JP3370430B2 - Non-slip varnish - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-slip varnish for preventing the collapse of loads used in paper containers such as cardboard and cartons and various paper bags.

[0002]

2. Description of the Related Art Agricultural products, marine products, and various other foods,
Various industrial products are packaged and transported in paper containers such as cardboard and cartons, or various paper bags.

In recent years, in the packaging and transportation of these products, the efficiency of physical distribution has been improved by automating various packaging lines and palletizing the transportation lines. However, the collapse of cargo due to slipping of corrugated cardboard cases becomes a big problem. There is.

Therefore, in order to solve such a problem, a non-slip varnish of an adhesive type is mainly used, for example, after a pattern is printed on a corrugated cardboard case with a water-based printing ink, and then the whole surface or a laminated surface is a top surface and / or a ground surface. Was partially coated.

As the adhesive type anti-skid varnish, an emulsion of adhesive acrylic copolymer, ethylene / vinyl acetate copolymer or the like is exclusively used,
There are those which are printed and coated by an appropriate printing or coating means, and those which are coated by heating and melting a solid resin such as ethylene-vinyl acetate copolymer by a special hot melt coating device.

However, the anti-skid varnish using an emulsion having tackiness has the purpose of achieving a higher anti-slip effect. If the tackiness is increased, blocking may occur, which may damage the surface of a paper container or cause dust during transportation. However, the product value of the paper container was significantly reduced due to the adhesion of dust, etc.

Further, when the solid resin is used, a special apparatus for heating and melting and coating is required, so that the printing machine for the paper container and the paper bag cannot be used as it is, and there is a problem that the working efficiency is lowered. It was

Further, in order to solve these problems,
JP-A-2-34671 discloses a non-slip varnish composed of an acrylic emulsion having a core / shell structure, and JP-A-2-245086 discloses a rubber latex, an aqueous resin, and a water-soluble metal complex salt. A non-slip varnish has been proposed.

However, the non-slip varnish using the acrylic emulsion having the core / shell structure has a lower film-forming property when the core portion is increased, and the abrasion resistance is decreased, and conversely, when the shell portion is increased, blocking resistance is increased. The anti-slip varnish using rubber latex has a problem that the rubber ages due to ultraviolet rays when used for a long period of time, and the abrasion resistance, water resistance, and anti-slip effect decrease. It was

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve these problems of the prior art, and has excellent blocking resistance and long life especially under high temperature and high humidity environment. It is intended to provide a non-slip varnish that does not deteriorate in anti-slip effect, water resistance and abrasion resistance even when used over a period of time.

[0011]

[Means for Solving the Problems] That is, the present invention provides an aqueous resin emulsion, a cross-linking agent that reacts with a carboxyl group,
Provided is an antiskid varnish which is mainly composed of an alkali compound and water and which satisfies the following conditions 1 and 2.

Condition 1. The aqueous resin emulsion is an aqueous resin emulsion obtained by emulsion-polymerizing a2 in the presence of the following a1, and having a weight ratio of a1 / a2 = 10/90 to 40/60.

A1. A polymeric emulsifier comprising an alkali-soluble resin having a carboxyl group in the molecule, an acid value of 200 to 350, and a glass transition temperature of 60 ° C. or higher.

A2. The glass transition temperature of the polymer is -50 to 1
Radical-polymerizable monomer selected in the range of 0 ° C.

Condition 2. The amount of the cross-linking agent used is from 0.2 to all carboxyl groups present in the anti-skid varnish.
It is 2.0 equivalents.

In a more preferred aspect of the present invention, the polymer emulsifier is at least one selected from the group consisting of acrylic resins, styrene-acrylic resins, styrene-maleic acid resins and styrene-acrylic-maleic acid resins. A non-slip varnish characterized by the above.

As a more preferred embodiment of the present invention, there is provided a non-slip varnish characterized in that the radical-polymerizable monomer is mainly composed of a mixture of methyl methacrylate and 2-ethylhexyl acrylate.

As a more preferred embodiment of the present invention, there is provided a non-slip varnish wherein the cross-linking agent is a water-soluble metal complex salt.

[0019]

[Operations and Examples] The anti-slip effect and the blocking resistance can be obtained by selectively providing the anti-slip varnish film with the tacky resin portion imparting the slip resistance and the non-tacky resin portion imparting the blocking resistance. Attempts have been made at the same time to improve the conflicting performance.

For example, the combination of an aqueous resin emulsion having a low glass transition temperature and a water-soluble resin having a high glass transition temperature as the binder resin is the simplest method, but it must be in a state in which both are extremely well mixed. However, no sufficient effect was obtained, and in many cases, an anti-slip varnish having both a high anti-slip effect and excellent blocking resistance could not be obtained.

Further, a so-called core / shell type aqueous resin emulsion in which an adhesive resin portion and a non-adhesive resin portion are separately polymerized in the same system is used. However, since the non-adhesive resin part has no film forming ability,
In order to have a high film-forming ability, a large amount of adhesive resin was required, and it was difficult to obtain a non-slip varnish having high film strength and excellent blocking resistance.

On the other hand, in the aqueous resin emulsion of the present invention, the alkali-soluble resin used as the polymer emulsifier is non-adhesive and has film-forming property, and the non-adhesive polymer emulsifier and emulsion polymerization are used. All of the above problems can be solved by the fact that the cohesive component obtained by the method exists in the same state as when it is well mixed.

Furthermore, the polymeric emulsifier of the present invention is characterized in that it is crosslinked by a crosslinking agent, for the following reason.

Especially in the summer, the anti-skid varnish is applied and the contents are packed and stored in a warehouse, which is in a high temperature and high humidity condition. Under these environmental conditions,
Conventional non-crosslinkable alkali-soluble resin absorbs moisture and plasticizes, and the blocking resistance is significantly lowered, whereas crosslinking of the resin according to the present invention prevents moisture absorption and lowers blocking resistance over a long period of time. It is possible to obtain a non-slip varnish free from scratch.

The anti-skid varnish of the present invention will be specifically described below.

First, the aqueous resin emulsion used in the present invention can be obtained by emulsion-polymerizing a radical-polymerizable monomer using an alkali-soluble resin as a polymer emulsifier.

Examples of the alkali-soluble resin used as the polymer emulsifier include an acrylic resin, a styrene-acrylic resin, a styrene-maleic acid resin having a carboxyl group in the molecule so that the acid value is 200 to 350. Styrene-acrylic-maleic acid resin or the like can be used.

Here, the acrylic resin, styrene-acrylic resin, styrene-maleic acid resin and styrene-acrylic-maleic acid resin are a copolymer resin of an acrylic monomer, a styrene monomer and an acrylic resin, respectively. Copolymer resin with a monomer, a copolymer resin of a styrene-based monomer and a maleic acid-based monomer, and a styrene-based monomer,
It is a three-way copolymer resin of an acrylic monomer and a maleic acid monomer.

Further, the acrylic monomer, styrene monomer and maleic acid monomer are the monomer components shown below.

Acrylic monomer: (meth) acrylic acid, and its alkyl ester (alkyl group having 1 to 18 carbon atoms), its mono- or dialkylamide (alkyl group having 1 to 18 carbon atoms), hydroxyalkyl thereof Ester (hydroxyalkyl group having 2 to 4 carbon atoms) and the like, and specifically, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate,
Hexyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, methyl (meth) acrylamide, ethyl (meth) acrylamide, butyl (meth) acrylamide, hexyl (meth) acrylamide, 2-
Examples thereof include hydroxyethyl (meth) acrylate.

Styrenic monomer: styrene and its derivatives, and specific examples of the derivative include α-methylstyrene, chlorostyrene, vinyltoluene and the like.

Maleic acid type monomer: (anhydrous) maleic acid, and its mono- or dialkyl ester (alkyl group having 1 to 18 carbon atoms), its mono- or bis- (mono or dialkyl) amide (of alkyl group) Carbon number 1
18), its mono- or di (hydroxyalkyl) ester (hydroxyalkyl group having 2 to 4 carbon atoms), and the like, specifically, monomethylmalate, dimethylmalate, monoethylmalate, diethylmalate, mono Examples thereof include butyl maleate, monooctyl maleate, monomethyl maleic acid amide, monodimethyl maleic acid amide, monoethyl maleic acid amide, monobutyl maleic acid amide, and mono-2-hydroxyethyl maleate.

The alkali-soluble resin obtained by copolymerizing the above monomers and used as a polymeric emulsifier has an acid value of 20.
It has an acid value of 0 to 350, preferably 250 to 350 and a glass transition temperature of 60 ° C or higher. If the acid value of the alkali-soluble resin is smaller than the above range, or the glass transition temperature is lower than the above range, the blocking resistance of the obtained anti-slip varnish decreases, while if the acid value exceeds the above range, The anti-slip effect of the anti-slip varnish is reduced.

Further, as an alkaline compound for neutralizing these alkali-soluble resins, ammonia, dimethylethanolamine, diethylethanolamine,
Examples thereof include triethylamine, tributylamine, morpholine, diethanolamine and triethanolamine, but from the viewpoint of the water resistance of the non-slip varnish, it is preferable to use ammonia or a volatile amine.

On the other hand, as the radically polymerizable monomer to be subjected to emulsion polymerization in the presence of the above-mentioned polymeric emulsifier, the above-mentioned alkyl ester of (meth) acrylic acid (having 1 to 18 carbon atoms in the alkyl group), Examples include styrene-based monomers,
The polymer obtained can be used alone or in a mixture thereof in a range where the glass transition temperature thereof is −50 to 10 ° C., preferably −30 to 0 ° C.

Among them, acrylic acid 2 is more preferable.
-It is mainly composed of a mixture of ethylhexyl and methyl methacrylate.

When the glass transition temperature of the obtained polymer is lower than -50 ° C, the anti-slip varnish has a low blocking resistance, and when it is higher than 10 ° C, the anti-slip varnish has a low anti-slip effect.

These polymeric emulsifiers, alkali compounds,
And using a radically polymerizable monomer provided for emulsion polymerization, as a method for producing an aqueous resin emulsion,
First, a unit amount of an alkali-soluble resin in the presence of a polymerization initiator in an ester solvent such as ethyl acetate or isopropyl acetate, a ketone solvent such as acetone or methyl ethyl ketone, a lower alcohol solvent, or an organic solvent such as glycol or a derivative thereof. After polymerizing the body components, the organic solvent is distilled off to obtain a solid resin. Then, in the presence of an alkaline compound, the solid resin is dissolved in water to form a polymeric emulsifier, and a mixture of a monomer and a polymerization initiator to be subjected to emulsion polymerization is gradually added,
A method of polymerizing to obtain an aqueous resin emulsion can be used.

Here, examples of the polymerization initiator include persulfates such as potassium persulfate, sodium persulfate and ammonium persulfate, organic peroxides such as benzoyl hydroperoxide, azobisisobutyronitrile and the like. Azo compounds can be used, and if necessary, they can be used in combination with a reducing agent as a redox initiator.

The weight ratio of the alkali-soluble resin used as the polymeric emulsifier to the radical-polymerizable monomer used for emulsion polymerization is 10-90 to the alkali-soluble resin / radical-polymerizable monomer. 40/60, preferably 20 / 80-
The range is 35/75. When the weight ratio of the alkali-soluble resin is smaller than the above range, the stability of the obtained aqueous resin emulsion and the blocking resistance of the anti-slip varnish are reduced, while when it exceeds the above range, the slip of the anti-slip varnish is reduced. The stopping effect decreases.

In the present invention, other aqueous binder resins can be added within a range that does not impair the effects of the present invention. Examples of such other aqueous binder resin include shellac, casein, rosin maleic acid resin, aqueous polyester resin, water-soluble cellulose, acrylic resin, styrene-acrylic resin, styrene-maleic acid resin, styrene-acrylic-maleic acid resin, etc. Can be used.

Next, examples of the crosslinking agent used in the present invention include water-soluble metal complex salts which react with a carboxyl group.

The water-soluble metal complex salt means Zn, Zr, Sn,
A polyvalent metal such as Ti is reacted with an inorganic acid such as carbonic acid or phosphoric acid or an organic acid such as tannin, gallic acid, humic acid, salicylic acid, benzoic acid or paraoxybenzoic acid to form a metal complex salt, and further ammonia, ethylenediamine. ,
It is water-solubilized by neutralizing with primary or secondary amines such as methylamine, ethylamine, dimethylamine, diethylamine and dimethylethanolamine.

Specific examples thereof include zinc ammonium carbonate, zinc ammonium phosphate, zinc ammonium gallate, zinc ammonium humate, zinc ammonium benzoate, and similar metal complex salts of tin, zirconium and titanium.

As a method for producing these water-soluble metal complex salts,
First, a slurry is prepared by adding ammonia water or an aqueous amine solution to a hydroxide or oxide of a polyvalent metal, and adding the above-mentioned acid or its ammonium salt or amine salt thereto to solubilize the metal compound. Can be obtained by

The amount of these water-soluble metal complex salts used is 0.2 with respect to the total carboxyl groups of the alkali-soluble resin used as a polymeric emulsifier and other aqueous binder resin present in the anti-slip varnish. ˜2.0 equivalents, preferably 0.5 to 1.5 equivalents.

If the amount of the water-soluble metal complex salt used is less than the above range, the blocking resistance under high temperature and high humidity will be poor, while if it is increased, the odor of the non-slip varnish will become strong and on the coating machine. Stability is reduced.

Further, when a higher anti-slip effect is required, the inorganic fine particle filler is added up to about 10% by weight or the organic fine particle filler is added up to about 20% by weight with respect to the solid content of the anti-slip varnish. be able to.

Specific examples of the inorganic fine particle filler include silica powder, silica gel, glass powder, talc, clay, calcium carbonate, magnesium carbonate, zinc white, barium sulfate, and the like, and specific examples of the organic fine particle filler. Examples thereof include fine powders obtained from resins such as acrylic, polystyrene, styrene / acrylic, nylon, polyester, polyethylene, polypropylene, vinyl chloride, acrylonitrile, phenol, epoxy, polyamide, silicone and polyurethane.

If the amount of the inorganic or organic fine particle filler added exceeds the above range, the fluidity of the non-slip varnish and the whitening of the printed matter are unfavorably caused. Further, for the same reason, as the particle diameter of the inorganic or organic fine particle filler, the average particle diameter of 20 μm or less can be more preferably used.

Further, the anti-skid varnish of the present invention comprises a defoaming agent, a viscosity modifier, a water-miscible solvent for adjusting the drying property,
A fluidity adjusting agent (for example, an extender pigment) for improving printability can be added.

As a method for producing a non-slip varnish using the above materials, a stirrer such as a high speed mixer is used to add and stir each material in an amount to achieve the composition specified in the present invention. Methods are available.

The non-slip varnish of the present invention can be used before or after printing on a paper container or paper bag, in the printing process, after printing, after box making or bag making.
A method of coating by roller coating, spraying or the like can be used, but coating is preferably performed in the printing step from the viewpoint of work efficiency.

The non-slip processed product obtained from this non-slip processing method has a high slip angle, good blocking resistance in an environment of high temperature and high humidity, and has a non-slip property even when used for a long period of time. No deterioration in angle, water resistance and abrasion resistance.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. Unless otherwise specified, “parts” and “%” represent “parts by weight” and “% by weight”, and ratios are weight ratios.

First, the components of the non-slip varnish (aqueous resin emulsion, alkali-soluble resin, crosslinking agent, filler) will be described.

<Production Example of Alkali-Soluble Resin Used as Polymer Emulsifier> A four-necked flask equipped with a stirrer, a thermometer, a cooling pipe, and a nitrogen gas introduction pipe was charged with 60 parts of ethyl acetate, and the amount was 75 to 85. After heating to 0 ° C., a mixture of 40 parts of the monomer component shown in Table 1 and 0.4 part of ditert-butyl peroxide as a reaction initiator was added dropwise over 2 hours while introducing nitrogen gas. Further, while maintaining the same temperature, polymerization was carried out for 2 hours, and then the solvent was evaporated under reduced pressure to obtain a copolymer.

After 40 parts of this copolymer was crushed, it was mixed with stirring in 60 parts of water in which an equivalent amount of ammonia was dissolved.
The mixture was heated and dissolved at 0 ° C. to obtain alkali-soluble resin aqueous solutions 1 to 7 having a solid content of 40% to be used as a polymeric emulsifier.

[0059]

[Table 1]

<Production Example of Aqueous Resin Emulsion Using Polymer Emulsifier> In the same apparatus as in the production example of polymer emulsifier,
A polymeric emulsifier and water were added according to the formulation of Table 2, and the mixture was kept at 80 to 85 ° C. while introducing nitrogen gas, and a mixture of 0.3 part of the monomer and ditertiary butyl peroxide according to the formulation of Table 2 was added. After dropping for 2 hours,
The mixture was further reacted for 2 hours to carry out emulsion polymerization to obtain aqueous resin emulsions 1 to 16.

[0061]

[Table 2]

<Production Example of Aqueous Resin Emulsion Using Surfactant> Butyl acrylate, styrene, methacrylic acid (the ratio of butyl acrylate / styrene / methacrylic acid is 71.4 / 12.6 / 16.0) is used. Then
Ammonium persulfate was used as a catalyst, a polyoxyethylene-based surfactant was used as an emulsifier, and the solid content was 50% and the glass transition temperature was −22.7 ° C. according to a usual emulsion polymerization method.
An aqueous resin emulsion 17 having an acid value of 100 was obtained.

<Alkali-soluble resin solution (aqueous resin 1)
Production Example of Methyl Methacrylate 52.4%, Acrylic Acid 21.8%, Styrene 11.8%, Butyl Acrylate 1
4.0% was copolymerized by a conventional method to obtain an aqueous solution of alkali-soluble resin ammonia (aqueous resin 1) having a solid content of 35% and a glass transition temperature of 70 ° C.

<Crosslinking Agent> 15.0 parts of zinc oxide, 26.0 parts of 25% aqueous ammonia, 17.0 parts of ammonium carbonate,
42.0 parts of water was mixed to prepare a water-soluble zinc complex salt.

<Filler> Filler A: polystyrene, average particle size 6 μm (softening point 2
00 ° C.) Filler B: silica, average particle size 5 μm (Syloid 16
1. Fuji Devison Chemical Co., Ltd.) <Examples and Comparative Examples of Antiskid Varnish> Examples 1 to 14 and Comparative Examples 1 to 9 according to the formulations in Tables 3 and 4.
A non-slip varnish was prepared.

<Evaluation of Examples and Comparative Examples> A K liner for corrugated board was coated with a non-slip varnish obtained in Examples 1 to 14 and Comparative Examples 1 to 9 using a Mayer bar having a diameter of 0.2 mm, and then a sliding angle was obtained. The blocking resistance was evaluated. In addition, a K-liner for corrugated board was coated with a water-based printing ink with a Mayer bar having a diameter of 0.2 mm, and then, Example 1 was further applied.
.About.14 and Comparative Examples 1 to 9 were coated with a non-slip varnish having a diameter of 0.2 mm to evaluate abrasion resistance and water resistance. The respective results are shown in Tables 3 and 4. The evaluations of A and B are in the practical range, and those of C and D are not practical.

<Evaluation Test Method and Evaluation Criteria> • TA under the environmental conditions of a sliding angle atmosphere temperature of 20 ° C. and a relative humidity of 60%
The slip angle was measured according to the tilt method test described in PPI.

(Evaluation criteria) A: A slip angle of 40 ° or more. B: A slip angle of 35 to 40 °. C: A slip angle of 30 to 35 °. D: A slip angle of less than 30 °.

Blocking resistance Under environmental conditions of an atmospheric temperature of 50 ° C. and a relative humidity of 90%, the varnish-coated surfaces are brought into contact with each other, and a load of 5 kg / 25 cm ² is applied for 24 hours. I observed the situation.

(Evaluation Criteria) A: Peeling off without any resistance. B: The liner is easily peeled off with a stress enough to bend the liner. C: Peeling off by strongly pulling the contact surface. D: The contact surface is damaged at the time of peeling.

· Friction resistance Using a vibration type friction resistance tester, with a load of 500 g, 50
The abrasion resistance was evaluated based on the presence or absence of damage on the coated surface after rubbing 0 times.

(Evaluation criteria) A: There is no damage on the coated surface. B: The coated surface has streaky damage. C: The entire coated surface is damaged.

Water resistance The water resistance was evaluated based on the presence or absence of damage on the coated surface when the cloth was soaked with water under a load of 500 g and the cloth was rubbed twice, using a vibration resistance type friction resistance tester.

(Evaluation criteria) A: There is no damage on the coated surface. B: The coated surface has streaky damage. C: The entire coated surface is damaged.

[0075]

[Table 3]

[0076]

[Table 4]

[0077]

As described above in detail with reference to the examples, the anti-skid varnish of the present invention has good blocking resistance under a high temperature and high humidity environment and for a long period of time. Anti-slip effect, abrasion resistance, water resistance, and blocking resistance do not deteriorate.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ identification code FI C09D 133/06 C09D 133/06 (58) Fields investigated (Int.Cl. ⁷ , DB name) C09D 1/00-13/00 C09D 101/00-201/10 B29D 9/00 B32B 1/00-35/00 C08K 3/00-13/08 C08L 1/00-101/16 C08C 19/00-19/44 C08F 6/00-246 / 00 C09J 1/00-5/10 C09J 9/00-201/10

Claims (4)

(57) [Claims] 1. A non-slip varnish which is mainly composed of an aqueous resin emulsion, a cross-linking agent which reacts with a carboxyl group, an alkali compound and water and which satisfies the following conditions 1 and 2. Condition 1. The aqueous resin emulsion is obtained by emulsion polymerization of a2 in the presence of the following a1, and a1 as a weight ratio.
A water-based resin emulsion having a / a2 of 10/90 to 40/60. a1. Acid value having carboxyl group in molecule 200-35
0, a polymer emulsifier made of an alkali-soluble resin having a glass transition temperature of 60 ° C or higher. a2. A radically polymerizable monomer selected in such a range that the glass transition temperature of the polymer is −50 to 10 ° C. Condition 2. The amount of the cross-linking agent used is 0.2 to 2.0 equivalents with respect to all the carboxyl groups present in the anti-skid varnish. 2. The polymer emulsifier is at least one selected from the group consisting of acrylic resins, styrene-acrylic resins, styrene-maleic acid resins and styrene-acrylic-maleic acid resins. The non-slip varnish described in 1. 3. The radical-polymerizable monomer is mainly composed of a mixture of methyl methacrylate and 2-ethylhexyl acrylate.
Non-slip varnish described. 4. The anti-skid varnish according to claim 1, wherein the cross-linking agent is a water-soluble metal complex salt.