JP3984407B2 - Glass products - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to glass products such as glass bottles and glass tableware.
[0002]
Conventionally, a glass product such as a glass bottle is often coated by applying a solid lubricant (mainly polyethylene) coating liquid on the surface (mainly the outer surface) of the glass product near the outlet of the slow cooling furnace (so-called cold end). By performing such coating, the glass product is provided with slipperiness and scratch resistance, and the strength of the glass product is improved.
[0003]
[Problems to be solved by the invention]
When such a coating is applied to a glass product, slipperiness and scratch resistance are imparted, while the coating surface becomes hydrophobic, and there is a problem that dirt is easily attached. The cause of the dirt is mainly oily dirt adhering to a guide such as a conveyor for conveying the glass product, and the dirt is transferred to the surface of the glass product in the course of conveying the glass product by the conveyor.
[0004]
In addition, the adhesiveness of the glass product surface is reduced by the coating, and there is a problem that the label is easily peeled off when the label is applied to the surface.
[0005]
An object of the present invention is to make the surface of a glass product that has been subjected to a coating treatment difficult to get dirty and to improve label adhesion.
[0006]
[Means for Solving the Problems]
In the present invention, a cellulose derivative such as carboxymethyl cellulose and hydroxyethyl cellulose is added to a material in which a fine solid lubricant is present in an emulsion state in water so that the weight ratio of the cellulose derivative to the solid lubricant is 1 to 20: 1. It is a glass product characterized in that a mixed coating liquid is applied at a cold end of a glass product molding process to form a coating film on the surface.
[0007]
The coating liquid in the conventional coating is not mixed with a cellulose derivative , and a coating film of only a solid lubricant (mainly polyethylene) is formed on the surface of the glass product, but by mixing the cellulose derivative with the coating liquid, A cellulose derivative is mixed in the coating film, and wettability is imparted to the surface.
[0008]
By imparting wettability to the surface, it becomes difficult for oily stains to be attached, and even if attached, it is easy to drop in the water washing step. Moreover, the adhesiveness by preferable pastes, such as starch paste, improves because the surface approaches hydrophilicity.
[0009]
As the solid lubricant, polyethylene, polyethylene wax, modified polyethylene wax, carnauba wax or a mixture thereof can be used. In particular, since carnauba wax itself contains a hydrophilic group, the hydrophilicity of the coating film surface is further improved.
[0010]
Cellulose derivatives, carboxymethyl cellulose, hydroxyethyl cellulose, and the like.
[0011]
The weight ratio of the cellulose derivative to the solid lubricant in the coating solution is desirably 1 to 20: 1. If the amount of the hydrophilic substance is less than this, the antifouling effect and the adhesion improving effect are not sufficient, and if it is too much, the strength and the slipperiness are adversely affected.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
A glass bottle with a capacity of 160 ml hot-coated with sulfurous acid gas was collected, heated as a pretreatment at 400 ° C. for 1 hour, and after natural cooling to 130 ° C., the coating solution was sprayed onto the outer surface of the glass bottle (60 ml / ml ). The glass bottles of Examples 1 to 4 and Comparative Examples 1 and 2 were prepared. Moreover, the coating liquid was coated by the dipping method on the surface of the glass plate, and the glass plate of Examples 5-7 and the comparative example 3 was created. In these coating liquids, the solid lubricant is polyethylene, the cellulose derivative is carboxymethylcellulose (hereinafter abbreviated as “CMC”), and the concentration ( wt %) is as follows (the CMC is not added in the comparative example).
Example 1: Polyethylene 0.2%, CMC 0.1%
Example 2: Polyethylene 0.2%, CMC 0.2%
Example 3: Polyethylene 0.2%, CMC 0.4%
Example 4: Polyethylene 0.13%, CMC 0.26%
Example 5: Polyethylene 0.1%, CMC 0.04%
Example 6: Polyethylene 0.1%, CMC 0.08%
Example 7: Polyethylene 0.1%, CMC 0.16%
Comparative Example 1: Polyethylene 0.2%
Comparative Example 2: 0.13% polyethylene
Comparative Example 3: 0.1% polyethylene
[0013]
A soil adhesion test was performed on each of the six glass bottles of Examples 1 to 3 and Comparative Example 1. In this dirt adhesion test, a line simulator with a glass bottle set is rotated at a predetermined speed (33 BPM) while warm water (50 ° C) is applied to the glass bottle, and the dirt adhering to the guide of the line simulator is applied to the glass bottle. This was done by attaching and evaluating the appearance. In the glass bottle of Comparative Example 1, all six bottles were contaminated. In the glass bottles of Example 1, dirt was adhered to all six bottles, but the degree of adhesion was less than that of Comparative Example 1. In the glass bottle of Example 2, dirt was attached to three bottles, and no dirt was attached to the three bottles. As for the glass bottle of Example 3, dirt adhered to one, and no dirt adhered to five bottles. Thereby, it was confirmed that the adhesion of dirt decreased as the amount of CMC added increased. Example 3 in which the ratio of polyethylene to CMC was 1: 2 had the most excellent antifouling effect.
[0014]
A strength test was performed on the glass bottles of Example 4 and Comparative Example 2. The internal pressure test, vertical load test, mechanical impact test and running impact test were performed after the outer surface was scratched for 2 minutes. The lubricity angle test was performed on an undamaged glass bottle. The results are shown in Table 1, and it was confirmed that Example 4 and Comparative Example 2 had substantially the same strength and lubricity.
[Table 1]
[0015]
For Examples 5 to 7 and Comparative Example 3 , the material breakage rate was measured in order to evaluate the adhesiveness. The material breakage rate is expressed by the ratio of the area of the label where the label is affixed to the bottle with the starch paste with the specified method. The larger the value, the better the adhesion. It will be. As a result, Comparative Example 3 was 0%, Example 5 was 49%, Example 6 was 35%, and Example 7 was 100%. It was confirmed that the adhesion was improved by adding CMC to the coating solution. It was. FIG. 1 is a graph of this result, with the horizontal axis representing the amount of CMC mixed (wt%) and the vertical axis representing the material breakage rate (%).
[0016]
The coating liquids of Examples 1 to 3 and Comparative Example 1 were examined for wettability and water repellency. The coating solutions of Examples 1 to 3 and Comparative Example 1 were coated on the surface of the glass plate by the dipping method to prepare samples. In order to investigate the wettability, a water drop was dropped on the sample, and the shape of the water drop was evaluated. In Comparative Example 1 , water droplets greatly increased. From Example 1 to Example 3 , the way of rising gradually became smaller and the spread became larger. Thereby, it was confirmed that wettability became large, so that the addition amount of CMC was increased. In the water repellency test, the sample was dipped in a white liquid (DDI) and then pulled up, and the sample was vertically evaluated for the remaining amount of the white liquid on the sample surface. In Comparative Example 1, almost no white liquid remained. In Example 1 , the white liquid remained on almost the entire surface of the sample, but the remaining amount was small, and the transparent part was more. In Examples 2 and 3, the entire surface of the sample was pure white, and the white liquid remained without any gaps. Thereby, it was confirmed that water repellency became small, so that the mixing amount of CMC was increased.
[0017]
【The invention's effect】
The glass product of the present invention maintains the same strength and slipperiness as a conventional coated glass bottle, has little dirt adhesion, and has excellent label adhesion.
[Brief description of the drawings]
1 is a test result of material breakage rates of Examples 5 to 7 and Comparative Example 3. FIG.

Claims (2)

Coating liquid in which a cellulose derivative such as carboxymethyl cellulose and hydroxyethyl cellulose is mixed with a material in which fine particulate solid lubricant is present in an emulsion in water so that the weight ratio of the cellulose derivative and the solid lubricant is 1 to 20: 1. A glass product characterized in that it is applied at the cold end of the glass product molding process to form a coating film on the surface.   2. The glass product according to claim 1, wherein the solid lubricant is polyethylene, polyethylene wax, modified polyethylene wax, carnauba wax or a mixture thereof.

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