JP2004196563A - Coating agent for glass vessel, coating method, and glass vessel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating agent which ensures such adhesiveness of a label as to cause no problem in ordinary use and enables easy stripping of a label from a glass vessel when a person strips the label intendedly. <P>SOLUTION: A silane coupling agent is added to a solid lubricant coating agent containing a solid lubricant and a surfactant for dispersing the lubricant in water. When a coating film is formed with the resulting coating agent, a label is made to be easy to strip. When silicone is further added to the coating agent, the strippability of a label is further improved and the lubricity of a bottle is also improved. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a coating agent applied to the outer surface of a glass container such as a glass bottle, a method of coating a glass container using the coating agent, and a glass container having the outer surface coated with the coating agent and having a label attached thereto. .
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a coating (so-called cold end coating) for applying a solid lubricant coating agent to an outer surface of a glass container has been performed near an outlet of a lehr (so-called cold end). By performing such coating, lubricity and scratch resistance are imparted to the glass container, and the strength of the bottle is improved. The solid lubricant coating agent is obtained by adding a surfactant to a solid lubricant such as polyethylene, polyethylene wax, modified polyethylene wax, and carnauba wax to disperse these fine particles in water to form an emulsion.
[0003]
When performing the above cold end coating, so-called hot end coating is often performed as a pretreatment. This is because a tin compound (mainly tin tetrachloride) or a titanium compound (mainly titanium tetrachloride) acts on the outer surface of the high-temperature glass container immediately after molding near the entrance of the lehr, and tin oxide or tin oxide is applied to the outer surface of the glass container. It forms a titanium oxide film. By performing the hot end coating, the adhesion of the cold end coating film to the glass surface is improved. In many cases, a glass container such as a glass bottle is coated with a label after being subjected to the hot end coating and the cold end coating described above.
[0004]
JP-A-2001-302284 and JP-A-2001-328613 disclose a technique that performs cold-end coating with the above-mentioned solid lubricant coating agent and enables label adhesion with starch glue having low adhesive strength. Normally, starch glue does not adhere to the solid lubricant coating film, but by adding a hydrophilic substance to the solid lubricant coating agent, it imparts hydrophilicity to the coating film and enables label adhesion with starch paste that has less environmental impact. Things.
[0005]
[Problems to be solved by the invention]
On the other hand, when the used glass container is collected and the glass is recycled, it is necessary to remove the label attached to the glass container. However, in the conventional glass container, it is complicated to peel off the label, and this point has been an obstacle in recycling the glass.
[0006]
The present invention relates to a coating agent and a coating method for a glass container which can easily peel off the label from the glass container when forcefully peeling off while having adhesiveness of the label which does not cause a problem in normal use. And a glass container.
[0007]
[Means for Solving the Problems]
The present invention provides a solid lubricant and a solid lubricant coating agent containing a surfactant for dispersing the same in water, wherein a silane coupling agent is added to the solid lubricant coating agent for a glass bottle, and A solid lubricant coating agent for glass bottles, characterized by adding a coupling agent and silicone.
[0008]
The silane coupling agent is represented by the general formula YSi (CH3) 3-nXn, X is halogen such as chlorine, OR (alkoxy group) or hydrogen, Y is an organic residue capable of reacting with an organic compound such as a polymer, Examples include vinyl, methacryl, epoxy, amino, and mercapto groups. As the silane coupling agent, for example, the following can be used.
Vinyltrimethoxysilane,
Vinyltriethoxysilane,
2- (3,4 epoxycyclohexyl) ethyltrimethoxysilane,
3-glycidoxypropyltrimethoxysilane,
3-glycidoxypropylmethyldiethoxysilane,
3-glycidoxypropyltriethoxysilane,
p-styryltrimethoxysilane,
3-methacryloxypropylmethyldimethoxysilane,
3-methacryloxypropyltrimethoxysilane,
3-methacryloxypropylmethyldiethoxysilane,
3-methacryloxypropyltriethoxysilane,
3-acryloxypropyltrimethoxysilane,
N-2 (aminoethyl) 3-aminopropylmethyldimethoxysilane,
N-2 (aminoethyl) 3-aminopropyltrimethoxysilane,
N-2 (aminoethyl) 3-aminopropyltriethoxysilane,
3-aminopropyltrimethoxysilane,
3-aminopropyltriethoxysilane,
3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine,
N-phenyl-3-aminopropyltrimethoxysilane,
Hydrochloride salt of N- (vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane,
Special amino silane,
3-ureidopropyltriethoxysilane,
3-chloropropyltrimethoxysilane,
3-mercaptopropylmethyldimethoxysilane,
3-mercaptopropyltrimethoxysilane,
Bis (triethoxysilylpropyl) tetrasulfide,
3-isocyanatopropyltriethoxysilane,
[0009]
The concentration of the silane coupling agent is suitably from 0.01 to 1 mass%. If it is less than 0.01 mass%, the effect of easy label peeling is small, and if it is more than 1 mass%, the adhesive strength of the label becomes too weak.
[0010]
As shown in FIG. 1, the silane coupling agent blended in the coating agent of the present invention becomes a silanol group SiOH by hydrolysis and binds to glass. On the other hand, the organic residue Y is a hydrophobic group, is exposed on the surface of the coating film, and comes into contact with the paste applied on the coating film.
[0011]
As the solid lubricant, those similar to those used for conventional solid lubricant coating agents can be used, and for example, polyethylene, polyethylene wax, modified polyethylene wax or carnauba wax can be used. Further, two or more solid lubricants may be mixed. To the coating agent of the present invention, a surfactant is added to disperse the fine particles of the solid lubricant in water to form an emulsion state. As the surfactant, for example, the same one as in the past such as potassium oleate can be used. Further, other additives such as a solid plasticizer may be added similarly to the conventional solid lubricant coating agent.
[0012]
Silicone is a polymer having a main chain composed of a siloxane bond and having a side chain of an organic group bonded to Si, and a general term for (RnSiO (4-n) / 2) n. For example, polydimethylsiloxane can be used. Since silicone has low biotoxicity, it can be safely added to coating agents for glass containers for food.
[0013]
The coating film formed by coating the conventional solid lubricant coating agent has some irregularities on the surface, but when silicone is added, the particles of silicone are very fine, so the surface of the coating film is smoothed, The adhesiveness of the adhesive is slightly reduced. In addition, since the silicone itself has a releasing property, the silicone particles are exposed on the surface of the coating film, so that the adhesiveness of the adhesive decreases. Therefore, by adding an appropriate amount of silicone to the solid lubricant coating agent, the label can be removed from the glass container when the label is to be forcibly peeled off while maintaining the adhesiveness of the label which is not a problem during normal use. It can be easily peeled off. Further, the addition of silicone increases the lubricity of the coating film.
[0014]
When adding silicone, the amount of silicone to be added should be 1 to 75% based on the total amount of the solid lubricant, silicone and surfactant in terms of bottle strength, scratch resistance, lubricity and easy release of the label. Appropriate.
[0015]
FIG. 2 is an explanatory view of a coating film formed by a conventional solid lubricant coating agent. In the figure, the upper part is a coating film formed on the glass surface (or the cold end coating film surface), and a solid lubricant (such as polyethylene wax) is adhered to the glass surface. There is a portion where the glass surface is exposed. The middle part of the figure shows a state in which a glue and a label are stuck on this coating film. The lower part of the figure shows a state where the label is peeled off. Since the glue adhered on the solid lubricant is easily peeled off, the label can be peeled off, but the glue adhered to the glass surface is hardly peeled off, and the label remains. For these reasons, it is presumed that it was difficult to remove the label from the glass container coated with the conventional solid lubricant coating agent.
[0016]
FIG. 3 is an explanatory diagram in which a coating film by the coating agent of the present invention is estimated. In the same figure, the upper part is a coating film formed on a glass surface (or a cold end coating film surface), and a solid lubricant (eg, polyethylene) is adhered to the glass surface, and a portion between the solid lubricant and the solid lubricant is not adhered. The silane coupling agent adheres to the glass surface. In the silane coupling agent, the lower silanol group adheres to the glass surface, and the upper side is an organic residue. Further, the surface of the solid lubricant is smoothed by exposing the silicon particles, and the releasability is also increased. The middle part of the figure shows a state in which a glue and a label are stuck on this coating film. The lower part of the figure shows a state where the label is peeled off. The glue adhering to the solid lubricant is more easily peeled off by the action of silicone, and the silane coupling agent has a weak bond between the silanol group and the glass surface, so that the entire label can be easily peeled off.
[0017]
The present invention is also a method for coating a glass bottle, characterized in that the solid lubricant coating agent of the present invention is applied to an outer surface of the glass bottle near an outlet of an annealing furnace in a glass container manufacturing process. The temperature of the glass container near the outlet of the annealing furnace is not particularly limited, and may be normal (around 100 ° C.). As a coating method, an appropriate method such as spraying, brushing, and soaking may be adopted. In the case of spraying, the flow rate of the coating agent is suitably from 25 to 500 ml / min. Drying of the coating agent after application may be air drying or forced drying, but air drying is usually sufficient.
[0018]
Further, the present invention is a glass container characterized in that the solid lubricant coating agent of the present invention is applied to the outer surface of a glass container to form a coating film, and a label is attached on the coating film. There is no particular limitation on the glue to which the label is attached, but for example, a normal starch-based synthetic glue or acrylic glue can be used.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
〔Example〕
The following components were mixed with water to prepare the solid lubricant coating agent of the example. The oxidized polyethylene wax is approved by FDA (Food and Drug Administration), and polydimethylsiloxane is a food additive.
Oxidized polyethylene wax + surfactant (nonionic): 0.225 mass%
Silane coupling agent (3-methacryloxypropyltrimethoxysilane): 0.2 mass%
Silicone (polydimethylsiloxane): 0.075 mass%
A tin oxide film was formed on the body of a glass bottle having a capacity of 120 ml by hot-end coating, and further, at a flow rate of 240 ml / min. A solid lubricant coating was applied. Thereafter, the coating agent was air-dried and allowed to cool naturally until the bottle temperature reached room temperature, and a label having a size of 40 × 150 mm was affixed to the formed coating film on the body of the bottle with a starch synthetic paste. It was created. The glue was applied using a bar coater # 7 so that the amount of glue was 0.5 g per label. The label affixed to this glass bottle was sufficiently resistant to normal packing, transportation, and use of the glass bottle and did not come off.
[0020]
(Comparative example)
The following components were mixed with water to prepare a solid lubricant coating agent of Comparative Example.
Oxidized polyethylene wax + surfactant (potassium oleate): 0.4 mass%
A tin oxide film was formed by hot-end coating on the body of a 120-ml glass bottle as in the example, and a flow rate of 250 ml / min was applied to the body of the glass bottle by a spray gun at the outlet of a lehr where the bottle temperature was gradually cooled to about 100 ° C. Was applied with the solid lubricant coating agent of Comparative Example. After that, the coating agent was air-dried and allowed to cool naturally until the bottle temperature reached room temperature.The same label as in the example was applied to the formed coating film on the body of the bottle using the same paste and the same method. Created a bottle. The label affixed to this glass bottle was sufficiently resistant to normal packing, transportation, and use of the glass bottle and did not come off.
[0021]
The label material breakage rate was measured for the bottles of the examples and the comparative examples that were left at room temperature for 24 hours after the label was applied. The label was peeled off from the four corners, and a value (%) obtained by dividing the remaining area by the original label area was defined as the material breakage rate. The smaller the numerical value of the material rupture ratio, the better the peelability of the label. The results (average) are as follows, and it was proved that the labels of the bottles of the examples were much easier to peel off.
Example: 0.5% (n = 10)
Comparative example: 42% (n = 5)
[0022]
The lubricating effect of the coating agents of the examples and the comparative examples was evaluated by measuring the slip angles of the bottles of the examples and the comparative examples before applying the label. The measurement of the slip angle was performed based on the Japan Glass Bottle Association Standard (established on June 15, 1977, revised on October 30, 1998) 7.14 Surface slip angle measurement method. This is a set of three glass bottles that are tilted in a bales stack and tilted to show the slipperiness of the bottle surface at the angle at which the bottle on top starts to move (measured at four locations for one set of bottles). ), The smaller the value, the greater the lubricity. The slip angle was measured for bottles treated with a line simulator and untreated bottles. A line simulator manufactured by American Glass Research Co., Ltd. was used. 36 bottles were placed on a rotating disk and rotated at a rotation speed of 33 bpm for 5 minutes while sprinkling water at normal temperature. By treating with a line simulator, it is possible to experimentally add physical damage that is normally applied to glass bottles in production lines, filling lines, and distribution processes. The measurement results of the slip angle are as follows, and it was found that both the untreated and the processed line simulators had excellent slipperiness, and the reduction in the slip angle after the line simulator processing was small.
Example (line simulator unprocessed): 10.2 (n = 10 sets)
Example (line simulator processing): 10.5 (n = 10 sets)
Comparative example (line simulator unprocessed): 12.9 (n = 5 sets)
Comparative example (line simulator processing): 14.2 (n = 5 sets)
[0023]
The bottles of the example and the comparative example before label attachment were damaged by a line simulator for 2 minutes, and then subjected to an internal pressure resistance test, a vertical load test, a mechanical impact test, a traveling impact test, and a thermal impact test. The effect of the coating agent of the comparative example on the strength of the glass container was compared, but no difference was found in the strength of the bottle between the example and the comparative example.
[0024]
【The invention's effect】
According to the present invention, in a normal use mode, the label is not peeled off from the glass container, but when the label is forcibly peeled off, the label can be easily peeled off from the glass container. When the glass is recovered and the glass is recycled, the labor for removing the label can be significantly reduced, which can contribute to a reduction in the cost of recycling the glass. In particular, when silicone is added to the coating agent, the ease of release of the label is improved, and the lubricity is also improved.
[0025]
In addition, the present invention eliminates poor appearance (drip, lack of transparency, etc.) caused by a large amount of coating, because even if there is a gap in the solid lubricant of the coating film, the effect on label releasability is small. can do.
[0026]
The silane coupling agent used in the present invention becomes a stable substance by being added to a solid lubricant coating agent and applied to a glass container, and hardly flows out to water or acid. In addition, since silicone has low toxicity to living bodies, there is no possibility that a silane coupling agent or silicone is added to a coating agent for a glass container for food, thereby adversely affecting the human body.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a silane coupling agent.
FIG. 2 is an explanatory view of a coating film formed by a conventional solid lubricant coating agent.
FIG. 3 is an explanatory view of a coating film formed by the solid lubricant coating agent of the present invention.

Claims (7)

A solid lubricant coating agent comprising a solid lubricant and a surfactant for dispersing the solid lubricant in water, wherein a silane coupling agent is added to the solid lubricant coating agent. A solid lubricant coating agent comprising a solid lubricant and a surfactant for dispersing the same in water, wherein a silane coupling agent and silicone are added to the solid lubricant coating agent for a glass bottle. 3. The solid lubricant coating agent for glass bottles according to claim 1, wherein the solid lubricant of the solid lubricant coating agent is polyethylene, polyethylene wax, modified polyethylene wax or carnauba wax. 4. The solid lubricant coating agent according to claim 1, wherein the concentration of the silane coupling agent is 0.01 to 1 mass%. 5. The solid lubricant coating agent according to claim 2, wherein the ratio of the silicone to the fixed lubricant + silicone + surfactant is 1 to 75%. A method for coating a glass bottle, comprising applying the solid lubricant coating agent according to any one of claims 1 to 5 to an outer surface of the glass bottle near an outlet of an annealing furnace in a manufacturing process of the glass container. A glass container having a coating film formed by applying the solid lubricant coating agent according to any one of claims 1 to 5 on an outer surface, and a label attached to the coating film.

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