent for the air-conditioner radiator to 100 % by weight. According to the invention, a fatty alcohol polyoxyethylene ether is used as a surfactant in the cleaning agent for an air-conditioner radiator. In the structure of the fatty alcohol polyoxyethylene ether, a carbon atom number of the fatty alcohol unit is from 12 to 14, and a number of the oxyethylene unit is from 7 to 9, and preferably 7. More specifically, the fatty alcohol polyoxyethylene ether has a structure represented by the following formula (I): wherein n is from 12 to 14, and m is from 7 to 9, and preferably 7. The preferable examples of commercially available fatty alcohol polyoxyethylene ethers are products AEO-7 and AEO-9 (trade names) available from Sasol company. According to certain embodiments of the invention, the content of the fatty alcohol polyoxyethylene ether in the cleaning agent for an air-conditioner radiator is preferably 2-20 % by weight, and more preferably 4- 10 % by weight based on the total weight of the cleaning agent for an air-conditioner radiator.

According to the invention, an organic acid is used in the cleaning agent for an air-conditioner radiator to remove the contamination. According to certain preferable embodiments of the invention, the organic acid is a carboxylic acid having 2 to 6 carbon atoms. More preferably, the organic acid is one or more selected from the group consisting of citric acid, acetic acid, oxalic acid and the like. The organic acid is most preferably citric acid. According to certain preferable embodiments of the invention, the content of the organic acid in the cleaning agent for an air-conditioner radiator is preferably 2- 10 % by weight, and more preferably 3-5 % by weight based on the total weight of the cleaning agent for an air-conditioner radiator.

According to the invention, the cleaning agent for an air-conditioner radiator further contains a passivating agent for inhibiting metal corrosion (also known as a metal corrosion inhibitor). According to certain preferable embodiments of the invention, the passivating agent is a quaternary ammonium type passivating agent. More specifically, the passivating agent is a quaternary ammonium reaction product of naphthenic acid, ethylenediamine dimer and benzyl chloride. The preferable examples of commercially available passivating agents are: a product of Lan826 (trade name) available from Beijing Blue Star Company; and a product of Dodicor 2725NF (trade name) available from Clariant Company. According to certain preferable embodiments of the invention, the content of the passivating agent in the cleaning agent for an air-conditioner radiator is preferably 0.1 -2 % by weight, and more preferably 0.5- 1 % by weight based on the total weight of the cleaning agent for an air-conditioner radiator.

According to the invention, the cleaning agent for an air-conditioner radiator may further contain a wetting agent defined as a class of substances which can reduce the surface tension of the cleaning agent and function to improve the wettability of the cleaning agent such that the cleaning agent more easily penetrates into the finny structure of the air-conditioner radiator so as to improve the cleaning effect. Preferably, the wetting agent is an alcohol having 1 to 18 carbon atoms. More preferably, the wetting agent is one or more selected from the group consisting of isopropanol, ethanol, stearyl alcohol and the like. Most preferably, isopropanol is used as the wetting agent. According to certain preferable embodiments of the invention, the content of the wetting agent in the cleaning agent for an air-conditioner radiator is preferably 3-20 % by weight, and more preferably 5-10 % by weight based on the total weight of the cleaning agent for an air-conditioner radiator.

In addition to the above listed components, the cleaning agent for an air-conditioner radiator according to the invention may further contain other additives such as pigments, dyes and flavors and the like according to requirements as long as the cleaning effect and corrosion resistant effect of the cleaning agent for an air-conditioner radiator according to the invention are not impaired.

According to the invention, the cleaning agent for an air-conditioner radiator may further contain deionized water for adjusting the cleaning agent for an air-conditioner radiator to a suitable concentration.

The cleaning agent for an air-conditioner radiator according to the invention can be prepared in a very simple way. Specifically, the components (for example, a fatty alcohol polyoxyethylene ether, an organic acid, a passivating agent, a wetting agent and distilled water) having corresponding weights can be weighted and homogenously mixed under stirring according to the practical requirements.

Testing Methods

In the invention, the properties of the samples obtained in examples are characterized by the following methods. 1. Test for cleaning performance

The cleaning performance of each formulation was evaluated by using man-made dusts in the test.

20 g of Shell helix super 1 OW-40 engine oil was placed in a 200 ml clean breaker. 40 g of S1O₂ (Shanghai Shantou Guanghua Chemical Reagent Co., Ltd.), 20 g of AI₂O₃ (Shanghai Shantou Guanghua Chemical reagent Co., Ltd.), 10 g of Fe203 (Shanghai Shantou Guanghua Chemical reagent Co., Ltd.), 20 g of CaO (Shanghai Shantou Guanghua Chemical reagent Co., Ltd.) and 10 g of MgO (Shanghai Shantou Guanghua Chemical reagent Co., Ltd.) were added to the breaker under stirring so as to prepare man-made dusts. Thereafter, a conventional filter device was prepared. A blank filter paper was weighted using an analytical balance, and the weight was recorded as Wl . 200 g of a cleaning agent sample was placed in a 500 ml of clean breaker. 10 g of the above prepared man-made dusts were added to the breaker and some dusts would be slowly dissolved by the cleaning agent. After 30 min., residual dusts were collected by filtering all materials through a filter device. The filter paper with the residual dusts were taken out and dried in an oven at 100° for 1 h. The filter paper was taken out from the oven and cooled to room temperature. Thereafter, the filter paper was weighted and the weight was recorded as W2.

The cleaning rate of the cleaning agent sample was calculated according to the following formula: Cleaning Rate = ( 10+W 1 - W2) ÷ 10 x 100%

The cleaning performance of the cleaning agent sample was calculated from the cleaning rate based on the following criterion:

2. Test for corrosion resistance of metal

The corrosion on aluminum and cast iron of each cleaning agent sample was evaluated in the test.

A Si9Cu4 aluminum strip (Shengxinda Metal Test Pieces Company) and a HT250 Cast iron strip (Shengxinda Metal Test Pieces Company) having a length of 10 mm, a width of 10 mm and a thickness of 1 mm were used for the test. Specifically, all surface blemishes were removed from all 6 sides of the metal strip with a 150# sand paper. The metal strip was finished using a 400# sand paper. The metal strip was immersed in a cleaning solvent isooctane for 5 min. The metal strip was removed from the cleaning solvent and the cleaning solvent isooctane on the metal strip was wiped off. The metal strip was weighted using an analytical balance, and the weight was recorded as Wl . Then, 100 g of a cleaning agent was placed in a 250 ml of plastic bottle with a cover. The metal strip was placed into the bottle and a cover was mounted thereon. Then, the plastic bottle was placed in the oven at 50° for 2 days or 1 month. Thereafter, the plastic bottle was taken out from the oven and the metal strip was taken out therefrom. The metal strip was immersed in the cleaning solvent and then taken out and the cleaning solvent was wiped off. The metal strip was weighted using an analytical balance and the weight was recorded as W2.

The corrosion rates of the cleaning agent sample on aluminum and cast iron were calculated according to the following formula:

Corrosion Rate= (Wl -W2)/W1 x 100%

In the above test, the greater the corrosion rate was, the more severe the corrosion of the cleaning agent sample on aluminum and cast iron was.

3. Real car test

The air-conditioner radiator of a Skoda Octavia 1.6 automobile driven for 59000 KM was tested using a cleaning agent sample in the test. The improvement degree of cooling rate of the air-conditioner radiator was used to evaluate the actual cleaning effect of the cleaning agent sample. The testing method was follows.

After cleaning the air-conditioner radiator using a cleaning agent sample, the air-conditioner was turned on and the temperatures of air output from the air-conditioner before and after the cleaning were monitored using a pen-type electronic thermometer (BOYANG TP3001). Timing was started from 25° and the temperature was recorded once every 30 seconds. If the output temperature of the pre-cleaned air-conditioner when it has been turned on for 5 min was recorded as Tl and the output temperature of the cleaned air-conditioner when it has been turned on for 5 min was recorded as T2,

Improvement degree of cooling rate = (Tl-T2)/(25-Tl)x l00%

Then, the temperature (°) of air output from the air-conditioner versus the recorded time

(min) was plotted.

Examples

The illustrated examples of the invention are detailed below. It would be understood that the range of the invention is not limited by these examples. The range of the invention shall be controlled by claims.

The raw materials used in the examples according to the invention were shown below.

Table 1

Product Name Chemical Name Supplier

AEO-7 Ethoxylated C12-C14 alcohols (N=7) Sasol

AEO-9 Ethoxylated C12-C14 alcohols (N=9) Sasol

citric acid citric acid Shangdong Lemon Biochemical acetic acid acetic acid Shangdong Lemon Biochemical ethanol ethanol Jinzhou Petro

IPA isopropanol Jinzhou Petro

stearyl alcohol 1 -stearyl alcohol Jinzhou Petro

Lan826 quaternary ammonium compound (N=3) Beijing Blue Star

Dodicor 2725NF quaternary ammonium compound (N=7) Clariant

Dl-water deionized water Xinda Example 1

10 g of AEO-7, 200 g of citric acid, 500 g of IPA and 100 g of Lan826 were added to 190 g of deionized water and homogenously stirred using a stirrer so as to produce a cleaning agent composition Fl (the cleaning agent composition comprises 1 % by weight of AEO-7, 20 % by weight of citric acid, 50 % by weight of IPA, 10 % by weight of Lan826 and 19 % by weight of Dl-water based on the total weight of the cleaning agent composition).

Examples 2 to 11

The cleaning agent compositions F2 to Fl 1 were produced in the same procedures as in the example 1, except that various components and contents thereof were changed as shown in

Table 2.

Table 2

Components (% by weight)

1 2 3 4 5 6 7 i 9 10 11

AEO-7

0 0 0 0 5 0

AEO-9

0

citric acid

0 .5 0 acetic acid

ethanol

0

IPA

0 0 0 0 stearyl alcohol

0

Lan826

0 .5 .1 .5 0

Dodicor 2725NF

.5 .5 deionized water

9 7.5 .9 4 4 4 4 7.5 7.5 0

Total

00 00 00 00 00 00 00 00 00 00 00 The above cleaning agent compositions Fl to F9 and an existing commercially available cleaning agent CI for radiator (see Table 3 for the components and contents thereof) were tested according to the above test of cleaning performance. The detailed results were shown in Table 4. Table 3

components (% by weight)

Alkylphenol polyoxyethylene ether

Fatty alcohol polyoxyethylene ether sodium sulfate

Sodium hydroxide deionized water

Table 4

examples/comparative examples pH Cleaning Rate /% performance

Fl 2.06 37.4 good

F2 2.63 51.2 very good

F3 3.19 32.3 good

F4 2.41 51.6 very good

F5 3.84 35.9 good

F6 2.40 50.3 very good

F7 2.40 48.1 good

F8 4.02 35.6 good

F9 3.67 21.4 normal

CI 10.72 9.7 very poor

It can be seen from the results shown in Table 4 that the acidic cleaning agent according to the invention has better cleaning effect as compared with the comparative cleaning agent (CI) for radiator as an alkaline cleaning agent. The cleaning agent compositions F 1 to F8 have an optimal cleaning performance.

The above cleaning agent compositions Fl, F2, F3, F8, F10, Fl 1 and the comparative cleaning agent (CI) for radiator were tested according to the above test of corrosion resistance of metal. The detailed results are shown in Table 5. Table 5

It can be seen from the results shown in Table 5 that the cleaning agent composition according to the invention has excellent ability of inhibiting the corrosion to aluminum and cast iron and is greatly superior over the comparative alkaline cleaning agent (CI) for radiator.

In addition, the cleaning agent composition F2 was tested according to the above real car test. The detailed results were shown in Table 1. It can be seen from the results shown in Table 1 that the output temperature of the pre-cleaned air-conditioner when it had been turned on for 5 min was reduced by 16.2°, while the output temperature of the cleaned air-conditioner when it had been turned on for 5 min was reduced by 17.6°. In other words, the cleaning rate over the initial 5 min is improved by 8.6%.

Although the invention has been described above in detail with reference to the examples and comparative examples, it should be noted that the invention is not limited to the examples and comparative examples. The invention may be changed or modified without departing from the range of the spirit of the invention.