TW201508019A - Vinylidene chloride resin film and method for producing same - Google Patents

Abstract

Provided are: a vinylidene chloride resin film which has a shear adhesion at 13 DEG C of 5 kgf or more, preferably a vinylidene chloride vinyl chloride copolymer film, in particular, a vinylidene chloride resin film wherein the vinylidene chloride resin is prepared by suspension polymerization in an aqueous medium in the presence of a suspending agent the content of which based on the mass of a monomer component that forms the resin is less than 300 ppm; and a method for producing the vinylidene chloride resin film.

Description

Vinylidene chloride resin film and method for producing same

The present invention relates to a vinylidene chloride-based resin film which can be used for a wrap film or the like which is excellent in adhesion to a packaged article and a film, and a method for producing the same.

The vinylidene chloride-based resin film is a film having excellent oxygen barrier properties, water vapor barrier properties (moisture resistance), and transparency, and can be heated in a microwave oven, so it can be used as a wrap film for business and household use, and as a food. The film for automatic filling and packaging is widely used for packaging fresh fish, raw meat, processed meat, fresh vegetables, cooked foods, etc., in order to obtain oxygen and moisture resistance.

As a vinylidene chloride-based resin which forms a vinylidene chloride-based resin film, from the viewpoints of extrusion processability, crystallinity, transparency, softening temperature and the like of the film, it is generally used such as vinylidene chloride or vinyl chloride. A vinylidene chloride copolymer obtained by copolymerization of a monomer copolymerized with vinylidene chloride (hereinafter may be referred to as "co-monomer" or "Comonomer").

As a method for producing a vinylidene chloride-based resin, a suspension polymerization method and an emulsion polymerization method are known. The vinylidene chloride-based resin obtained in the emulsion polymerization method is prone to thermal deterioration due to residual emulsifier or the like, and thus is generally used. Suspension polymerization. The suspension polymerization method is a method in which a vinylidene chloride and a co-monomer are suspended in an aqueous medium containing a suspending agent and a polymerization initiator, and polymerization is carried out in this state. As a suspending agent, Patent Document 1 discloses a cellulose ether such as methyl cellulose or hydroxypropylmethylcellulose, and it is described that the suspending amount is preferably 0.05 to 0.1% by weight based on the weight of the monomer. Further, as a suspending agent, Patent Document 2 discloses that methyl cellulose having a soluble fraction of 0.1 to 2.0% by weight is used with respect to 1,2-dichloroethane, and as a specific example, it is described as a relative A total of 67.5 kg of vinyl chloride and vinyl chloride was used, and 67.5 g of methyl cellulose was used.

The vinylidene chloride-based resin film is generally prepared by melt-extruding a vinylidene chloride-based resin, and then stretching it, and then winding it on a paper tube and storing it in a paper box. By including various additives such as a plasticizer, a stabilizer, and a tackifier in the vinylidene chloride-based resin, extrusion processability and film properties can be improved. In addition, in the use of the film for automatic filling and packaging, in order to prevent problems in the manufacturing process and the packaging process of the vinylidene chloride resin film, a lubricant may be contained as needed.

In particular, a vinylidene chloride-based resin film is used as a film for wrap film and automatic filling and packaging, and therefore, adhesion between the film and the packaged article and adhesion between the films are required. Patent Document 3 discloses a film in which a mineral oil such as a paraffin wax is added, and as an additive method, a method of applying to a film, impregnation, blowing, and intrusion in an extrusion step may be mentioned. Patent Document 4 discloses a liquid paraffin added for improving the adhesion of a vinylidene chloride-based resin film, and the displacement is changed, and the film adhesion and the pull-out property pulled out from the paper cassette for storing the film are disclosed. The problem of equalization can be added to the para-dichloroethylene resin before extrusion molding, and the surface of the film after coating is coated. Flowing paraffin.

Further, Patent Document 5 discloses that in order to impart adhesion to a vinylidene chloride-based resin film, it is considered that liquid paraffin, a surfactant, and the like are liquid at normal temperature, and the heat is stable during melt molding, and is easy to use. It may contain 0.01 to 3 parts by weight of a tackifier having a viscosity of 10 to 100 cps at 25 ° C with respect to 100 parts by weight of the resin. Further, it is disclosed that when an excessive amount of a tackifier is added or an tackifier having a too low viscosity is added, the extrusion processability is liable to be deteriorated, and the film has a tendency to be wet-adhesive, and on the other hand, the viscosity is too high and may be squeezed. The workability is easily deteriorated, so it is not preferable.

Therefore, the vinylidene chloride-based resin film is required to be a vinylidene chloride or the like which is excellent in adhesion to the packaged product and the film, even if it does not contain or apply a tackifier such as a liquid paraffin. The resin-like film further requires a vinylidene chloride resin film which is not inferior in pull-out property and transparency.

[Practical Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 10-504847

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2003-137911

[Patent Document 3] Japanese Patent Laid-Open No. Hei 10-87876

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2004-202752

[Patent Document 5] Japanese Patent Laid-Open No. Hei 10-324809

An object of the present invention is to provide a vinylidene chloride-based resin film which can be used for a wrap film or the like which is excellent in adhesion to a packaged product and a film without adding or applying a tackifier.

In order to solve the above problems, the present inventors have found that a polyvinylidene chloride resin film having a shear strength (Shear Adhesion Strength) of a certain value or more at a temperature of 13 ° C, in particular, a vinylidene chloride resin is used. The film formed by suspension polymerization under a microsuspension can solve the problem and complete the present invention.

That is, according to the present invention, there is provided a vinylidene chloride-based resin film characterized in that the shear adhesive strength at a temperature of 13 ° C is 5 kgf or more.

Further, according to the present invention, as the embodiment, the following vinylidene chloride resin film of (1) to (6) is provided.

(1) The vinylidene chloride-based resin film as described above, wherein the vinylidene chloride-based resin is in an aqueous medium in the presence of a suspending agent having a content of less than 300 ppm based on the mass of the monomer component forming the resin. The suspension polymerization is carried out to prepare a person.

(2) The vinylidene chloride-based resin film as described above, wherein the suspending agent content is less than 150 ppm based on the total mass including the aqueous medium.

(3) The vinylidene chloride-based resin film as described above, which does not contain a tackifier.

(4) A vinylidene chloride-based resin film as described above, which contains a tackifier.

(5) The vinylidene chloride-based resin film as described above, wherein the vinylidene chloride-based resin is prepared by suspension polymerization in the presence of a tackifier.

(6) a vinylidene chloride-based resin film as described above, wherein vinylidene chloride The resin is vinylidene chloride. Vinyl chloride copolymer.

Further, according to the present invention, there is provided a method for producing a vinylidene chloride-based resin film, which comprises the following steps 1 and 2: 1) in the presence of a monomer component for forming a vinylidene chloride-based resin. a step-by-step suspension polymerization in an aqueous medium under a suspension having a content of less than 300 ppm to prepare a vinylidene chloride-based resin; and 2) melt-extruding a vinylidene chloride-based resin containing a vinylidene chloride-based resin The composition is further extended in the step 2, and the shear adhesion at a temperature of 13 ° C is 5 kgf or more.

According to the present invention, as an embodiment, a method for producing a vinylidene chloride-based resin film of the following (A) and (B) will be provided.

(A) The method for producing a vinylidene chloride-based resin film as described above, wherein the step 1 and the step 2 are carried out without a tackifier.

(B) A method for producing a vinylidene chloride-based resin film as described above, wherein the step 1 is carried out by suspension polymerization in the presence of a tackifier.

Effect of the invention

According to the present invention, a vinylidene chloride-based resin film characterized by a shear adhesion of 5 kgf or more at a temperature of 13 ° C, in particular, a vinylidene chloride-based resin is present in the presence of a monomer component in which the resin is formed, and the content is insufficient. The film prepared by suspension polymerization in an aqueous medium under a suspension of 300 ppm can effectively provide a fresh-keeping property which is excellent in adhesion to the packaged article and the film without adding or coating a tackifier. Membranous vinyl chloride Resin-like film.

Further, according to the present invention, it is characterized in that it comprises the following steps 1 and 2: 1) in an aqueous medium in the presence of a suspending agent having a content of less than 300 ppm based on the mass of the monomer component forming the vinylidene chloride-based resin. a step 1 of preparing a vinylidene chloride-based resin by suspension polymerization; and 2) extruding a vinylidene chloride-based resin composition containing a vinylidene chloride-based resin, and further extending the step 2 at a temperature of 13 ° C The method for producing a vinylidene chloride resin film having a shear adhesion of 5 kgf or more can effectively provide a method for easily producing a vinylidene chloride resin film which can be used without adding or coating a tackifier. A wrap film or the like having excellent adhesion between the packaged article and the film.

Implementation 1. Vinylidene chloride resin

As a vinylidene chloride-based resin which forms a vinylidene chloride-based resin film having a shear adhesion of 5 kgf or more at a temperature of 13 ° C, oxygen barrier properties and water vapor barrier properties (moisture resistance) are currently considered. Further, it is excellent in transparency and can be heated in a microwave oven, and a vinylidene chloride-based resin which forms a vinylidene chloride-based resin film for use as a wrap film or a film for automatic filling and packaging can be used.

Specifically, in the present invention, the vinylidene chloride-based resin may be 60 to 98% by mass of vinylidene chloride, and at least one monomer (co-monomer) copolymerizable with vinylidene chloride is 2 to 40% by mass. % (vinylidene chloride and comonomer A vinylidene chloride copolymer formed by a total mass of 100% by mass.

Examples of the monomer (co-monomer) copolymerizable with vinylidene chloride include vinyl chloride; methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate or acrylic acid. Alkyl acrylate such as octaester (alkyl group having 1 to 18 carbon atoms); methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate or methacrylic acid An alkyl methacrylate such as octaester (alkyl group having 1 to 18 carbon atoms); a vinyl cyanide such as acrylonitrile or methacrylonitrile; an aromatic vinyl such as styrene; and a fat having 1 to 18 carbon atoms such as vinyl acetate. a vinyl ester of a carboxylic acid; an alkyl vinyl ether such as methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether or lauryl vinyl ether (alkyl group having 1 to 18 carbon atoms); Ethylene polymerizable unsaturated carboxylic acid such as methacrylic acid, maleic acid, fumaric acid or methylene succinic acid; maleic acid, fumaric acid, methylene succinic acid An alkyl ester of an ethylene polymerizable unsaturated carboxylic acid (may also be a partial ester. The alkyl group has 1 to 18 carbon atoms), and a diene Monomer, functional group-containing monomer, polyfunctional monomer, and the like. These comonomers may be used alone or in combination of two or more. Among the co-monomers, vinyl chloride, methyl acrylate or butyl acrylate is preferred. The co-monomer is particularly preferably vinyl chloride, so the vinylidene chloride-based resin is particularly preferably vinylidene chloride. Vinyl chloride copolymer.

The content ratio of the vinylidene chloride to form the vinylidene chloride-based resin is 100% by mass, preferably 70% by mass or more, and more preferably 80% by mass or more based on the total mass of the vinylidene chloride and the comonomer. The upper limit of the content ratio of the vinylidene chloride is not particularly limited. However, from the viewpoints of extrusion processability and the like, it is generally 97% by mass, and is usually 95% by mass. Therefore, the formation of vinylidene chloride The content ratio of the comonomer of the resin-like resin is preferably 30% by mass or less, and more preferably 20% by mass or less. The lower limit of the content ratio of the comonomer is not particularly limited, and is generally 3% by mass, and is usually 5% by mass.

2. Modulation of vinylidene chloride resin

The vinylidene chloride-based resin which forms a vinylidene chloride-based resin film having a shear adhesion of 5 kgf or more at a temperature of 13 ° C, specifically, a vinylidene chloride and a vinylidene chloride The copolymer of the copolymerized monomer (co-monomer) can be generally obtained by suspension polymerization or emulsion polymerization of vinylidene chloride and a comonomer. The suspension polymerization method is a method in which a mixed dispersion oil droplet of vinylidene chloride and a comonomer is formed by mechanical stirring in an aqueous medium containing a suspending agent, and polymerization is carried out by using a polymerization initiator in this state. The emulsion polymerization method is a method in which a vinylidene chloride and a comonomer are polymerized in a surfactant microcapsule in an aqueous medium using an emulsifier (surfactant) and a water-soluble polymerization initiator. In general, a vinylidene chloride-based resin produced by an emulsion polymerization method is likely to cause thermal deterioration of the resin due to the emulsifier (surfactant) remaining. The present invention is characterized in that a vinylidene chloride-based resin film having a shear adhesion of 5 kgf or more at a temperature of 13 ° C is obtained by melt extrusion molding, and therefore it is preferred to produce a vinylidene chloride-based resin by a suspension polymerization method using a suspending agent.

Suspending agent

Examples of the suspending agent for producing a vinylidene chloride-based resin by suspension polymerization include methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and hydroxypropoxymethyl cellulose. , water-soluble such as carboxymethyl cellulose Cellulose derivatives; polyvinylpyrrolidone, polyacrylic acid, polyvinyl alcohol, polymethyl vinyl ether, polypropylene decylamine, polyethyleneimine and other homopolymers; anhydrous maleic acid. a copolymer of vinyl acetate copolymer or the like or various random copolymers, graft copolymers, segment copolymers, macromonomers, and the like, and natural high molecular substances such as starch and gelatin. As the suspending agent, methylcellulose, hydroxypropylcellulose, and hydroxypropoxymethylcellulose are preferable, and methylcellulose is especially preferable. The suspending agent can be used singly or in combination of two or more. In addition, the suspending agent can be used as it is, or can be used as an aqueous solution, an aqueous emulsion, an aqueous suspension, and can be dissolved in an organic solvent such as toluene. If necessary, in addition to the above suspending agents, auxiliary stabilizers may be used. Examples of the auxiliary stabilizer include an anionic surfactant, a cationic surfactant, a nonionic surfactant, an amphoteric surfactant, and a long-chain alcohol.

When the vinylidene chloride-based resin of the vinylidene chloride resin film having a shear adhesion of 5 kgf or more at a temperature of 13 ° C is formed, the content of the suspending agent is vinylidene chloride and a comonomer. The content of the monomer component of the dichloroethylene resin is preferably less than 300 ppm based on the mass. Therefore, in the vinylidene chloride-based resin film of the present invention, the vinylidene chloride-based resin preferably has a content (hereinafter referred to as "monomer mass basis content" based on the mass of the monomer component forming the resin. It is prepared by suspension polymerization in an aqueous medium under a suspension agent of less than 300 ppm. The monomer mass basis content of the suspending agent is more preferably less than 280 ppm, further preferably less than 260 ppm. The lower limit of the monomer mass basis content of the suspending agent is not particularly specified, but the viewpoint of the dispersion stability of the monomer component forming the vinylidene chloride-based resin in the aqueous medium in suspension polymerization is generally 30 ppm, and most is 50 ppm. . The suspending agent can be added in one portion at a time, or can be added in several portions, and the addition time is not limited.

If the vinylidene chloride-based resin is prepared by suspension polymerization in a suspension having a monomer content of 300 ppm or more, the shear adhesion of the obtained vinylidene chloride resin film at a temperature of 13 ° C may not be obtained. When the amount is 5 kgf or more, the molding processability of the vinylidene chloride-based resin is deteriorated. For example, considering the dispersion stability of the monomer component of the vinylidene chloride-based resin during suspension polymerization, the monomer content of the suspension agent in the aqueous medium is currently 300-8000 ppm, mostly 350-5000 ppm, basically 400~3000ppm, if the suspending agent content is too much, it is presumed that the vinylidene chloride-based resin (usually in the form of particles) obtained after suspension polymerization is tightly coated with the suspending agent, resulting in resin in the melt molding. When the (particles) are not sufficiently melted, the moldability of the film or the like is deteriorated, and it is presumed that the surface heterogeneity of the vinylidene chloride-based resin film obtained by the formation of a trace amount of the insoluble matter or the like is increased. The shear adhesion is less than 5kgf, mostly less than 4.7kgf, which is basically less than 4.5kgf.

Further, from the viewpoint of the stability of the polymerization reaction during suspension polymerization and the balance between the moldability and the film characteristics of the vinylidene chloride-based resin, in the suspension polymerization, in addition to the monomer component of the vinylidene chloride-based resin, The suspending agent content is also the total mass of the suspension contained in the polymerization reaction in the aqueous medium, and the total amount of the suspension including the aqueous medium (water, ethanol, etc.) of the suspension, that is, the total amount including the aqueous medium. The suspension content (hereinafter referred to as "total mass basis content") is preferably less than 150 ppm, more preferably less than 135 ppm, still more preferably less than 120 ppm. The lower limit of the total mass basis content of the suspending agent is not particularly specified, but the viewpoint of the dispersion stability of the monomer component forming the vinylidene chloride-based resin in the aqueous medium in suspension polymerization is generally 15 ppm, and most is 25 ppm. .

Further, in view of further improving the balance between the stability of the polymerization reaction during suspension polymerization and the balance between the moldability and the film properties, in suspension polymerization, the suspension is based on the mass of the aqueous medium, and the content (hereinafter referred to as "aqueous" The medium reference content ") is preferably less than 260 ppm, more preferably less than 240 ppm, still more preferably less than 220 ppm. The lower limit of the aqueous medium reference content of the suspending agent is not particularly limited, but the viewpoint of the dispersion stability of the monomer component forming the vinylidene chloride-based resin in the aqueous medium in suspension polymerization is generally 25 ppm, and most is 40 ppm. .

[Polymerization Initiator]

Examples of the polymerization initiator for producing a vinylidene chloride-based resin include percarbonate-based initiators such as diisopropyl peroxydicarbonate, dioctyl peroxydicarbonate, and dilauryl peroxydicarbonate; Peroxyacid initiators such as peroxy neodecanoic acid ternary butyl ester, peroxy neodecanoic acid hexyl hexyl ester, and peroxy neodecanoic acid pentanyl ester; peroxidic lauryl sulfhydryl, diisobutyl peroxide, 2 a dithiol peroxide initiator such as ethyl octyl ketone peroxide or 3,5,5-trimethylhexyl decyl peroxide; tertiary butyl peroxide and secondary oxidized a peroxydiacetate di(trialkyl) initiator such as diisopropyl peroxydicarbonate; azobisisobutyronitrile, azobisisoheptanenitrile, 2,2'-azobis An azo initiator such as (4-methoxy-2,4-dimethylvaleronitrile); and a water-soluble peroxide such as potassium persulfate or ammonium persulfate, or a reduction of these added amines or sodium hydrogen sulfite Agent Subsequent substances, etc. The polymerization initiator can be used singly or in combination of two or more. The polymerization initiator can be used as it is, or can be used as an aqueous solution or an aqueous dispersion, and can be used as an organic solvent solution such as toluene.

The amount of the polymerization initiator used is preferably from 100 to 7,000 ppm, more preferably from 300 to 5,000 ppm, based on the mass of the vinylidene chloride and the comonomer, that is, the monomer component forming the vinylidene chloride-based resin. More preferably, it is 500-3000 ppm.

[Other additives]

When the vinylidene chloride-based resin of the vinylidene chloride-based resin film having a shear adhesion of 5 kgf or more at a temperature of 13 ° C is prepared, it may be prepared to contain a preparation other than the suspending agent and the polymerization initiator described above. Various other additives used in the case of vinylidene chloride-based resins. In other words, in order to improve the extrusion processability of the obtained vinylidene chloride-based resin, or to adjust the properties of the vinylidene chloride-based resin film formed of the vinylidene chloride-based resin in a balanced manner, for example, a plasticizer may be mentioned. , stabilizers, antioxidants, pH adjusters, UV absorbers, tackifiers, antistatic agents, anti-adhesives, anti-fogging agents, fillers (fillers), and pigments, etc. . Further, as other additives, a lubricant may be contained depending on the use and needs. As the other additive, any of an organic substance (other polymers may be used) or an inorganic substance may be used.

At present, a vinylidene chloride resin film which can be used for a wrap film or the like which is excellent in adhesion to a packaged product and a film generally contains a tackifier, and a tackifier is used in the process of preparing a vinylidene chloride resin, that is, polymerization. Stage, added to The monomer component of the vinylidene chloride-based resin is formed, or the vinylidene chloride-based resin prepared by melt extrusion is further extended, that is, the film production stage. The present invention is characterized in that a vinylidene chloride resin film having a shear adhesion of 5 kgf or more at a temperature of 13 ° C is used in a polymerization stage (a process of preparing a vinylidene chloride resin) or a film production stage (melting and extruding a vinylidene chloride) In any of the steps of the resin-like composition and the step of extending the process, it can be obtained by a production method without a tackifier, but it can also be in a polymerization stage (a process of preparing a vinylidene chloride-based resin). It is prepared by suspension polymerization under the presence of a tackifier and preparation of a vinylidene chloride-based resin.

[tackifier]

A tackifier is a substance that attaches to an object that is easy to adhere to. Examples of the hot melt adhesive include sorbitan fatty acid ester, propylene glycol fatty acid ester, and glycerin fatty acid ester, for example, sorbitan mono(tri)oleate, glycerol mono(tri)oleate, and the like. And a liquid saturated hydrocarbon such as an alkane or a cycloalkane. The tackifier may be used alone or in combination of two or more. Examples of the liquid saturated hydrocarbon compound include a cyclic hydrocarbon processing oil, a paraffin wax, and a flowing paraffin, and particularly preferred is a flowing paraffin wax. The present invention is characterized in that it is a vinylidene chloride resin film having a shear adhesion of 5 kgf or more at a temperature of 13 ° C, and may not contain a tackifier. However, the vinylidene chloride-based resin film of the present invention may also contain a tackifier, and at this time, the film has a higher shear bond strength at a temperature of 13 ° C.

When suspending polymerization is carried out in the presence of a tackifier, the viewpoint of the pull-out property is considered in the preparation of the vinylidene chloride-based resin, and the content of the tackifier is based on the mass of the monomer component forming the vinylidene chloride-based resin. Monomer quality benchmark The content) is generally from 100 to 10,000 ppm, preferably from 200 to 5,000 ppm, more preferably from 300 to 3,000 ppm, still more preferably from 400 to 1,000 ppm. If the content of the tackifier is too large, the extrusion processability may be deteriorated, or the obtained vinylidene chloride resin film may become wet and difficult to use. Further, the total mass basis content of the tackifier is generally from 50 to 5,000 ppm, preferably from 100 to 2,500 ppm.

[plasticizer]

As the plasticizer, a plasticizer contained in a vinylidene chloride-based resin can be used at present. For example, acetonitrile tributyl citrate (ATBC), glycerin diethyl laurate (GDAML), dibutyl sebacate (DBS), dioctyl sebacate, and diethylated monoglyceride may be mentioned. (DALG) and so on. The plasticizer is generally used in a ratio of 500 to 100,000 ppm, and most preferably 5,000 to 80,000 ppm, based on the mass basis.

(stabilizer)

As a stabilizer, a stabilizer contained in a vinylidene chloride-based resin can be used at present. For example, an epoxidized oil such as epoxidized soybean oil (ESBO) or epoxidized linseed oil (ELO); a decylamine derivative of a fatty acid alkyl ester; magnesium hydroxide; and tetrasodium pyrophosphate may be mentioned. The stabilizer is generally used in a ratio of 300 to 50000 ppm, and usually 1000 to 40,000 ppm, based on the mass basis.

〔Antioxidants〕

As an antioxidant, it is currently possible to use a vinylidene chloride resin. Contains antioxidants. For example, a phenolic antioxidant such as triethylene glycol ether-bis(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate (or "antioxidant T"); thiodipropyl Dialkyl lauryl ester (also known as "antioxidant S"), alkyl thiodipropionate having 12 to 18 alkyl groups such as di(octadecyl) thiodipropionate; and triterpene phenylphosphite A phosphite antioxidant such as an ester or a pentaerythritol diphosphite of thiodipropionate. The antioxidant may be used alone or in combination of two or more. Preferably, triethylene glycol ether-bis(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate (antioxidant T) and alkyl thiodipropionate are used in combination. The antioxidant is used in a ratio of usually from 5 to 50,000 ppm, and usually from 15 to 10,000 ppm, based on the mass of the monomer. Further, it is preferred to add a part of the antioxidant to the polymerization reaction system in advance and start the polymerization. Further, an antioxidant may be added to the polymerization reaction system, thereby stopping the polymerization reaction.

[pH adjuster]

The pH of the polymerization reaction system is preferably adjusted to pH 3 to 9, more preferably to pH 4 to 8. When pH adjustment is performed, it is preferable to use an inorganic phosphate as a pH adjuster. The inorganic phosphate is preferably an alkali metal salt such as phosphoric acid, metaphosphate or polyphosphoric acid, or a phosphate such as an alkaline earth metal salt. For example, sodium pyrophosphate, potassium pyrophosphate, disodium dihydrogen pyrophosphate, dipotassium dihydrogen phosphate, monosodium phosphate, and monopotassium phosphate may be mentioned, and hydrates of these may also be used. In particular, it is preferred to use sodium pyrophosphate and disodium dihydrogen pyrophosphate or to use a combination of sodium pyrophosphate and monosodium phosphate to adjust the pH of the polymerization reaction system. The pH adjuster is generally used in a ratio of from 1 to 10,000 ppm, and usually from 10 to 1,000 ppm, based on the mass of the monomer.

(lubricant)

The vinylidene chloride-based resin which is characterized by a vinylidene chloride-based resin film having a shear adhesion of 5 kgf or more at a temperature of 13 ° C, particularly for use in a wrap film, does not need to contain a lubricant, but is used for automatic filling and packaging. When used, it may contain lubricant as needed.

As the lubricant, a lubricant contained in a vinylidene chloride-based resin can be selected at present. For example, an inorganic lubricant such as carbon dioxide, zeolite or calcium carbonate, or an organic lubricant such as a saturated fatty acid decylamine, an unsaturated fatty acid decylamine or a substituted decylamine may be mentioned. The monomer mass basis content of the lubricant is generally from 100 to 10,000 ppm, preferably from 150 to 7,000 ppm, more preferably from 200 to 5000 ppm.

[Other additives]

In addition to the specifically specified additives, other additives may be contained in the process of preparing the vinylidene chloride-based resin, that is, in the polymerization stage. As other additives, various additives contained in the vinylidene chloride-based resin can be selected at present, and the content thereof can be determined as appropriate. For example, the titanium dioxide pigment which is also a filler has an effect of preventing discoloration of food contents such as sausages due to ultraviolet rays, but it is also likely to cause resin decomposition products to adhere to the mold outlet. Therefore, it is necessary to select an optimum additive and its content depending on the application.

[suspended polymerization]

Forming a vinylidene chloride-based resin of a vinylidene chloride-based resin film having a shear adhesion of 5 kgf or more at a temperature of 13 ° C, and suspending it The floatation polymerization method is not particularly limited, and suspension polymerization can be carried out batchwise or continuously under the conditions of a polymerization temperature of 20 to 95 ° C and a polymerization pressure of normal pressure of 1 MPa. Specifically, for example, in a stainless steel reactor (polymerizer), a suspending agent (aqueous solution) and a pH adjuster may be dissolved in an aqueous medium such as deionized water or distilled water, and the air in the system may be replaced as needed. A gaseous environment such as nitrogen or argon. Next, an additive such as a polymerization initiator, a stabilizer, a plasticizer, and an adhesion promoter added as needed is dissolved in a mixed monomer of vinylidene chloride and a comonomer, and is pressed into the aqueous medium to form a suspension. That is, a spare raw material mixture. Next, the alternate raw material mixture is stirred by a stirrer to form a mixed monomer droplet of vinylidene chloride and a comonomer, and at this time, polymerization is generally started by raising the temperature. Further, the polymerization reaction is continued while adjusting the temperature (preferably, continuously increasing the temperature). The polymerization temperature and the polymerization time are determined as appropriate depending on the type and amount of the vinylidene chloride and the comonomer, and the type and amount of the polymerization initiator. Generally, the polymerization is carried out at a temperature of 25 to 90 ° C, preferably 30 to 85 ° C. ~100 hours, preferably 2 to 60 hours, more preferably 3 to 50 hours. After the polymerization reaction, the antioxidant may be introduced into the polymerization reaction system to stop the polymerization. After the completion of the polymerization and dusting, the slurry containing the vinylidene chloride-based resin is recovered, and after dehydration, washing and drying, a vinylidene chloride-based resin is obtained.

3. Vinylidene chloride resin film

The present invention is characterized in that it is a vinylidene chloride-based resin film having a shear adhesion of 5 kgf or more at a temperature of 13 ° C, and is a vinylidene chloride which can be used for a wrap film or the like which is excellent in adhesion to a packaged article and a film. a resin-like film which is made of a vinylidene chloride-based resin and contains as needed A vinylidene chloride-based resin composition of the agent and/or other resin is formed.

[vinylidene chloride resin composition]

When a vinylidene chloride-based resin film is formed from a vinylidene chloride-based resin, the properties of the vinylidene chloride-based resin film are balanced for the purpose, and for example, a plasticizer, a stabilizer, an antioxidant, an ultraviolet absorber, or the like may be contained. Adhesives, antistatic agents, anti-adhesives, anti-fogging agents, antibacterial agents, fillers (fillers), pigments, and lubricants for use and needs. The vinylidene chloride-based resin prepared by the suspension polymerization described above contains various components such as a stabilizer and a plasticizer which are added during the polymerization reaction, and therefore, various vinylidene chloride resin films can be used according to the requirements. Further, various components added during the polymerization reaction are added, or various components which are not added during the polymerization reaction are newly added to the vinylidene chloride-based resin to form a vinylidene chloride-based resin composition having a desired composition. As for the amount of the component added to the vinylidene chloride-based resin, it can be determined as appropriate depending on the type of the component and the characteristics of the vinylidene chloride resin film required by the person.

[other aggregates]

In the vinylidene chloride-based resin composition, if necessary, other polymers may be contained as the resin component in addition to the vinylidene chloride-based resin. Thereby, the extrusion processability of the vinylidene chloride-based resin can be improved, or the properties of the vinylidene chloride-based resin film formed of the vinylidene chloride-based resin can be improved in a balanced manner. As other polymers, ethylene can be cited. a vinyl acetate copolymer; a copolymer of ethylene and acrylic acid, methacrylic acid or an alkyl ester thereof; or MBS resin (methyl methacrylate, butadiene, styrene copolymer) and the like. When the content of the other polymer is contained, the content thereof is not particularly limited, and is usually 0.1 to 20 parts by mass, and usually 1 to 15 parts by mass, per 100 parts by mass of the vinylidene chloride-based resin.

The thickness of the vinylidene chloride-based resin film of the present invention is not particularly limited, but is generally 1 to 50 μm, preferably 4 to 45 μm, and more preferably 7 to 40 μm. If the thickness is too thick, the cutting property may be insufficient or the film feel may be deteriorated. If the thickness is too thin, the film may be easily broken.

[Shear adhesion at 13 ° C]

The vinylidene chloride-based resin film of the present invention is characterized in that the shear adhesive strength at a temperature of 13 ° C is 5 kgf or more. Since the shear-bonding force of the vinylidene chloride-based resin film is 5 kgf or more, it is possible to provide a sufficient adhesion to foods such as dishes and the like, and particularly to store and store foods in a refrigerator, and the pull-out property and transparency are not inferior. A vinylidene chloride resin film. The shear adhesive strength of the vinylidene chloride-based resin film at a temperature of 13 ° C is preferably 5.5 kgf or more, and more preferably 6 kgf or more. The upper limit of the shear adhesive strength of the vinylidene chloride-based resin film at a temperature of 13 ° C is not particularly specified, but the viewpoint of good pull-out property and transparency is generally 30 kgf, and most of them are 15 kgf, depending on the application. It can be 10kgf or 8kgf.

[Measurement method of shear adhesion at 13 °C]

The measurement method of the shear adhesive strength of the vinylidene chloride-based resin film at a temperature of 13 ° C is as follows. That is, it is stored in a constant temperature room at a temperature of 13 ° C. A film having a width of 50 mm and a length of 155 mm was cut out as a sample film on an hour-old vinylidene chloride resin film. In a temperature of 13 ° C, a rectangular open rectangular box made of a mirror stainless steel plate having a surface roughness Ra of 0.05 μm and a thickness of 2 mm and having a length of 125 mm, a width of 290 mm, and a height of 90 mm is placed in a substantially central portion in the width direction of the box. The sample film was placed in the longitudinal direction of the box and pressed with a finger, and the two ends of the sample film were attached to both sides of the stainless steel box, and respectively hanged 15 mm (width 50 mm) toward the height of the box. Next, using a Tensilon universal testing machine, the center portion of the sample film was pressed at a speed of φ 45 mm and a speed of 50 mm/min. The maximum value of the load load when the sample film was peeled off from the sealing surface of the stainless steel case in the non-ruptured state was measured, and this was taken as the shear adhesive force (unit: kgf) of the vinylidene chloride resin film at a temperature of 13 °C.

The present invention is characterized in that it is a vinylidene chloride-based resin film having a shear adhesion of 5 kgf or more at a temperature of 13 ° C, and is a vinylidene chloride which can be used for a wrap film or the like which is excellent in adhesion to a packaged article and a film. The resin-like film is coated with a tackifier such as a liquid paraffin on the surface of the film in order to achieve the above-described adhesiveness as in the prior art. However, it is also possible to use a vinylidene chloride-based resin film which is coated with a tackifier on the surface of the film as needed.

[pull out]

The present invention is characterized in that a vinylidene chloride-based resin film having a shear adhesion of 5 kgf or more at a temperature of 13 ° C has a good pull-out property, and the film can be easily pulled out from a carton stored on a paper tube. The pull-out property of the vinylidene chloride-based resin film can be evaluated by the following method. That is, it will be wound on a 36mm outer diameter paper tube. The vinylidene chloride-based resin film was cut into a 30-cm-wide film and placed in a commercially available plastic wrapper (manufactured by Wu Yu Co., Ltd.), and stored in a constant temperature room at a temperature of 23 ° C for 24 hours, and then evaluated by hand. . The evaluation criteria are as follows. If the evaluation is "◎", the pull-out is good.

<Evaluation Benchmark>

◎: The film is not sticky, and the film can be smoothly pulled out.

○: The film is basically not sticky and can be pulled out.

×: The film is sticky, and sometimes the film falls out of the box together with the paper tube.

[transparency]

The present invention is characterized in that a vinylidene chloride-based resin film having a shear adhesion of 5 kgf or more at a temperature of 13 ° C is excellent in transparency. The transparency of the film can be evaluated by the following method. In other words, the haze value (HAZE) of the vinylidene chloride-based resin film after storage in a constant temperature room at a temperature of 23 ° C for 24 hours was measured, and when the value was 2% or less, it was evaluated that the vinylidene chloride resin film was transparent. When the haze value exceeds 2%, it is not possible to evaluate that the vinylidene chloride-based resin film is transparent, and in particular, when it exceeds 5%, it is evaluated as opaque.

4. Method for producing a film formed of a vinylidene chloride-based resin

The present invention is characterized in that a film formed of a vinylidene chloride-based resin having a shear adhesion of 5 kgf or more at a temperature of 13 ° C can be produced by a known film production method, and the production method thereof is not particularly limited. From the viewpoint of obtaining a film excellent in adhesion and effectively and stably, it is preferable to be as follows The method for producing a vinylidene chloride-based resin film is characterized by comprising the following steps 1 and 2: 1) suspension having a content of less than 300 ppm based on the mass of the monomer component forming the vinylidene chloride-based resin a step of suspending polymerization in an aqueous medium to prepare a vinylidene chloride-based resin in a step 1; and 2) melt-extruding a vinylidene chloride-based resin composition containing a vinylidene chloride-based resin, and further extending the mixture In the second step, the shear adhesive strength at a temperature of 13 ° C is 5 kgf or more.

That is, the present invention is characterized by a vinylidene chloride-based resin film having a shear adhesion of 5 kgf or more at a temperature of 13 ° C, preferably based on the quality of the monomer component present in the presence of the vinylidene chloride-based resin (Step 1). a suspension polymerization polymerization in an aqueous medium under a suspension agent having a content of less than 300 ppm to prepare a vinylidene chloride-based resin, and preparing a vinylidene chloride-based resin composition containing a vinylidene chloride-based resin to be melted and extruded. It is prepared by further expanding as needed, and it is more preferable to carry out the process of melt-extruding the vinylidene chloride-based resin composition (step 2) and extending it.

Specifically, the vinylidene chloride-based resin composition containing the following materials is melt-extruded in a manner of a suspension of less than 300 ppm based on the mass of the monomer component forming the vinylidene chloride-based resin. A vinylidene chloride-based resin prepared by suspension polymerization in an aqueous medium under an agent; and an additive and/or other resin as needed as described above. More specifically, a Henschel high-speed agitator, a vane type agitator, and a vinylidene chloride-based resin which forms a vinylidene chloride-based resin composition, and additives and/or other resins (these are collectively referred to as "raw materials") are used. Spiral band a well-known dry mixing device such as a blender, which is heated and mixed at a normal temperature of ~80 ° C, depending on the situation or at a temperature of over 80 ° C; or a screw feeder is used in the hopper device of the extruder. These raw materials are mixed and supplied to the extruder as a raw material of the powder mixture by these methods, or the raw material which is extruded into a pellet shape is supplied to the extruder, and then melt-extruded into a film shape. The melt extrusion is performed by heating and melting the raw material in a cylinder, and extruding it by a T die or a ring die (round die) to obtain a flat film or a tubular film. The tubular film may also be cut along the direction of the extrusion axis as needed to form a single-layer thick or double-layered flat film.

Then, the flat film or the tubular film can be uniaxially or biaxially stretched by a well-known stretching method such as a flat film method, a roll method, and an expansion method, thereby obtaining a vinylidene chloride-based resin film. It is not particularly limited, but is preferably an expansion method. In addition, after the tubular film is stretched, it may be cut along the direction of the extrusion axis as needed to form a flat film having a single layer thickness or a double thickness. The extension ratio can be determined as appropriate, and is not particularly limited, but the vertical (or "MD") and the horizontal (or "TD") are generally 2 to 6 times, preferably 2.5 to 5.5 times.

According to the present invention, in the steps 1 and 2, the method for producing a vinylidene chloride-based resin film containing no tackifier can be used to produce the second embodiment of the present invention characterized by a shear adhesion of 5 kgf or more at a temperature of 13 ° C. A vinyl chloride resin film. Further, according to the present invention, in the step 1 of preparing a vinylidene chloride-based resin, the method for producing a vinylidene chloride-based resin film which is subjected to suspension polymerization in the presence of a tackifier can be used to produce the present invention, which is characterized by a temperature of 13 ° C. A vinylidene chloride resin film having a bonding strength of 5 kgf or more is sheared.

Example

Hereinafter, the present invention will be further described by way of examples and comparative examples, but the present invention is not limited to the examples. In the examples and comparative examples, the properties of the resin raw materials and the film or the physical properties were measured as follows.

〔membrane thickness〕

The thickness of the vinylidene chloride-based resin film was measured using a gauge of 0.001 mm and manufactured by Teclock Co., Ltd.

[Shear adhesion at 13 ° C]

The shear adhesive strength of the vinylidene chloride-based resin film at a temperature of 13 ° C is 50 mm in width and 155 mm in length from a vinylidene chloride resin film stored in a thermostatic chamber at a temperature of 13 ° C for 24 hours or more as described above. A sample film of a size and a rectangular opening made of a mirror-finish stainless steel plate having a surface roughness Ra of 0.05 μm and a thickness of 2 mm and having a length of 125 mm, a width of 290 mm, and a height of 90 mm, and using a TENSILON universal testing machine manufactured by A&D Co., Ltd. The RTG-1210 performs measurements.

[pull out]

The pull-out property of the vinylidene chloride-based resin film was evaluated by the following method. In other words, the vinylidene chloride resin film which was wound on a paper tube having an outer diameter of 36 mm was cut into a width of 30 cm, and placed in a commercially available plastic wrapper (manufactured by Wu Yu Co., Ltd.), and stored in a constant temperature room at a temperature of 23 ° C. After 24 hours, the evaluation was carried out by hand. The evaluation criteria are as follows. If the evaluation is "◎", it means pulling out. Good sex.

<Evaluation Benchmark>

◎: The film is not sticky, and the film can be smoothly pulled out.

○: The film is basically not sticky and can be pulled out.

×: The film is sticky, and sometimes the film falls out of the box together with the paper tube.

[transparency]

The transparency of the film was evaluated by the following method. In other words, the haze value (HAZE) of the vinylidene chloride-based resin film after storage in a constant temperature room at a temperature of 23 ° C for 24 hours was measured, and when the value was 2% or less, it was evaluated that the vinylidene chloride resin film was transparent.

[Example 1] (Modulation of vinylidene chloride resin)

In a stainless steel 20 L autoclave having a paddle type agitator, 1.062 g of methylcellulose dissolved as a suspending agent, and 2.4 g of sodium pyrophosphate 10 hydrate as a pH adjuster, sodium dihydrogen pyrophosphate 10 hydrate were placed. 2.4 g of deionized water was 7700 g, and the reaction system was replaced with nitrogen. Next, 10 g of diisopropyl peroxydicarbonate as a polymerization initiator, 295 g of tributyl citrate as a plasticizer, 161.0 g of epoxidized soybean oil as a stabilizer, and triethylene glycol as an antioxidant. Alcohol ether-bis(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate (manufactured by Ciba-Geigy Co., Ltd., trade name IRGANOX (registered trademark) 245, antioxidant T) 0.166 g, pressed Dissolved with dichloro A mixture of 5,453 g of ethylene and 1197 g of vinyl chloride (the content ratio of vinylidene chloride was 82% by mass) was used as a backup raw material mixture. Regarding the suspending agent in the alternate raw material mixture, the content (hereinafter referred to as "monomer basis") is 250 ppm based on the mass of the monomer, that is, the monomer component forming the prepared vinylidene chloride-based resin, to the aqueous medium. Based on the mass, the content (hereinafter referred to as "aqueous medium standard") was 216 ppm, and the content (hereinafter referred to as "total mass basis") was 112 ppm based on the total mass including the aqueous medium.

While stirring these alternate raw material mixtures, the temperature was raised to 47 ° C and polymerization was started, and the temperature was continuously raised over 22 hours until the temperature reached 57 ° C, and then the temperature was maintained, and the polymerization was further carried out for 5 hours. Further, when the preparation was completed, the pH of the polymerization reaction system was adjusted to 7.2. To stop the polymerization, triethylene glycol ether-bis(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate (antioxidant T) 1.35 g, and thiodipropionic acid dilaurin 1.35 g of the ester (DLTDP, antioxidant S) was dissolved in 50 g of a vinylidene chloride monomer, and it was pressed into the reaction system. After stirring for 1 hour, the internal pressure was released, and the polymer slurry was taken out from the autoclave. After the obtained slurry was dehydrated, it was dried by a dryer at a temperature of 50 ° C for 20 hours to obtain a vinylidene chloride-based resin (1) (vinylidene chloride-vinyl chloride copolymer) powder. The polymer yield was 87.5%.

(Manufacture of a vinylidene chloride resin film)

The vinylidene chloride-based resin (1) was melt-extruded into a tubular film using an annular die having a temperature of 167 ° C and a diameter of 40 mm. After cooling, propylene glycol was injected into the tubular film as an opening agent. Secondly, the compressed air is sealed in the tubular film, thereby expanding 3 times in the longitudinal direction and 4 times in the lateral direction, and then using the coil. The roll was taken up on a paper tube having an outer diameter of 36 mm to obtain a vinylidene chloride resin film having a thickness of 30 μm and a width of 110 mm. The obtained vinylidene chloride-based resin film is transparent, and can be easily pulled out from the paper tube on which the film is taken up, and has a good pull-out property. The measurement results of the suspending agent content (monomer basis and total mass basis) of the vinylidene chloride-based resin film, the film thickness, and the shear adhesive force at 13 ° C (hereinafter referred to as "shear adhesion") are shown in Table 1. Shown.

[Embodiment 2]

A vinylidene chloride-based resin film was obtained in the same manner as in Example 1 except that the thickness of the obtained vinylidene chloride resin film was changed to 10 μm. The obtained vinylidene chloride-based resin film is transparent and has excellent pull-out properties. The measurement results of the suspending agent content, the film thickness, and the shear adhesive strength of the vinylidene chloride-based resin film are shown in Table 1.

[Example 3]

When preparing a vinylidene chloride-based resin, 1.33 g of methylcellulose was used as a suspending agent, and at the same time as a polymerization initiator, a plasticizer, a stabilizer, an antioxidant, and a mixed monomer, 5.2 g of mobile paraffin was used as a viscosity-increasing agent. In the same manner as in Example 1, a vinylidene chloride-based resin was prepared to obtain a vinylidene chloride-based resin (2) (vinylidene chloride-vinyl chloride copolymer) powder. The mass ratio of the suspending agent to the mixed monomer was 200 ppm, and the total mass basis was 90 ppm. Further, the mass of the tackifier relative to the mixed monomer was 782 ppm, and the total mass basis was 351 ppm. Then, using the vinylidene chloride-based resin (2), the melt extrusion speed was adjusted, and as in the first embodiment, a thickness of 20 μm and a width were obtained. 110mm vinylidene chloride resin film. The obtained vinylidene chloride-based resin film is transparent and has excellent pull-out properties. The measurement results of the suspending agent content, the tackifier content (monomer quality standard content, the same below), the film thickness, and the shear adhesive strength of the vinylidene chloride resin film are shown in Table 1.

[Example 4]

In the same manner as in Example 3, a vinylidene chloride-based resin was prepared to obtain a vinylidene chloride-based resin (3), in the same manner as in Example 3, except that 0.97 g of methylcellulose was used as a suspending agent. Partially dichloroethylene. Vinyl chloride copolymer) powder. The mass ratio of the suspending agent to the mixed monomer was 150 ppm, and the total mass basis was 67 ppm. Further, the mass of the tackifier relative to the mixed monomer was 782 ppm, and the total mass basis was 351 ppm. Then, a vinylidene chloride-based resin film (3) was used, and a vinylidene chloride-based resin film having a thickness of 20 μm was obtained in the same manner as in Example 3. The obtained vinylidene chloride-based resin film is transparent and has excellent pull-out properties. The measurement results of the suspending agent content, the tackifier content, the film thickness, and the shear adhesive strength of the vinylidene chloride-based resin film are shown in Table 1.

[Comparative Example 1]

When preparing a vinylidene chloride-based resin, 2.68 g of methylcellulose was used as a suspending agent, and at the same time as a polymerization initiator, a plasticizer, a stabilizer, an antioxidant, and a mixed monomer, 5.2 g of mobile paraffin was used as a viscosity-increasing agent. In the same manner as in Example 1, a vinylidene chloride-based resin was prepared to obtain a vinylidene chloride-based resin (4) (vinylidene chloride-vinyl chloride copolymer) powder. Suspension The mass basis of the agent relative to the mixed monomer was 403 ppm, and the total mass basis was 181 ppm. Further, the mass of the tackifier relative to the mixed monomer was 782 ppm, and the total mass basis was 351 ppm. Then, a vinylidene chloride-based resin film having a thickness of 30 μm and a width of 110 mm was obtained in the same manner as in Example 1 using a vinylidene chloride-based resin (4). The measurement results of the suspending agent content, the tackifier content, the film thickness, and the shear adhesive strength of the vinylidene chloride-based resin film are shown in Table 1.

[Comparative Example 2]

In the same manner as in Example 3, a vinylidene chloride-based resin was prepared in the same manner as in Example 3, except that 2.68 g of methyl cellulose was used as a suspending agent, and a vinylidene chloride-based resin (5) was obtained. Partially dichloroethylene. Vinyl chloride copolymer) powder. The mass basis of the suspending agent relative to the mixed monomer was 403 ppm and the total mass basis was 181 ppm. Further, the mass of the tackifier relative to the mixed monomer was 782 ppm, and the total mass basis was 351 ppm. Then, a vinylidene chloride-based resin film (5) was used, and a vinylidene chloride-based resin film having a thickness of 20 μm was obtained in the same manner as in Example 3. The measurement results of the suspending agent content, the tackifier content, the film thickness, and the shear adhesive strength of the vinylidene chloride-based resin film are shown in Table 1.

As can be seen from Table 1, the vinylidene chloride-based resin is prepared by suspension polymerization in an aqueous medium in the presence of a suspension agent having a content of less than 300 ppm based on the mass of the monomer component forming the resin, that is, Example 1~ In the vinylidene chloride-based resin film of the present invention, the shear adhesive strength at a temperature of 13 ° C is 5 kgf or more, and therefore it is a sufficient adhesion to food containers such as dishes and the like, particularly in a refrigerator. And a vinylidene chloride resin film which is not inferior in pull-out property and transparency.

In particular, the vinylidene chloride-based resin is prepared by suspension polymerization in the presence of a suspension having a suspending agent content of less than 150 ppm based on the total mass including the aqueous medium, that is, the dichlorochloride of Examples 1 and 2. In the vinyl resin film, the vinylidene chloride resin film does not contain a tackifier, but the shear adhesive strength at a temperature of 13 ° C is 5.5 kgf and 5.7 kgf, and has sufficient adhesion to dishes and the like.

Further, it is also known that when the vinylidene chloride-based resin film further contains a tackifier, that is, in the vinylidene chloride-based resin film of Examples 3 and 4, the shear adhesive strength at a temperature of 13 ° C is 6.2 kgf and 7.2 kgf. Therefore, there is sufficient adhesion to dishes and the like.

On the other hand, when the vinylidene chloride-based resin was prepared by suspension polymerization in a suspension having a content of 403 ppm based on the mass of the monomer component forming the resin, that is, the vinylidene chloride of Comparative Examples 1 and 2 was prepared. In the resin-like film, although the vinylidene chloride-based resin film contains a tackifier, the shear adhesive strength at a temperature of 13 ° C is 4.2 kgf and 4.6 kgf, so that foods for storing foods, especially in the refrigerator, are stored in the refrigerator. The container or the like does not have sufficient adhesion.

Industrial availability

According to the present invention, a vinylidene chloride-based resin film characterized by a shear adhesion of 5 kgf or more at a temperature of 13 ° C, in particular, a vinylidene chloride-based resin is present in the presence of a monomer component in which the resin is formed, and the content is insufficient. The film prepared by suspension polymerization in an aqueous medium under a suspension of 300 ppm provides a sufficient adhesion to the food container such as tableware, especially in a refrigerator, and is pulled out and transparent. It is a non-inferior vinylidene chloride resin film, so it is highly industrially applicable.

Further, according to the present invention, it is characterized in that it comprises the following steps 1 and 2: 1) in an aqueous medium in the presence of a suspending agent having a content of less than 300 ppm based on the mass of the monomer component forming the vinylidene chloride-based resin. Suspension polymerization, Step 1 of preparing a vinylidene chloride-based resin; and 2) melt-extruding a vinylidene chloride-based resin composition containing a vinylidene chloride-based resin, and further extending the step 2, shear bonding at a temperature of 13 ° C A method for producing a vinylidene chloride-based resin film having a force of 5 kgf or more, and a method for easily producing a vinylidene chloride-based resin film having a food container for storing foods in a refrigerator, etc. It is sufficiently close, and the pull-out property and transparency are not inferior, so the industrial use possibility is high.

Claims (10)

A vinylidene chloride-based resin film characterized in that the shear adhesive strength at a temperature of 13 ° C is 5 kgf or more. The vinylidene chloride-based resin film according to claim 1, wherein the vinylidene chloride-based resin is a suspending agent having a content of less than 300 ppm based on the mass of the monomer component forming the resin. It is prepared by suspension polymerization in an aqueous medium. The vinylidene chloride-based resin film according to claim 2, wherein the suspending agent content is less than 150 ppm based on the total mass including the aqueous medium. The vinylidene chloride-based resin film according to any one of claims 1 to 3, which does not contain a tackifier. The vinylidene chloride-based resin film according to any one of claims 1 to 3, which contains a tackifier. The vinylidene chloride-based resin film according to claim 5, wherein the vinylidene chloride-based resin is prepared by suspension polymerization in the presence of a tackifier. For example, the partial dichloroethane described in any one of claims 1 to 6 The vinyl resin film, wherein the vinylidene chloride resin is a vinylidene chloride π-chloroethylene copolymer. A method for producing a vinylidene chloride-based resin film, comprising the following steps 1 and 2: 1) a suspending agent having a content of less than 300 ppm based on the mass of a monomer component forming a vinylidene chloride-based resin a step of suspending polymerization in an aqueous medium to prepare a vinylidene chloride-based resin; and 2) a step of melt-extruding a vinylidene chloride-based resin composition containing a vinylidene chloride-based resin, and then extending the mixture 2. The shear adhesion at a temperature of 13 ° C is 5 kgf or more. The method for producing a vinylidene chloride-based resin film according to claim 8, wherein the step 1 and the step 2 are carried out without a tackifier. The method for producing a vinylidene chloride-based resin film according to claim 8, wherein the step 1 is carried out by suspension polymerization in the presence of a tackifier.