JPS6051636A - Process for masking scratch on glass vessel - Google Patents

Abstract

PURPOSE:To form a coating film having superior masking property and water resistance by coating a compsn. comprising a specified polyether compd. modified with alkoxysilyl group and a curing catalyst on the position on a glass vessel where scratch has generated. CONSTITUTION:A compsn. is obtd. by dissolving or dispersing a mixture consisting of 100pts.wt. polyether compd. modified with alkoxysilyl group as expressed by the formula (wherein R<1> is 1-4C univalent hydrocarbon group; R<2> is 1-5C divalent hydrocarbon group; a is 2 or 3; 2<=m<=100; 2<=n<=100; 0.2<=m/(m+n)<= 0.8; 4<=(m+n)<=150), and 0.05-10pts.wt. curing catalyst (e.g. dibutyltin dilaurate) in an org. solvent (e.g. ethanol). The compsn. is coated on the scratch on the glass vessel, allowed to stand for 5-72hr at room temp., thus cured film of 0.5- 10mum thickness having no tackiness on the surface is obtd. Coating film having superior masking property for scratch can be also formed by this method on a surface wetted by dew condensation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for shielding a glass container from scratches. In other words, the present invention relates to a method of manufacturing a glass container that is scratch-proof.

Currently, glass containers used for beer, soft drinks, etc. are usually collected from the market after use and used repeatedly. Glass containers that are collected and used repeatedly in this way are subject to scratches on their surfaces due to contact with other glass containers or other objects during the reconstitution and distribution processes, resulting in significant damage to the appearance of reconstituted beverages. The current situation is that the product value is decreasing.

In order to cover up scratches on glass containers, it has been considered to apply some type of shielding agent to the area where the scratches occur on the surface of the glass container, and several types of shielding agents have already been proposed.

However, to the best of the inventors' knowledge, nothing satisfactory has been found. The reason why no satisfactory scratch shielding agent has been found for glass containers that are collected and reused is that there are several requirements that a scratch shielding agent must meet at the same time, and conventional shielding agents are unsatisfactory in this respect. That's why.

Scratch-blocking agents for glass containers that are collected and reused are generally required to satisfy the following requirements.

(1) Good scratch-shielding properties, (2) Good water resistance of the applied film, (3) No surface tackiness (stickiness) of the applied film, (4) Cures at room temperature, and can be used as a film. (5) Not only should the shielding agent itself not be a platinum, but if a solvent is used, the solvent should be free from chemicals; (6) The applied film should be washed with an alkaline solution during the bottle washing process. The coating must be easily and completely peeled off, and the peeled product must not contaminate the alkaline solution (it can be applied even to surfaces with heavy condensation).In other words, the applied film must have scratch-shielding properties in the first place It goes without saying that it must be of good quality, but this coating must also have good water resistance.Glass containers filled with beer, soft drinks, etc. must be immersed in cold water in a showcase during the summer. Therefore, the coating must be water resistant to the extent that it will not peel off even if it is immersed in water for at least one week.In addition, such glass containers are often handled with bare hands, so If the coating has a sticky surface, it will not only cause unpleasant feelings such as stickiness to the handler, but also there is a risk that dust in the atmosphere will adhere to the coating surface during the distribution process and contaminate the coating surface. If heating is required to cure the film to obtain strength and other physical properties required for the film, there is a risk that the content of the additive will change in quality (scratches occur most often due to contact between Ja particles during the filling process). (Because of this, it is common to apply a scuff masking agent after filling.) The same applies when irradiation with light is required instead of heating.

From this point of view, the shielding agent needs to be one that forms a non-sticky cured film at around room temperature and acquires the required physical properties as a film.

Since such glass containers contain beverages, the coating material must be non-toxic and odorless; however, if the coating is formed from a solution, the solvent used must also be non-toxic. (This requirement is also required from the working environment) Therefore, organic solvents other than water and alcohol should not be used; after all, the coating material itself or its precursor may contain water or alcohol, especially ethanol, This means that it must be soluble in

Furthermore, it is important that this coating has good removability during alkaline solution washing in the bottle washing process, and that the peeled off material does not contaminate the alkaline solution. That is, after this type of glass container is collected, it is washed and sterilized with an alkaline solution in a bottle washing machine (usually, this is done using a 2-4% caustic soda aqueous solution at a temperature of 60-80°C for about 10-20 minutes). ) and then reused, so if the coating is not completely removed by the alkaline solution in the bottle washer and some of it remains on the glass surface, such uneven surfaces The scratch masking agent is then reapplied to the surface, and the aesthetic appearance of the coated surface is inevitably compromised. In this case, if the shielding agent removed by the alkaline solution turns into an oily substance in the alkaline solution, it may involve other dirt to form oil balls and re-contaminate the cleaned bottle. Further, if the peelable shielding agent becomes a solid substance and floats in the alkaline solution, it may adhere to the inside of the washed bottle and be mixed into the beverage as a foreign substance. Therefore, it is preferable that the abrasion shielding agent removed by the alkaline solution is fermented into alkaline heart fluid. In addition, a method has been proposed to cover the scratches by applying an alkaline solution to the scratched surface of the glass container with a strong coating (permanent coating) that will not peel off. Scratches are unavoidable, and when it is washed with an alkaline solution, the coating tends to turn white and deteriorate in appearance. In order to obtain a permanent film, it is generally necessary to make the film thick (50 microns or more), which leads to problems such as high cost, and the inventors believe that the permanent film method is not practical. It is a terrible thing to offer.

In addition to these requirements, a further performance required as a scuff-blocking agent is suitability for application to dew-condensing surfaces. Carbonated drinks or draft beer that is not heat-treated to kill yeast are usually filled after being cooled to below 10°C. When a bottle filled with a low-temperature beverage is exposed to hot and humid conditions in the summer, dew condenses on the surface and the bottle becomes wet. The scuff masking agent needs to be able to be applied without problems to even the most uneven surfaces and to meet the desired requirements.

As mentioned above, there have been several proposals as scratch-shielding agents, and there are also quite a variety of coating materials known, including those for preventing scratches and bottle breakage, but none of these are effective. It did not meet all of the above requirements. For example, (1) surfactants have poor water resistance, especially those with an HLB of 9 or more, and when immersed in water, the coated film will peel off in about 4 to 5 hours, and the surface tackiness is generally low. It has the disadvantage of being thick. [2+-e rough-ins are fluid) ξ rough-ins have extremely poor water resistance, while unidirectional ξ rough-ins (melting point 42°C or higher) have good removability with alkaline solutions in washing machines for coated films. However, it has the disadvantage that the peeled substances float in the form of a scum on the surface of the alkaline solution, which re-adheres to the glass surface and contaminates it. (3)
When organic polymers are applied in the form of an aqueous emulsion, the resulting film has extremely poor water resistance unless treated with heat or light irradiation, and when applied in the form of an organic solvent solution, the resulting film has poor water resistance. Although it has good water resistance and surface tack, it is difficult to remove with an alkaline solution in a washing machine, and there are problems such as the toxicity of the organic solvent used. (4) To improve the shortcomings of (11 to (3)) above,
No. 7-17863 proposes an abrasion shielding agent containing organopolysimixane as a product. This product meets 1 to 7 of the above 7 requirements as a scratch shielding agent.
This is an excellent product that satisfies 6 items. However, this has the problem that when applied to the surface of dew condensation, the hydrophobic nature of the organopolycloxane resin causes "repellency" on the surface of the wet glass container and reduces the shielding performance. It turns out.

SUMMARY OF THE INVENTION The present invention aims to provide a solution to the above-mentioned problems, and attempts to achieve this object by using a specific alkoxysilyl group-modified polyether compound as a scratch screening agent.

That is, the method for shielding scratches on glass containers according to the present invention includes applying a composition containing the following components A and B to the scratches on the glass container and curing the composition at substantially room temperature. It is something to do.

Component A: an alkoxysilyl group-modified polyether compound represented by the following general formula, where R is a monovalent hydrocarbon group having 1 to 4 carbon atoms; R2 is a divalent hydrocarbon group having 1 to 5 carbon atoms. 2 or 3. 2≦m≦100.2≦n≦100. 0.2≦m/m-1-H≦0.8.4≦m+n≦150
However, several RlR and a may be different in the same compound.

Component B Component A Catalytic effect for curing This particular alkoxysilyl group modification? According to the application and curing of the riether, it is possible to use ethanol as a solvent (if used) and to form a film with the desired physical properties at room temperature, and the formation
The resulting coating has excellent scratch-shielding properties and water resistance, and has no problems with stickiness, removability, and solubility in alkaline solutions when washed with alkali in a washing machine after collection.

Furthermore, the scratch-shielding composition of the present invention can be applied to surfaces wet with dew condensation, and even in that case, it forms a film with the required physical properties that is excellent in scratch-shielding properties, so it can be applied to wet surfaces. It is also applicable to beverage bottles that are cold-filled for beer, carbonated soft drinks, and the like.

3. Detailed Description of the Invention Component A The alkoxycryl group-modified polyether compound A used in the present invention is represented by the above general formula. This is because the alkoxysilyl group, which is a reactive group, undergoes a hydrolysis and condensation reaction as shown in the following formula by the action of the curing catalyst B, and a crosslinked product (cured film) is formed on the glass surface.

, , Curing catalyst B.

:810R+I (20=StO't(+Roii (hydrolysis reaction), curing contact #B.

2miS 10H=810S 1-' +H20 (condensation (
Crosslinking) Reaction) R in compound A is a monovalent hydrocarbon group having 1 to 4 carbon atoms, such as a methyl, ethyl, propyl, butyl group, as described above.
It is. A methyl group is most preferred from the viewpoint of curability, and an ethyl group is most preferred from the viewpoint of toxicity. a indicating the number of RO groups is 2 or 3. If a is 1, the curing properties will be poor, resulting in disadvantages such as tackiness in the coated film and decreased water resistance, which is not preferable.

R of compound A is for firmly bonding the alkogial 7-lyl group, which is a reactive group, and the polyether, which is the main chain, and is a divalent hydrocarbon group having 1 to 5 carbon atoms, such as methylene, Examples include ethylene, propylene, butylene, and methylbutylene groups.

The limitations on m and n of compound A are based on the following reasons. That is, if m and n are less than 2 or the sum of m and n is less than 4, the curability will be poor and the water resistance will be poor. m and n are each 100, and the sum of m and n is 150
If it exceeds the above range, the viscosity of the compound increases, the coating suitability decreases, and the removability with an alkaline solution also becomes poor. The ratio of m to the sum of m and n, m/m+n, preferably lies between 0.2 and 8, preferably between 0.3 and 0.7. This is because the ethylene oxide unit represented by C2■I40 is a hydrophilic group and the propylene oxide unit represented by C3H60 is a hydrophobic group.
When m/m-1-H is less than 0.2, the water resistance of the cured film is good, but the removability and solubility in alkaline solutions decrease, and when m/m-1-H exceeds 0.8, the cured film has This is because although the removability and solubility in alkaline solutions are satisfactory, the water resistance is lowered. Therefore, it is necessary that m and n have the above relationship.

Such an alkoxycryl group-modified polyether compound can be easily obtained by any known method including Sendai. - For example, there is an addition reaction of SiH-containing alkoxysilane with a preether having an allyl group at the terminal in the presence of a platinum-based catalyst, as shown in the following reaction.

(CH3)3-a ■ -C3H60(C2H40hiC3H60+TiC3H
6Si(OR).

In the formula, R, a, m%n are the same component B as before.As the curing catalyst which is component B, those known as condensation catalysts for alkoxy group-containing organopolysiloxanes can generally be used. Specifically, (a) organic tin compounds such as dibutyltin dilaurate, dibutyltin dilaurate, (b) titanate esters such as tetracylovir titanate, tetrabutyl titanate, tetraoctyl titanate, (c) aluminum organic compounds,
For example, acetylacetone aluminum salt and the like are exemplified.

The amount of component B used is 0.05 to 100 parts by weight of component A.
10 parts by weight, preferably 0.1 to 5 parts by weight, is suitable.

Composition The scratch masking composition used in the present invention comprises the above component A.
and component B. Here, "containing" means including not only these two components but also various auxiliary components such as solvents, dispersants, surfactants, colorants, fillers, etc. It is something.

When using an organic solvent in the case of an I-dispersion without a solution, ethanol is preferred from the viewpoint of safety and hygiene. However, if circumstances permit, other alcohols, especially lower alcohols such as methanol, pro9ol, butanol, or other organic solvents with the required solubility can be used.

A surfactant can also be added for the purpose of improving the wettability of the shielding agent to the surface of the glass container, and the removability and solubility of the cured film with an alkaline solution. Any surfactant can be used, but from the viewpoint of safety and hygiene, monoglycerides, sorbitan esters, sucrose esters, etc. are preferred. To coat the container, any conventional method such as dipping, spraying, brushing, 70-coater, transfer, or any other method can be used. The area to be applied is the area where the scratch occurs, but it goes without saying that it is not limited to the area where the scratch occurs.

After application, if you leave it at room temperature (5 hours to 3 days), you can easily obtain a cured film with no surface tackiness, but it will shorten the curing time.
There is no problem in removing the solvent used and heating to a degree that does not impair the quality of the contents (for example, about 50"C) as necessary.

Although the thickness of the cured film is arbitrary, the effects of the present invention can be best enjoyed when it is relatively thin. Therefore, 0
．． A suitable range is 5 to 10 μm, preferably 1 to 3 μm. If it is thinner than 0.1/Am, the abrasion shielding property will be insufficient, while if it is thicker than 10 μm, the peelability with an alkaline solution during washing will be insufficient.

Practical Soap Examples Examples 1 to 10 and Comparative Examples 1 to 3 The composition shown in Table 1 was transferred to the surface of a peel bottle that had partially turned white due to scratches so that the coating film was about 1 μm thick. It was applied and left at room temperature for 3 days to harden. The results of measuring the performance of the obtained coating film were as shown in the same table.

The performance of the @ membrane was measured as follows.

2) Water resistance: Immerse in water at 25°C and measure the immersion time until the film partially peels off. If the immersion time is one week or more, it is judged as "good", and if the soaking time is less than one week, it is judged as "poor".

3) Adhesion = 2 - Based on cellophane adhesive tape peel test. Displayed as the number of 100 gonomes that did not peel off with cellophane adhesive tape.

4) Peelability in washing machine: 3.5% caustic soda aqueous solution 77
Peelability when washed at 0°C/10 minutes 5) Adhesion: 140 mm from the upper body area of a large Peel bottle
10mm (vertical direction) x 40mm centered on the uphill (
After applying the composition in the circumferential direction) and leaving it at room temperature for 3 days, the coated surface was rotated once on ω Mekuyu case random powder to measure the adhesion amount of case random.
Calculate the amount of adhesion per hit. In addition, the adhesiveness of the uncoated glass surface is 0.3 mg/cm2, and the non-curing shielding agent surfactant (Nlupitan ester product name "Sno ξ-n" manufactured by Kao Atlas II) is It was 8.5 mg/cm2.

6) Wetability: A partially whitened beer bottle is filled with ice water and left in an atmosphere of 5°C/90% to form dew condensation on the surface. The coating film of the composition on this surface is approximately 1 μm.
The appearance and scratch-shielding properties of the coating film were transferred and cured at room temperature for 3 days.

Claims (1)

[Scope of Claims] The present invention is characterized in that a composition containing the following components A and B is applied to a site where a scratch occurs on a glass container and is cured at substantially room temperature. How to shield glass containers from scratches. Component A: an alkoxysilyl group-modified polyether compound represented by the following general formula, where R is a monovalent hydrocarbon group having 1 to 4 carbon atoms R is a divalent hydrocarbon group having 1 to 5 carbon atoms a is 1,900+4 Or 3゜2≦m≦100.2≦n≦1001 0.2≦m/m-)n≦0.8.4≦m+n≦150, and there are multiple R1. R2 and a may be different in the same compound. Component B Component A curing catalyst