JP2016088770A - Coating agent for glass container surface treatment having improved ink coating adhesiveness and glass container using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel coating agent for glass container surface treatment having improved ink coating adhesiveness easy to prepare a coating agent and capable of securing good residual property of a printing ink to a glass container surface in addition to inhibition of scratch on the glass container surface.SOLUTION: There is provided a coating agent for glass container surface treatment adhered to a glass container surface by cold end after molding a glass container and then conducting hot end coat, containing polyethylene wax in an emulsion status and a reactive silane coupling agent having a vinyl group, an acryl group or an ureido group and water and having concentration of the polyethylene wax in the emulsion status of 0.1 to 0.5 wt.% and concentration of the reactive silane coupling agent in the coating agent for glass container surface treatment of 0.05 to 0.5 wt.%.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a coating material for glass container surface treatment with improved ink coating properties and a glass container using the same, and in particular, enables friction reduction between glass containers and also provides ink coating properties to the glass container surface. The present invention relates to a surface treatment coating to be enhanced and a glass container coated with the coating.

  In the production of glass containers such as glass bottles, it is extremely difficult to avoid contact between the containers. The contact tends to cause scratches on the glass container surface. There was a problem that the strength of the container varied due to the scratch. In order to solve such a problem, a polyethylene wax aqueous emulsion coating is generally applied. This coating agent is sprayed on the glass container surface at the cold end of the glass container manufacture. As a result, the frictional resistance at the time of contact between the glass containers is reduced, and the effect of suppressing the damage is improved.

  Thereafter, a coating agent using various alkoxysilanes and an organic polymer material has been proposed in order to make the coating agent used in the cold end adhere more strongly to the glass container surface and remain (see Patent Document 1, etc.). ). The application of the coating agent described above shows a certain effect on the protection of the glass container surface. As a result, improvements have been made in the suppression of injury. However, according to the coating material of Patent Document 1, preparation and preparation of the coating material at the time of use were complicated.

  Many glass containers are used for filling and distributing beverages and foods. For this reason, printing on the surface of a glass container is often increasing for the purpose of tracing (traceability) during production and distribution. For example, an ink jet printer or the like is used, and characters, symbols, and the like are directly printed on the glass container surface after filling and sealing the contents in the glass container. As described above, in addition to suppressing scratches, printing survivability and printability on the surface of a glass container have been required.

  However, in conventional coating with an aqueous emulsion coating, it has not been possible to ensure sufficient printability. In particular, it has been regarded as a problem that printing is lost by washing after filling the contents.

  From such circumstances, a coating for surface treatment has been sought that is relatively easy to prepare a coating, suppresses scratches, and further improves the remaining of ink during printing. . Further, on the side of the customer who fills a painted glass container, a glass container with improved handling convenience and improved printing survivability has been demanded.

Japanese Patent No. 5031939

  The present invention has been made in view of the above points, and it is easy to prepare a coating material, and in addition to suppressing scratches on the surface of the glass container, also ensures good printing ink persistence on the surface of the glass container. Provided is a glass container surface treatment coating agent having improved ink coating properties and a glass container using the same.

  That is, the invention of claim 1 is a glass container surface treatment coating agent that is applied to the surface of the glass container at a cold end after hot end coating is performed after the glass container is formed. The agent comprises an emulsion state polyethylene wax, a reactive silane coupling agent having a vinyl group, an acrylic group, or a ureido group, and water, and the emulsion state occupies the glass container surface treatment coating agent. The concentration of the polyethylene wax is 0.1 to 0.5% by weight, and the concentration of the reactive silane coupling agent in the glass container surface treatment coating agent is 0.05 to 0.5% by weight. The glass container surface treatment coating composition having improved ink coating properties.

  The invention according to claim 2 is the ink according to claim 1, wherein the glass container surface treatment coating agent is coated on the surface of the glass container in a temperature range in which the surface temperature of the glass container is 80 to 130 ° C. at a cold end. The present invention relates to a coating material for glass container surface treatment with improved coating properties.

  A third aspect of the present invention relates to a glass container coated with the glass container surface treatment coating agent having improved ink coating properties according to the first or second aspect.

  According to the glass container surface treatment coating composition with improved ink application properties according to the invention of claim 1, the glass container surface is coated on the glass container surface at the cold end after hot end coating is performed after the glass container is molded. The glass container surface treatment coating composition comprises a polyethylene wax in an emulsion state, a reactive silane coupling agent having a vinyl group, an acrylic group, or a ureido group, and water. The concentration of the polyethylene wax in the emulsion state in the glass container surface treatment coating agent is 0.1 to 0.5% by weight, and the reactive silane coupling agent in the glass container surface treatment coating agent The coating concentration is 0.05 to 0.5% by weight, so that the preparation of the coating is easy and the glass container surface is not damaged. Persistence of good printing ink to the glass container surface may also ensured Te.

  According to the glass container surface treatment coating material with improved ink coatability according to the invention of claim 2, in the invention of claim 1, the glass container surface treatment paint has a surface temperature of the glass container at the cold end. Since the surface of the glass container is coated in a temperature range of 80 to 130 ° C., it is possible to ensure the remaining of the printing ink and stable production.

  According to the glass container of the invention of claim 3, since the glass container surface treatment coating agent with improved ink applicability according to claim 1 or 2 is applied, the slippage between the glass containers is enhanced and the glass container is scratched. The factor goes down. In addition, the convenience of checking and tracking product information after filling is also enhanced.

It is process drawing which shows the outline | summary of manufacture of a glass container.

  Glass containers represented by glass bottles and the like cannot avoid contact with each other at each stage of transportation, filling of contents, cleaning, inspection, display, and the like. In this case, since the glass has a relatively high hardness, the surface thereof is easily damaged (cracked) when the containers contact each other. By the way, the Mohs hardness of soda lime glass used for a general glass container is about 6.5 degrees.

  There is a possibility that the structural strength of the glass container itself is lowered due to the scratch on the surface of the glass container. Therefore, tin oxide and its compounds have been conventionally coated on the surface of a glass container such as a glass bottle at a point before slow cooling (hot end). A coating of tin oxide or the like is referred to as a hot end coating or hot end coating, and is a typical technique for preventing damage to the glass container surface. In addition to the tin oxide coating at the hot end, the time for the glass containers to contact and rub against each other is further reduced by further improving the lubricity of the surface of the glass containers, and the cause of damage can be reduced.

  The glass container surface treatment coating agent with improved ink coatability defined in the present invention is a glass container surface that has been subjected to hot end coating, and is thus made slippery between glass containers thereafter. Property) and suppresses surface scratches. Secondly, the printing ink remaining on the surface of the glass container after coating is improved to improve the remaining of the printing ink. Mainly a coating for these purposes.

  For this reason, the glass container is first formed into the shape of a glass container, and a coating (hot end coating) of tin oxide or the like is applied to the outer surface of the glass container after forming on the upstream end side (hot end) of the slow cooling furnace. Then, in the subsequent cold end, the glass container surface treatment coating material with improved ink coating properties of the present invention is applied (coating). In this case, as defined in the invention of claim 2, the coating (coating) of the coating agent is performed when the surface temperature of the glass container reaches a temperature range satisfying 80 to 130 ° C.

  The range value of the glass container surface temperature at the time of application of the surface treatment coating agent is a range derived from verification in Examples described later. When the surface temperature of the glass container is lower than 80 ° C., the remaining of the printing ink which is the object of the present invention is lowered. About the case where the surface temperature of a glass container exceeds 130 degreeC, the temperature control after slow cooling is not easy. Therefore, the above temperature range is appropriate in consideration of stable production.

  A glass container surface treatment coating material with improved ink coating properties is a mixture comprising polyethylene wax in an emulsion state, a reactive silane coupling agent having a vinyl group, an acrylic group, or a ureido group, and water. It is a liquid agent. That is, the glass container surface treatment coating agent is a dilute colloidal liquid in which polyethylene wax and a reactive silane coupling agent are homogeneously dispersed in water. If necessary, a surfactant, a stabilizer or the like for enhancing dispersibility may be added. Hereinafter, the main components will be further described.

  Any polyethylene wax in the emulsion state is generally used and any available type can be used. The polyethylene wax in an emulsion state is a state in which fine particles of polyethylene are dispersed in water and diluted in water. When the glass container having the above surface temperature is coated, the polyethylene wax is softened on the surface of the glass container and an appropriate polyethylene film is formed. For this reason, a simple resin film is formed on the surface of the glass container after the coating of the coating agent. Therefore, the slipperiness (slidability) between the glass containers is increased, and as a result, the damage is suppressed.

  Regarding the blending of the polyethylene wax in an emulsion state, the weight ratio of the polyethylene wax in the total amount of the glass container surface treatment coating is in the range of 0.1 to 0.5% by weight. The concentration (% by weight) of polyethylene wax was measured with a refractometer.

  The said range is prescribed | regulated considering comprehensively the reaction with the reactive silane coupling agent mentioned later, and a desired property. When the blending ratio of the polyethylene wax is less than 0.1% by weight, the polyethylene wax itself is too small and does not contribute to the slipperiness of the glass container. On the other hand, when the blend of polyethylene wax exceeds 0.5% by weight, no further improvement in performance is expected, so the upper limit was set to 1.

  The reactive silane coupling agent compounded in the glass container surface treatment coating is a compound composed of silicon and a hydrocarbon group. Some types contain nitrogen. In particular, a compound having a “vinyl group”, “acryl group”, or “ureido group” in the molecule, or a derivative thereof. For example, it is selected from various silane compounds such as vinylmethoxysilane, vinylethoxysilane, 3-acryloxypropyltrimethoxysilane, and 3-ureidopropyltrialkoxysilane.

  The effect of the reactive silane coupling agent is to improve the ink applicability. Since the glass container which finished hot end coating is the above-mentioned surface temperature, it can be said that reaction of a reactive silane coupling agent accelerates more. Therefore, it is considered that the application (adhesion) to the surface of the glass container after the hot end coating is good.

  Regarding the blending of the polyethylene wax in the emulsion state, the weight ratio of the reactive silane coupling agent to the total amount of the glass container surface treatment coating is in the range of 0.05 to 0.5% by weight. This ratio is defined to improve the reaction with the polyethylene wax and to improve the ink coatability. When the amount is less than 0.05% by weight, the silane coupling agent is relatively small and the desired ink coatability is not observed. When the amount is more than 0.5% by weight, the ink coatability is already stable with sufficient performance, and no further improvement is expected. Then, the upper limit at the time of measurement was made into the upper limit of the weight ratio on a mixing | blending.

  As an example of preparation of a glass container surface treatment coating material with improved ink coating properties, an emulsion of polyethylene wax is added to water and diluted to a predetermined concentration. The reactive silane coupling agent in an amount converted from the coating amount is added here. The mixed solution is gently stirred at about room temperature. During this time, the crosslinking reaction by the above-mentioned condensation is promoted, and the polyethylene polymer is modified by the reactive silane coupling agent. A glass container surface treatment coating agent having improved ink coating properties after the preparation is completed. The glass container surface treatment coating is not usually prepared due to the reactivity of the reactive silane coupling agent. Only the amount required for the application process on that day is prepared each time.

  FIG. 1 is a process diagram showing an outline from the formation of a glass container to the completion through the coating of a coating material for surface treatment of a glass container with improved ink coating properties of the present invention. Molten glass, which is a raw material for the glass container, is cut into a lump called a gob by a predetermined amount, sent to a known molding machine such as an IS machine, and molded into an appropriate container shape such as a bottle. In the hot end after molding, tin oxide or the like is coated on the surface of the glass container at a stage of 400 to 650 ° C. (hot end coating).

  Then, it is conveyed to a slow cooling furnace, the temperature of the glass container is lowered to around 200 ° C., and thermal deformation and the like are eliminated. In the cold end after slow cooling, when the surface temperature is lowered to 80 to 130 ° C., the coating (coating) of the glass container surface treatment coating agent having improved ink coating properties of the present invention prepared as described above is applied. Is done. The coating method is not particularly limited, and is performed by an appropriate method and apparatus. For example, spraying with a spray gun or the like.

  The polyethylene in the glass container surface treatment coating adhering to the glass container surface is easily softened by the heat of the glass container surface and spreads on the surface, and the coating strength is increased. After that, the glass container is completed through inspection. Glass containers are shipped to consumers and used for filling beverages, various liquids such as medicines, or articles.

  In a glass container coated with a coating material for surface treatment of a glass container with improved ink applicability, a film is formed by hot end coating and the hardness is increased. Furthermore, the lubricity of the surface is improved by the application of polyethylene. Therefore, direct contact between the glasses and friction between the glasses are avoided, and damage to the glass containers is suppressed for improving the hardness. At the same time, the modification of the polyethylene resin proceeds from the reaction accompanying the reactive silane coupling agent. Thus, the coating of the coating material on the surface of the glass container is stable and easy peeling is suppressed. Therefore, the adhesion of the glass container surface treatment coating to the conveying device, the conveying path and the like when the glass container completed as a product is transferred to a filling device, a labeling device, or the like is further reduced.

  Moreover, before or after filling the contents into the glass container, the surface of the glass container is printed and printed with printing ink. In this case, the use of a printing ink jet printer for business use, industrial use, etc. is assumed, and the ink is sprayed on the surface of the glass container from the discharge part of the printer in the form of dots (dots). The printing on the surface of the glass container is various information such as a manufacturing lot, date, manufacturer name, manufacturing location, and the like. In addition, printing such as container decoration may be performed. This facilitates the confirmation and tracking of product information.

[Raw materials used]
As a glass container to be coated, a glass bottle formed from soda lime glass was prepared. All the glass bottles have the same shape, and the inner volume is 400 mL. Prior to the application of the glass container surface treatment coating agent of Examples and Comparative Examples described later, for any glass bottle, a hot end of tin oxide is used by a conventional method in a hot end before annealing after molding. Coating was performed.

  A polyethylene wax in an emulsion state (Tegoglas (registered trademark) RP40LT) was used (denoted as PW in the table). Vinylmethoxysilane (SC1) and vinylethoxysilane (SC2) as silane coupling agents having “vinyl group”, 3-acryloxypropyltrimethoxysilane (SC3) as silane coupling agent having “acrylic group”, “ureido 3-ureidopropyltrialkoxysilane (SC4) was used as a silane coupling agent having a group. In addition, aminopropyltriethoxysilane (SC5) was used as a silane coupling agent having functional groups other than the above three types. The silane coupling agent is represented as SC1 to SC5 in the table.

[Preparation of glass container surface treatment coating]
Examples and Comparative Examples were prepared by diluting polyethylene wax and various silane coupling agents in water and stirring them appropriately at room temperature in order to obtain the concentrations (% by weight) shown in Tables 1 to 8 below. A coating was prepared. The density | concentration in a table | surface is the ratio which occupies for the weight of the coating agent for glass container surface treatments to be completed. Since polyethylene wax and silane coupling agent are extremely dilute with respect to the total weight of the coating material, there is no problem in volume conversion. A refractometer (manufactured by Atago Co., Ltd., refractometer RX-007α) was used for measuring the concentration (% by weight) of polyethylene wax.

[Coating of glass container surface treatment]
When applying the coating materials of Examples 1 to 15 and Example 22, and Comparative Examples 1 to 7 and Comparative Example 14, the glass bottle whose surface temperature was 100 ° C. after slow cooling after hot-end coating, Each of the coating materials of Examples and Comparative Examples obtained by the above preparation was sprayed with a spray gun and applied. When coating the coating materials of Examples 16 to 21 and Comparative Examples 8 to 13, the glass bottles having the surface temperatures shown in the table after slow cooling after hot-end coating were obtained by the above-mentioned preparation. And each coating material of the comparative example was sprayed with a spray gun and applied.

  In each example, the spray amount is about 60 mL / min, and the coating agent is sprayed during one rotation of the bottle (about 1 second) so that the coating agent does not hang down the surface of the bottle. Allowed to cool. By a series of cold end coatings, the required number of glass bottles (glass containers) corresponding to each glass container surface treatment coating agent were prepared.

[Evaluation of remaining ink]
In evaluating printability after cold end coating, which is the object of the present invention, ink for an inkjet printer machine for glass bottle printing manufactured by Hitachi Industrial Equipment Co., Ltd. was used, and its remaining property was evaluated. The same ink is filled using a syringe equipped with a standard needle MN-28G-13 manufactured by Iwashita Engineering Co., Ltd., and 80 per bottle is applied to the shoulder portion of each coated glass bottle of each Example or Comparative Example. The ink was stippled evenly. After the ink was dried, the ink stippled portion was submerged in a hot water bath with a water temperature of 50 ° C. in an ultrasonic cleaner and washed for 10 minutes. After washing, the number of stippling remaining on the glass bottle surface was counted. Then, the ink residual ratio was calculated in comparison with the initial number of stippling. The ink remaining rate (%) was defined as “ink remaining rate (%) = [1 − {(initial number of stippling−number of stippling after washing) ÷ initial number of stippling}] × 100”. The initial number of strokes is 80 points. For example, when 72 points remain after cleaning, [1 − {(80−72) ÷ 80] × 100 = 90. That is, the ink remaining rate is 90%.

  After obtaining the ink residual ratio (%) of the samples of each Example and Comparative Example, an example in which the ink residual ratio was 90% or more was evaluated as “good” ink residual ability evaluation. That is, it is an example suitable for use with less ink peeling. An example in which the ink remaining rate was less than 90% was evaluated as “bad” ink remaining property evaluation. This is an example that is not suitable for use.

[Surface slip evaluation]
Surface slipperiness evaluation conforms to the measurement method stipulated in “7.14 Surface slip angle measurement” of Japan Glass Bottle Association standard (established on June 15, 1977, revised on October 30, 1998 (3)). did. Glass bottles coated with the coating agents for glass container surface treatment of each Example and Comparative Example were prepared. Two bottles were placed in a lying state on a holding table of a tester having a slipping angle conforming to the rules for measuring the surface slip angle, and one bottle was placed on the bottle in a lying state. With the three glass bottles stacked, the angle at which the uppermost glass bottle started to slide by tilting the holding table of the tester was measured. Measurement was performed three times for one sample (Example or Comparative Example). That is, a total of nine glass bottles were used for one sample. And the average of 3 times of measured values was calculated | required, and it was set as the surface slip angle (degree) of the said sample.

  After determining the surface slip angle (°) of the sample of each example and comparative example, an example in which the surface slip angle was 10 ° or less was evaluated as “A”. An example where the surface slip angle was 10 ° or more and less than 20 ° was evaluated as “B”. An example in which the surface slip angle was 20 ° or more was evaluated as “C”. That is, the frictional resistance is less as the evaluation of “A”. Therefore, there is little resistance at the time of contact between glass containers (bottles), and damage can be reduced.

[Evaluation of liquid preparation operability]
When mixing and preparing polyethylene wax and silane coupling agent, which are raw materials for the glass container surface treatment coating material of each example and comparative example, and water for dilution, the ease of mixing of the solution (dispersibility of the components) The quality of the solution was judged by sensory evaluation on the viscosity (fluidity) and component change (stability). The coating material of the example in which no particular problem occurred during the preparation of the coating material was evaluated as “good”, and the coating material of the example that interfered with any of the above was evaluated as “bad”.

[result]
Tables 1 to 8 show the raw materials used and the results of the aforementioned evaluation and measurement items for the examples and comparative examples. In order, polyethylene wax concentration (% by weight), silane coupling agent type and concentration (% by weight), bottle temperature during coating (° C), ink remaining rate (%), ink remaining quality evaluation, surface slipperiness evaluation (3 stages) and liquid preparation operability (good or bad).

[Discussion]
[Range of component content]
Comparative Example 1 corresponds to a conventional polyethylene wax-only coating agent. According to Comparative Example 1, the performance required for a normal glass container coating is provided. However, the desired ink residual property of Comparative Example 1 is not preferable. On the other hand, according to Examples 1 to 22, the ink residual ratio was greatly improved by adding various silane coupling agents. Moreover, the same Example also has the performance required for the coating agent of the conventional glass container. Therefore, in consideration of the ink residual ratio, the coating material needs to contain both a polyethylene wax and a silane coupling agent.

  Comparative Examples 2, 4, and 6 are preparation examples in which the concentration was diluted for each type of silane coupling agent. When these were compared with Examples 1, 6, and 11, In Examples 2, 4, and 6, the ink remaining property was lowered. Therefore, in order to realize good ink remaining properties, as specified in Examples 1, 6 and 11, the blending of the silane coupling agent needs to be 0.05% by weight or more. In addition, from the results of Comparative Examples 3, 5, and 7, the improvement of each index including the ink residual property was flat even when the composition of the silane coupling agent was 1% by weight. Therefore, the further upper limit of the silane coupling agent is set to 1% by weight because further contribution to performance improvement is scarce.

  As is apparent from Examples 1 to 22, the blending of the polyethylene wax is 0.05% by weight (Examples 1, 6, 11) and 0.5% by weight (Examples 5, 9, 11). 15). Therefore, the blending amount range was set between these examples.

[Temperature range during painting]
Examples 16 to 21 and Comparative Examples 8 to 13 are comparisons of the influence of temperature when the glass container surface treatment coating agent is applied. In Comparative Examples 8, 10, and 12 having a temperature lower than that of Examples 16, 18, and 20, ink residual properties were lowered. Probably because the cross-linking reaction between polyethylene wax and silane coupling agent was not accelerated. Comparative Examples 9, 11, and 13 having a temperature higher than those of Examples 17, 19, and 21 were good in the ink residual property evaluation. However, it is not always easy to control the temperature of the glass container surface to the temperature after the slow cooling due to problems such as production facilities. Therefore, a slightly lower temperature is desirable because of production control difficulties.

  In Examples 16 to 21, the remaining ratio of ink is comparable to other examples, and other evaluations are good. Therefore, in consideration of the deterioration in properties of Comparative Examples 8, 10, and 12, the preferable container surface temperature when the glass container surface treatment coating agent is applied to the glass container at the cold end is in the temperature range of 80 to 130 ° C. .

[Types of silane coupling agents]
Example 22 is an example in which the type of the silane coupling agent having a “vinyl group” is changed from SC1 to SC2. Example 22 also showed good results as in Example 3 and the like. Next, also in the example of the silane coupling agent (SC3) having “acrylic group” and the example of the silane coupling agent (SC4) having “ureido group”, the type of the silane coupling agent is not changed. Good results were shown. However, in Comparative Example 14 using the silane coupling agent (SC5) having an “amino group”, there was a problem in the operation of the liquid preparation. Therefore, the results greatly differ depending on which type of silane coupling agent is used. From the trial and general trend of this example, it was concluded that a reactive silane coupling agent having a vinyl group, an acrylic group, or a ureido group is superior.

[About surface whitening]
After drying the glass bottle coated with the glass container surface treatment coating agent of each Example and Comparative Example, the surface of each glass bottle was visually observed. As a result of observation, no whitening occurred on the surfaces of the glass bottles of Examples and Comparative Examples. Therefore, it was confirmed that the coating material for glass container surface treatment using a reactive silane coupling agent having a vinyl group, an acrylic group, or a ureido group does not cause appearance defects such as surface whitening.

  The glass container surface treatment coating composition with improved ink coating properties of the present invention is easy to prepare a coating material, and is effective in suppressing scratches and the like occurring in a glass container, and also increases the persistence of printing ink. be able to. Therefore, the glass container coated with the coating agent can be effectively used for display or investigation of product information.

Claims (3)

A glass container surface treatment coating agent that is applied to the surface of the glass container at a subsequent cold end after hot end coating is performed after molding the glass container,
The glass container surface treatment coating agent comprises a polyethylene wax in an emulsion state, a reactive silane coupling agent having a vinyl group, an acrylic group, or a ureido group, and water.
The concentration of the polyethylene wax in the emulsion state in the glass container surface treatment coating agent is 0.1 to 0.5% by weight,
The concentration of the reactive silane coupling agent in the glass container surface treatment coating agent is 0.05 to 0.5% by weight. .   The glass with improved ink coatability according to claim 1, wherein the glass container surface treatment coating agent is applied to the surface of the glass container in a temperature range in which the surface temperature of the glass container is 80 to 130 ° C. at a cold end. Coating agent for container surface treatment.   A glass container coated with the glass container surface treatment coating agent according to claim 1 or 2 having improved ink coating properties.

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