JPH05132065A - Surface-treated glass bottle - Google Patents

Abstract

PURPOSE:To apply low adsorption and elution suppression property to a glass bottle so as to eliminate elution of glass composition to secure stability of content solution over a long time by forming a coating layer of silicone fluoride on an inner surface of the glass bottle. CONSTITUTION:This glass bottle 1 has low adsorption and elution suppression property applied to a glass bottle by forming a coating layer 2 of silicone fluoride on the inner surface, wherein coating solution for surface treatment mainly contains tetraethyl orthosilicate and perfluoroalkylsilane, which are mixed and stirred with a predetermined amount of water and alcohol to produce the solution. This coating solution is coated on the inner surface of the glass bottle and baked, thereby forming the coating layer 2 on the inner surface of the glass bottle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass bottle (automatic bottle, surface-treated so as to have low adsorption and elution suppressing properties).
(Including tube bottles), a method for producing a coating liquid for surface treatment used for imparting the above properties, and a method for producing a glass bottle using the coating liquid obtained by the production method.

[0002]

2. Description of the Related Art Conventionally, dimethyl silicone resin and fluororesin have been used as releasing agents, water repellents and oil repellents. For example, a dimethyl silicone resin layer, that is, a silicone coat, is formed on the inner surface of a glass bottle, an ampoule or the like. By applying the above method, water repellency is imparted to the glass surface and the adsorption of the content liquid is reduced.

On the other hand, when the constituent components of the glass bottle are dissolved into the content liquid of the bottle, it causes alteration of the content liquid, and therefore it is desired to suppress the dissolution as much as possible.

Therefore, a recovery rate test for investigating to what extent the adsorptivity is reduced (that is, recovery rate is improved) by applying the above-mentioned silicone coat, and how much elution is suppressed by the silicone coat A dissolution test was carried out for ruuka.

The bottle to be tested is a borosilicate glass bottle (capacity of 2 m) which is commercially available due to its excellent chemical durability.
1) was used, and a silicone-coated bottle having an inner surface coated with silicone and a non-treated bottle not subjected to any treatment were used for comparison.

In the recovery rate test, a bottle to be tested is filled with a prescribed amount of water, then the bottle is turned upside down to discharge the water, and the amount (weight) of the recovered water is filled (the weight). It was calculated by dividing by.

In the dissolution test, the same test bottle as above was filled with 90% of water, and was put in an autoclave for 121
After heat treatment at 60 ° C. for 60 minutes, the element eluted in water was quantified by atomic absorption spectrometry.

Table 1 shows the results of each of the above tests.

[0009]

[Table 1]

[0010]

From the above test, it was found that the recovery rate of the silicone-coated bottle was considerably higher than that of the untreated bottle, and the adsorptivity thereof was almost satisfactory. However, the elution concentration was not so different between the silicone-coated bottle and the untreated bottle, and it was found that the elution-inhibiting effect of the silicone coat could not be expected at all.

In general, when the content liquid of a glass bottle is an expensive liquid chemical, it is necessary to take out the last drop to efficiently use the liquid chemical. Therefore, it is desirable that the glass bottle has low adsorbability (high recovery rate). ing.

On the other hand, borosilicate glass is not easily attacked by water, and the content liquid is always neutral, so it is called neutral glass. However, it is not completely invaded by water, and as can be seen from the above-mentioned elution test, the glass constituents elute, although in a very small amount. Such a small amount of elution component not only impairs the stability of the content liquid by changing the pH value of the content liquid or causing precipitation,
May adversely affect the test specimen.

Therefore, according to the present invention, a glass bottle having a sufficiently low adsorptivity and a high elution suppressing effect by applying a surface treatment, a method for producing a surface treatment coating liquid used for imparting such properties, and the coating thereof. It is an object to provide a method for manufacturing a glass bottle using a liquid.

[0014]

In order to solve the above problems, the glass bottle according to the present invention is provided with a low-adsorption property and elution-inhibiting property by forming a coating layer of silicone fluoride on the inner surface. It is a thing.

The method for producing a coating liquid for surface treatment according to the present invention is characterized in that tetraethyl orthosilicate and perfluoroalkylsilane are used as main raw materials, and these are mixed and stirred with a predetermined amount of water and alcohol. Is.

The glass bottle manufacturing method according to the present invention is characterized by coating the inner surface of the glass bottle with the coating solution obtained by the above manufacturing method and baking the coating solution.

The above-mentioned tetraethyl orthosilicate is Si
Having a molecular formula of (C ₂ H ₅ O) ₄ , the silica glass (SiO ₂ ) substance that is a solid content is chemically bonded and firmly adheres to the substrate by hydrolysis, thereby suppressing the elution of the constituent components of the substrate. To form a coating film. The ratio as a raw material is used in the range of 21.9 to 43.8 wt%. 21.
If it is 9 wt% or less, the coating film becomes thin, and the elution suppressing effect decreases. On the other hand, when the content is 43.8 wt% or more, the coating solution becomes cloudy and a uniform coating solution cannot be obtained.

The above perfluoroalkylsilane has the following molecular formula.

CF ₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃ (KBM7103 manufactured by Shin-Etsu Chemical Co., Ltd.) CF ₃ (CF ₂ ) ₃ CH ₂ CH ₂ CH ₃ Si (OCH ₃ ) ₂ (KBM7402 manufactured by Shin-Etsu Chemical Co., Ltd.) CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (OCH ₃ ) ₃ (KBM7803 manufactured by Shin-Etsu Chemical Co., Ltd.) In the above molecular formula, the side chain perfluoroalkyl group has a characteristic of low surface energy peculiar to a fluorine compound. ,Water-repellent·
Exhibits oil repellency and reduces surface adsorption. At the same time, the coating film is chemically bonded to the surface of the substrate through oxygen from silicon and firmly adheres thereto. The ratio as a raw material is 3.0
% To 30.0 wt% is used. 3.0 wt%
When it is below, the contact angle of water droplets on the coat film becomes 90 ° or less, which is not desirable. On the other hand, if it is 30.0 wt% or more, the coating liquid becomes cloudy and a uniform coating film cannot be obtained.

A satisfactory value can be obtained by using KBM7803 alone, but it cannot be used frequently because the side chain is long and expensive. Therefore, a satisfactory contact angle can be obtained by mixing the above three kinds of KBM in appropriate amounts. For example, KBM
7103: KBM7402: KBM7803 = 8: 1:
A mixture of 1 is preferable.

Alcohol is an auxiliary raw material added to obtain a homogeneous solution and is used in the range of 59.4 to 26.2 wt%. If it is 26.2 wt% or less, a homogeneous coating solution cannot be obtained, and 59.4 wt% or more can be added, but it will not be added excessively because it affects the decrease of the solid content in the solution.

Water is added to hydrolyze tetraethyl orthosilicate, and the theoretical molar ratio of water to tetraethyl orthosilicate may be 2: 1, but in order to sufficiently carry out the hydrolysis reaction. Is preferably added in excess, and the above molar ratio is preferably 6: 1. If added more than this, the coating liquid becomes cloudy and does not become a homogeneous solution.

In the above-mentioned method for producing a coating liquid, in order to adjust the pH value of the coating liquid to around 3,
The required amount of hydrochloric acid is added as a catalyst.

[0024]

EXAMPLE A method for producing a coating solution used for producing a glass bottle having a coating layer of silicone fluoride on the inner surface, and an example of coating the inner surface of the glass bottle with the coating solution obtained by the method. explain.

First, an example of a method for producing a coating solution will be described. To a solution prepared by mixing 36.5 wt% tetraethyl orthosilicate and 13.2 wt% ethanol, add a predetermined amount of water, 13.2 wt% ethanol, and a required amount of hydrochloric acid as a catalyst and stir. To do. The addition of water causes the solution to generate heat due to the hydrolysis reaction. After stirring for 2 hours, 7.3 wt% perfluoroalkylsilane (mixed in the above ratio) and 11.0 w
t% methanol was mixed and stirred for 1 hour to obtain a coating solution for surface treatment.

Next, an example of a method for coating the inner surface of a glass bottle with the coating solution obtained by the above manufacturing method will be described.

First, the above coating solution was filled in a glass bottle made of borosilicate glass (capacity: 2 ml), allowed to stand for about 30 seconds, then discharged into another container, and the glass bottle was set in a centrifuge. Shake off the excess coating liquid. Then coat the coated glass bottle for 1 hour ~
After drying for 1 day, first in a precision thermostatic bath, first at 20 ℃ at 100 ℃
It is heated for a minute to volatilize unnecessary water and alcohol in the coating film, and is further heated at 360 ° C. for 20 minutes to bake the coating film. The baking temperature is preferably raised to near the heat resistant temperature of the glass bottle in order to strengthen the bond of the coating film, but it is necessary to be 360 ° C. or lower in order to prevent thermal decomposition of the fluoroalkyl group.

Thus, as shown in FIG. 1, a glass bottle 1 having a coating layer 2 of silicone fluoride on its inner surface was obtained.

[0029]

[Experimental Example] A glass bottle 1 (implemented product) having a coating layer 2 of a fluorosilicone obtained in the above-described examples was subjected to a recovery test and a dissolution test. These test methods are the same as those performed on the conventional products described above.

The results of the recovery rate test are shown in Table 1 and FIG. 2 together with the test results of the above conventional products. As is clear from the results of this test, it was found that the embodied product had properties equal to or higher than those of the silicone-coated bottle.

The results of the dissolution test are shown in Table 1 and FIG. 3 together with the test results of the above conventional product. As is clear from the results of this test, it was found that the actual products had a significantly higher dissolution inhibiting effect than the silicone-coated bottle and the untreated bottle.

[0032]

As described above, the surface-treated glass bottle according to the present invention has a sufficiently low adsorptivity and has an effect of suppressing elution. Further, when the coating liquid obtained by the production method of the present invention is coated on a substrate surface such as the inner surface of a glass bottle and baked, the adsorptivity of the substrate surface is reduced and the effect of suppressing the elution of the constituent components of the substrate is exerted. is there.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of a surface-treated glass bottle.

[Figure 2] Graph of recovery rate test results

3A and 3B are graphs of dissolution test results, respectively.

[Explanation of symbols]

 1 glass bottle 2 coating layer

Claims (3)

[Claims] 1. A surface-treated glass bottle, which is provided with a low-adsorption property and an elution-inhibiting property by forming a coating layer of silicone fluoride on the inner surface. 2. A method for producing a coating liquid for surface treatment, which comprises using tetraethyl orthosilicate and perfluoroalkylsilane as main raw materials and mixing and stirring them with a predetermined amount of water and alcohol. 3. A method for producing a surface-treated glass bottle, which comprises coating the inner surface of the glass bottle with the coating solution obtained by the production method according to claim 2 and baking the coating solution.