JPS6017346B2 - Surface-modified vinyl alcohol polymer film and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vinyl alcohol polymer film with improved slip properties and other properties, and a method for producing the same.

Vinyl alcohol polymer films such as polyvinyl alcohol films have poor slip properties as they are, and they tend to block when stacked or rolled up. Therefore, it is necessary to attach fine inorganic or organic powder to the film surface. However, if a sufficient amount of powder is attached to improve slip properties and anti-blocking properties, there is a problem that heat sealing properties and adhesive sealing properties are impaired. There is also the problem that the powder easily falls off.

In addition, methods have recently been devised in which, in place of powder, for example, polystyrene, acetal resin, nylon, etc. are used as an emulsion or dissolved in a solvent for coping, but the effects of improving slip properties and anti-blocking properties are not necessarily sufficient. Furthermore, there is a disadvantage that the excellent gloss and transparency inherent to polypynyl alcohol films are significantly reduced. The present invention has a fluorosurfactant present on the surface of a vinyl alcohol polymer film, and has succeeded in completely solving the above-mentioned conventional problems.

That is, the surface-modified vinyl alcohol polymer film of the present invention exhibits the following excellent effects.

'1} High slip property, static friction coefficient 20qo,
At 80% RH, the static friction coefficient is, for example, 0.30 to 0.40, which is significantly superior to the static friction coefficient of commercially available equivalent products, which is, for example, around 0.8.

This property means that the film can be collected smoothly, the roll is beautiful, and the bags are easy to align during bag making, which is a great practical advantage. {21 Excellent blocking resistance.

Even if you stack a large number of films or bags, or wind up the film on a winder, the films will not stick together. Don't cause teasing. Shows sufficient blocking resistance even at high temperatures and high humidity. Ushio Does not impair heat sealability. Even with ordinary commercially available products, if the amount of dusting or coating is increased, the slip properties and anti-blocking properties will be improved accordingly, but the heat sealability will be drastically reduced and the product will eventually lose its practicality.
However, in the surface-modified film of the present invention, although the slip properties and anti-blocking properties are significantly improved as described above, the heat seal properties are hardly impaired. [4]
Does not impair adhesive sealing properties.

In the same way as described in [3' above, in the present invention, the sealing properties of the adhesive are hardly impaired. (6) Pass the printing test.

Even if the treated film of the present invention is printed using vinylon ink and the printed film is subjected to a peel test with an adhesive tape, a kneading test, and a scratch test,
The printed surface will not fall off or become unclear. This is because in the present invention, the coating rate of the film surface by the fluorosurfactant is small, and the adhesion to the film is good due to the effect of the hydrophilic stem in the molecule, which makes it able to withstand the above tests. Seem. '6) Transparency and gloss are not impaired.

Even with the fluororesin treatment of the present invention, compared to untreated products,
Transparency and gloss are not only not impaired, but are even improved. The following method can be mentioned as a method for making a fluorine-based surfactant exist on the surface of a vinyl alcohol polymer film.

'1' A method of applying a solution or dispersion of a fluorosurfactant to one or both sides of a vinyl alcohol polymer film and drying it.

t2) 0.01 to 2.
A method of purifying a material to which 0% by weight of a fluorine-based surfactant has been added.

In the method '1-, the fluorosurfactant is applied in the form of a solution or dispersion.

In addition to water, solvents include alcohol (methanol, ethanol, isopropanol, etc.), ketones (acetone,
methyl ethyl ketone, etc.), ethers (diethyl ether, butyl cellosolp, dioxane, tetrahydrofuran, etc.), esters (methyl acetate, ethyl acetate, etc.),
Hydrocarbons (benzene, toluene, xylene, heptane, etc.), halides (percrene, etc.), amide compounds (dimethylformamide, etc.), etc. are used. Mixed solvents of these (water-isoprobanol, water-methanol, water-butylcellosolve, etc.) can also be used. Among these solvents, water is the most preferred from an industrial standpoint because it does not contaminate the working environment or cause fire, and it is inexpensive. The film may be coated on one side or both sides, and may be applied not only to the entire surface but also to a portion thereof. Application may be performed by any method such as roll coating, brush coating, immersion, curtain flow coating, doctor knife coating, and spraying.

Drying may be performed at room temperature or under heating. A reduced pressure drying method is also appropriately employed. When coating, characteristic powders such as silicon dioxide, calcium carbonate, aluminum oxide, and titanium oxide may be added, as well as polyvinyl alcohol and other adhesive polymers as anti-shedding agents, antifoaming agents, and general surfactants. ,
Other additives may also be blended.

Particularly useful is colloidal silica. The amount of the fluorine-based surfactant to be applied as the active ingredient is 0.001 to 0.05 days/day, preferably 0.004 to 0.04 days/day, which is sufficient.

This amount is only 1'10 or less of the amount conventionally used for modifying polyvinyl alcohol films, but in the present invention, it is surprising because it contains a long mirror alkyl group substituted with fluorine. It produces excellent results, and the desired effect can be obtained even in small amounts unimaginable with other substances. Such vinyl alcohol polymer films include not only flat films but also cylindrical films and sheets, as well as hollow fibrous materials, bottle-shaped or box-shaped containers, etc. These films may be heat treated, or It may be subjected to a ball stretching treatment, a lamination treatment with another base material, or the like.

In the '21 method, a vinyl alcohol polymer is added with a fluorine surfactant in an amount of 0.01 to 2.0% by weight, adjusted to an aqueous solution with a concentration of about 15 to 25%, and then prepared in a drum or Cast film in belt shape or water content 20
A method is adopted in which a hydrous vinyl alcohol polymer adjusted to about 70% is extruded into a film using an extruder.

For meltable vinyl alcohol polymers (such as saponified olefin-vinyl ester copolymers and saponified unsaturated sulfonic acid (salt)-vinyl ester copolymers), a melt film forming method can also be employed. In these cases, it is thought that the fluorosurfactant bleeds into the surface layer during film formation, resulting in surface modification of the film.

In the method (2), the amount of fluorosurfactant added is 0.01 to 2. If it is less than this, the modifying effect will be insufficient, and if it is more than this, the blocking resistance will be reduced and the printability will be reduced.

Now, the vinyl alcohol polymer in the present invention refers to a partial or completely saponified product of a vinyl ester polymer or a vinyl ester polymer, or a subsequently modified product.

For example, 'apa1' polyvinyl alcohol prepared by saponifying about 50 to 100 mol% of vinyl acetate, 'b) vinyl acetate as the king and other copolymerizable monomers such as olefin (ethylene, propylene, etc.). , Q-butene, Q
-octene, Q-dodecene, Q-octadecene, etc.),
Unsaturated monocarboxylic acids (acrylic acid, methacrylic acid, crotonic acid, etc.) or their ethers or salts, unsaturated polyhydric carboxylic acids (maleic acid, fumaric acid, itaconic acid, etc.) or their partial or complete esters or salts, anhydrides), unsaturated sulfonic acids (ethylene sulfonic acid, allyl sulfonic acid, methalylsulfonic acid, etc.) or their salts, amides (acrylamide, methacrylamide, etc.),
A copolymer with nitrile (acrylonitrile, methacrylonitrile, etc.), vinyl enal, vinyl ketone, pinyl chloride, etc., in which part or all of the vinyl acetate component is saponified (the proportion of other copolymerizable monomers is 50 mol) % or less, particularly 20 mol% or less.However, when ethylene is used as a comonomer, the ethylene content may be up to about 95 mol%), {c} above [a}, {b'
Examples include acetalization, urethanization, phosphate esterification, cyanoethylation, and modified products after grafting vinyl monomers. As a fluorosurfactant,
It has a long-chain alkyl group highly substituted with fluorine and a hydrophilic group in the same molecule, and the surface tension of its 0.5% aqueous solution at a temperature of 2°C is 39 skin e/g or less, preferably 1
Fluorosurfactants having 5 to 3 peaks e/arc are suitable for the purposes of this invention. If the solubility in water is small and 0
．． When it is difficult to prepare a 5% aqueous solution, it is sufficient that the surface tension of the saturated aqueous solution is 3 Wy/hc or less. The surface tension of distilled water is 7. The most highly fluorine-substituted alkyl group includes, for example, a group in which most or all of the hydrogen atoms of an alkyl group having 5 to 20 carbon atoms are substituted with fluorine. Two or more such groups may exist in the same molecule. Examples of hydrophilic stems include those having groups such as sulfonate, carboxylate, ethanolamine, and polymers of ethylene oxide. Particularly preferred are R CmF2m+, S02NCH2CH20(CH2CH2
0) A compound represented by nH, m = 5 to 2, n = 5
~20, R=alkyl group.

The coefficient of static friction of the modified vinyl alcohol polymer film of the present invention is considerably smaller than that of ordinary mineral dusted products; for the purpose of the present invention, the coefficient of static friction is 20q.
o, 0.55 or less at 65%RH, preferably 0.
Conditions should be selected so that the number is 5 or less.

Next, the method of the present invention will be further explained with reference to Examples.

Hereinafter, the term "%" refers to % by weight, excluding cases where it is expressed as mol % and % of haze. Example 1 A polyvinyl alcohol film of the formula R C8F,7S02NCH2CH20 (CH2CH20) was coated on one side of a polyvinyl alcohol film (degree of polymerization of polyvinyl alcohol: 1700, degree of saponification 99.5 mol%), which was produced by a casting method and had a length of 130 mm and a thickness of 30 mm.
,.

The surface tension of a 0.5% aqueous solution at a temperature of 23°C is 18. Using a 22.5 mesh roll, apply a 0.4% aqueous solution of a fluorinated/ionic surfactant (Mega Fac F-142 manufactured by Dainippon Ink & Chemicals Co., Ltd.) to a film speed of 5.
Roll coating was performed at a coating rate of 5 mm/min and a coating amount (gross) of 9.4 mm/m, and then roll drying was performed at a roll surface temperature of 140 oo. The coating amount is net o. o075 Evening/It's the end. The static friction coefficient and various physical properties of the thus obtained film were measured.

The results are shown in Table 1. Example 2 0.1 of the fluorine-based nonioso surfactant used in Example 1
% aqueous solution to which 0.3% of colloidal silica (Snowtex 2, manufactured by Nissan Chemical Industries, Ltd.) was added to water, and coating and drying were carried out in the same manner as in the examples.

The total coating amount of the fluorine-based surfactant and colloidal silica was 0.0075 mm/m on net. Control example
1. Control example of the raw material film of Example 1 (without coating) 2. An aqueous suspension of colloidal silica (average particle size 15 degrees) at a concentration of 1.6% was applied to the raw material film of Example 1 and dried. The amount of application is 0.039/Fil'em net.

Control Example 3 The raw material film of Example 1 was coated with an aqueous dispersion of polystyrene (
The film was coated with a film with a concentration of 1.6% and an average particle size of 0.1 french, and the dry coating amount was 0.03 m/m in net.

The results of Example 2 and Comparative Examples 1 to 3 are shown in Table 1. Table 1 (Note) The static friction coefficient was measured using a Toyo Seiki slide tester.
Friction between films was measured at 20°C and 70% RH.

Blocking resistance was determined by heating the sample at 30°C and 80%RH for 2 hours.
After allowing it to stand still for 4 hours to reach equilibrium moisture content, a large number of samples of the size of KIO Kaya and XIO were stacked together under the same conditions, and after being left under a load of 1.0 & for 24 hours, the state of adhesion was determined. A: No adhesion at all B: Slight adhesion observed, but usable 0: Adhesive, plate-like object, unusable For heat sealing, use a burner, sealing temperature lower blade 100°C, upper blade 300°C, pressure 1.0K evening/female, 0
．． The adhesive strength was measured at a tensile strength of 1800 after being rolled for 5 seconds.

The grade sealability was determined by using calcium bromide (35% concentration) house water methanol adhesive and measuring the adhesive strength at 1800 tensile strength 5 hours after applying the glue. The printing test was performed after solid printing using Toyo Ink's Vinylon 61 white ink.
The sample was left at 20° C. and 65 RH for 24 hours, and the following tests were conducted. Adhesive tape test: Adhere cellophane adhesive tape to the printing surface K and then peel off the tape suddenly. Kneading test: Hold the film up and down with your hands and knead it up and down.

Scratch test: Place the print side up on a glass plate and scratch it with your thumb nail. In these tests, a test in which the printing ink was not observed to fall off the film with the naked eye was considered to have passed, and the number of tests was expressed as the number of passes. The degree of cloudiness was measured using a reflection/transmittance meter RM-15A manufactured by Color Technology Research Institute.

Naoko.

When the experiment was carried out in the same manner as in Control Example 2 except that a silicon oxide powder with a particle size of 11 or more was used instead of colodal silica, the transparency of the film was impaired, the printing test was poor, and the sealability was also improved by using colodal silica. The result was slightly inferior to that of . Examples 3 to 5 The film of Example 1 was coated with 0.3 of the following fluorosurfactant.
% aqueous solution was applied and dried.

The amount of coat was approximately 0.0056 coats/metre in net.
Example 3 Formula R C8F,7S02NCH2CH20 (CH2CH20)
, the surface tension of a 0.5% aqueous solution at a temperature of 23qC expressed in 5 days is 20. yne/arc fluorine/ionic surfactant (Megafuck F-143 manufactured by Dainippon Ink & Chemicals Co., Ltd.) Example 4 The surface tension of a 0.5% aqueous solution represented by the formula R C8F,7S02NCH2COOK at a temperature of 23oo is 15. Example 5 Fluorinated anionic surfactant of 7 dyne/arc (Megafac F-120, manufactured by Dainippon Ink & Chemicals Co., Ltd.)
The surface tension of a 5% aqueous solution at a temperature of 2yo is 29y /
The results of the skin fluorine-based anionic surfactant (Monflo 31 manufactured by Kao Atlas Co., Ltd.) are shown in Table 2.

Table 2 Example 6 Medium 25-layer film formed by T-die melt extrusion method, thickness 4
C6F, 7 group and polymerized ethylene oxa The surface tension of a 0.5% aqueous solution containing a do group at a temperature of 20. A 0.5% aqueous solution of a fluorine-based nonionic surfactant (Megafac F-14 manufactured by Dainippon Ink & Chemicals Co., Ltd.) was applied and dried.

The coating amount was 0.01 evening/day. Comparative Example 5 Raw material film of Example 6 Comparative Example 6 An aqueous suspension of colloidal silica (average particle size 15) was applied with a net to the elbow for 0.03 minutes per hour to the raw material film of Example 6, and dried.

Control Example 7 The raw material film of Example 7 was coated with an aqueous polystyrene dispersion (
The film was coated with a film with a concentration of 1.6% and an average particle size of 0.1 μm, and the dry coating amount was approximately 0.03 mm/force.

The above Example 6 and Control Examples 5 to 7 are shown in Table 3.

Table 3 (The temperature of the upper blade was 180°C.

) Example 7 A Q-dodecene-modified polyvinyl alcohol film with a thickness of 30 mm and a thickness of 30 mm formed by an inflation melt extrusion method (copolymerization ratio of Q-dodecene 5.0 mol%, vinyl acetate component) degree of 99.5
(mol%) was cut into two sheets, the front and back, to obtain a flat film.

Next, on one side of this film, a fluorinated nonionic surfactant (Kao Atlas Co., Ltd.) whose surface tension at 23°C of a 0.5% aqueous solution containing highly fluorinated multi-side chain alkyl groups is 2% Company-made Monflo-51) 0
．． A 5% aqueous solution was applied and dried. The coating amount was 0.01 evening/day. Then, the same process was applied to the remaining side. Comparative Example 8 Raw material film of Example 9 Comparative Example 9 Colloidal silica (
An aqueous suspension with an average particle size of 15 cm) was added to the net for 0.03 minutes/day.
Apply and dry.

Control Example 10 An aqueous polystyrene dispersion (concentration 1.6%, average particle size 0.1 mm) was applied to both sides of the raw material film of Example 9, and the net coating amount per dry side was 0.03 mm. / Lino Film.

The results of Example 7 and Control Examples 8 to 10 are shown in Table 4.

Table 4 (Heat-sealing temperature is 250°C for the upper blade and Example 8 Polyvinyl is added to a mixture of 10 parts of polypynyl alcohol with a degree of polymerization of 1700 and a degree of saponification of 99.5 mol%, 50 parts of water, and 1 part of glycerin. A fluorine-based surfactant (used in Example 1) was added in an amount of 0.3% based on alcohol, and mixed and dissolved under heating.

Claims (1)

[Claims] 1. A surface-modified vinyl alcohol polymer film in which a fluorine-based surfactant is present on the surface of the vinyl alcohol polymer film. 2. The fluorine-based surfactant has a long-chain alkyl group highly substituted with fluorine and a hydrophilic group in the same molecule, and the surface tension of its 0.5% aqueous solution at a temperature of 23°C is 35
The film according to claim 1, which is a fluorine-containing surfactant having a surfactant of dyne/cm or less. 3. A method for producing a surface-modified vinyl alcohol polymer film, which comprises applying a solution or dispersion of a fluorosurfactant to the surface of the vinyl alcohol polymer film and drying it. 4. A method for producing a surface-modified vinyl alcohol polymer film, which comprises forming a film by adding 0.01 to 2.0% by weight of a fluorine-containing surfactant to a vinyl alcohol polymer.