JP2506689B2 - Marking film and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION “Industrial field of application” The present invention relates to a marking film and a manufacturing method thereof. More specifically, the present invention relates to a marking film having no distortion, excellent weather resistance and mildew resistance, and a manufacturing method thereof.

"Prior art" As a manufacturing method of a marking film, vinyl chloride resin for paste is mixed with a plasticizer, a stabilizer, an ultraviolet absorber, etc., and further diluted with a solvent to form an organosol, which is cast and heated. The method of forming a film is generally used. Further, a method of blending a vinyl chloride resin with a plasticizer, a stabilizer, an ultraviolet absorber, etc., melting the composition with a kneading device such as a Banbury mixer, and then forming it into a film with a forming device such as a calender is also performed. ing. Then, as a plasticizer used for such a marking film, a polyester-based plasticizer containing a dibasic acid as an acid component is generally used in order to impart weather resistance.

Among these marking film production methods, the method using an organosol requires the use of an organic solvent as a diluent because the polyester plasticizer used has a high viscosity and poor processability. Since such an organic solvent is volatilized during film formation, special equipment such as a solvent recovery device is required in the method using the organosol,
It is difficult to handle, the equipment cost is high, and cracks are likely to occur due to the rapid evaporation of the organic solvent during film formation,
There were drawbacks such as difficulty in controlling molding conditions.

Further, the method using a calendar or the like is difficult to set the molding conditions because the polyester plasticizer as described above is used, and since the distortion of the film formed is large, when it is applied as a marking film, it shrinks. There is a drawback that it is easy to cause.

Against these problems, a method for producing a marking film has been proposed in which an aqueous emulsion liquid containing a vinyl chloride resin latex and an emulsified polyester plasticizer is cast by a coating machine to form a film. However, even with such a production method, the deterioration of the marking film due to hydrolysis of the polyester resin used as the plasticizer and damage of the mold was unavoidable.

"Problems to be Solved by the Invention" In view of such circumstances, the present inventor has diligently studied to obtain a marking film having no distortion and no deterioration caused by a plasticizer, and should be blended with a vinyl chloride resin. As the polyester plasticizer, particularly liquid poly-β-methyl-δ
-By using valerolactone, it was found that a marking film free from distortion and excellent in weather resistance and mildew resistance can be easily obtained, and completed the present invention.

"Means for Solving Problems" That is, an object of the present invention is to provide a marking film having no distortion, excellent weather resistance and mildew resistance, and a manufacturing method thereof.

Thus, the gist of the present invention is that, in vinyl chloride resin, 20 parts by weight or more and 200 parts by weight or less of liquid poly-β-methyl-δ-valerolactone per 100 parts by weight of the vinyl chloride resin. A marking film comprising a vinyl chloride resin composition contained therein and an aqueous emulsion liquid comprising the above composition are cast and heated to form a film.

 The present invention will be described in detail below.

As the vinyl chloride resin using the marking film of the present invention, vinyl chloride or a mixture of vinyl chloride and a comonomer copolymerizable therewith is generally selected from suspension polymerization, bulk polymerization, fine suspension polymerization, emulsion polymerization, etc. All those manufactured by the method of are used. However, in the production of the marking film of the present invention, the state of the vinyl chloride resin latex produced by the emulsion polymerization method or the fine suspension polymerization method as it is, the liquid poly-β-methyl-
It is preferably used by mixing with δ-valerolactone. Further, as the main emulsifier used for the polymerization of vinyl chloride,
Any anionic surfactant can be used,
Considering the water resistance of the produced marking film, it is desirable to use a higher fatty acid ammonium salt, and further considering the weather resistance, it is most preferable to use ammonium myristic acid as the main emulsifier.

Further, in the production of the marking film of the present invention, when polymerizing vinyl chloride, a latex polymerized in the presence of liquid poly-β-methyl-δ-valerolactone described below may be used as it is.

Thus, as a comonomer copolymerizable with vinyl chloride, for example, vinyl acetate, vinyl propionate, vinyl ester such as vinyl laurate, methyl acrylate,
Acrylic esters such as ethyl acrylate and butyl acrylate, methacrylic acid esters such as methyl methacrylate and ethyl methacrylate, maleic acid esters such as dibutyl maleate and diethyl maleate, and fumaric acid esters such as dibutyl fumarate and diethyl fumarate. Vinyl ethers such as vinyl methyl ether, vinyl butyl ether, vinyl octyl ether,
Vinyl cyanides such as acrylonitrile and methacrylonitrile, α-olefins such as ethylene, propylene and styrene, vinyl halides other than vinyl chloride such as vinylidene chloride and vinyl bromide, and these comonomers include vinyl chloride. It is used in the range of 30% by weight or less, preferably 20% by weight or less in the constituent components of the resin. Of course, the comonomers are not limited to those mentioned above.

Liquid poly-β-methyl- which is one component of the present invention
The δ-valerolactone preferably has a weight average molecular weight measured by GPC of 1,000 or more.

When the weight average molecular weight of poly-β-methyl-δ-valerolactone is less than 1,000, poly-β-methyl-
The δ-valerolactone is likely to be lost due to migration, volatilization, etc., and the durability of the marking film tends to be poor. From the viewpoint of durability, it is desirable that the molecular weight of poly-β-methyl-δ-valerolactone is large, but on the other hand, when the molecular weight is large, not only the ability to plasticize the vinyl chloride resin is lowered, but also poly-β- Since the production cost of methyl-δ-valerolactone increases and it is economically disadvantageous, it is advantageous to use a molecular weight of about 100,000 or less.

Poly-β-methyl-δ-valerolactone has an asymmetric carbon, is low in crystallinity, and becomes liquid even at a high molecular weight, and thus is significantly advantageous as compared with a polymer obtained from other lactone compounds. .

Poly-β-methyl-δ-valerolactone can also be obtained by ring-opening polymerization of β-methyl-δ-valerolactone,
It can also be obtained by polycondensation of 3-methyl-5-hydroxyvaleric acid, which is a hydroxycarboxylic acid having the corresponding number of carbon atoms.

The composition ratio of the vinyl chloride resin and the liquid poly-β-methyl-δ-valerolactone depends on the degree of plasticization of the vinyl chloride resin, the use of the marking film obtained from these compositions, and further various requirements. Although it is different, the latter is 20 to 200 for 100 parts by weight of the former.
It may be appropriately selected from the range of parts by weight. Liquid poly-β
When the amount of -methyl-δ-valerolactone is less than 20 parts by weight, a flexible film cannot be obtained, while when it is more than 200 parts by weight, a tough film cannot be obtained.

The composition used for the marking film of the present invention is a vinyl chloride resin, a liquid poly-β-methyl-δ-valerolactone, and, if necessary, a plasticizer, a stabilizer, a colorant, a foaming agent other than the above. , A cross-linking agent, a filler and the like can be contained.

The marking film of the present invention is manufactured by various manufacturing methods. For example, a vinyl chloride resin, liquid poly-β-methyl-δ-valerolactone, and a composition containing other additives, if necessary, may be used as a roll-type, Banbury-type, or Henschel-type mixer or extruder. After sufficiently mixing or kneading with the above, it can be produced by molding into a film by a usual molding method such as a calender method, a T-die method, an inflation method.

The marking film of the present invention can be manufactured by the following casting method because it is the simplest in terms of manufacturing operation and has excellent physical properties.

As the first step, vinyl chloride resin latex (A)
Is prepared by emulsion polymerization or fine suspension polymerization. Separately, liquid poly-β-methyl-δ-valerolactone is uniformly dispersed in water in the presence of an emulsifier to obtain a poly-β-methyl-δ-valerolactone emulsion ( After preparing B), both are mixed.

As a method for mixing the vinyl chloride resin latex (A) and the poly-β-methyl-δ-valerolactone emulsion (B), the vinyl chloride resin latex (A) is previously mixed with the poly-β-methyl-δ-valerolactone emulsion. After mixing 10 to 90% of (B) and heating at a temperature not exceeding 90 ° C., the rest of the poly-β-methyl-δ-valerolactone emulsion (B) is mixed to prepare an aqueous emulsion liquid. The method is preferred. If the vinyl chloride resin latex is not heated even when mixed with the poly-β-methyl-δ-valerolactone emulsion, or the amount of the poly-β-methyl-δ-valerolactone emulsion premixed with the vinyl chloride resin latex is If it is less than 10%, the strength of the film tends to be insufficient, and poly-β-methyl-δ-premixed with the vinyl chloride-based resin latex in advance.
If the amount of valerolactone emulsion is more than 90%, cracking tends to occur during film formation.

Since the aqueous emulsion liquid obtained by mixing the both contains bubbles, gels, and agglomerates that may cause seeds during film formation, it is desirable to remove coarse particles of 30 μm or more due to excess. In order to reduce pinholes and the like in the film, a method in which the aqueous emulsion liquid from which coarse particles have been removed is further deaerated with a known vacuum defoaming machine or the like is preferably used.

Also, vinyl chloride resin latex and liquid poly-β-
The solid content concentration of an aqueous emulsion liquid that essentially requires an emulsion in which methyl-δ-valerolactone is emulsified is
It is preferably in the range of 20 to 80% by weight, particularly preferably in the range of 40 to 60% by weight. If the concentration of solids is lower than 20%, the amount of water to be evaporated is large, resulting in poor productivity, and if it is higher than 80%, it becomes difficult to adjust the thickness of the final film. It is not preferable.

In the second step, the above-mentioned aqueous emulsion liquid is cast on a base material coated or not coated with a release agent, for example, paper, a metal thin plate, a heat resistant resin thin plate or the like. As a casting method, for example, a known roll coating method, gravure coating method, reverse coating method, knife coating method or the like is preferably adopted.

In heating and melting the coating film formed by such a casting method, predrying is performed at a temperature of around 100 ° C to evaporate most of the water content, and then gelled and melted in the range of 160 ° C to 250 ° C. preferable. When the film is heated at a high temperature of 160 ° C. to 250 ° C. from the beginning, cracks are likely to occur in the finally obtained film.

The film that has undergone gelling and melting can be wound up together with the film alone or the substrate after cooling to around room temperature.

"Effect of the invention" The marking film of the present invention uses liquid poly-β-methyl-δ-valerolactone for softening the vinyl chloride resin, and therefore has excellent mildew-proofing properties, and the molecular weight of this softening agent is Since it is comparatively larger than that of conventional plasticizers, less migration of softening agent, deterioration due to migration can be reduced and durability,
Excellent weather resistance.

Further, when the marking film is produced by the method of the present invention, liquid poly-β-used as a plasticizer (softening agent) is used.
Even when the viscosity of methyl-δ-valerolactone is high, the above-mentioned poly-β can be obtained by selecting the production method thereof.
-Methyl-δ-valerolactone can be easily made into an aqueous emulsion, and can be mixed with a vinyl chloride resin latex to be applied as an aqueous emulsion liquid to form a film, so that marking without distortion is extremely easy. The effect that a film is obtained is exhibited.

"Examples" Next, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

The coating properties, weather resistance, and mold resistance of Examples and Comparative Examples were measured or evaluated as follows. The results are tabulated.

<Coatability> The viscosity of the aqueous emulsion or organosol was measured at 5 rpm with a Brookfield viscometer. The method with low viscosity has good coatability.

<Weather resistance> The film obtained by film formation was subjected to non-sprinkling and sprinkling in a Sunshine Weatherometer manufactured by Suga Test Instruments Co., Ltd.
The residual ratio of the physical properties after exposure for 1,000 hours was measured.

<Mold resistance> Cut the obtained film into 100 cm ² size and
It was attached to the inside of a constant temperature water tank containing water, and the generation of mold after 1 month was visually observed and evaluated.

 The evaluation criteria are as follows.

A: No mold is found on the film.

◯: Generation of mold is recognized in 1/3 or less of the film.

Δ: Generation of mold is recognized in 1/3 to 2/3 of the film.

×: The occurrence of mold on 2/3 or more of the film.

Example 1 Ultraviolet absorber (trade name: Tinuvin PS, manufactured by Ciba-Geigi Co., Ltd.)
40 gr was dissolved in 700 gr of poly-β-methyl-δ-valerolactone (weight average molecular weight 12,000), and a 0.5% aqueous solution of hydroxylmethyl cellulose 360 gr, oleic acid 13 gr and 25
% Aqueous ammonia solution 3.8gr and mixed with a homomixer for 10 minutes to obtain a poly-β-methyl-δ-valerolactone emulsion.

60% of the poly-β-methyl-δ-valerolactone emulsion, a 25% aqueous ammonia solution 7.5 gr, and a weight average particle diameter of 1.2μ obtained by fine suspension polymerization using a myristic acid ammonium salt as a main emulsifier, and a solid content of 43 Mix with 4650gr of vinyl chloride resin latex 4wt% by weight and stir at 70 ℃ for 2
Held for hours.

After cooling the mixture to 50 ° C., the poly-β-
The remaining 40% of the methyl-δ-valerolactone emulsion,
Rutile type titanium oxide (Product name CR-90 manufactured by Ishihara Sangyo Co., Ltd.) 1000
After adding gr and stabilizer dioctyl tin laurate (BT-11 manufactured by Adeka Argus Co., Ltd.) to 40 gr, the total solid content concentration was adjusted to 52% by weight. The obtained aqueous emulsion liquid is further
After passing through a wire mesh of 100 mesh, vacuum defoaming was performed. This aqueous emulsion was used for evaluation of coatability.

The obtained aqueous emulsion liquid was applied onto a release paper using a doctor knife so that the film thickness would be 60 μm. Then 110
After drying by heating in an oven at ℃ for 3 minutes, 190
A film was formed by heating in an oven at ℃ for 2 minutes.

The obtained marking film was evaluated for weather resistance and mildew resistance. The results are shown in the table.

Comparative Example 1 In Example 1, poly-β-methyl-δ-valerolactone was used as a polyester plasticizer (adipic acid and diol (1,
3-butanediol: 1,4-butanediol = 50: 50) and a molecular weight modifier (2-ethylhexanol)) were obtained in the same manner as in Example 1 except that an aqueous emulsion liquid was obtained and subjected to viscosity measurement. A film was obtained in the same manner as in Example 1 and evaluated for weather resistance and mold resistance.

Claims (4)

(57) [Claims] 1. A vinyl chloride resin, wherein the vinyl chloride resin
A marking film made of a vinyl chloride resin composition containing 20 parts by weight or more and 200 parts by weight or less of liquid poly-β-methyl-δ-valerolactone per 100 parts by weight. 2. The marking film according to claim 1, wherein the liquid poly-β-methyl-δ-valerolactone has a weight average molecular weight of 1,000 or more. 3. An aqueous emulsion solution comprising a vinyl chloride resin latex and liquid poly-β-methyl-δ-valerolactone is cast to form a film by heating. A method for producing the described marking film. 4. An aqueous emulsion liquid is prepared by previously converting liquid poly-β-methyl-δ-valerolactone into an aqueous emulsion emulsion, 10 to 90% of which is mixed with a vinyl chloride resin latex to a temperature not exceeding 90 ° C. 4. The method for producing a marking film according to claim 3, which is obtained by mixing the remainder of the liquid poly-β-methyl-δ-valerolactone aqueous emulsion emulsion after heating to 1.