JP2013071974A - Aqueous coating composition and glass product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous coating composition for glass, which maintains scratching prevention function even if it is subjected to a hot water treatment or high temperature steam treatment, reduces the contamination of a transfer line caused by ablation or dropping-out, is adaptable to an ultra-high speed filling line, and imparts stable labeling and easy peelability to a surface of glass, and to provide a glass product coated with the composition.SOLUTION: The aqueous coating composition is obtained by incorporating a resin (A) and a resin (B) into water in a dispersed state in the presence of a base. The resin (A) is polyethylene wax having a softening point of 110°C or higher, and the resin (B) is at least one of an α-olefin/maleic acid anhydride copolymer and a partial reaction product of the copolymer. The glass product is obtained by coating the surface of a glass article with the composition.

Description

  The present invention relates to an aqueous coating composition for surface treatment, in particular, an aqueous coating composition for glass surface treatment for increasing the lubricity of the surface of a glass product to make it difficult to be scratched, etc., and the surface is coated with the composition. In addition, it relates to glass products that are excellent in scratch resistance, abrasion resistance, slipperiness, and line contamination reduction in glass container user factories. In particular, the present invention requires extremely severe heat resistance such as exposure of hot water of 70 to 80 ° C. or higher to high temperature steam for the purpose of sterilization in an ultrafast filling line of food manufacturers and pharmaceutical manufacturers. The present invention relates to an aqueous coating composition capable of retaining the above function even under conditions.

  Conventionally, anionic surfactants, nonionic surfactants, polyethylene waxes have been used to increase the slipperiness of glass product surfaces to prevent scratches and the like, thereby preventing strength deterioration due to scratches. A coating agent containing an aqueous emulsion or the like is used. In the manufacture of glass containers, this type of coating is called a cold end coating. Glass containers are often washed before filling their contents and are treated with hot water after filling for the purpose of sterilizing the contents. It is preferred to use a cold end coating agent containing insoluble polyethylene wax in the form of an aqueous emulsion. As this type of cold end coating agent, a composition obtained by emulsifying polyethylene wax with an anionic surfactant (potassium salt of higher fatty acid) is known (see Patent Document 1).

  On the other hand, in recent years, glass container production lines and filling lines for glass container users such as food manufacturers and pharmaceutical manufacturers have been increasing the speed and sterilization conditions at higher temperatures year by year. The problems of cold end coating wear, transportation line contamination due to wear and drop off from the glass container surface, softening of the coating agent on the glass container surface and slippage deterioration due to water absorption have become apparent.

  In order to solve these problems, a cold end coating agent containing polyethylene wax and a silane coupling agent has been developed (see Patent Document 2), and certain results have been obtained. As the production line speeds up, there is a need for a cold-end coating agent that enables coating that is less likely to wear or fall off.

  In addition to this, labeling on the surface of glass containers (labeling) has traditionally focused on easy release of labels (a feature that can be easily removed when trying to peel off labels during recycling). Improvements have also been made, but as production lines become increasingly faster, labeling technology that is easier to peel and more stable than before has come to be demanded.

  Conventionally, in addition to a cold end coating agent, a composition containing a resin (polyethylene, polypropylene, polystyrene, polyurethane, vinyl chloride resin, acrylic resin, epoxy resin, ionomer resin) and a silane coupling agent as a coating agent for glass containers. It is described in the publication (patent documents 3 and 4). However, according to the description, these coating agents are coating agents for forming a thick film of at least about 2 to 50 μm, and when they are coated on the bottle surface, the surface slip angle is It is shown that it is as large as 20 ° or more (that is, the slipperiness is poor). In this document, as an example of an ionomer resin, a copolymer of a lower olefin having 2 to 7 carbon atoms and maleic acid or other unsaturated carboxylic acid is neutralized at least partially (alkali metal or alkaline earth metal). Although various other resins are listed, specific examples of the coating agent include polyurethane resin emulsions or copolymers of methacrylic acid and ethylene as resin components (Chemical S-100 (registered trademark)). The thing using is only described.

  An aqueous coating composition comprising a copolymer of an α-olefin and maleic anhydride, a resin comprising a partial ester thereof, and a silane coupling agent has been developed (Patent Document 5). By using this coating agent, it is possible to prevent contamination of the conveyance line due to wear and drop off from the glass container surface even in a normal high-speed line. However, in recent years, food manufacturers and pharmaceutical manufacturers have been using ultra-high-speed lines that fill more than 1000 bottles per minute, and the higher the sterilization conditions, the higher the hydrophilicity and the softening. If a resin with a low point is used, slipping in the line becomes insufficient due to softening or water absorption of the resin, causing a problem that the glass container cannot follow ultra-high speed filling.

Japanese Patent Publication No.42-1758 (right column on page 3, etc.) JP 2002-241145 A JP-A-57-165466 JP-A-57-3869 International Publication No. 2007/097376

  Under such circumstances, an object of the present invention is an aqueous coating composition for glass, which is (1) subjected to a hot water treatment performed for washing glass containers and sterilizing the contents after coating. Can maintain the function of preventing damage to the glass container surface, and (2) can reduce the contamination of the conveying line, especially the conveyor guide, caused by wear and drop of the coating on the glass container surface. It is exposed to hot water of 70-80 ° C or higher, high-temperature water vapor, etc., and has a feature that it can maintain sufficient slipperiness even in an ultrahigh-speed line that fills 1000 or more per minute. It is to provide a coating composition.

  A further object of the present invention is to provide a glass container, sheet glass or other glass product whose surface is coated with an aqueous coating composition for glass having the above characteristics.

  A still further object of the present invention is an aqueous coating composition for glass having the above-described characteristics, and (1) stable labeling is possible on the surface of the coated glass container, and (2) distribution. Water-based coating composition for glass that gives the surface of glass products the ability to easily peel off labels when they are going to be peeled off during recycling (easy peelability). Is to provide.

  A still further object of the present invention is to provide a glass container, a sheet glass or other glass product whose surface is coated with the above-described easily-peelable glass aqueous coating composition.

  As a result of repeated studies to solve the above-mentioned problems, the inventors of the present invention have (1) as a resin, a polyethylene wax having a softening point of 110 ° C. or higher, an α-olefin / maleic anhydride copolymer, and the copolymer. Of the partial reaction product of the coalescence (that is, the graft modified by reacting at least a part of the maleic anhydride monomer unit with an alcohol compound or an amine or amino acid to form an ester, amide or imide) When an aqueous coating composition is used in combination with at least one of the above, when the glass surface is treated with this, the resin can be stably adhered to the glass surface, and the formed surface has a low coefficient of friction. Therefore, strength deterioration of glass products (glass containers, sheet glass, etc.) can be prevented, and (2) the aqueous coating composition is cold For glass products that are moderately coated on the surface of glass containers as a glass coating composition, contamination of conveyor lines such as conveyor guides due to coating wear and dropout on the glass container production line and the user side (such as food factories) is reduced. (3) Sufficient slipperiness can be maintained even in an ultrahigh-speed line that is exposed to hot water of 70 to 80 ° C. or higher for sterilization purposes, high-temperature steam, etc., and is charged at 1000 or more per minute, 4) Furthermore, labels and seals (things to be attached to the side of the product) using starch-based glue or synthetic resin adhesives can be securely attached, and there is a risk that they will peel off naturally during the distribution process. However, it can be easily removed when trying to peel them off during recycling, and it can be reliably applied with sheet glass (for example, door glass) Glass products can be selected by controlling the amount of coating, both the property of being easily peeled (after use) when peeled off (easily peelable) and the conflicting property of sticking the adhered label firmly. It was found that it can be applied to the surface of The present invention has been completed based on these findings.

That is, the present invention provides the following.
1. An aqueous coating composition comprising a resin (A) and a resin (B) dispersed in water in the presence of a base, wherein the resin (A) is a polyethylene wax having a softening point of 110 ° C. or higher. The aqueous coating composition, wherein the resin (B) is at least one of an α-olefin / maleic anhydride copolymer and a partial reaction product of the copolymer.
2. The aqueous coating composition according to 1 above, wherein the weight mixing ratio of the resin (A) and the resin (B) is (A) / (B) = 35/65 to 80/20 in terms of the weight of the potassium salt.
3. The aqueous coating composition according to 1 or 2 above, wherein the acid value of the resin (A) is 20 to 40 mg-KOH / g and the acid value of the resin (B) is 100 to 300 mg-KOH / g.
4). 4. The aqueous coating composition according to any one of 1 to 3 above, wherein the softening point of the resin (A) is 130 ° C. or higher.
5. The aqueous coating composition according to any one of 1 to 4 above, wherein the penetration of the resin (A) at 25 ° C is 0.1 mm or less.
6). 6. The aqueous coating composition according to any one of 1 to 5 above, wherein the α-olefin has 10 to 50 carbon atoms.
7). 7. The aqueous coating composition according to any one of 1 to 6 above, wherein the partial reaction product of the copolymer is graft-modified by alkyl esterification in at least some of the maleic anhydride monomer units.
8). 8. The aqueous coating composition according to 7 above, wherein the alkyl esterification is a monoalkyl esterification.
9. 9. The aqueous coating composition according to any one of 1 to 8 above, wherein the total concentration of the resin (A) and the resin (B) is 0.05 to 1% by weight in terms of the weight of their potassium salts.
10. 10. The aqueous coating composition according to any one of 1 to 9 above, wherein the acid value of the resin (A) is 25 to 35 mg-KOH / g and the acid value of the resin (B) is 120 to 250 mg-KOH / g.
11. The aqueous mixture according to any one of 1 to 10 above, wherein the weight mixing ratio of the resin (A) and the resin (B) is (A) / (B) = 40/60 to 75/25 in terms of the weight of the potassium salt. Coating composition.
12 12. The aqueous coating composition according to any one of 1 to 11 above, wherein the α-olefin has 14 to 40 carbon atoms.
13. A glass product comprising a surface coated with the aqueous coating composition according to any one of 1 to 12 above.
14 14. The glass product according to 13, wherein the glass product having the surface coated with the aqueous coating composition is obtained by hot-end coating the surface before the coating.
15. The glass product according to 13 or 14, which is a glass container.
16. 13. The glass product according to the above 13, which is a plate glass.
17. A glass surface treatment method comprising contacting a glass surface with any one of the aqueous coating compositions 1 to 12 at a surface temperature of 80 to 130 ° C.

  The glass product subjected to surface treatment with the above aqueous coating composition has a predetermined polyethylene wax (resin (A)), a predetermined α-olefin / maleic anhydride copolymer and a copolymer on the surface thereof. The resin [resin (B)], which is at least one of the partial reaction products of the polymer, coexists and adheres in the form of a salt. For this reason, the friction coefficient of the glass surface is lowered by the action of these resins, and the effect of preventing scratching of the glass surface is thereby exhibited, and as a result, the strength of the glass is prevented from being deteriorated. In addition, glass containers that have been surface-treated with the aqueous coating composition are less likely to contaminate conveyor lines such as conveyor guides on the production line or user side (food factories, etc.), and heat of 70 to 80 ° C. or higher for sterilization purposes. Even in an ultra-high speed line that is exposed to water, high-temperature steam, etc. and is charged at a rate of 1000 or more per minute, it has a distinctive feature that it can maintain sufficient slipperiness. In addition, glass products that have been surface-treated with the aqueous coating composition should be securely affixed with labels and seals (things to be affixed to the side of the product) using starch-based glue or synthetic resin adhesives. However, it is easy to carry out even with an ultra-high-speed line, and is also suitable for achieving easy peeling labeling.

Outline view from the side of the line simulator Plan view showing the structure near the gate of the line simulator Outline diagram showing surface slip angle measurement method The graph which shows the surface slip angle after the no-washing and hot-water washing of the glass container obtained in Examples 1-4 and Comparative Examples 1-2, respectively. Photographs showing typical surface states of the guide members after the line simulator test of the glass containers obtained in Examples 5 and 6 and Comparative Examples 3 and 4, respectively. The graph which shows the change of the surface slip angle of the glass container of Example 5, 6 and the comparative example 4 with a line simulator test elapsed time.

  In this specification, the “glass container” includes glass bottles, glass tableware, vases, and the like.

  In the aqueous coating composition of the present invention, the polyethylene wax [resin (A)] having a softening point of 110 ° C. or higher can be stably dispersed in an ultrafine particle state in the presence of a base. When used for the preparation of the aqueous coating composition of the present invention, the resin (A) may be an aqueous dispersion having a solid content of, for example, about 25 to 45% by weight, dispersed in water in the presence of a base.

  The softening point of the resin (A) is set to 110 ° C. or higher when the softening point is lower than 110 ° C., and is exposed to hot water of 70 to 80 ° C. or higher, high-temperature steam, etc. This is because, in the ultra-high speed line of a glass container user who fills 1000 or more, the coating cannot maintain sufficient slipperiness and the glass container may not be able to follow this filling speed. The softening point of the resin (A) is more preferably 130 ° C. or higher in consideration of high-temperature sterilization and ultrahigh-speed filling.

  In the aqueous coating composition of the present invention, the resin [resin (B)], which is at least one of an α-olefin / maleic anhydride copolymer and a partial reaction product of the copolymer, is present in the presence of a base. It can be stably dispersed in an ultrafine particle state. When used for the preparation of the aqueous coating composition of the present invention, the resin (B) may be an aqueous dispersion having a solid content of, for example, about 10 to 20% by weight, dispersed in water in the presence of a base.

  In the present invention, the resin (A) and the resin (B) are preferably contained in the aqueous coating composition at a specific mixing ratio.

The weight mixing ratio of the resin (A) and the resin (B) contained in the aqueous coating composition of the present invention is (A) / (B) = 35 / 65-80 / 20 in terms of the weight of their potassium salts. It is preferable. This is because when the weight ratio of the resin (A) is less than 35% of the total weight of the resin (A) and the resin (B) (therefore, the weight ratio of the resin (B) exceeds 65%), 70 There is a risk of being unable to follow the ultra-high speed line of a glass container user who is exposed to hot water of up to 80 ° C or higher, high-temperature steam, etc., and filling more than 1000 bottles per minute, and conversely the weight ratio of resin (A) Exceeding 80% (therefore, the resin (B) weight ratio is less than 20%), the adhesion of the coating to the glass surface deteriorates, the contamination of the conveyor guide on the filling line becomes severe, and the strength of the glass container May also deteriorate.
The weight mixing ratio of the resin (A) and the resin (B) is calculated in terms of the weight of potassium salt in consideration of the use in high temperature, ultra-high speed filling line, contamination of the filling line, maintenance of strength of the glass container, etc. A) / (B) = 40/60 to 75/25 is more preferable, and (A) / (B) = 50/50 to 75/25 is still more preferable.

The acid value of the resin (resin itself before being dispersed in water) contained in the aqueous coating composition of the present invention is 20 to 40 mg-KOH / g for the resin (A) and 100 to 300 mg- for the resin (B). KOH / g is preferred.
When the acid value of the resin (A) is less than 20 mg-KOH / g, the dispersion stability of the resin (A) in the aqueous coating composition is lowered, and the adhesion of the label or seal to the coating surface is insufficient. Contamination of the conveyor guide for glass container users may become severe. On the other hand, if the acid value exceeds 40 mg-KOH / g, the label or seal may not be easily peelable.

When the acid value of the resin (B) is less than 100 mg-KOH / g, the dispersion stability of the resin (B) in the aqueous coating composition is lowered, and the adhesion of the label or seal to the coating surface is insufficient. There is a risk of becoming. On the other hand, if the acid value exceeds 300 mg-KOH / g, the water resistance of the coating is lowered, and the easy peelability of the label or seal may not be obtained. In addition, the water absorption of the coating increases, and there is a risk that high temperature sterilization for glass container users and use in an ultra-high speed filling line may become impossible.
Considering dispersion stability of aqueous coating composition, adhesiveness of labels and seals, easy peelability, water resistance of coating, high temperature sterilization, use in high speed filling line, reduction of contamination of conveyor guide, etc. The acid value is 25 to 35 mg-KOH / g, and the acid value of the resin (B) is more preferably 120 to 250 mg-KOH / g. Here, the “acid value” refers to the number of milligrams of potassium hydroxide required to neutralize the carboxyl group contained in 1 g of resin.

  Further, the saponification value of the resin (B) (the resin itself before being dispersed in water) contained in the aqueous coating composition of the present invention is preferably 150 to 320 mg-KOH / g, and 160 to 270 mg-KOH / g. More preferably, it is g. Here, “saponification value” refers to the number of milligrams of potassium hydroxide required to saponify 1 g of resin, and corresponds to the sum of acid value and ester value.

  The number average molecular weight (GPC method, standard substance: polymethyl acrylate) of the resin (B) contained in the aqueous coating composition of the present invention is preferably 1500 to 4000. If the number average molecular weight is less than 1500, the wear resistance of the coating may be reduced. On the other hand, if it exceeds 4000, the softening point of the resin becomes high, and the spread of the resin on the glass surface is limited, and the surface friction coefficient may not be sufficiently reduced. The resin preferably has a softening point (ASTM D127 method) of 60 to 130 ° C. in consideration of adhesion to the glass product surface during application by spraying or the like.

Further, the penetration (ASTM D1321 method) at 25 ° C. of the resin (A) contained in the aqueous coating composition of the present invention is preferably 0.1 mm (1 dmm) or less. If the penetration of the resin (A) exceeds 0.1 mm, the coating resin will be insufficiently hard, and a sufficiently small coefficient of friction will not be maintained, resulting in hot water of 70-80 ° C or higher, high temperature steam, etc. There is a risk that it will not be possible to follow the ultra high-speed line of a glass container user who is exposed and fills 1000 or more bottles per minute.
Considering use in a high-temperature sterilization and high-speed filling line, the penetration of the resin (A) is more preferably 0.05 mm (0.5 dmm) or less.

  Moreover, it is preferable that carbon number of the alpha olefin which is a structural monomer of resin (B) contained in the aqueous coating composition of this invention is 10-50. This is because if the carbon number is less than 10, the coefficient of friction on the coating surface becomes high and the effect of preventing scratches on the glass surface may be reduced. If the carbon number exceeds 50, the dispersibility in water is reduced. At the same time, the surface free energy becomes too low, and there is a possibility that labels and stickers cannot be attached. Considering the surface friction coefficient, dispersibility, labeling suitability, etc., the α-olefin has more preferably 14 to 40 carbon atoms, and particularly preferably 18 to 34 carbon atoms. Although the α-olefin may be used alone, a mixture of two or more kinds may be used. The copolymerization method of the α-olefin with maleic anhydride and / or the maleic anhydride partial reactant may be carried out in the absence of a solvent or in combination with a solvent, and may be carried out according to a conventional method such as radical polymerization. it can.

In the aqueous coating composition of the present invention, as the partial reaction product of the α-olefin / maleic anhydride copolymer, at least a part of the maleic anhydride monomer unit of the α-olefin / maleic anhydride copolymer is converted into an alcohol-based coating composition. Examples thereof include those obtained by graft modification by reacting with a compound, amine, amino acid or the like to form an ester, amide or imide. In controlling the acid value, it is preferable to use an ester that is a reaction product with an alcohol compound. That is, those having maleic acid monoalkyl ester or dialkyl ester as the structural unit derived from maleic anhydride are preferred, and those containing more monoalkyl ester than dialkyl ester are more preferred. It may be substantially composed mainly of monoalkyl ester and substantially free of dialkyl ester. Although there is no restriction | limiting in particular as an alcohol compound here, As a preferable example, C1-C20, More preferably, C1-C16, Most preferably, C1-C8 alcohol can be mentioned. Specific examples include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, tert-butyl alcohol, pentanol, hexanol, heptanol, octanol, and higher carbon number alcohols such as decyl. Alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, etc. are mentioned. As a modification method such as esterification, maleic anhydride may react with an alcohol compound in a monomer and then polymerize to obtain a desired resin, or may be graft-modified after polymerization.
The acid value may be increased by a method such as separately introducing a carboxyl group into the alkyl side chain.

  In the aqueous coating composition of the present invention, in order to uniformly disperse the resin (A) in water in the presence of a base, a nonionic surfactant having a polyoxyethylene chain in the structure can be contained. There are no particular limitations on such nonionic surfactants other than having a polyoxyethylene chain in the structure, for example, polyhydric alcohol ester ethylene oxide adduct, polyethylene glycol monoester, polyethylene glycol diester, higher alcohol ethylene oxide addition Products, alkylphenol ethylene oxide adducts, and the like.

  On the other hand, in the aqueous coating composition of the present invention, the resin (B) can be dispersed in water in the presence of a base without adding a surfactant other than the resin. If the resin has an acid value and a molecular weight within the above ranges, it is not necessary to add a surfactant separately for dispersion. By not including the surfactant for dispersing the resin (B) in the aqueous coating composition of the present invention, the amount of the surfactant as a whole can be reduced. As a result, the surface condition of the coating becomes less dependent on the conditions of the hot water sterilization treatment using a bottle or pasterizer, so that the labeling and easy peelability are stable. It is also advantageous for preventing water bubbles after washing.

  There are no particular restrictions on the type of base used for dispersing the resin, but ammonia, triethylamine, triethanolamine, N, N-dimethylaminoethanol, N, N-diethylaminoethanol, NaOH, KOH, and the like are preferable examples. It is done.

  The total concentration of the resins (A) and (B) in the aqueous coating composition of the present invention is preferably 0.05 to 1% by weight in terms of their potassium salt weight. This is because if the total concentration is less than 0.05% by weight, sufficient slipperiness may not be obtained, and the exposed ratio of the glass surface may increase, and the easy peelability of the label or seal may not be achieved. On the other hand, if the total concentration exceeds 1% by weight, the glass surface becomes slightly opaque, the appearance may be deteriorated, the economy is also poor, and the problem of contamination of the conveyor guide may also be manifested. This is because labels and seals may be peeled off during the distribution process. Considering prevention of scratches on the glass surface, appropriate adhesion of labels and seals, appearance, contamination of the conveyor guide, etc., the total concentration is more preferably 0.07 to 0.5% by weight.

The water-based coating composition of the present invention may contain a silane coupling agent depending on the purpose, for example, to make label easy peelability more reliable. As the silane coupling agent, those having an amino group are preferable. The silane coupling agent is represented by the general formula, R _n SiX _4-n (n is 1, 2 or 3. When n is 2 or 3, R may be the same or different), and organic and inorganic substances These compounds are used for various purposes as compounds having affinity for both, and various compounds are commercially available. In the general formula, X is a hydrolyzable group, and examples thereof include an alkoxy group, an acetoxy group, an oxime group, an enoxy group, and an isocyanate group. R is a variety of organic groups having a carbon atom directly bonded to Si, such as an alkyl group that may be substituted, an alkenyl group that may be substituted, and atoms other than carbon such as oxygen, nitrogen, etc. And a group in which two or more alkyl groups which may be substituted or alkenyl groups which may be substituted are connected via each other. Various substituents are known for the silane coupling agent. Of these various silane coupling agents, those having an amino group as a substituent are particularly preferred in the present invention. The silane coupling agent R _n SiX _4-n has a property that the group X in the molecule undergoes hydrolysis in water and is gradually or quickly converted to the group OH. In the present invention, the term “silane coupling agent having an amino group” refers to those in the form of R _n SiX _4-n , and those that have undergone partial or complete hydrolysis, which may be partially condensation polymerized. Includes everything you did.

  It has been found by the present inventors that a silane coupling agent having an amino group is extremely effective for firmly bonding the resin (A) and the resin (B) to the glass surface. The silane coupling agent having an amino group used in the present invention is not particularly limited, but examples include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β-aminoethyl-γ-amino. Examples thereof include propyltrimethoxysilane, N-β-aminoethyl-γ-aminopropyltriethoxysilane, N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane, and the like.

  The concentration of the silane coupling agent in the aqueous coating composition of the present invention is preferably 0.01 to 1% by weight, more preferably 0.05 to 0.5% by weight. When the silane coupling agent concentration is less than 0.01% by weight, the adhesive strength of the resin (A) and the resin (B) to the glass surface is weakened, and the durability of the coating may be reduced. On the other hand, increasing the concentration of the silane coupling agent beyond 1% by weight does not change the effect and is not economical.

  In the present specification, the “aqueous coating composition” means a composition containing water as a main medium, and so long as it does not exclude the coexistence of other media miscible with water.

  In order to coat a glass product with the aqueous coating composition of the present invention, the aqueous composition may be brought into contact with the outer surface of a glass product such as a glass container or a plate glass when heated. For example, the composition may be simply sprayed, but is not limited to this, and other methods may be used. Considering work efficiency, coating deposition efficiency, and the like, the outer surface temperature is usually preferably in the range of about 80 to about 130 ° C, more preferably in the range of about 90 to about 120 ° C.

  In order to increase the strength and adhesion of the organic coating on the glass container, the glass container is hot by contacting with steam such as butyltin trichloride, tin tetrachloride and titanium tetrachloride before annealing after molding. End coating (surface treatment with tin oxide or titanium oxide) is performed in many cases, but the cold end coating composition of the present invention should be widely and suitably used for glass containers regardless of whether or not hot end coating is performed. Can do.

  The glass product of the present invention is an ordinary starch-based paste conventionally used for labeling of glass containers (after being washed as it is or after being washed according to the user's usage mode), and is made of a paper label or seal. The easy peelability can be realized by sticking. As such starch-based paste, starch or modified starch as the main component, or starch-acrylic mixed system such as starch or modified starch is the main component and contains about 45-65% water. Can be used. In addition, even in a synthetic resin adhesive or a heat-sensitive label to which a synthetic resin adhesive has been applied in advance, a label or a seal can be attached to achieve easy peelability.

The apparatus and method used for evaluation in the present invention will be described.
1. Label peeling test When a paper label is attached to a glass container in a laboratory, a linear pattern (with a line width of 1.2 mm and a line interval of 1.1 mm) on a 200 mesh screen is used so that the amount of glue used is not excessive. The total length and front width are adjusted to the label size), and glue is applied directly to the back side of the paper label using a squeegee and applied to the glass container surface. When attaching paper labels to glass containers in food factories, pharmaceutical factories, etc., use normal or thermal labelers.
The corner of the paper label affixed to the surface of the glass container is peeled off with a nail, the peeled portion is picked off, the label is peeled off, and the peeling operation is performed once when the label is broken. ◎ When the label is peeled off once without rupturing, ○ when the label is peeled off after 2 or 3 times, the label is not completely peeled after the third operation, but the residual rate is 30% or less The case of Δ is evaluated as Δ, and the case where the residual rate exceeds 30% is evaluated as ×.

2. Conveyor Guide Contamination Evaluation Acceleration Test The accelerated test for conveyor guide contamination evaluation in glass container production lines, food manufacturers, and pharmaceutical manufacturers' filling lines is performed using a line simulator. The term “line simulator” as used herein is traditionally used in the glass bottle industry as a means of experimentally predicting physical damage that would normally be applied to the surface of glass containers placed in the distribution process after manufacture. American Glass Research (AGR International, INC., Butler,
PA, USA). Various settings and usage methods such as the structure and dimensions are as follows.

  FIG. 1 is a schematic view seen from the side of the line simulator. The line simulator has a substantially cylindrical shape and forms an outer frame of the apparatus body. Inside the open cover 18 at the top, the rotating disk 1 (made of stainless steel) is fixed to the upper surface. A rotating disk 2 (made of Bakelite) having the same diameter that rotates together with the rotating disk 1 is provided. The rotating disks 1 and 2 are driven by a motor 3 and rotated at a predetermined speed. A plastic guide rail 4 having a substantially circular cross section is provided annularly in two upper and lower stages along the entire inner wall of the cover 18. On the rotating disk 2 is mounted one of the circular exchange plates 7 selected according to the prescription from four sizes according to the size of the glass container to be tested, and by a screw-type fixing device having a handle 8. Attached to the shafts of the rotating disks 1 and 2. The replacement plate 7 is provided with a bracket 6 along its outer periphery, and a plastic guide rail 5 having a substantially circular cross section is provided on the outer peripheral side of the bracket 6 in two upper and lower stages. In the figure, three spacers 9 are inserted under the rotating disk 1. These spacers 9 that can be individually separated serve to support the rotating disk 1 from below and are used to adjust the height of the rotating disk 1. That is, according to the height of the glass container to be tested, according to the rules described later, several (0 to 3) spacers 9 are inserted between the rotating disk 2 and the exchange plate 7 to thereby rotate the rotating disk. The height of 1 (and therefore of the rotating disc 2 at the same time) is adjusted. The glass containers to be tested are arranged upright on the rotating disk 2 between the guide rails 4 and 5.

In FIG. 1, reference numeral 10 denotes a gate protruding on the rotating disk 2. As illustrated in detail in FIG. 2, the gate 10 is in the form of a lever supported rotatably around a vertical axis at a fulcrum located outside the cover 18. It is arranged so as to protrude through the inside of the cover 18 and above the rotating disk 2. In FIG. 1, only the tip of the lever of the gate 10 is shown. One end of a coil spring 11 is attached to the gate 10 in the vicinity of its tip. A block 19 having a female screw that passes through is fixed to the outer surface of the cover 18. A gate adjustment screw 20 a is screwed into the female screw, and the tip of the gate adjustment screw 20 a passes through the block 19 and protrudes inside the cover 18. The other end of the helical spring 11 is attached to the tip of the gate adjustment screw 20a. Reference numeral 20b denotes a gate adjustment fixing screw, which is rotated around the adjusted gate adjustment screw 20a and pressed against the block 19, so that the gate adjustment screw 20a can be fixed at that position so as not to move.

  In FIG. 1, 12 is a spray head for spraying water at room temperature on the outer surface of the glass container placed on the rotating disk 2 (inner diameter 2 mm). The hung water falls from the gap between the rotating disks 1 and 2 and the cover 18 and falls into the drain trap 14 through the gap between the circular aluminum plate 16 inclined downward on the outer periphery and the cover 18. And discharged through the drain connection port 15. The rotation time of the rotating disks 1 and 2 is set to a predetermined length by operating the set timer 13.

FIG. 2 is a plan view showing the structure near the gate 10 of the line simulator shown in FIG. As shown in FIG. 1, the gate 10 is supported so as to be rotatable about a fulcrum A around a vertical axis. One end of the helical spring 11 is attached to the tip of the gate adjusting screw 20a, and the other end is attached to a cylindrical pin provided near the tip of the gate 10. On the gate 10, the same guide member “Newlite (registered trademark) plate” (ultra high molecular weight polyethylene manufactured by Sakushin Kogyo Co., Ltd.) 10 a as the conveyor guide material is fixed to the surface in contact with the glass container with a countersunk screw. The guide member 10a is used for evaluation of contamination when the glass containers are in continuous contact. 21 and 22 represent two of the glass containers arranged in the apparatus. A number of glass containers are arranged on the rotating disk 2 between the guide rails 4 and 5 in the manner described later in the test. The arrow indicates the direction of rotation of the rotating disk 2.

Referring to FIG. 2, the dimensions of each part are as follows.
1) Inner diameter of guide rail 4: 613 mm
2) Outer diameter of cover 18: 637 mm
3) Shortest distance between the outer periphery of the cover 18 and the fulcrum A: 19 mm
4) Angle formed by the central axis of the gate adjusting screw 20a and the fulcrum A with respect to the central axis of the rotating disk 1: 26.3 °
5) Distance between fulcrum A and gate tip: 178 mm
6) Distance between guide member tip surface and cover 18: 30 mm

<Selection method of replacement plate>
In addition, the exchange plates 7 (No. 1 to 4) of four sizes with the bracket 6 and the guide rail 5 have an outer diameter of the guide rail 5 of 48.3 cm (No. 1) and 44.5 cm, respectively. No. 2), 40.3 cm (No. 3) and 32.0 cm (No. 4). The size of the replacement plate 7 used in the test is selected according to the outer diameter of the glass container. Ie:
1) Glass container outer diameter 58.4 mm or less 1
2) Glass container outer diameter 58.4-73.7 mm ... No. 2
3) Glass container outer diameter 73.7 to 96.5 mm ··· No. 3
4) Glass container outer diameter 96.5-129.5 mm No. 4

<Spacer arrangement method>
The spacer 9 shown in FIG. 1 is arranged as follows according to the height of the glass container to be tested. Ie:
1) Container height of 228.6 mm or less: All three spacers 9 are arranged between the rotating disk 1 and the aluminum plate 16.
2) Container height 152.4 to 254.0 mm: Two spacers 9 are arranged between the rotating disc 1 and the aluminum plate 16, and one spacer 9 is arranged between the rotating disc 2 and the exchange plate 7. Place between.
3) Container height 177.8 to 279.4 mm: One spacer 9 is arranged between the rotating disk 1 and the aluminum plate 16, and the two spacers 9 are arranged between the rotating disk 2 and the exchange plate 7. Place between.
4) Container height 203.2 to 304.8 mm: All three spacers 9 are arranged between the rotating disk 2 and the exchange plate 7.

<Gate adjustment method>
See FIG. In evaluating the coating on the surface of the glass container having a diameter of about 45 mm, the gate adjustment screw 20a is positioned so that the distance between the front end of the guide member 10a having a thickness of about 5 mm attached to the gate 10 and the cover 18 is 40 mm. Then, the gate adjustment screw is fixed by tightening the gate adjustment fixing screw 20b. Here, the helical spring 11 used in the line simulator has a natural length of 3.6 cm, a length of 1.3 cm when the tip of the gate adjusting screw 20a hits a cylindrical pin near the tip of the gate 10, and The spring constant is 65.4 N / cm.

<Rotation speed, amount of squirting water>
Number of rotations of the rotating disks 1 and 2: 35 rotations / minute Amount of water ejected from the spray head 12: 200 mL / minute

<How to use>
In accordance with the above rules, the replacement plate 7 and the spacer 9 are attached according to the outer diameter and height of the glass container to be tested, and the gate is adjusted and fixed. In a state where the glass containers are in contact with the inner periphery of the guide rail 4 so as not to leave a gap between the glass containers, the glass containers are arranged in a row between the leading glass container and the last glass container. Arrange sequentially until the interval is less than one glass container. The set timer 13 is set to a desired time, and the flow rate of water ejected from the spray head 12 is set. The rotation of the rotating disks 1 and 2 is started, and the operation of the apparatus is continued for a set length of time while water from the spray head is applied to the outer surface of the glass container.

<Function of line simulator>
As the rotating disks 1 and 2 rotate, the glass containers (21, 22 etc.) placed on the rotating disks 1 and 2 are sequentially sent to the gate 10 to push the gate 10 one after another and resist the urging by the helical spring 11. Then, the gate 10 is spread and passed, but at that time, the coating on the surface of the glass container is rubbed off by friction with the guide member, and the degree of contamination of the guide member changes depending on the magnitude of the coating. By placing the glass container in this state for a certain period of time, the line simulator process makes it possible to evaluate the durability of the coating of the glass container on the transfer line in a short time under more severe conditions.

3. Surface slip angle measurement method Japan Glass Bottle Association standard (established on June 15, 1977, added and revised on May 19, 2010 (7)) "7.12 Surface slip angle measurement method" It is stipulated that the surface slip angle should be measured according to the procedures and standards.
<Sample>
(1) Sample bottle: Collect a bottle after the coating agent is completely dried, and let it cool until the bottle temperature reaches room temperature.
(2) Collecting sample bottles: Collect 9 or more sample bottles for each measurement. However, do not touch the bottle surface with your hands during sampling and measurement.
<Measurement method> (See Fig. 3)
(1) Place the sample bottles 32 and 33 in contact with each other on the bottle holder 34 horizontally with the parallel adjustment screw 37, bring the bottle bottoms into close contact with the stoppers, and apply stoppers so that the bottles 32 and 33 are not displaced laterally. .
(2) Place the sample bottle 31 on the sample bottles 32 and 33 and stack them in a triangle.
(3) All three sample bottles should be arranged in the same direction, and the bottle surface should be in contact with the straight surface, avoiding surfaces with sculptures and seams.
(4) Turn the handle 36 to gradually tilt the bottle holder, and read and record the scale at which the sample bottle 31 started to slide.
(5) Three bottles are used for one measurement and are not used again. However, perform the measurement three times or more.

4). Strength Measurement Method The internal pressure strength was measured according to JIS S2302-1994 “Internal pressure test method for glass bottles for carbonated beverages”, and the number of samples was 20. The mechanical impact strength was measured according to JIS S2303-2003 “Mechanical impact test method for glass bottles for carbonated beverages”, and the number of samples was 20 for each of the upper and lower contact points (portions where the bottles contacted).

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further in detail, it is not intending that this invention is limited by these Examples.

[Examples 1-4 and Comparative Examples 1-2]
<Resin and aqueous dispersion>
As the resin (A), a polyethylene wax having a softening point of 138 ° C. [manufactured by Honeywell, trade name: A-C392, acid value 30 mg-KOH / g (hereinafter, unit omitted), penetration <0.05 mm (<0. 5 dmm)] was prepared as an aqueous dispersion by a conventional method using a nonionic surfactant (higher alcohol ethylene oxide adduct) in the presence of potassium hydroxide (aqueous dispersion A). The concentration of polyethylene wax is 35% by weight in terms of its potassium salt weight.
As the resin (B), a copolymer of α-olefin, maleic anhydride and maleic anhydride mono-isopropyl ester (α-olefin has more than 10 carbon atoms) [manufactured by Baker Petrolite, trade name: Ceramer 1608 , CAS No. 75535-27-2, acid value 154, saponification value 190 mg-KOH / g (hereinafter, unit omitted), number average molecular weight 2580], and an aqueous dispersion by a conventional method in the presence of potassium hydroxide Prepared (Aqueous Dispersion B). The concentration of the resin (B) is 16.8% by weight in terms of its potassium salt weight.

<Preparation of each aqueous coating composition>
(1) 6.7 g of the aqueous dispersion B was added to 1000 mL of ion exchange water and mixed to obtain an aqueous coating composition for glass surface treatment (cold end coating). This composition contains the resin (B) but does not contain the resin (A) (Comparative Example 1).
(2) 2.7 g of the aqueous dispersion A was added to 1000 mL of ion exchange water and mixed to obtain an aqueous coating composition for glass surface treatment (cold end coating). This composition contains resin (A), but does not contain resin (B) (Comparative Example 2).
(3) A solution prepared by adding 1.08 g of aqueous dispersion A to 500 mL of ion-exchanged water and a solution prepared by adding 4.02 g of aqueous dispersion B to 500 mL of ion-exchanged water and mixing them are combined for glass surface treatment. An aqueous coating (cold end coating) composition was obtained. The weight mixing ratio of the resin (A) and the resin (B) was (A) / (B) = 0.36 / 0.64 in terms of their potassium salt weight (Example 1).
(4) A solution prepared by adding 1.35 g of aqueous dispersion A to 500 mL of ion-exchanged water and a solution prepared by adding 3.35 g of aqueous dispersion B to 500 mL of ion-exchanged water and mixing them together are used for glass surface treatment. An aqueous coating (cold end coating) composition was obtained. The weight mixing ratio of the resin (A) and the resin (B) was (A) / (B) = about 0.46 / 0.54 in terms of their potassium salt weight (Example 2).
(5) A solution prepared by adding 1.62 g of aqueous dispersion A to 500 mL of ion-exchanged water and mixing a solution obtained by adding 2.68 g of aqueous dispersion B to 500 mL of ion-exchanged water and mixing them are used for glass surface treatment. An aqueous coating (cold end coating) composition was obtained. The weight mixing ratio of the resin (A) and the resin (B) was (A) / (B) = about 0.55 / 0.45 in terms of their potassium salt weight (Example 3).
(6) A solution prepared by adding 2.02 g of aqueous dispersion A to 500 mL of ion-exchanged water and a solution prepared by adding 1.68 g of aqueous dispersion B to 500 mL of ion-exchanged water and mixing them are combined for glass surface treatment. An aqueous coating (cold end coating) composition was obtained. The weight mixing ratio of the resin (A) and the resin (B) was (A) / (B) = 0.72 / 0.28 in terms of their potassium salt weight (Example 4).

<Coating process>
Next, a glass container for a drink having an internal volume of 100 mL and a mass of 103 g, which was hot-end coated on the surface by a conventional method, was prepared and held at 115 ° C. for 60 minutes in a constant temperature dryer. The above 6 types of water-based coating compositions for glass surface treatment are transferred to a cup of a hand-type spray gun, and the amount of spray supplied from the compressor and its pressure are adjusted by the hand of the spray gun, so that the spray amount is 70 mL / Fixed to minutes. Next, the glass containers heated to an outer surface temperature of about 100 ° C. are placed one by one in the center of the turntable, and while the turntable is rotated twice (about 2 seconds per rotation), about 50 cm is placed on the glass container. By spraying the coating composition from a distance, the composition was uniformly applied to the outer surface of the glass container without dripping. After the application, the glass container was allowed to cool to room temperature as it was. By this procedure, as many cold-end coated glass containers as necessary for the following tests were prepared.

<Evaluation of lubricity>
The evaluation of the slipperiness of the glass container surface was performed based on the above-mentioned Japanese Glass Bottle Association Standard 7.12 surface slip angle measurement method (n = 12). As a result of the measurement of the glass container without washing, the surface slip angle was Comparative Example 1: 11 to 14 ° (average value 12.1 °), Example 1: 7 to 10 ° (average value 9.3 °). Example 2: 6-9 ° (average value 7.6 °), Example 3: 6-8 ° (average value 7.4 °), Example 4: 6-7 ° (average value 6.5 °), Comparative Example 2: The angle was 6 to 8 ° (average value 7.3 °).
Moreover, the surface slip angle of the glass container which was immersed in 80 degreeC hot water for 10 minutes (hot water washing) and dried was Comparative Example 1: 7-10 ° (average value 8.6 °), Example 1: 6-8 ° (Average value 6.8 °), Example 2: 5 to 7 ° (Average value 6.2 °), Example 3: 5 to 7 ° (Average value 5.8 °), Example 4: 5 to 6 ° (average value 5.5 °), Comparative Example 2: 7 to 9 ° (average value 8.6 °). The sliding angle measured separately about the glass container of the same specification which did not perform cold end coating was 25-30 degrees. From these facts, the coatings of Examples 1 to 4 showed lower surface slip angles with respect to Comparative Examples 1 and 2 on the surface of the glass container obtained without washing or with hot water (Table 1). reference). FIG. 4 shows the relationship between the weight ratio of the resin (A) in the total weight of the resin (A) and the resin (B) in terms of potassium salt weight and the average value of the surface slip angle.

[Comparative Example 3]
<Resin and aqueous coating composition>
A polyethylene wax having a softening point of 101 ° C. (trade name: A-C629, acid value 15) manufactured by Honeywell Co., Ltd. in the presence of potassium hydroxide and using a higher alcohol ethylene oxide adduct and potassium oleate as emulsifiers in a conventional manner. A dispersion was prepared (aqueous dispersion C; solid content concentration: about 12% by weight).
This was diluted 100 times with ion-exchanged water to prepare 100 L of a glass surface treatment aqueous coating (cold end coating) composition. This coating composition has been used for a long time.

<Coating process>
Three spray guns on the surface of a glass container for drinks with an internal volume of 100 mL and a mass of 103 g, which has been hot-end coated in the manufacturing line of a bottle factory and further strained in a slow cooling furnace with an outer surface temperature of about 100-110 ° C. Was used to spray the coating composition. The amount of spray was 70 mL / min per gun, and spraying was performed for 35 glass containers in a row while the spray gun was running from both sides of the row for about 3.2 seconds.

<Evaluation of lubricity>
After cooling to room temperature, the slipperiness of the glass container surface was evaluated based on the method for measuring the surface slip angle of the Japan Glass Bottle Association Standard 7.12 (n = 12). The surface slip angle of the unwashed glass container was 6 to 8 °, respectively.

<Evaluation of guide member contamination>
195 new glass containers on which the above coating treatment was performed using the above aqueous coating composition were prepared. 39 lines were run on a line simulator (LS), the total number was changed every 10 minutes, and the test was conducted for a total of 50 minutes. When the contamination on the surface of the guide member fixed to the gate of the line simulator after the test was observed, the glass container of Comparative Example 3 significantly contaminated the guide member (see FIG. 5D).

[Examples 5, 6, Comparative Example 4]
<Aqueous coating composition and coating treatment>
100 L of the same aqueous coating composition for glass surface treatment (cold end coating) as in Examples 3 and 4 and Comparative Example 2 was prepared, and the aqueous coating compositions of Examples 5 and 6 and Comparative Example 4 were used. Using these, glass coating of the same standard was spray coated under the same conditions and procedures as described in the “Coating” section of Comparative Example 3.

<Evaluation of lubricity 1>
After spray coating, the glass container surface was allowed to cool to room temperature, and the evaluation of the slipperiness of the glass container surface was performed based on the method for measuring the surface slip angle of the Japanese Glass Bottle Association Standard 7.12 (n = 12). The surface slip angle of the unwashed glass container is as follows: Example 5: 7 to 10 ° (average value 7.8 °), Example 6: 6 to 8 ° (average value 7.3 °), Comparative example 4: 6 It was ˜9 ° (average value 7.2 °) (see Table 2).

<Evaluation 2>
Coating was performed in accordance with the description of the above-mentioned “Aqueous coating composition and coating treatment”, and 117 coated glass containers were prepared for each composition, and 39 were divided into 3 groups. For each of the 39 glass containers in each group, the change in surface lubricity due to the treatment by the line simulator (LS) was measured for each of the treatment times of 1, 3 or 5 minutes.
Evaluation was made based on the surface slip angle measurement method (each n = 12). The results are shown in Table 2. Further, FIG. 6 shows changes in the LS test elapsed time and the average value of the surface slip angle. From these results, it can be seen that in the glass containers treated with the aqueous coating compositions of Examples 5 and 6, the increase in the surface slip angle was significantly suppressed as compared with Comparative Example 4, and the slipperiness was maintained. On the other hand, the coating of Comparative Example 4 that does not contain the resin (B) and does not contain the silane coupling agent falls off from the surface of the glass container and cannot keep the surface slipping.

<Evaluation 1 of contamination of guide member>
Coating was performed in accordance with the description in the above-mentioned “Aqueous coating composition and coating treatment”, and 195 newly coated glass containers were prepared for each composition. The test was carried out for each of the glass containers of Examples 5 and 6 and Comparative Example 4 for a total of 50 minutes by applying 39 lines each to a line simulator (LS) and changing the total number every 10 minutes. When the contamination of the surface of the guide member fixed to the gate of the line simulator after the test was observed, the glass container coated with the aqueous coating agent of Comparative Example 3 was significantly contaminated (see FIG. 5 (d)). On the other hand, the contamination of the guide member in the glass container coated with the aqueous coating agent of Examples 5 and 6 and Comparative Example 4 was slight (see FIGS. 5A, 5B, and 5C).

<Evaluation of contamination of guide member 2>
Coating was performed in accordance with the description of the above-mentioned “Aqueous coating composition and coating treatment”, and about 7500 coated glass containers were prepared for each composition. These glass containers were subjected to a line adequacy test at a line rate of 1,200 bottles / min, where hot water treatment and high-temperature steam treatment were performed. Any of the glass containers of Examples 5 and 6 and Comparative Example 4 could be filled at a rate of 1,200 bottles / minute with little contamination of the guide members of the line.

<Evaluation of label peelability>
In addition, a paper label (132 mm × 60 mm, 90 g / m ² ) was attached to the glass container that passed through this line with a labeler using starch-acrylic glue. The labeling was performed stably and the adhesive strength was strong. In the label peeling test after drying, the label could not be peeled off.

<Evaluation of internal pressure resistance and mechanical impact strength>
Coating was performed in accordance with the description in the above section “Aqueous coating composition and coating treatment”, and 120 coated glass containers were prepared for each composition. These glass containers were measured for internal pressure resistance and mechanical impact strength after being treated with a line simulator for 0 and 5 minutes. The number of samples in the internal pressure test was set to 20, and the mechanical impact test was set to 20 for the upper and lower contact points. The results are shown in Table 3. In Examples 5 and 6, the strength is sufficiently maintained even after the treatment for 5 minutes, and the coating composition used for the glass container of Example 5 is particularly excellent in strength maintenance. The glass container of Comparative Example 4 was inferior in strength to the glass container of Comparative Example 3 treated with the conventional coating composition.

Example 7
<Coating process>
100 L of the same glass surface treatment aqueous coating (cold end coating) composition as in Example 5 was prepared, subjected to hot end coating treatment in a bottle factory production line, and further subjected to slow straining in a slow cooling furnace, and an outer surface temperature of about 100 to 110 The coating composition was sprayed on the surface of a glass container for drinks having an internal volume of 100 mL and a mass of 103 g using three spray guns. The spray amount was 45, 55, 65 or 75 mL / min per gun, and spraying was performed while running the spray gun for about 3.7 seconds from both sides of the row to 30 rows of glass containers. .

<Evaluation of lubricity>
After cooling to room temperature, the slipperiness of the glass container surface was evaluated based on the method for measuring the surface slip angle of the Japan Glass Bottle Association Standard 7.12 (n = 12). The surface slip angles of the unwashed glass containers were 6 to 8 ° (average 7.0 °) and 6 to 8 ° (average 7.1) for 45, 55, 65, and 75 mL / min per gun, respectively. °), 6-7 ° (average value 6.4 °), 5-7 (average value 5.9 °). Moreover, as a result of measuring the glass container which was immersed in hot water at 80 ° C. for 10 minutes and then dried, the surface slip angles were 7 to 9 ° (average value 7.7 °) and 7 to 8 ° (average value), respectively. 7.8 °), 7-8 ° (average value 7.4 °), and 6-8 ° (average value 7.1 °).

<Evaluation of label peelability>
Made of paper coated with starch-acrylic paste when the above glass container is immersed in hot water at 80 ° C. for 10 minutes and then dried, filled with hot water at 73 ° C., and at a surface temperature of 60-65 ° C. A label (132 mm × 60 mm, 90 g / m ² ) was attached to the surface. The paste was applied to the back side of the paper label by passing a linear pattern formed on a 200 mesh screen using a squeegee. The amount of glue applied per label was 0.15 to 0.20 g. The evaluation was carried out after drying for 10 days at room temperature with 6 sprays per gun at a flow rate of 45 and 75 mL / min.

  For glass containers using 3 spray guns and a spray rate of 45 mL / min per gun, each label was securely affixed to the glass container and was not affected at all even if the surface was rubbed strongly with a finger. . When these films were subjected to a peel test, the number of x was 6. That is, in a glass container in which the spray amount per gun is 45 mL / min, the strong adhesion of the paper label pasted with starch-acrylic paste after hot water washing of the glass container surface is maintained.

  For glass containers using 3 spray guns and a spray rate of 75 mL / min per gun, each label was securely affixed to the glass container and was not affected at all even if the surface was rubbed strongly with a finger. . A peel test was conducted on these labels. As a result, ◎ was 2 and ○ was 4. In other words, in a glass container with a spray amount per gun of 75 mL / min, the paper label attached with starch-acrylic glue after hot water washing of the glass container surface shows the easy peelability.

  From the above results, the glass surface treatment aqueous coating (cold end coating) composition used in Example 7 [the weight mixing ratio of the resin (A) and the resin (B) is (A ) / (B) = approx. 0.55 / 0.45], by controlling the flow rate during coating, the glass container is provided with both the surface to which the label adheres firmly and the surface to achieve easy peeling of the label It was found that the aqueous coating composition can flexibly respond to the conflicting purpose.

The present invention relates to an aqueous coating agent for obtaining a glass product whose strength is prevented from being deteriorated by preventing scratches due to a decrease in the friction coefficient of the surface, and a glass product treated with the coating agent. Contamination of the conveyor guide due to falling off can be reduced, and stable labeling is possible with either starch glue or synthetic resin adhesive, and there is no risk of the label peeling off naturally during the distribution process. When it is going to peel off a label at the time of recycling after use, the glass product which has the characteristic (easy peelability) that it can peel easily can be obtained.
Also, glass products treated with the aqueous coating agent of the present invention are exposed to hot water of 70 to 80 ° C. or higher, high-temperature water vapor or the like for sterilization purposes, and in an ultrahigh-speed line that fills 1000 or more bottles per minute. , It has a distinctive feature that it can maintain sufficient slipperiness.

1 = Rotating disc (stainless steel)
2 = Rotating disc (Bakelite)
3 = motor 4 = guide rail 5 = guide rail 6 = bracket 7 = exchange plate 8 = handle 9 = spacer 10 = gate 11 = spring 12 = spray head 13 = set timer 14 = drain trap 15 = drain connection port 16 = Aluminum plate 17 = Packing 18 = Cover 19 = Block 20a = Gate adjustment screw 20b = Gate adjustment fixing screw 21 = Glass container 22 = Glass containers 31-33 = Sample bottle 34 = Bottle holder 35 = Scale plate 36 = Handle 37 = Parallel adjustment screw

Claims (17)

  An aqueous coating composition comprising a resin (A) and a resin (B) dispersed in water in the presence of a base, wherein the resin (A) is a polyethylene wax having a softening point of 110 ° C. or higher. The aqueous coating composition, wherein the resin (B) is at least one of an α-olefin / maleic anhydride copolymer and a partial reaction product of the copolymer.   The aqueous coating composition of Claim 1 whose weight mixing ratio of resin (A) and resin (B) is (A) / (B) = 35 / 65-80 / 20 in conversion of the potassium salt weight.   The aqueous coating composition according to claim 1 or 2, wherein the acid value of the resin (A) is 20 to 40 mg-KOH / g, and the acid value of the resin (B) is 100 to 300 mg-KOH / g.   The aqueous coating composition according to any one of claims 1 to 3, wherein the softening point of the resin (A) is 130 ° C or higher.   The aqueous coating composition according to any one of claims 1 to 4, wherein the penetration of the resin (A) at 25 ° C is 0.1 mm or less.   The aqueous coating composition according to claim 1, wherein the α-olefin has 10 to 50 carbon atoms.   The aqueous coating composition according to any one of claims 1 to 6, wherein the partial reaction product of the copolymer is graft-modified by alkyl esterification in at least a part of maleic anhydride monomer units.   The aqueous coating composition of claim 7, wherein the alkyl esterification is a monoalkyl esterification.   The aqueous coating composition according to any one of claims 1 to 8, wherein the total concentration of the resin (A) and the resin (B) is 0.05 to 1% by weight in terms of the weight of their potassium salts.   The aqueous coating composition according to any one of claims 1 to 9, wherein the acid value of the resin (A) is 25 to 35 mg-KOH / g, and the acid value of the resin (B) is 120 to 250 mg-KOH / g.   The weight mixing ratio of the resin (A) and the resin (B) is (A) / (B) = 40/60 to 75/25 in terms of the weight of the potassium salt, according to any one of claims 1 to 10. Aqueous coating composition.   The aqueous coating composition according to claim 1, wherein the α-olefin has 14 to 40 carbon atoms.   A glass product comprising a surface coated with the aqueous coating composition according to claim 1.   14. The glass product of claim 13, wherein the glass product having a surface coated with the aqueous coating composition has the surface hot-end coated prior to the coating.   The glass product according to claim 13 or 14, which is a glass container.   The glass product of claim 13 which is a plate glass. A glass surface treatment method comprising contacting a glass surface with an aqueous coating composition according to any one of claims 1 to 12 at a surface temperature of 80 to 130 ° C.