JPS6022662B2 - Method for manufacturing lightweight bottles with stable chemical durability and mechanical strength - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a lightweight pin having stable chemical and mechanical strength. More specifically, the present invention relates to a method for producing a lightweight bottle that effectively utilizes the thermal history of heat retained in the glass bottle and has stable chemical resistance and mechanical strength. Conventionally, glass pins with increased chemical durability and glass bottles with increased mechanical strength are well known individually, but in addition to effectively combining them, we have created a silk-based product that also has a lightweight effect. However, there is still no known glass bottle that efficiently and synergistically combines these effects to meet specific uses. Especially recently, b
There has been a sudden increase in demand for lightweight glass bottles that stably maintain mechanical strength and chemical durability for use in industrial applications.
The present inventor has previously proposed the special face proposed by the present applicant in 1973.
Based on the lightweight reinforced glass pin invented in No. 114554 (Japanese Unexamined Patent Publication No. 54-10792) entitled "Uniform and Thin-walled Tempered Glass Container and Method for Manufacturing the Same", as a result of intensive research to meet the above requirements, the invention The present invention has been completed as a new manufacturing process for lightweight reinforced glass pins with chemical durability based on the effective use and rational combination of. That is, in the present invention, the average actual body thickness X is 1.5 to
3.0 skin, minimum actual wall thickness of the torso X (1-0.3)
For glass bottles with a relationship of more than the ribs and a maximum actual wall thickness of the body less than the skin, dehydration is performed under high temperature conditions to form a low-concentration alkaline layer on the inner surface of the glass bottle. The first gist is to combine the step of performing alkali treatment and the step of performing ion exchange treatment to form a compressive stress layer on the glass surface. And, as a second gist, for the specific glass bottle,
Under the high temperature condition, a dealkalization process is performed to form a low concentration alkali layer on the inner surface of the glass bottle, and the alkali inside is replaced with another alkali beyond the low concentration alkali layer, and the glass surface is This method is combined with a step of performing ion exchange treatment to form a compressed layer. In the present invention, the average actual body wall thickness x is 1.
5 to 3.0 fence, and the minimum actual wall thickness of the same part of 8 is X(1-
0.3) Above the ribs, the maximum actual wall thickness at the same part of 8 is X (100.
3) A glass bottle with the following relationship is a bottle that does not have the extreme concavity on the inner surface of the bottle called a "hakama" formed by the conventional glass bottle molding method, and is designed to reduce the weight and strength of the bottle, especially mechanically. It contributes to uniformity in strength, and is mainly efficiently manufactured using the applicant's proprietary glass bottle forming technology called the H-1 process. In the treatment of this particular bottle, a major feature of the present invention is that a dealkalization treatment using ammonium sulfate, sulfur dioxide gas, chlorofluorocarbon gas, etc. is performed in a step prior to the ion exchange treatment. The chemical reaction on the heated glass surface caused by ammonium sulfate, sulfur dioxide gas, chlorofluorocarbon gas, etc. is well known, so it will not be described in detail, but this reaction forms a low-concentration alkaline layer on the glass surface, which means that it is chemically stable. A highly concentrated silica layer is formed, which improves chemical stability against the contents it comes into contact with. In the present invention, by forming a compressive stress layer by ion exchange on the glass surface layer with a thickness exceeding the low concentration alkali layer on the glass bottle surface, the chemical durability of the inner surface of the glass bottle can be improved. The combination of improved mechanical strength and improved mechanical strength due to the formation of balanced compressive stress layers on the inner and outer surfaces of the glass bottle provides glass bottles with stable mechanical strength and chemical durability. A combination of ion exchange treatment followed by dealkalization treatment should not be performed. This is because the compressive stress formed by the ion exchange treatment is relaxed by the temperature of the subsequent dealkalization treatment, making it difficult to obtain the desired strength. Therefore, a combination of ion exchange treatment after dealkalization treatment is essential. The ion exchange treatment method is a known method,
For example, it can be carried out by the molten alkali salt bath immersion method or the alkaline salt aqueous solution spray/heat treatment method, but the method described in Tokushu No. 52-13049 (Japanese Unexamined Patent Publication No. 54-63117) proposed earlier by the present applicant. A method of strengthening glass products can be employed very conveniently. Mochigan Showa 52-1304
The method for strengthening glass products No. 9 is to add an organic thickener that disappears during heat treatment to an aqueous solution or suspension of an alkali metal inorganic salt for ion exchange to form a paste-like fluid. It is characterized by applying the body to glass products and heat-treating them. Furthermore, in the manufacturing process of the glass bottle, SnC14 paper, SnC12 (C ratio) 2 vapor, SnC14 aqueous solution, etc. are misted or sprayed on the high temperature glass surface, especially the outer surface, before the dealkalization treatment. A highly hard tin oxide film is formed on the surface (other than that, titanium,
A metal oxide film can also be applied by applying an organic compound such as zirconium. ) The first film treatment step and the subsequent step of the ion exchange treatment step (
More specifically, after ion exchange treatment, cooling, washing residual potassium salt, and drying), fatty acids such as oleic acid, surfactants such as polyoxyethylene sorbitan monooleate, and olefins are added. By roughly combining the double coating treatment process with the second coating treatment process of coating an organic glass surface protective agent such as a synthetic resin such as a polymer or ethylene-methacrylic acid polymer, the scratch resistance strength can be improved. This can lead to prevention of decrease in mechanical strength. In the present invention, the glass bottle has an average actual body wall thickness X of 1.5 to 3.
．． He is an enemy, and the minimum actual chest thickness is × (1-0.3)
The reason why it was necessary that the maximum and thorax parenchymal thickness be less than or equal to x (100.3) sides is because of the mechanical strength when an ion-exchange compressive stress layer is applied to the glass surface and the This is based on the balance of weight reduction and was determined based on data. According to this, the average real body wall thickness x large 4 affects the weight reduction effect, which is inversely proportional to the increase in strength due to the glassware itself, and the average real body wall thickness and the minimum real body wall thickness The size of the difference in wall thickness affects the stability (uniformity) of mechanical strength. When the average actual arm thickness X is 1.5 mm, the weight reduction effect can be sufficiently achieved, but the balance with the glass pin strength is lost, making it difficult to put it into practical use. Therefore, X
= 1.5 skin or more is required. Also, X is 3. If the distance is exceeded, the object of the present invention, which is weight reduction, cannot be achieved.
Therefore, the range of X=1.5 to 3.0 ribs is most preferable because it provides a balance between light weight effect and strength depending on the usage mode. When the actual wall thickness of the body is less than the X(1-0.3) side, it means the existence of so-called "hakama", which is undesirable because it causes a decrease in strength and non-uniformity of strength. Furthermore, if the maximum actual wall thickness of the body exceeds x (100.3) ribs, the factors that lead to an increase in weight will be greater than those that will contribute to an increase in strength, and one of the objectives of the present invention will not be achieved. Note that the fluorocarbon gas is CC13F
, CC12F2, C2CI4F2, C2CI3F3, etc. Hereinafter, the present invention will be explained in more detail based on Examples. For thin glass bottles molded using the applicant's original press-and-blow method for thin glass bottles (H-1 process), high temperatures after molding (approximately 600 qo) are used.
), dimethyltin dichloride (SnC
12(CH3)2) Atomize and contact the gas, and spray S02 inside the bottle. The bottle was introduced and heat treated in a heating furnace (slow cooling furnace) to coat the outer surface of the bottle with a tin oxide film and dealkalize the inner surface of the bottle. After that, the bottle was mixed with the main component of potassium nitrate (KN03).
:K2S04=9:1) for about 10 minutes to perform ion exchange strengthening treatment. During this time, it is natural to avoid contact between the bottles as much as possible in order to strengthen the bottles without reducing their initial strength. The temperature of the salt melting bath was controlled to be higher than the melting point of the salt (460-49000). The treated bottles taken out of the molten salt rack are cooled, then washed and dried. Finally, an emulsion of ethylene-methacrylic acid polymer was sprayed onto the outer surface of the bottle, and a thin film of the polymer was applied to form a final product. Next, the measured values of each characteristic of the product of this example are compared to the product of comparative example (a conventional glass bottle subjected to the exact same strengthening treatment as in the example above) and the product of reference example [1] (the glass bottle described above). A lightweight glass bottle obtained from a process in which the dealkalization process was removed from the process in the example), Reference Example [D] product (a process in which the order of the dealkalization process and ion exchange strengthening process in the process in the example was changed) The results are shown in Table 1 in comparison with the measured values for each of the lightweight glass bottles (obtained from lightweight glass bottles). (This example product, comparative example product, reference example [1], [
0] Both products have the same external shape. ) Table 1 As is clear from Table 1, the products of the present invention are compatible with comparative examples and reference examples [1
],

Compared to [0], although it has the same shape and almost the same capacity, it is significantly lighter in weight.
The average values of internal pressure resistance strength and impact resistance strength have improved, and the remarkable effect is that the minimum value of each strength has increased and the variation in each strength has become smaller (standard deviation: small). It is. Furthermore, the importance of the combination of processes is clear from Mugiichi's data. It has excellent characteristics of stability and uniformity.

Claims (1)

[Scope of Claims] 1. Average actual body thickness X is 1.5 to 3.0 mm, minimum actual body thickness X (1-0.3) mm or more, maximum actual body thickness X (1-0.3) mm or more; A step of subjecting a glass bottle having a wall thickness of X(1+0.3) mm or less to a dealkalization treatment under high temperature conditions to form a low concentration alkali layer on the inner surface of the bottle, and then performing a dealkalization treatment on the glass bottle having a wall thickness of X(1+0.3) mm or less, and then treating the glass bottle with the low concentration alkali layer. Stable chemical durability characterized by the combination of a process of ion exchange treatment to replace the alkali inside the layer with another alkali and form a compressive stress layer on the glass surface. A method for manufacturing a lightweight bottle with mechanical strength. 2. Claim 1 which combines a first coating treatment step in which a metal oxide film is applied in a step before the dealkalization treatment step and a second coating treatment step in which an organic glass surface protective agent is coated after the ion exchange treatment step. A method for producing a lightweight bottle having stable chemical durability and mechanical strength according to item 1.