JPH0781123B2 - Adhesive for fruit paper - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive for fruit paper used for protection of fruits, and more particularly to an adhesive for specially processed paper processed by impregnating paraffin or silicone resin. Is.

[0002]

BACKGROUND OF THE INVENTION Fruit paper is generally used in the form of a bag, and this bag covers the fruit at an early stage of its growth to remove fruits such as pears, apples and grapes. It is used not only to protect from pests but also to allow appropriate transmission of ultraviolet rays to promote smooth growth of fruits.

When making a fruit bag, the fruit paper is made into a bag shape,
Adhere the periphery of the bag other than the opening with an adhesive. that time,
Since it is difficult to apply the water-repellent specially processed paper evenly with the water-based resin adhesive, it has been conventionally necessary to use the solvent-based resin adhesive.

However, the use of solvent-based resin adhesives has the following drawbacks. That is, (1) depending on the solvent,
Since the specially processed impregnation component dissolves, it adversely affects the transmission of ultraviolet rays and the like, which is not good for fruit growth,
(2) There are safety, hygiene, and toxicity problems caused by solvents.
(3) Adhesion is too strong and the fruit is contaminated with the adhesive.
(4) The cost is high.

Further, as a conventionally known water-based emulsion type adhesive for water-repellent paper, for example, there is JP-A-53-91940, which is an emulsion containing an ethylene-vinyl acetate copolymer as a main component. The wax paper, which is the object of the present invention, cannot be laminated at all with the emulsion alone.

Further, an adhesive for water-repellent corrugated board containing vinyl acetate emulsion and acrylic-styrene copolymer latex as essential components is disclosed in JP-A-58-98239. It requires heat treatment and cannot be bonded at room temperature.

[0007]

SUMMARY OF THE INVENTION The present inventor is keen to develop an adhesive for fruit papers, which improves the above-mentioned drawbacks of solvent-based adhesives and has superior adhesive properties and workability to known aqueous emulsion adhesives. As a result of examination, the following adhesives were found to be excellent.

That is, the adhesive of the present invention is an adhesive for adhering fruit paper that has been subjected to water repellent treatment, and is a resin of ethylene-vinyl acetate copolymer emulsion having an ethylene content of 5 to 35% by weight. 30 to 200 parts by weight of an organic solvent having a boiling point of 50 to 150 ° C., and a total amount of 0.1 to 5 parts by weight of 100 parts by weight of a nonionic surfactant and anionic surfactant. Is an adhesive for fruit paper.

[0009] upper Symbol ethylene - acetic acid vinyl content of vinyl acetate copolymer emulsions are 95 to 65 wt%.

The ethylene-vinyl acetate copolymer emulsion used in the adhesive of the present invention has an ethylene content of 5 to 35% by weight and a vinyl acetate content of 95 to 65% by weight.
The range of is preferable. If it is out of this range, it is difficult to maintain the emulsion state.

The ethylene-vinyl acetate copolymer emulsion may be an ethylene-vinyl acetate-vinyl chloride copolymer emulsion obtained by copolymerizing ethylene, vinyl acetate and other components such as vinyl chloride. it can. In that case, the composition ratio can be, for example, ethylene / vinyl acetate / vinyl chloride = 5 to 35/95 to 50/0 to 15% by weight.

As the polymerization catalyst, known peroxides known to act as free radical catalysts, such as ammonium,
Examples thereof include sodium, potassium, or potassium-containing persulfate, hydrogen peroxide, perborate, and butyronitrile peroxide.

The organic solvent must have a boiling point of 50 to 150 ° C. and can be selected from a wide range of organic solvents such as hexane, acetone, xylene and toluene. The amount used is 30 to 100 parts by weight of the resin content of the ethylene-vinyl acetate copolymer emulsion.
200 parts by weight, preferably 100 to 180 parts by weight. When the amount of the organic solvent is less than 30 parts by weight, the adhesiveness is deteriorated, and when it exceeds 200 parts by weight, the viscosity is too high and the workability is deteriorated, and the fruit is adversely affected.

[0014] nonionic surfactants, polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl over ethers, sorbitan fatty acid esters, polyoxyethylene-amyl ester, and aliphatic monoglyceride.

As the anionic surfactant, an aliphatic salt, a higher alcohol sulfate ester salt, an alkylbenzene sulfonate, an alkylnaphthalene sulfonate, a naphthalene sulfonic acid formalin condensate, a dialkylsulfosuccinate, and a polyoxy salt. Ethylene alkyl sulphate , polyoxyethylene alkyl aryl
Ether sulfate and the like.

Two or more kinds of these surfactants can be used as long as the nonionic surfactant and the anionic surfactant are used in combination, and the total amount of the surfactants is ethylene-vinyl acetate copolymer. It is preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the resin content of the combined emulsion. The ratio of the nonionic surfactant and the anionic surfactant can be appropriately selected, and for example, they can be used in the same amount.

[0017]

The adhesive for fruit paper of the present invention improves the drawbacks of solvent-based adhesives and, despite being an aqueous emulsion adhesive, exhibits excellent adhesion to fruit paper. It can be bonded at room temperature and has excellent workability.

[0018]

EXAMPLES The adhesive of the present invention will be described below with reference to examples.

Example 1 [Preparation of adhesive] The following components were mixed to give a concentration of 28.7%,
An adhesive having a viscosity of 2400 cps (BL type viscometer, rotor No. 3, rotation speed 30) and pH = 6.0 was prepared. Ratios are parts by weight.

Ethylene-vinyl acetate copolymer emulsion (concentration 55%, OM-4200 manufactured by Kuraray Co., Ltd.) 50 parts Xylene 15 parts n-Hexane 15 parts Polyoxyethylene nonyl phenyl ether (emulsifier) 0.5 parts Polyoxyethylene alkyl Ali chromatography ether [preparation of adhesive] sulfate (emulsifier) 19 parts 0.5 parts water example 2 the following components were mixed concentration 26.1%, viscosity 1600cps
(BL type viscometer, rotor No. 3, rotation speed 30), pH
= 6.0 adhesives were prepared. Ratios are parts by weight.

Ethylene-vinyl acetate-vinyl chloride copolymer emulsion (vinyl chloride content 10%, concentration 50%) 50 parts xylene 15 parts n-hexane 5 parts polyoxyethylene nonylphenyl ether (emulsifier) 0.5 parts polyoxy ethylene alkylaryl chromatography ether sulfate (emulsifier) 19 parts 0.5 parts water applying adhesive obtained in the above examples 1 and 2 [effect test on adhesion testing and fruit] on the surface of the pear bag wax paper It was applied using a container. Coating amount is 30-40
μm (when dried). Immediately after the application, it was overlapped with the back surface of the wax paper and pressure-bonded with a rubber roller. 20 this
After leaving it to stand at 24 ° C. × 65% RH for 24 hours to dry it, a peeling test was performed. As a result, the wax paper adhered with the above adhesive was not peeled by the adhesive layer, and the wax paper was broken. Further, the wax paper laminated by the above method was immersed in water for 24 hours, and then a peeling test was conducted. Also in this case, the wax paper was broken without peeling off at the adhesive layer.

No dissolution of the resin component of the wax paper was observed, and no adverse effect on the fruit was observed.

As a comparative example, the same adhesion test and fruit as above were carried out using (1) ethylene-vinyl acetate copolymer emulsion (OM-4200, manufactured by Kuraray Co., Ltd.) and (2) a known solvent-based adhesive. Impact test was conducted.

When only the emulsion adhesive of (1) was used, it could not be used because it was peeled off on the adhesive side of the wax paper. In the case of the solvent-based adhesive of (2), the adhesive strength is such that the wax paper is broken as in the present invention, but the resin on the surface of the wax paper dissolves and the light transmission of this dissolved part The rate increased and stains appeared on the fruit surface. Furthermore, with solvent-based adhesives, the resin component of the wax paper exudes inside the wax paper bag together with the solvent and contacts the fruit surface,
Growth of the fruit in that part was inhibited.

Claims (1)

[Claims] 1. An adhesive for bonding water-repellent treated fruit paper, comprising a resin component 10 of an ethylene-vinyl acetate copolymer emulsion having an ethylene content of 5 to 35% by weight.
Organic solvent having a boiling point of 50 to 150 ° C. with respect to 0 part by weight 3
An adhesive for fruit paper, comprising 0 to 200 parts by weight, and a nonionic surfactant and an anionic surfactant in a total amount of 0.1 to 5 parts by weight.