JP2607225B2 - How to remove formaldehyde - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing formaldehyde contained in wood, particularly in wooden chopsticks.

[0002]

2. Description of the Related Art Recently,
The present inventor has used commercially available wooden chopsticks (in general, cedar, willow,
Many are made of firewood, Ezomatsu, and birch. ) Was confirmed to contain formaldehyde.

The amount was 0.1 to 9.6 PPM as a result of measuring various samples.

[0004] It is well known that formaldehyde is harmful to the human body.

At present, the food sanitation law regulates the inclusion of formaldehyde in appliances and packaging materials, but there is no regulation on wooden chopsticks.

The present inventors have conducted various investigations as to why formaldehyde is contained in commercially available wooden chopsticks.

For example, does formaldehyde be contained in wood itself, which is a material for wooden chopsticks? In addition, during the process of manufacturing wooden chopsticks, a fumigation step is also performed for insect control, etc., and is formaldehyde contained in the wooden chopsticks by the fumigation step? After various investigations, the cause of formaldehyde contained in wooden chopsticks is unknown. However, in any case, it is clear that wooden chopsticks containing formaldehyde are commercially available.

[0008] The present invention provides a method of removing formaldehyde for efficiently removing formaldehyde contained in wooden chopsticks.

[0009]

The gist of the present invention will be described.

The present invention relates to a method for removing formaldehyde from wood containing formaldehyde, the method comprising boiling the wood in boiling water.

[0011] The present invention relates to a method for removing formaldehyde from wood containing formaldehyde, the method comprising leaving the wood in an anaerobic environment and in an alcohol atmosphere for a predetermined time.

A method for removing formaldehyde in wood containing formaldehyde, wherein a closed space containing a water-absorbing member impregnated with ethanol is provided, and the wood is disposed in the closed space. A method for removing formaldehyde, characterized in that an oxygen scavenger is disposed in the inside, carbon dioxide or nitrogen is filled in the sealed space, and the sealed space is left at a temperature of 10 ° C. or more and 70 ° C. or less for a predetermined time.

The present invention relates to a method for removing formaldehyde from wooden chopsticks containing formaldehyde, wherein the wooden chopsticks are boiled in boiling water.

A method for removing formaldehyde from wooden chopsticks containing formaldehyde, the method comprising leaving the wooden chopsticks in an anaerobic environment and in an alcohol atmosphere for a predetermined period of time. is there.

A method for removing formaldehyde in wooden chopsticks containing formaldehyde, comprising providing a closed space containing a water-absorbing member impregnated with ethanol, disposing the wooden chopsticks in the closed space, The present invention relates to a method for removing formaldehyde, comprising disposing an oxygen scavenger in an enclosed space, filling the enclosed space with carbon dioxide or nitrogen, and leaving the enclosed space at a temperature of 10 ° C. or more and 70 ° C. or less for a predetermined time. .

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is a summary of the results of the following experiments, which are summarized in the claims. As described above, the fact that formaldehyde is contained in wooden chopsticks is a fact that has not been known until now, and there has been no precedent for a method of removing formaldehyde.

First, the inventor tried an experiment in which wooden chopsticks (hereinafter, wooden chopsticks used in the experiment were made of cedar) were simply dried. However, drying alone has no effect because the formaldehyde removal rate is about 5 to 30%.
This is presumed that the protein in the wood is bound to formaldehyde, and drying alone does not remove formaldehyde.

The present inventor believes that formaldehyde is not naturally removed with the passage of time, but remains with the wood by binding to proteins in the wood with the passage of time. Therefore, it has been found that formaldehyde in wooden chopsticks that comes into contact with food needs to be removed somehow. This is the motivation for completing the present invention.

Next, the present inventor focused on the fact that formaldehyde is soluble, and conducted an experiment of boiling wooden chopsticks containing formaldehyde.

As a result, as shown in the following Table 1, it was confirmed that formaldehyde was removed well as expected.

[0021]

[Table 1]

However, the above-mentioned means of boiling is possible in ordinary households, but it is practically impossible to perform it on a wooden chopsticks production line, for example. That is to say, boiling means that the chopsticks get wet. Therefore, a drying step is indispensable after the boiling means, and the step becomes dry accordingly.

Therefore, the present invention carried out the following experiments 1, 2, and 3 in order to find a method capable of easily removing formaldehyde in a production line.

[Experiment 1] One wooden chopstick was cut finely (about 3 cm), wrapped in gauze, hung in a closed container containing 2 ml of a 99% ethanol solution, and left overnight at about 30 ° C. did.

[Experiment 2] Wooden chopsticks were irradiated with ultraviolet rays.

[Experiment 3] A sealed container was prepared in an anaerobic state (filled with carbon dioxide) with an oxygen scavenger, and a sponge impregnated with 2 ml of a 99% ethanol solution was provided at the bottom of the container. Wooden chopsticks were placed in the container and left at 30 ° C to 35 ° C for 15 hours and 30 minutes.

Here, the oxygen scavenger refers to a material that chemically absorbs oxygen. The oxygen scavenger used in this experiment 3 was “Gaspack CO ₂ system” (component: sodium hydrogen carbonate, citric acid) manufactured by BBL, and was approximately 5000 c
When the gas pack 1 co in a container m ³ Add with water 10 ml, within the container is 5-10% in 20 minutes to 30 minutes
(The atmospheric pressure does not fluctuate).

The results are shown in Table 2 below.

[0029]

[Table 2]

From the results shown in Table 2, it was found that formaldehyde was removed at a rate of 60.5% by combined use of ethanol in an anaerobic environment.

It is well known that formaldehyde takes the following oxidation process, and is said to be an easily oxidizable substance.

[0032]

(Equation 1)

The inventor of the present invention has found that formaldehyde has the property of being easily oxidized as described above and has the property of being easily dissolved in alcohol. Experiments 1 and 3 above were carried out under the inference that it might be possible.

Experiment 2 is an experiment conducted based on the hypothesis that irradiation of ultraviolet rays would excite the molecular motion of formaldehyde and formaldehyde would be decomposed.

Subsequently, the present inventor confirmed whether the factors exhibiting this removal rate are a, whether it is due to ethanol, b, whether it is due to an anaerobic environment, or c, whether it is due to a combination of the above a and b. In the sense that the following experiments 4 and 5 were performed.

[Experiment 4] In the same manner as in [Experiment 3],
The following four tests were performed.

Test 1. 5 ml of 99% ethanol + oxygen scavenger in the same amount as in Experiment 3 + 30 ° C. to 35 ° C./2 days Test 2. 5 ml of ethanol 5% + oxygen scavenger in 2 times the amount in Experiment 3 + 30 ° C. to 35 ° C. / 15 hours 30 minutes Test 3.99% ethanol 5 ml + the same amount of oxygen scavenger as in Experiment 3 + 60 ° C. to 70 ° C./15 hours 30 minutes Test 4. The same amount of oxygen scavenger as in Experiment 3 + 30 ° C to 35 ° C / 1
5 hours 30 minutes [Experiment 5] Formaldehyde was intentionally injected to grasp the effect of high concentration of formaldehyde, and wooden chopsticks with a formaldehyde content of about 10 PPM were used in the same manner as in [Experiment 3]. The following two tests were performed. still,
Test 6 is a test performed to determine the effect when the standing temperature is low.

Test 5.99% ethanol 5 ml + oxygen absorber 2 times the amount of Experiment 3 + 30 ° C. to 35 ° C./15 hours and 30 minutes Test 6.99% ethanol 5 ml + oxygen absorber as the same amount as Experiment 3 + 10 ° C./15 Time 30 minutes The results are as shown in Table 3 ([Experiment 4]) and Table 4 ([Experiment 5]).

[0039]

[Table 3]

[0040]

[Table 4]

From Tables 3 and 4 above, there is no effect only in the anaerobic state. There is no effect even when the storage temperature is high. There is no effect even when the storage temperature is low. The stronger the anaerobic state, the stronger the effect by adding ethanol. Was confirmed.

The method of leaving wooden chopsticks in an anaerobic environment and ethanol atmosphere as described above can be performed without any trouble on a wooden chopstick production line.
Therefore, it is possible to easily produce wooden chopsticks containing no formaldehyde.

[0043]

According to the present invention, as described above, formaldehyde in wood, especially wooden chopsticks, can be efficiently removed.

Claims (6)

(57) [Claims] 1. A method for removing formaldehyde from wood containing formaldehyde, the method comprising boiling the wood in boiling water. 2. A method for removing formaldehyde from wood containing formaldehyde, the method comprising leaving the wood in an anaerobic environment and in an alcohol atmosphere for a predetermined time. 3. A method for removing formaldehyde in formaldehyde-containing wood, comprising providing a closed space containing a water-absorbing member impregnated with ethanol, disposing the wood in the closed space, A method for removing formaldehyde, comprising disposing an oxygen scavenger in a closed space, filling the closed space with carbon dioxide or nitrogen, and allowing the sealed space to stand at 10 ° C. or more and 70 ° C. or less for a predetermined time. 4. A method for removing formaldehyde from wooden chopsticks containing formaldehyde, the method comprising boiling the wooden chopsticks in boiling water. 5. A method for removing formaldehyde from wooden chopsticks containing formaldehyde, wherein the wooden chopsticks are left in an anaerobic environment and in an alcohol atmosphere for a predetermined time. 6. A method for removing formaldehyde in wooden chopsticks containing formaldehyde, comprising providing a closed space containing a water-absorbing member impregnated with ethanol, and disposing the wooden chopsticks in the closed space. A method for removing formaldehyde, comprising disposing an oxygen scavenger in the enclosed space, filling the enclosed space with carbon dioxide or nitrogen, and allowing the enclosed space to stand at 10 ° C. or more and 70 ° C. or less for a predetermined time.