JPS61138640A - Liquid for surface-treatment of polyvinyl alcohol film - Google Patents

Abstract

PURPOSE:To obtain a liquid for the surface-treatment of a PVA film effective to prevent the blocking of the film, by compounding a vinyl chloride resin with a PVA resin, a silicone water-repellent, and fine particles having an average particle diameter falling within a specific range, at specific ratios. CONSTITUTION:The objective surface-treating liquid can be produced by compounding (A) 100pts.(wt.) (resin bases) of an emulsion of a vinyl chloride resin, e.g. vinyl chloride-vinyl acetate copolymer with (B) 50-500pts. (resin basis) of an aqueous solution of PVA, e.g. aqueous solution of a saponified vinyl acetate-acrylamide compolymer, (C) 10-100pts. of a silicone water-repellent (as an aqueous solution or emulsion) and (D) 30-300pts. of fine particles having average particle diameter of 5-1,000mmu, e.g. silica, starch, etc. The surface- treatment liquid is diluted with water to a solid concentration of 0.5-10%, and applied to the surface of a PVA film at a rate of 0.01-0.5g/m<2> (solid basis, per one surface of the film).

Description

[Detailed description of the invention] [Industrial application field] The non-invention is polyvinyl alcohol (hereinafter abbreviated as PvA)
This invention relates to a surface treatment liquid for thread films (and in particular, to a surface treatment liquid that prevents blocking without reducing the original properties of the film such as transparency).

[Prior art and its drawbacks]

PVA-based films have excellent transparency, surface gloss, printability, mechanical strength, and non-static properties, and are widely used as packaging materials for textiles and the like. However, the physical properties of the PVA film change sensitively due to changes in temperature and humidity, and therefore, when the film surfaces are moved slightly against each other under hot and humid conditions, a blocking phenomenon is likely to occur. When making high-speed bags using an automatic bag making machine, there are drawbacks such as problems with line drawing of the film and layers forming on the equipment.Also, when bagging textile products, it is difficult to open the opening. Sexuality deteriorates significantly. For this reason, various improvements have been attempted in the past. 1) There is a method of spraying finely powdered inorganic substances onto the surface of the PVA film (
% Kai 51-138772). However, although this method is effective in preventing blocking, it reduces the transparency of the film, and if the powder falls off and is attached to textile products, especially products dyed in dark colors, it can significantly reduce the quality of the product. Lose. In addition, 2) a method of preventing blocking by applying a solution of a polymeric substance in an organic solvent to a PVA film is also known (see Japanese Patent Laid-Open No. 51-145077). However, the polymeric substance used in this method is usually It is hydrophobic and has poor adhesion with PVA-based films, making it difficult to heat-seal, and the coating layer and PVA-based film tend to peel off easily.Also, unless zinc chloride, lithium chloride, etc. are used, the adhesion is poor. There is a point where the distance drops significantly.

Furthermore, it is not preferable from the viewpoint of safety and public safety to use an anti-depressant bath.

In history, 6) Is there a method known to prevent blocking by distributing various resin emulsions on a PVA film?
Perhaps due to the difference in the refractive index of the VA film, the transparency decreases and layer color impressions such as blue and white appear. Furthermore, blocking occurs in high temperature and high humidity conditions, and it is not always possible to add seven cocoons.

Therefore, as a result of intensive research, the inventor discovered that 0.0% PVA is a vinyl chloride resin (n D=
1.54), PVA tree B effect (n r:, =1.55
), a silicone water spraying agent (n D = 1.4), and a fine particle material with an average particle size of 5 to i 000 mμ (n p = 1-54 for 5i02) in specific proportions. The inventors have discovered a solution to the various drawbacks and have developed the present invention.

That is, the non-invention is (A) vinyl chloride resin emulsion, (B) PVA resin water bath liquid, (C) silicone water repellent water bath emulsion, and) microparticles with an average particle size of 5 to i 000 mμ. This is a surface treatment liquid for PVA-based films consisting of an aqueous dispersion of.

Here, the PVA-based film that is subject to uninvented treatment is, for example, PV film obtained by saponifying polyvinyl acetate.
A is produced from a modified PvA obtained by saponifying a vinyl acetate-based copolymer containing as a co-component a small amount of a monomer that can be co-polymerized with vinyl acetate. It also includes films made by heat-treating these films. There is no limit to the electrical degree and saponification degree, but usually 1 degree is 500 to 5.
000° saponification degree of 75 molt or more is suitable as a film.

(A) Vinyl chloride resins include, for example, vinyl chloride homopolymers and vinyl chloride-vinyl acetate copolymer. Vinyl chloride resins themselves have excellent surface gloss and transparency, but even if only emulsions of these resins are applied to PVA films, they have the disadvantage of insufficient adhesion and easy peeling, so they are not used alone. cannot be used. These resins and resin emulsions can be manufactured by known methods. Emulsions of vinyl chloride resins are those that use anionic, nonionic, or cationic emulsifiers, and those that have excellent storage stability when mixed with other constituents or as coatings. Appropriately select one that does not impair transparency after construction.

(B) PVA yarn is made from saponified polyvinyl acetate.
VA and its derivatives, and recently, monomers that can be copolymerized with vinyl and 1! r1. There are saponified products of copolymers with acid vinyl.

The monomers include olefins (ethylene, propylene, α-butene, etc.), unsaturated monocarboxylic acids (acrylic acid, methacrylic acid, crotonic acid, etc.), esters or salts thereof, unsaturated polycarboxylic acids (maleic acid, etc.), acids, fumaric acid, itaconic acid), their moieties or esters, salts or anhydrides, unsaturated sulfonic acids (ethylene sulfonic acid, etc.), their salts, amides (acrylamide, methacrylamide, etc.), Nitrile (acrylonitrile), vinyl ether, vinyl ketone, vinyl chloride, etc. can be used.

The reason for the addition of ``main'' is that the second side treatment agent forms a dense layer on the PVA film.

As the silicone water repellent (C), a commercially available product is used.

Select and use materials that have a good adhesion prevention effect with a small amount of nitrification that does not affect printability or transparency, depending on the degree of need. The water solution or emulsion of the silicone water spray agent itself has an excellent anti-blocking effect, but
^ If a surface coating with anti-blocking effect under hot and humid conditions is applied, the adhesion of the printing ink to the PVA film will be impaired and the ink will peel off.

The fine particles in (2) may be either inorganic or organic. For example, inorganic materials include silica, Merck, aluminum oxide, etc., and organic materials include starch, resin powder, etc. However, in order not to impair the appearance and transparency, it is necessary that the average particle diameter be 5 to 1000 yxμ. In addition, to prevent the fine particles from getting mixed up in the bath, apply PVA as a shielding agent.
If an attempt is made to reduce the anti-blocking effect only by applying a layer to the surface of the film, an excessive amount of fine particles will be required, and the appearance and transparency will be impaired.

Here, in the present invention, in order to eliminate the disadvantages of using each of these constituent components alone, [F]) and (CL), the resin content of [F] is 5 parts for the resin content of 100341 parts of [F].
0~500] [-Jim, good! L<k'! , 100~.
500 parts by weight, (C) silicone water hydrating agent 10-10
0 parts, preferably 20 to 60 parts, and 60 to 300 parts, preferably 50 to 100 parts, of the fine particles of (1) are blended and mixed to prepare an aqueous surface treatment agent. In this case, if the blending amount of (B)) is 50 parts, PVA
The layering properties of the film deteriorate, and when the amount exceeds 500 parts, the anti-blocking effect becomes unfavorable. If the blending amount is less than 10 TL-1 parts, the anti-blocking effect will be low, and if it exceeds 100 TL-1 parts, printing problems will be affected.

If the blending amount is less than 60 mm, the anti-blocking effect will not be improved much (if it exceeds 500 mm, the appearance will be impaired and fine particles will be more likely to peel off.

It is desirable that the surface treatment liquid limited above be applied to one side or the inner surface of the PvA film, or that the applied amount be 0.0 to 0.5 g/m'' per side in terms of solid content. .01117m"If unshaved, sufficient blocking effect will not be produced, and PvA exceeding 0.5g#L"
This impairs the adhesion and heat sealability of adhesives to the film.

The method of coating the surface is not particularly limited, and various methods such as coating, dipping, and spraying may be employed.

During application, the surface treatment liquid used varies depending on the amount of application, explosive properties, equipment, etc., and usually has a solid fraction of 0.5 to 1.
It is diluted with water to about 0% and ready for use.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples. Note that the parts and axes in the examples are all based on Rando standards.

Example valley #! iL Onka was mixed according to the formulation shown in the first example, a coating mixture was prepared, and the mixture was coated on a PvA film, and its physical properties were investigated. Furthermore, physical properties? Supplementation of the r-value was performed using iL10 test results and ranked based on the evaluation of 8 Å or higher.

Table 1 (Note 1) The abbreviations of compounds in Table 1 indicate o.

(Al) Styrene/methacrylic methyl pyrolyte (styrene/methacrylic methyl = 40760) emulsion (A111450% (A2) Vinyl chloride emulsion (mAf 1 minute 50%).

(A3) I tt tt (#25
%) (Bx) PVA (JIL degree 1,700, saponification degree 99.8 mol%) water bath liquid (Kizuki Umami content 5%).

(B2) Vinyl acetate-acrylamide co-polymerization saponification I
27 (acrylic amide 2 1000, degree of saponification 88 mol%) Water #! Liquid (Jugetsu Umabun 5 Chi) 4 (Bz) Vinegar Cl Hinyl-Lauryl Vinyl Ether Copolymer Saponified Product (Lauryl Vinyl Ether 17%, Dispersion Degree 1,200, Saponification Degree 95 mol%) Water IG Solution (W Fat minute 5
%).

(C0) Silicone water repellent [POLON C j (manufactured by Shin-Etsu Chemical Co., Ltd., silicone content 20%), (C2) Silicone water repellent emulsion [POLON
MWSJ (11!Etsu Kagaku 4.Silicone 60cm)
(Dl) Ultrafine particles [AERO8IL 5 0 0J
(Japan Aerosol, average particle size 7 doors μ included (B2) super @ Azusa body [AERO8IL coK-8 4
J (manufactured by Nippon Aerosol, 15 nL μ) (B3) Colloidal Silica 1 Snotex Cl (Nichima Kakoko 4.0, average Edadoko 10-20 doors μ imitation particle size 20% 6 [2) m labor indicates the plastic work cost per meter of piece.

(Note 3) The ridge in the abbreviation for chemical compounds in the MG1 table indicates the pure ratio of the valley component.

The physical properties of the Examples and Comparative Examples were 6111 meters and the evaluation was as follows.

(1) Cut the anti-blocking film into 10cIIL x 151 pieces and heat at 60℃, 80℃.
%R. H. 24-hour release Ttti&, 20 pieces, 200. Spread the weight of V evenly on it, and then
Leave it for 4 hours. The charges are swam in the dark, and the releasability and sliding properties of the films are compared.

A: Good removability and slipperiness B: It's a bit close, but no problem. C: Dense layer, practically problematic.

(2) Transparency Transparency and gloss were compared using four pages of film.

A: There is almost no decrease in transparency or gloss due to coating.

B: Is it cloudy or not? C: Cloudiness and decreased transparency.

(3) Evaluation using a single layer of 50% zinc chloride, 15% water, and 65% methanol. Cut the film into pieces of 2 CIIL x 1 Q cm, put one drop of the above layering agent on one end, and fold one end of the same size film into a piece of paper.
After 60 minutes, both ends of the laminated film are pulled.

A: Good contact, good contact strength, and may be cut from areas other than the dependent layer.

B: Poor contact layer, adhesive strength is good, but peels off from the contact layer C: Poor contact layer, peels off from the ridge f part.

(A) Comparison of skin properties under 540'010.5 second conditions using a heat-sealable bar sealer.

A: Heat sealed to light.

B: The layers are in contact, but they peel off at each station.

C: Zenyanagi (no layering).

(5) Print the Yoba ink for vinylon film on a printable film, and check the ink coverage during printing, ``cracking'' and ``peeling'' of the ink when placed at 60℃, 88 volumes, for 24 hours. Give praise.

A: Good ink freezing, ink cracking, peeling
None at all.

B; Ink "riding" or defective ink, ink "cracking", "
There is a little peeling.

C; l z z
A lot.

(6) Place 4 layers of color-sensitive film on a black im board, iIt
Compare colors, white coloring.

A: There is almost no blue or white coloring on the film, and it is almost unchanged from before coating.

B; It is colored blue and white, but there is no problem O C: Evening color and white coloring are visible.

〔Effect of the invention〕

The use of the uninvented surface-treated slag provides excellent blocking properties and transparency.

Claims (1)

[Claims] (A) vinyl chloride resin emulsion, (B) polyvinyl alcohol aqueous solution, (C) silicone water repellent aqueous solution or emulsion, and (D) average particle size 5 to
A surface treatment liquid for polyvinyl alcohol films consisting of an aqueous dispersion of fine particles of 1,000 mμ.