WO2003006548A1 - Composition of vinylidene chloride copolymer particles - Google Patents

Abstract

A composition of vinylidene chloride copolymer particles which, when extruded into a film or sheet, is capable of being stably extruded evenly and which has improved thermal stability. The vinylidene chloride copolymer particles are characterized by having a weight-average particle diameter of 200 to 500 µm and having a content of particles having a particle diameter smaller than 150 µm of 3 wt.% or lower. The vinylidene chloride copolymer composition is characterized by being obtained by compounding the copolymer particles with an ethylene/vinyl acetate copolymer and an ester of an α,ß-unsaturated carboxylic acid.

Description

 Description Vinylidene chloride copolymer particle composition <Technical field>

 The present invention relates to a vinylidene chloride-based copolymer composition, and a film and a sheet using the same. Background technology>

 Vinylidene chloride-based copolymers have excellent gas barrier properties against water vapor and oxygen and excellent oil resistance, and are therefore particularly suitably used for food packaging films and the like. Methods for producing vinylidene chloride-based copolymers used in food packaging films include suspension polymerization and emulsion polymerization, but the suspension polymerization method is used because there are no problems such as residual emulsifiers. . The suspension polymerization method is a method in which a mixed and dispersed oil droplet of vinylidene chloride and a polymerizable vinyl monomer is formed by mechanical stirring in water containing a dispersant, and then a polymerization initiator is added to carry out polymerization.

 When a food packaging film is to be obtained, the vinylidene chloride copolymer obtained by suspension polymerization is stretched by a normal melt molding method, or is stretched into a single-layer or multilayer film. Processed.

Generally, vinylidene chloride copolymers obtained by suspension polymerization are known to be in the form of particles as disclosed in Japanese Patent Publication No. 55-182242, Japanese Patent Publication No. 57-97575, and the like. A certain force Only a copolymer particle composition having a wide particle size distribution and a large specific gravity can be obtained. Also, USP 3,067,722 discloses a method for obtaining a bi-lidene-based copolymer particle composition by polymerizing biel chloride and vinylidene chloride-based resin by a combination of bulk polymerization and suspension polymerization. Have been. However, in this method, the resin could not be extruded stably, and it was difficult to obtain a film having a uniform thickness. That is, the amount of the copolymer filled from the die into the barrel fluctuates due to the variation in the shape and size of the bilidene chloride-based copolymer, which affects the discharge amount of the extruder. This allows The pressure of the film fluctuates, resulting in uneven film thickness of the extruded film. When a high-frequency seal is applied to obtain a film package with a non-uniform film thickness, the sealing strength is not uniform, and the production yield is likely to decrease. To solve this problem, it is necessary to stably supply a certain amount of the copolymer particle composition into the extruder. However, no technology specifically addressed this problem.

 On the other hand, vinylidene chloride-based copolymers are easily thermally decomposed during extrusion, causing carbides to flow out due to the thermal decomposition and the resulting film to turn yellow. Conventionally, the following proposals have been made to improve thermal stability.

By blending a copolymer of ethylene and vinyl acetate (hereinafter abbreviated as EVA) with a vinylidene chloride copolymer, the thermal stability during extrusion and the low-temperature properties of the obtained film are improved. Japanese Patent Application Laid-Open No. 55-104442 (EVA containing from about 5 to about 18% by weight of vinyl acetate and from about 0.1 to about 1.0 dg Z) About 5 to about 40% by weight), Japanese Patent Publication No. 3-503320 (combination of about 0.01 to about 2% by weight of EVA with a vinyl acetate content of about 28%), Japanese Patent Publication No. 40-161241 (pound having a vinyl acetate content of 3 to 20% is blended at 2 to 20% by weight), Japanese Patent Application Laid-Open No. 1-131268 (Japanese Patent Application Laid-open No. 3 blended about 3 0 percent by weight of EVA), re-published patent WO 9 6/3 4 0 5 0 (ethylene content 6 5-8 5 weight ⁰ /. of EVA 1-5-3 parts by mass). However, these methods did not provide sufficient thermal stability. On the other hand, as another method for improving extrusion processability, Japanese Patent Application Laid-Open No. 53-16753 (styrene-based polymer containing styrene having a specific softening point and melt viscosity or styrene-based polymer) is disclosed. Methyl methacrylate polymer blended), Patent No. 294 791 31 (Add at least 0.5 parts by weight of methyl methacrylate-butyl acrylate-styrene terpolymer to vinylidene chloride-methyl acrylate copolymer) ), Patent Publication No. 3 078 663 (comprising polymers derived from butyl acrylate, butyl methacrylate and methyl methacrylate), and Japanese Patent Application Laid-Open No. Japanese Patent Application Laid-Open No. 8-209926 (comprising an acrylate Z styrene copolymer) and Japanese Patent Application Laid-Open No. 7-268816 (styrene component) , Ac Butyl acrylate component Methyl methacrylate Styrene-based copolymer resin composed of

 However, according to these methods, even if the thermal stability is satisfied by blending various copolymers and additives, the suitability for food packaging and filling machines obtained from vinylidene chloride-based copolymers, gas barrier uniformity, etc. Characteristics are apt to deteriorate. On the other hand, when the molecular weight of the vinylidene chloride-based copolymer is reduced, the mechanical strength of the film decreases. In addition, if the extrusion process is performed continuously, thermal degradation products generated inside the extruder will affect the film obtained by adhering to the screw or die. Need to do. This reduces the time spent on extrusion production, thereby reducing productivity.

 An object of the present invention is to provide a vinylidene chloride-based copolymer having excellent extrusion stability and, as a result, a film having excellent film thickness uniformity, and a vinylidene chloride-based resin having excellent heat stability and extrusion stability. It is intended to provide a composition.

<Disclosure of Invention>

 In order to solve the above problems, the present inventors have proposed a vinylidene chloride-based copolymer composition having a specific particle size obtained from suspension polymerization and containing a small amount of fine particles of a certain amount or less, or It has been found that a vinylidene chloride-based copolymer particle composition having a bulk specific gravity may be used. Further, a composition obtained by blending the specific particle composition with a copolymer of ethylene monoacetate vinyl chloride and a copolymer obtained from two or more kinds of monomers selected from the group consisting of 3) unsaturated carboxylic acid ester monomers. It has been found that stable extrusion properties can be further improved by using the product, and the present invention has been accomplished.

That is, the main invention of the present application is that the weight average particle diameter is in the range of 200 to 500 / m and the ratio of particles having a particle diameter of less than 150 μm is 3 wt% or less. A vinylidene chloride copolymer particle composition characterized by the following, 100 parts by mass of the composition (A), and ethylene-vinyl acetate copolymer (B 1) 0.05 to 2.95. A composition comprising: parts by mass and 0.05 to 2.95 parts by mass of a copolymer (B 2) comprising two or more monomers selected from monomers of a and j3 unsaturated carboxylic acid esters And the sum of the compounding mass of (B 1) and the compounding mass of (B 2) is 3 parts by mass or less. It is a vinylidene copolymer composition.

<Best mode for carrying out the invention>

 The vinylidene chloride copolymer in the present invention is obtained by copolymerizing a vinylidene chloride monomer and a vinyl monomer copolymerizable with the monomer.

 Examples of the vinyl monomer copolymerizable with the biylidene chloride monomer include vinyl esters such as vinyl chloride chloride, vinyl acetate, and vinyl propionate; methyl acrylate, ethino acrylate, butyl acrylate, 2-ethylhexyl acrylate, and the like. Hydroxyshetinoleate tallate, hydroxypropiate / reatalylate, pheninoleate acrylate, cyclohexyl acrylate, daricidyl acrylate and methyl methacrylate, ethyl methacrylate, 2-ethyl hexyl methacrylate, hydro 'kisshet / remethacrylate, Q; such as droxyp mouth pinole methacrylate, feninole methacrylate, cyclohexinole methacrylate, and glycidinolemethacrylate; 3) unsaturated carboxylic esters Olefins such as ethylene and propylene; lauryl vinyl ethers such as methyl vinyl ether and ethynolebininoleatenore and bier ethers such as isobutyl vinyl ether; and others, itaconic acid, maleic acid, maleic anhydride, acrylonitrile, methacryloyl Examples include nitrile, styrene, methynolestyrene, a-methynolestyrene, chlorostyrene, and chloromethylstyrene. These polymerizable biel-based monomers may be used alone or as a mixture of two or more.

Of these, butyl chloride, methyl acrylate, methyl methacrylate, 2-ethylhexyl acrylate, acrylonitrile, and styrene are preferred. The vinylidene chloride-based copolymer particle composition of the present invention has a weight average particle diameter of 200 to 500 μπι. It is preferably from 230 to 400 / xm, and more preferably from 250 to 350 / xm. When the particle diameter is in this range, the extrusion load becomes constant, and stable extrusion can be performed. The resulting film thickness can be uniform. The particle size distribution can be measured with a Coulter Multisizer Single Particle Analyzer TA-II manufactured by Nikkaki Co., Ltd. In addition, the mass ratio of particles having a size of less than 150 m needs to be 3% by mass or less. If more fine particles are contained, the melt tension during extrusion processing will not be constant, and the film thickness will be non-uniform. More preferably, the content of particles of 150 / zm or less is 2.5% by mass or less.

Further or Is gravity is Shi preferred that made in view of the vinylidene chloride copolymer particle composition can be stably supply a constant amount of ^{0. 80 gZcm 3 ~l. 0 gZ} cm 3,. Preferably, it is 0.90 g / cm ^{3 to} 0.98 gZcm ³ . The bulk specific gravity can be measured based on JIS K-6722.

Further, preferable conditions of the particle composition are as follows: the weight average particle diameter is 230 to 400 μιη, and the weight ratio of the fine particles having a particle diameter of less than 150 m is 1.5 wt ° / ₀ or less, and the bulk specific gravity is 0.90 gZcm ^3. 00.98 gZc m ³ .

The weight average molecular weight of the vinylidene chloride-based copolymer particle composition is preferably about 60,000 to 200,000, and more preferably 70,000 to 150,000. More preferably, it is 80,000 to 130,000. When the content is in the above range, it is preferable from the viewpoints of thermal stability, suitability for a packing and filling machine, and gas barrier property. Two or more kinds of vinylidene chloride-based copolymer particle compositions having different weight average molecular weights may be blended at an arbitrary ratio so that the weight average molecular weight of the composition falls within the above range. The weight average molecular weight was measured using a polystyrene equivalent weight average molecular weight obtained by gel permeation chromatography. The following methods are available for obtaining the vinylidene chloride polymer particle composition of the present invention. First, the above-mentioned biylidene chloride monomer and a monomer copolymerizable therewith are copolymerized. Examples of the polymerization initiator used in the polymerization include, for example, diisopropyl peroxydicarbonate, dioctyl / peroxydicarbonate, dilauryl peroxydicarbonate, dimyristyl peroxydicarbonate, and diacetyl peroxydicarbonate. Oxydicarbonate, di-tert-butyl peroxydicarbonate, di (ethoxyxetyl) peroxydicarbonate, di (methoxyisopropyl) peroxydicarbonate, di (3 methoxybutyl) peroxydicarbonate, di ( 3 methoxy 3-methylbutyl) peroxydicarbonate, di (butoxyshethyl) peroxydicarbonate, di (2-isopropoxyshetyl) peroxydicarbonate Di- (2-ethylhexyl) baroxy dicarbonate, di- (2-isopropoxy shetyl) peroxy dicarbonate, dibenzi ^ / peroxy di-potassium ponate, di-six-hexyl-one-year-old xy-dicarbonate, zitasha V-butino-re-six Percarbonate-based initiators such as silveroxydicarbonate, etc .; tertiary butyl peroxy neodecanoate, tertiary hexyl peroxy neo decanoate, amyl peroxy neo decanoate, tertiary octyl bar Oxynedecaneate, 1-cumylperoxyneodecanate, 1-cyclohexyl 1-methylethylperoxyneodecanate, tert-butylperoxybivalate, amylperoxybivalate, Tasha Lioctyl peroxypivale, Tertiary hexinolenooxypivalate, α-cumylperoxypivalate, perhexyloxalate, ditertiary hexinoleoxypivalate, acetinolecyclohexynolesanoleforenoleperoxide, 1 · 1.3.3. Perester-based initiators such as tetramethylbutyl peroxyphenoxy acetate; lauroyl peroxide, diisopropyl oxyperoxide, and 2-ethylhexyl peroxy oxy , 3.5.5 Initiators of diasilboxides such as trimethylhexanoyl peroxide, etc .; t-butyl hydroperoxide, tert-butyltinoleperoxide, benzoinoleperoxide, benzoinoleperoxide, di-isopropyl ぺNoreoxy dicarbonate, t-butyltinolenooxyisobutyrate, t-hexyloxy Di one _t such glycolate - § Ruki helper O carboxylate diglycolate-based initiators;... 2 2, § azobisisobutyronitrile, 2-2 'Azobisu one 2 4-dimethyl-Barre Roni tolyl, 2 2, Azobis-4 methoxy 2.4 dimethylvaleronitrile, 4,4-azobis (4-monocyanopentanoic acid) 2.2, monoazobis (2-amidinopropane) hydride chloride, 2.2, azobis (N.N ') Dimethyleneisobutylamidine) An azo initiator such as chloride at the mouth; water-soluble peroxides such as potassium persulfate and ammonium persulfate; or reducing agents such as amine and sodium bisulfite. And the like. In order to make the polymerization reaction rate uniform, two or more polymerization initiators having different half-lives of 10 hours may be used in combination. These polymerization initiators can be used as they are, water emulsion, water suspension, etc. It can be used anyway.

 The amount of the initiator to be used is preferably from 100 to 7000 ppm, more preferably from 500 to 5000 ppm, based on the mixture of the vinylidene chloride monomer and the vinyl monomer. More preferably, it is 1000 to 3000 ppm.

 Next, the vinylidene chloride copolymer is polymerized to obtain a particle composition.

 In order to obtain a vinylidene chloride copolymer particle composition having a specific gravity in a specific range as in the present invention, a suspension polymerization method is preferable.

 Examples of the suspending and dispersing agent include homopolymers such as polyvinylpyrrolidone, polyacrylic acid, polyvinyl alcohol, polymethinolebininoleatenore, polyacrinoleamide, polyethyleneimine, poly (2-ethyl-2-oxazoline), and maleic anhydride. Synthetic polymers such as butyl monoacetate copolymer, various random copolymers, graft copolymers, block copolymers, macromonomers, etc .; methylcellulose, ethylcellulose, hydroxyshethylcellulose, hydroxypropynolecellulose, carboxymethylcellulose, etc. Water-soluble cellulose derivatives; natural polymer substances such as starch and gelatin. If necessary, an auxiliary stabilizer may be used in addition to the dispersion stabilizer. Examples of such co-stabilizers include a-on surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, and long-chain alcohols. Among them, methylcellulose, hydroxypropylcellulose and hydroxypropoxymethinoresenolerose are particularly preferred. The surface tension of a 0.2 wt% aqueous solution of these stabilizers at 20 ° C is preferably 5 mN / m or more from the viewpoint of the particle size to be obtained, and 6 OmN / m or less from the viewpoint of polymerization progression. Is preferred.

The addition amount of the suspension dispersant is preferably 30 ppr or more with respect to the vinylidene chloride-based monomer from the viewpoint of the stability of suspension polymerization, and 8,000 ppm or less from the viewpoint of the obtained particle size. preferable. It is more preferably from 100 to 5,000 pm, even more preferably from 200 to 3,000 pm. By setting the content in such a range, suspension stability is obtained, and the resin composition has a weight average particle diameter of 200 to 500 μm and a reduced amount of microparticles having a particle diameter of less than 150 μm. Can be produced efficiently it can. The suspension and dispersant may be added all at once or in portions, and the timing of their addition is not limited.

 In addition, since the corrosion rate of the equipment in the polymerization machine and in the post-process increases, the slurry pH of the vinylidene chloride copolymer is adjusted so that the slurry pH does not decrease too much during the initial stage or during the polymerization. An alkaline substance may be added to a necessary minimum.

 In the suspension polymerization reaction of vinylidene chloride-based monomer, vinylidene chloride-based monomer, water and a suspending and dispersing agent are charged into a polymerization machine in almost all predetermined amounts and stirred to form vinylidene chloride-based monomer droplets. After going, let it start.

 In order to improve the progress of the polymerization, it is preferable to set the inside of the reactor to an atmosphere such as a nitrogen gas or an argon gas. The polymerization temperature and polymerization time may be determined as appropriate depending on the type and amount of vinylidene chloride and the polymerizable vinyl monomer, the type and amount of the polymerization initiator, and the type and amount of the chain transfer agent, but generally from 30 ° C to 90 ° C. It is preferably 10 hours to 100 hours at ° C, more preferably 20 hours to 60 hours, and still more preferably 25 hours to 50 hours.

 The vinylidene chloride copolymer in the present invention includes a lubricant, a gelling improver, a pH adjuster, a chain transfer agent, an antistatic agent, a crosslinking agent, a defoaming agent, a stabilizer, a filler, an antioxidant, An additive such as a scale adhesion inhibitor may be appropriately added. These can be added at the beginning of the polymerization, during the polymerization, or after the polymerization.

 The stirrer used in the suspension polymerization is not particularly limited, and a baffle can be used if desired. Stirrers include turbine blades, fan turbine blades, faudler blades and blue margin blades, which are usually used for the polymerization of butyl chloride monomers. It is preferable to use Buffers include finger type, cylindrical type, D type and loop type.

In order to obtain the bilidene chloride-based copolymer particles having a specific weight average particle size according to the present invention, it is necessary to reduce the interfacial tension caused by the suspending agent and to maintain the stirring speed of the stirrer in a well-balanced manner. The polymerization must be completed so that the particles do not settle or stick to the reactor or stirring blades. For this purpose, it is particularly important to control the mechanical stirring conditions.Specifically, the polymer particles are suspended by selecting the stirring speed and stirring speed. And polymerize.

 In general, the stirring speed is set to a high speed so that the polymer particles are sufficiently suspended in order to suspend the polymer particles. In this case, the polymer particles are subjected to the shear force of the stirring blade, and the polymer particle diameter is reduced. In addition, if the stirring speed is reduced to increase the polymer particle diameter, sedimentation of the polymer starts, and further, coagulation and fixation of the polymer occurs, and the entire reactor may be fixed. For this reason, in the past, it was necessary to avoid low-speed rotation and to select high-speed rotation as much as possible in order to promote stable polymerization. As a result, the polymer particles were reduced to 200 zm or less.

 In the present invention, by finding a stirring speed at which suspension polymerization proceeds stably in the vicinity of the limit for preventing the sedimentation of the polymer, a polymer particle diameter range excellent in stable extrudability was achieved.

 For example, when a Faudler blade is used, it is preferable that the stirring speed represented by the following formula (1) is 0.7 sec or more because suspension polymerization is stably performed, and if the stirring speed is 5.5 m / sec or less, the resulting weight is obtained. The particle size of the coalesced is within an appropriate range, which is preferable. Specific conditions need to be changed according to the size of the stirring scale.

 Stirring speed (mZ sec) = η · π · ά / 60 (1)

 (η: stirring blade rotation speed (r pm), π: circumference, d: stirring blade span) For example, when the stirring blade span is 40 O mm φ, 1.3 to 4 in 60 to 2001 ”15111 Approximately 2 m / sec, and in the case of 2000ιηιηφ, approximately 20-5.3 rpm at 20-50 rpm.

 In order to further stabilize the extrusion processability, the vinylidene chloride-based resin particle composition of the present invention is added to 100 parts by weight of the vinylidene chloride-based resin particle composition (A) and an ethylene-butyl acetate copolymer (100 parts by weight). B 1) and Q; / 3 A vinylidene chloride copolymer composition containing a specific amount of a copolymer (B 2) composed of two or more monomers selected from monomers of unsaturated carboxylic acid esters Good.

The ethylene monobutyl acetate copolymer (B1) used in the present invention has an ethylene content in the range of 60 to 90 wt%, more preferably 70 to 90 wt%. In order to maintain the transparency of the formed film, these ethylene contents are 90 w The ethylene content is preferably at least 60 wt% from the viewpoint of the stability of the motor load of the extruder and the barrier property of the molding film.

 The blending ratio of the copolymer (B 1) is preferably in the range of 0.05 to 2.95 parts by mass with respect to 100 parts by mass of the vinylidene chloride-based copolymer particle composition (A), and is preferably The range is from 0.1 to 2.5 parts by mass, and more preferably from 0.2 to 2.0 parts by mass. When the blending ratio of the copolymer (B 1) is 2.95 parts by mass or less, the thermal stability is improved and the barrier property is maintained. Further, when the compounding amount is 0.05 part by mass or more, the effect of suppressing outflow of the degraded product becomes sufficient, and the thermal stability is also improved.

 The melt index (Ml) of the copolymer (B 1) is preferably from 3 to 180 g / min from the viewpoint of extrusion processability and gas barrier properties. Preferably it is 5 to 160 g / min. The weight average molecular weight is preferably in the range of 30,000 to 150,000.

 The copolymer (B 2) used in the present invention is a copolymer obtained from two or more monomers selected from monomers of α and unsaturated carboxylic acid esters. In addition, the unsaturated carboxylic acid ester monomer is preferably an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms, such as butyl acrylate, propyl acrylate, ethynole acrylate, methyl acrylate, and the like. 2-ethylhexyl oleate acrylate, hydroxyshetyl acrylate, hydroxypropino acrylate, phenyl acrylate, cyclohexyl acrylate, and extrudability. From the balance of gas barrier properties and the like, butyl acrylate, ethyl acrylate, and methyl acrylate are more preferable.

Further, the alkyl methacrylate monomer is preferably an alkyl methacrylate having an alkyl group having 1 to 8 carbon atoms, such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, or hydroxyxyl. Examples include tyl methacrylate, hydroxypropynolemethacrylate, pheninolemethacrylate, cycle hex / remethacrylate, and glycidinolemethacrylate, among which are the balance between extrudability and gas barrier integrity. Methyl methacrylate, ethyl methacrylate, and butyl methacrylate are preferred. α,] 3 unsaturated carboxylic acid ester monomer copolymer (B 2) can be used as a copolymer obtained by any polymerization method such as emulsion polymerization, suspension polymerization, solution polymerization and bulk polymerization. . Among these, emulsion polymerization is preferred. Examples of the emulsion polymerization method include seed polymerization, graft polymerization, and multi-stage polymerization, and a copolymer obtained by multi-stage polymerization is particularly preferable.

 In the multistage polymerization, after forming a polymer of a core phase, a graft phase and a stepwise polymerization are performed on the core phase, and a polymerization method of sequentially forming a shell phase is performed.

 Among these, it is preferable to use a monomer having a glass transition temperature of 0 ° C or lower as a polymer, such as an alkyl acrylate, as the core phase from the viewpoint of film formation.

 The core phase is obtained by polymerizing an alkyl acrylate monomer or a monomer mixture. For example, it is preferable to use butyl acrylate, propyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, and the like. . Particularly, butyl acrylate is preferred.

 As the shell phase, a monomer or a mixture of alkyl methacrylate and alkyl acrylate is used.For example, it is preferable to use methyl methacrylate, ethyl methacrylate, butyl methacrylate, butyl acrylate, methinoreal acrylate, and the like. . Particularly, methyl methacrylate is preferred. The mass ratio of the core phase and the shell phase is in the range of 10 to 90 wt%: 90 to 10 wt%, and polymerization is carried out in an optional ratio, preferably 30 to 70 wt%: 70 to 70 wt%. To 30 wt%, more preferably 50 to 70 wt%: 30 to 50 wt%. When the ratio of the shell phase is in the above range, the copolymer is uniformly dispersed in the film, and the sealing property is maintained.

 The proportion of alkyl methacrylate in the shell phase is preferably at least 60 wt%, more preferably at least 80 wt%. When the alkyl methacrylate is in the above range, it is compatible with the vinylidene chloride-based copolymer, and a uniform dispersion of the copolymer can be obtained.

The weight average molecular weight of these copolymers (B 2) is preferably 10,000 to 500,000, More preferably, it is 30,000 to 300,000, more preferably 50,000 to 250,000.

 The above range is preferable from the viewpoints of the meltability, heat stability, uniform dispersibility, and seal strength of the vinylidene chloride copolymer composition.

 The blending ratio of the copolymer (B2) is preferably in the range of 0.05 to 2.95 parts by mass with respect to 100 parts by mass of the vinylidene chloride-based copolymer particle composition (A) in terms of extrudability. Preferably, it is in the range of 0.1 to 2.5 parts by mass, more preferably 0.2 to 2.0 parts by mass. When the blending ratio of the copolymer (B 2) is 2.95 parts by mass or less, the barrier property can be maintained while the heat stability is good. Further, when the compounding amount is 0.05 parts by mass or more, the thermal stability is improved, for example, the effect of suppressing outflow of the decomposition product is sufficient.

 Further, the total of the blending mass of the copolymer (B1) and the blending mass of the copolymer (B2) is preferably 3 parts by mass or less. It is preferably in the range of 0.2 to 2.5 parts by mass, and more preferably in the range of 0.5 to 2.0 parts by mass. When the amount is 3 parts by mass or less, the balance between heat stability and barrier property is particularly good. When the amount is 0.1 parts by mass or more, the effect of suppressing the outflow of decomposition products is high, and the thermal stability is high.

 The vinylidene chloride-based copolymer particle composition obtained by the present invention may further include a known plasticizer, heat stabilizer, processing aid, light stabilizer, pigment, lubricant, antioxidant, filler, surfactant. And the like may be further contained.

 For example, a plasticizer such as dioctinolephthalate, acetyltributyl citrate, dibutyl sebacate, dioctyl sebacate and diisobutyl adipate, or a polyester plasticizer comprising a saturated aliphatic dicarboxylic acid and a polyhydric alcohol, or epoxy Epoxy stabilizers such as oxidized soybean oil, epoxidized amayu oil, epoxidized octyl stearate, epoxy group-containing resin, amide derivatives of alkyl esters, oxidized polyethylene, noraffin wax, polyethylene wax, montan ester wax, etc. Lubricants such as waxes, fatty acid esters such as glycerin monoester, etc., and mono- and bisamides of lunar fatty acid: sorbitan fatty acid esters, polyglycerin fatty acid esters, polyoxyethylene sorbitan fatty acid esters, etc. O emissions based surfactant plasticizer such like.

The mixing ratio of the above additives is 100 mass% of the vinylidene chloride-based copolymer particle composition. The amount is preferably from about 0.01 to about 10 parts by mass, more preferably from 0.05 to 6 parts by mass, per part.

 Vitamin E, cunic acid and its salts, magnesium hydroxide, sodium pyrophosphate, sodium dihydrogen pyrophosphate, tetrasodium pyrophosphate, magnesium oxide and calcium hydroxyphosphate, and salts of ethylenediaminetetraacetic acid , Butylhydroxyanisole, pentaerythritol toletrakis [3- (3,5-di-t-ptinole-1-4-hydroxyphene) propionate], 2,2, methylene-bis- (4-methyl-6-t-ppetitheno) Nore), octadecyl-3— (3,5-di-t-butyl-4-hydroxyphenyl) propionate, ethylenebis (oxyethylene) bis [3- (5-t-butynole-14_hydroxy-1m-tolyl) propionate] , 2-t-butyl-6-(3-t-2-hydroxy-5 Methynolebenzyl) — 4-Methinolephenylis acrylate, 2- [1-(2-hydroxy-1,3,5-di-t-pentinolephenyl) ethynole] -1,4,6-di-t-pentylphenylacrylate Phenolic antioxidants, such as thiodipropionic acid; diperylthiodipropionate, dimyristyl thiodipropionate, distearyl thiodipropionate, and other thiodipropionic acid alkyl esters; pentaerythritol-tetrakis (3) Pentaerythritol thiopropionates such as lauryl monothiopropionate, thiopropionate thiopropionate and thioether ether antioxidants, tris-noylphenol phosphite, tris (mono and / or dinonyl phenyl) phosphite, 4, 4, —Isopropylidene diphenol And phosphite-based antioxidants such as norephosphite and distearylinopentaerythritoloneresiphosphite. The antioxidants used in the present invention may be used as a mixture of two or more.

 The mixing ratio of the above-mentioned heat stabilizers is 0.0005 to 0.4 part by mass with respect to 100 parts by mass of the vinylidene chloride-based copolymer particle composition in terms of improving thermal stability. Is more preferable, and more preferably 0.01 to 0.1 part by mass.

Further, various additives such as filler such as silicon oxide and calcium carbonate may be added. The additives (B 1) and (B 2) are usually mixed in powder form before processing the vinylidene chloride-based resin, but when the vinylidene chloride-based monomer is polymerized, the slurry becomes one state. Alternatively, the polymerization may be carried out after adding to the vinylidene chloride monomer before polymerization.

 Additives are adsorbed or absorbed by the vinylidene chloride copolymer during extrusion and contribute to thermal stability. Additives other than plasticizers and heat stabilizers are preferably used as needed. The mixing method is not particularly limited, and a conventional method can be applied. For example, kneading using a two-roll machine, mixing using a blender such as a blade blender and ribbon blender, mixing using a Henschel high-speed mixer, etc., and a heating mixing method exceeding 60 ° C or a low-temperature mixing method not exceeding 60 ° C And so on. In addition, the vinylidene chloride copolymer particle composition (A) and the above-mentioned additives that are added as required are mixed in advance, and the copolymer (B 1) and the copolymer (B 2) are sequentially added. You may mix. At that time, the mixed resin temperature is about 80 ° C. or less, and preferably mixed in a temperature range of 50 ° C. to room temperature, and the homogeneity of the obtained bilidene chloride copolymer-containing resin composition is improved. Preferred from the point.

When mixing at a temperature of 60 ° C. or lower and when using a copolymer (B 1) having a low ethylene content, the powdering of the mixed composition powder is performed by a combination of adding the above-mentioned resins. This prevents the powder from digging into the screw during extrusion processing, and can further reduce fluctuations in motor load and extrusion amount. When the composition obtained from the vinylidene chloride copolymer composition and the additives (B 1) and (B 2) is supplied to the extruder as a raw material, the composition is continuously fed into the on-machine hopper device. It is preferable to use a feeder that measures and supplies quantitatively. Examples of the feeder include a screw feeder, a circle feeder, an electromagnetic feeder, a weight feeder, a positive displacement feeder, and the like. Among these, a method of mixing using a gravimetric feeder is preferable. Fluctuation of the motor load during extrusion and fluctuation of the extrusion amount can be suppressed, and steady supply to the extruder becomes possible, and stable extrusion becomes possible. In addition, the effect of suppressing the adhesion of decomposition products of the resin at the outlet of the die is improved, and coloring of the resin and outflow of decomposition products can be reduced. The vinylidene chloride-based copolymer composition of the present invention is melt-extruded and stretched, or formed into a film, a sheet or the like without stretching. As the molding method, for example, an inflation extrusion molding method using a circular die can be applied. The film obtained by orientation by biaxial stretching has a heat-shrinking property and a heat-resistant film that can be applied to so-called retort conditions of 120 ° C (pressure 0.25 MPa) for 20 minutes. It can be suitably used as a system. The stretching ratio is preferably from 2.0 to 4.5 times in the longitudinal direction and from 3.0 to 5.0 times in the transverse direction. The thickness of the single film is preferably 5 to 30 μm, more preferably 10 to 25 μιη. It is also used as a double film depending on the application. The film obtained under these conditions exhibits the mechanical strength of the film at the time of packaging and filling, and provides sufficient gas barrier properties after packaging and filling, and thus is particularly suitable for use in food preservation.

 In addition, a multilayer film or sheet can be formed by a coextrusion method or a laminating method so that the vinylidene chloride-based copolymer composition is further laminated on one gas barrier.

When extruding a vinylidene chloride-based copolymer particle composition or a composition obtained by adding a processing aid to the composition, the composition is supplied to an extruder via a vacuum hopper, whereby stable extrudability and heat stability are achieved. The performance is improved. One 6 degree of vacuum in the vacuum hopper. 6 is preferably not more than 6 X 1 0- ² MP a, more preferably _ 7. 9 9 X 1 0- 2 from a 1 0. 1 range of X 1 0- ² MP a It is. By supplying the composition to an extruder via a vacuum hopper set under such conditions, extrudability and stretchability can be stably maintained. It is stretched by a known method via a melt extruder connected to the lower part of the vacuum hopper, or is formed into a film, a sheet or the like without stretching.

By the above-mentioned extrusion processing method, the composition is stably supplied to the melt extruder, so that the fluctuation of the load of the extruder motor and the fluctuation of the extrusion amount can be suppressed to a small value. This improves the thermal stability, such as the coloring of the resin, the effect of suppressing the outflow of resin decomposition products, and the effect of suppressing the adhesion of decomposition products at the outlet of the die. In addition, bubble rupture during inflation molding is further improved and reduced. Examples>

 Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.

 In the examples and comparative examples, the following compounds and equipment were used.

 -Suspension dispersant

 (Ml) Methinole cellulose

 (2% aqueous solution viscosity 4000 mPas)

 (M2) Hydroxypropinolemethinoresenorelose

 (2% aqueous solution viscosity 4000 mPa ■ s)

 (M3) Hydroxypropinolemethinoresenolerose

 (Viscosity of 2% aqueous solution 400 mPas)

(S I) Faudler wing

 Ethylene monoacetate butyl copolymer (B1)

 (B1-1): vinyl acetate content == 30 wt%, melt index = 6 (B1-2): butyl acetate content = 25 wt%, melt index 5 (B1-3): vinyl acetate content = 20 wt%,

 Menoleto index = 1 60

 (B 1— 4): content of acetate acetate = 10 wt%, melt index = 75

] 3 unsaturated carboxylic acid ester copolymer (B 2)

 (B 2-1): B A / BMA / MMA = 14/16 / 70w t%

 Weight average molecular weight (Mw) 220,000

 (B 2-2) B A / MM A / MA = 40/5 5 / 5w t%

 Weight average molecular weight (Mw) 300,000

 (B 2— 3) B A / MMA = 50/50 w t%

 Weight average molecular weight (Mw) 50,000

 * Abbreviations above indicate the following monomers:

BA: Butyl acrylate BMA Butyl methacrylate

 MMA methyl methacrylate

 MA Methyl acrylate A method for measuring and evaluating characteristics in the present invention will be described.

1) Particle size distribution of vinylidene chloride copolymer particle composition

 The weight average particle size and the ratio of particles having a particle size of less than 150 μm were measured by a particle size distribution measurement method using a Coulter Multisizer / Particle Measurement System TA-II type (manufactured by Nikkaki Co., Ltd.).

 Level value and evaluation of weight average particle size

 In the range of 200 to 500 μιη: ◎

 What is less than 150 5 m: X

 Level value and evaluation of the ratio of vinylidene chloride copolymer particles less than 150 μm

0 L. 5 wt% or less ◎

 1.5 Wt% to 3 wt% or less 〇

 Over 3 w t% X

2) Bulk specific gravity

 The measurement was performed according to JISK—6722.

 (Powder tester PT-R type (Powder measuring device manufactured by Hosokawa Micron Co., Ltd.)) The following judgment was made based on the value of bulk specific gravity.

^{0. 9~ 1. 0 g / cm 3} : ◎

0.8-0.9 g / cm ³ 〇

0.8 gZc m ^{3 or} less X

 3) Weight average molecular weight

 The weight average molecular weight of the polymer particle composition was measured by gel permeation chromatography (GPC) as follows.

Measuring device: Toso Issei gel permeation chromatograph HLC-820 column: TSKgel SuperHM-H (Toso Isso) 7.8 mmX 30 cmX 2 Eluent: THF, flow rate: 1 ml / min, temperature: 40 ° C, detection: RI

 4) Stable extrudability: Fluctuation rate of supply rate of vinylidene chloride-based copolymer particle composition Use about 50 kg of vinylidene chloride-based copolymer particle composition, and set the feed rate using a screw feeder. The supply amount was measured at a fixed time in the range of 10 to 20 minutes (OOgZhr) (n = 5), and the simple average and standard deviation were obtained. The following formula (2) was used to determine the rate of change in the supply rate, which was used as a criterion for liquidity. In this case, Phytron SK-S (manufactured by Hoso Kadmicron) was used as the screw type feeder.

 Fluctuation rate of feed rate (%) = (simple average value of standard deviation) X I 00 (2) From this fluctuation rate, liquidity was determined as follows.

 0% ~ 5% ◎ (No problem in processability)

 Exceeds 5%: X (Poor processability, uneven supply)

 5) Uniformity of film thickness

The average thickness and standard deviation of the produced film at a length of about 300 m were measured, and the rate of change of the film thickness was determined by the following equation (3), which was used as a criterion for judging the extrudability. Fluctuation rate of film thickness ( _σ ) (%) = (standard deviation 膜厚 average film thickness) XI 00 (3) 0% to 2%: ◎ (No problem in extrusion processability)

Exceeding 2 ° / ₀ : X (Poor extrusion processability, uneven thickness)

 6) Decomposition product spill

 Decomposed products with a length of about lmm or more contained in the film were detected by visual observation.

 Represents less than 10 per 150 Om: ◎

 Represents 10 to less than 15 per 150 Om: 〇

 Represents 15 or more per 150 Om: X

 7) Suitability for packaging and filling machines

An automatic filling and ligating device (Asahi Kasei ADP food packaging and filling machine) that integrates the film supply unit, high-frequency sealing unit, automatic filling unit, and ligating unit is wrapped with a double film slit to a folding width of 4 Omm. Circle sealed with high frequency seal Water was filled as a filler in the cylindrical film, and a package was obtained in which both ends were clipped with metal wires. At that time, the state of the seal and the state of spark generation at the seal electrode were observed.

 -Operate at a sealing speed of 3 OmZ, seal for 60 minutes of operation time

 No troubles or sparks caused by the fire shall be observed. : ◎-The film is partially thin and the seal line is too molten

 Occurs once or twice every 60 minutes.ト ラ ブ ル Trouble caused by seal and spark spark

 More than once or twice in 60 minutes. X

8)

 The yellowing of the film was visually observed.

 The yellowing of the film is not noticeable. : ◎

 Represents the degree of coloring intermediate between X and ◎. : 〇

 Strong yellowing of the film. : X

9) Oxygen gas permeability: 100 ° C., 100 ° C. using an oxygen gas permeability measuring device (Oxtran 2/20 manufactured by Moden Control). /. Measured in relative humidity. The unit was cm ³ m ² day / atm, and the measurement was performed using double film.

 25 or less ◎

 25-30 〇

 30 or more X

 0) <Comprehensive evaluation>

 ◎ All evaluation items are satisfied as ◎.

 場合 When each evaluation item is satisfied, but 一部 is partially included.

 Poor X characteristics.

[Example 1]

Reactor equipped with a feeder blade (span diameter: 400 mm), finger, thermometer, and nitrogen gas inlet tube (volume of 300 l) Medium 脱 Deionized water 1 50 One liter of the suspension and a dispersant (Ml) were added with 150 liters to adjust 100 parts by mass of the dissolved suspension (concentration of the suspension / dispersant: 500 ppm). '

Next, 80 parts by weight of vinylidene chloride, after addition parts by weight vinyl chloride 20, initiator diisopropyl peroxide O carboxymethyl dicarbonate 0.1 5 parts by weight, epoxidized flax oil 2 parts, stirring speed .1. 4mZ _{S e C} and heated to 45 ° C under a nitrogen atmosphere to initiate polymerization. After continuing the reaction for about 10 hours, the temperature was raised to 55 ° C in about 1 hour, and the stirring speed was set to 1.2 times the initial speed (1.68 m / sec), and the polymerization was continued for another 15 hours. went. After the completion of the reaction, the separated vinylidene chloride-based copolymer particle composition had a weight average particle diameter of 260 μm, and the mass ratio of particles having a particle diameter of less than 150 im was 2.2 wt%. The bulk specific gravity was 0.90 gZcm ³ .

 The copolymer particle composition was dissolved in tetrahydrofuran, and the molecular weight in terms of polystyrene was measured by gel permeation chromatography. The weight average molecular weight was 120,000. (Vinylidene chloride-based copolymer particle composition (A-1))

 Table 1 shows the evaluation results of the properties of the vinylidene chloride-based copolymer particle composition. [Comparative Example 1]

 Polymerization was carried out in the same manner as in Example 1 except that the concentration of the suspending and dispersing agent was 300 ppm and the stirring speed was 4.5 mZ sec. The weight average molecular weight was 123,000. (Vinylidene chloride-based copolymer particle composition (A-6))

 Table 3 shows the results. [Example 2]

The concentration of the suspending dispersing agent and 300 p pm, except for using stirring speed 1. 2m / _S Θ c was subjected to the same polymerization as in Example 1.

 The weight average molecular weight was 1 16,000. (Vinylidene chloride copolymer particle composition (A-2))

The results are shown in Table 1. [Comparative Example 2]

A concentration of 0.1% of the suspending dispersant, except that the stirring speed 0. 6 m / _S ec embodiment;! The same polymerization was carried out.

 The weight average molecular weight was 120,000. (Vinylidene chloride copolymer particle composition (A-7))

 Table 3 shows the results.

[Example 3]

Polymerization was carried out in the same manner as in Example 1 except that the concentration of the suspending and dispersing agent was 0.03 ° / ₀ and the stirring speed was 1.0 mZ sec. The weight average molecular weight was 15,000. (Vinylidene chloride copolymer particle composition (A-3))

 The results are shown in Table 1.

[Example 4]

 Polymerization was carried out in the same manner as in Example 1 except that the concentration was 0.05% using a suspension dispersant (M2) and the stirring speed was 1.2 m / sec. The weight average molecular weight was 118,000. (Vinylidene chloride-based copolymer particle composition (A-4))

 The results are shown in Table 1.

[Comparative Example 3]

The same polymerization as in Example 1 was carried out except that the suspending and dispersing agent was (M2), the concentration was 0.1%, and the stirring speed was 0.6 m / _sec . The weight average molecular weight was 121,000. (Vinylidene chloride-based copolymer particle composition (A-8))

 Table 3 shows the results.

[Example 5]

Polymerization was carried out in the same manner as in Example 1 except that the concentration was 0.1% and the stirring speed was 1. Om / sec using a suspension dispersant (M3). The weight average molecular weight is 121,00 It was 0. (Vinylidene chloride-based copolymer particle composition (A-5)) The results are shown in Table 1.

[Example 6]

 100 parts by mass of the bi-lidene chloride-based copolymer particle composition (A-1) obtained in Example 1, 3 parts by mass of dibutyl sebacate as an additive, an antioxidant, a lubricant, and a red pigment in a total of 1 part by mass In addition, a vinylidene chloride copolymer particle composition was obtained.

Then fed into an extruder having a diameter of 4 Omm, the vacuum pressure in the vacuum hopper about _ 9. to 06 X 10- ² MP a was extruded in an annular, quenched with a cold bath at 10 ° C, then Pass through a 20 ° C hot tub. In addition, air was injected between the films sandwiched between two sets of pinch rolls having different rotational surface speeds to expand the film, and the film was oriented 2.8 times in the longitudinal direction and 3.7 times in the width direction. The obtained film was 10 Om long and had a single thickness of ²⁰ / m. The film thickness and the variation rate (σ) of the film thickness were measured. The results are shown in Table 2.

[Example 7]

Using Example 2 obtained in chloride Biyuriden copolymer particle composition (alpha-2), one 7. 99 x 10 the vacuum degree - except for using ² MP a in the same manner as in Example 6 Film Was manufactured. The results are shown in Table 2.

[Example 8]

Bi chloride obtained in Example 3 - isopropylidene copolymer particle composition using the (A-.3), except that as one 7. 99 x 10 one ² MP a a vacuum degree as in Example 6 To produce a film. The results are shown in Table 2.

[Example 9]

Using Example 4 obtained in vinylidene chloride copolymer particle composition (A- 4), except that as one 7. 99 x 10 one ² MP a the vacuum degree in the same manner as in Example 6 Film To Manufactured. The results are shown in Table 2. [Example 10]

Using Example 5 obtained in vinylidene chloride copolymer particle composition (A- 5), except that as one 6. 66 x 10- ² MP a the vacuum degree in the same manner as in Example 6 Film Was manufactured. The results are shown in Table 2.

[Example 11]

 A film was formed in the same manner as in Example 6, except that no vacuum hopper was used. The results are shown in Table 2.

[Comparative Example 4]

 A film was manufactured in the same manner as in Example 6 using the bi-lidene chloride-based copolymer particle composition (A-6) obtained in Comparative Example 1. Table 4 shows the results.

[Comparative Example 5]

 Using the vinylidene chloride-based copolymer particle composition (A-7) obtained in Comparative Example 2, a film was produced in the same manner as in Example 6. Table 4 shows the results.

[Comparative Example 6] '

Comparative Example 3 obtained in vinylidene chloride copolymer particle composition (A- 8) with the exception of the one 7. 99 x 10 one ² MP a the vacuum degree in the same manner as in Example 6 Film Was manufactured. Table 4 shows the results.

[Comparative Example 7]

A film was produced in the same manner as in Comparative Example 4, except that no vacuum hopper was used. Table 4 shows the results. [Example 12]

 With respect to 100 parts by mass of the vinylidene chloride copolymer particle composition (A-1) obtained in Example 1, 0.3 part by mass of ethylene monoacetate copolymer (B1-1), α,] 3 After mixing 0.3 parts by mass of the unsaturated carboxylate ester copolymer (B2-1), a total of 3.5 parts by mass of epoxidized tamae oil and dibutyl sebacate as additives, and an antioxidant , A lubricant, and a red pigment in a total amount of 1.5 parts by mass, and were mixed at a temperature of 50 ° C to obtain a vinylidene chloride copolymer composition.

Next, an extruder of diameter 40 mm, was extruded annularly in the vacuum of the vacuum hopper pressure of about one ^{9. 06 X 10- 2 (MP a} ), was quenched in a cooling bath at 10 ° C, of 20 ° C After passing through a hot water bath, air is pressed into the film sandwiched between two sets of pinch knurls with different rotating surface speeds to expand the film, stretching 2.8 times in the longitudinal direction and 3.7 times in the width direction. Oriented. The obtained film had a length of 100 m and a single thickness of 20 μηι. The variation rate (σ) of the film thickness of the produced film was measured. Table 5 shows the results.

[Example 13]

 Except for adding 0.5 parts by mass of ethylene-vinyl acetate copolymer (B1-2) and 0.5 parts by mass of (Β2-2) as α, β unsaturated carboxylic acid ester copolymer A film was produced in the same manner as in Example 12. Table 5 shows the results.

[Example 14]

1.0 parts by mass of the ethylene-vinyl acetate copolymer (B1-1) was added, and 0.3 parts by mass of (B2-2) was added as an α, j3 unsaturated carboxylic acid ester copolymer. except that the vacuum in the vacuum hopper pressure of about one ^{7. 99 X 1 0- 2 (MP} a) is a film was produced in the same manner as in example 1 2. Table 5 shows the results.

[Example 15]

1.5 parts by mass of (B1-3) was added as an ethylene monoacetate copolymer, and the amount of the [3] unsaturated carboxylic acid ester copolymer (B2-1) was 0.1 part by mass. age A film was produced in the same manner as in Example 12 except for the above.

 Table 5 shows the results.

[Example 16]

 1.0 parts by mass of (B1-3) was added as an ethylene-vinyl acetate copolymer, and 0.5 parts by mass of (Β2-2) was added as an α, / 3 unsaturated carboxylic acid ester copolymer. A film was produced in the same manner as in Example 12 except for the above. Table 5 shows the results.

[Example 17]

Deionized water and suspended dispersant (Ml) in a reactor (content volume: 300 liters) equipped with a feeder blade (span diameter: 40 Omm), finger baffle, thermometer and nitrogen gas inlet tube Was added, and 100 parts by mass of the dissolved suspension was adjusted (concentration of suspension / dispersant: 500 ppm) ₀

Next, after adding 80 parts by mass of vinylidene chloride, 20 parts by mass of vinyl chloride, 0.15 parts by mass of initiator diisopropylpropyl dicarbonate, and 2 parts of epoxidized amadi oil, the stirring speed was 1.4 m / _{The mixture} was heated to 45 ° C. in a nitrogen atmosphere to initiate polymerization. After continuing the reaction for about 10 hours, the temperature was raised to 60 ° C in about 1 hour, and the stirring speed was set to 1.2 times the initial speed (1.68 mZ sec), and the polymerization was continued for another 15 hours. I went. After the completion of the reaction, the separated vinylidene chloride-based copolymer particles had a weight average particle diameter of 260 m and a mass ratio of less than 150 / im was 2.3 wt%. The bulk specific gravity was 0.91 g / cm ³ .

The copolymer particles were dissolved in tetrahydrofuran, and the molecular weight in terms of polystyrene was measured by gel permeation chromatography. As a result, the weight average molecular weight was 100,000. (Vinylidene chloride-based copolymer particle composition (A-9)) 100 parts by mass of the vinylidene chloride-based copolymer particle composition (A-9), ethylene-vinyl acetate copolymer (B1- 4) 0.2 part by mass, _α ,) 3 unsaturated carboxylic acid ester copolymer (Β 2-3) Same as Example 12 except that 0.5 part by mass was used.

Lum manufactured. The results are shown in Table 6. [Example 18]

 1.5 parts by mass of ethylene monoacetate copolymer (B1-1), α,] 3 unsaturated power Conducted except that 0.05 parts by mass of ribonate copolymer (Β 2-3) was added. A film was produced as in Example 17. The results are shown in Table 6.

[Example 19]

 A film was produced in the same manner as in Example 18 except that the vacuum hopper was not used. The results are shown in Table 6.

[Example 20]

Deionized water and a suspending and dispersing agent (Ml) were added to a reactor (300 liter internal volume) equipped with a Faudler blade (span diameter 40 Omm), finger baffle, and thermometer nitrogen gas inlet tube. was adjusted suspension 100 parts by weight of dissolved (concentration 500 p pm suspending dispersant) ₀

Next, 90 parts by mass of bi-lidene chloride, 10 parts by mass of vinyl chloride, 0.15 parts by mass of diisopropyl propyl peroxydicarbonate initiator, and 2 parts of epoxidized amaji oil were added, followed by a stirring speed of 1.4 m / m. In seconds, the mixture was heated to 45 ° C under a nitrogen atmosphere to initiate polymerization. After continuing the reaction for about 10 hours, the temperature was raised to 55 ° C in about 1 hour, and the stirring speed was set to 1.2 times the initial speed (1.68 m / sec), and the polymerization was continued for another 10 hours. I went. After the reaction was completed, the separated vinylidene chloride-based copolymer particles had a weight average particle diameter of 260 μm, and the mass ratio of particles having a particle diameter of less than 150 μm was 2.0 wt%. The bulk specific gravity was 0.92 gZcm ³ .

The copolymer particles were dissolved in tetrahydrofuran, and the molecular weight in terms of polystyrene was measured by gel permeation chromatography to find that the weight average molecular weight was 90,000. (Vinylidene chloride-based copolymer particles (A-10)) 10 parts by mass of the obtained vinylidene chloride-based copolymer particle composition (A-10) was added to the vinylidene chloride-based copolymer particle composition. (A-1) 90 parts by mass, ethylene monoacetate vinyl copolymer (B1-1) 0.3 parts by mass, α,] 3 unsaturated carboxylic acid ester copolymer (B2-1) was prepared in the same manner as in Example 12 except that 0.3 parts by mass of (B2-1) was added. The results are shown in Table 6.

[Comparative Example 8]

 A film was produced in the same manner as in Example 12 except that α, unsaturated carboxylic acid ester (Β2) was not added. The results are shown in Table 7.

[Comparative Example 9]

 A film was produced in the same manner as in Example 12, except that the ethylene monoacetate butyl copolymer (B1) was not added. The results are shown in Table 7.

[Comparative Example 10]

Example 17 was repeated except that 1.5 parts by mass of the ethylene-vinyl acetate copolymer (B1-4) and 2.0 parts by mass of α, unsaturated power rubonic ester (Β2-1) were blended. A film was produced in the same manner. The results are shown in Table 7.

Table 1 Example

 Example 1 Example 2 Example 3 Example 4 Example 5

 Type of suspension / dispersant (M1) (M1) (Ml) (2) (3)

 Concentration of suspension / dispersant (%) 0.05 0.03 0.03 0.05 0.1

 Stirring speed (m / sec 1.4 1.2 1.0 1.2 1.0

 Weight average particle size 260 300 350 250 270

 (Judgment) ◎ ◎

 Weight ratio below 150 μm (%) 2.2 1,4 0.4 2.0 2.3

 (Judgment) o ◎ ◎ 〇 o

Bulk specific gravity (g / cm ³ ) 0.9 0.93 0.95 0.89 0.92

 (Judgment) o ◎ ◎ ◎ ◎

 Identification symbol for one type of polymer (A-1) (A-2) (A-3) (A-4) (A-5)

N3

 Example 6 Example 7 Example 8 Example 9 Example "10 Example 11 Polymer Type Used (A-1) (A-3) (A-5) (A-1) Rate of change in feed rate (%) 3.1 2.2 1.8 2.4 2.5 3.1

(Determination) ◎ ® ◎ ◎ ◎ ◎ vacuum (MPa) -9. 06 x 10- 2 -7. <99X10 over ^{2 -7. 99X10- 2 -7. 99} x 10- 2 -6. 66 x 10 one ² 0 film thickness ifim) 20 20 20 20 20 20 variation rate (beauty) 1.9 1.8 1.2 1.7 1.6 2.0

(Judgment) ◎ ◎ ◎ © ◎ ◎ Overall evaluation 〇 ◎ ◎ 〇 〇 〇

<

Table 3 Comparative example

 Comparative Example 1 Comparative Example 2 Comparative Example 3

 Types of suspending and dispersing agents (1) (Μ1),

 Concentration of suspension / dispersant (%) 0.03 0.Ϊ 0.1

 Stirring speed (m / sec) 3.1 0.6 0.6

 Weight average particle size (jUtn) 160 330 290

 (Judgment) X 〇 〇

 Weight ratio below 150 jUm (%) 40.7 1.8 2.9

 (Judgment) X ◎ 〇

 Bulk specific gravity (g / cm) 0.71 0.78 0.79

 (Judgment) X X X

 Identification symbol for one type of polymer (Α—6) (Α—7) (Α—8)

t

 Comparative example Comparative car example 比 Ratio | ΧExample 6 Comparative example 7 Polymer type (A—o (A— / ヽ) (A—8) ί>, supply rate fluctuation rate (%) 12.1 7.4 8.1 12.1

(Determination) XXXX vacuum (MPa) -9.06 X 10 one ² -9.06 x 10- ² one .99X10 one ² 0 Film thickness (jL / m) 20 20 20 20 variation rate (σ) 4.5 2.4 2.7 4.6

(Judgment) XXXX Overall evaluation XXXX

Table 5 Example 12 16

Co

o

Table 6 Examples 17 to 20

 Example 17 Example 18 Example 19 Example 20 Vinylidene chloride-based copolymer particles (Α-1) 90

 (Α-9) 100 (Α— 9) 100 (Α— 9) 100

Type and ratio (parts by mass) (Α-10) 10 Ethylene vinyl acetate copolymer

 (Β1—4) 0.2 (Β1—1) 1.5 (—1—1) 1.5 (Β1 -1) 0.3 Types (B1) and proportions (parts by mass)

a, β-unsaturated carboxylic acid ester

Copolymer (Β2) and ratio (mass (Β2-3) 0.5 (Β2-3) 0.05 (Β2-3) 0.05 (B2-D0.3 part)

Vacuum (MPa) -9.06Χ10— ² -9.06 X 10— ²⁰ -9.06 X 10 " ² Film thickness (〃m) 20 20 20 20 Fluctuation (σ) 1.5 1.2 1.6 1.8

(Judgment) ◎ © ◎ ◎ Decomposed product outflow ◎ ◎ ◎ ◎ Suitability for food packaging and filling machine ◎ 〇 〇 ◎ Film yellowing degree ◎ ◎ ◎ ◎ Oxygen gas permeability ◎ 〇 〇 ◎ Overall evaluation ◎ 〇 ◎ ◎

Table 7 Comparative Example 8 10

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

 This application is based on Japanese Patent Application (No. 2001-214424) filed on Jul. 13, 2001, the contents of which are incorporated herein by reference.

<Industrial applicability>

 Since the vinylidene chloride-based copolymer particle composition of the present invention can be extruded stably when melt-molded into a film or sheet, a film or sheet having excellent film thickness uniformity can be obtained. Furthermore, a composition comprising a copolymer of two or more monomers selected from monomers of ethylene monovinyl acetate copolymer and [3] unsaturated carboxylic acid ester is added to this copolymer particle composition. Thereby, it is possible to suppress the outflow of the resin decomposition product during the melt molding, suppress the adhesion of the resin decomposition product at the die outlet, and obtain a film or sheet excellent in suitability for a packing and filling machine and gas barrier property. Further, by extruding the above composition through a vacuum hopper, it is possible to improve the extrudability.

Claims

The scope of the claims 1. Bi-denidene chloride having a weight average particle diameter in a range of 200 to 500 m and a particle diameter of less than 150 / xm being 3 wt% or less. -Based copolymer particle composition. 2. bulk density of the vinylidene chloride copolymer ^{particles, 0. 8 0 gZcm 3 ~ 1.} O g / c ni claims, characterized in that a ^third preceding claim chloride vinylidene emissions based copolymerization Combined particle composition. 3. The copolymer particles according to claim 1 or 2, wherein the vinylidene chloride-based copolymer is obtained from copolymerization of vinylidene chloride and one or more monomers selected from polymerizable vinyl monomers. Composition. 4. The polymerizable butyl monomer is at least one selected from butyl chloride, methyl acrylate, methyl methacrylate, 2-ethylhexynoleate acrylate, atalylotrinole, and styrene. Item 4. The copolymer composition particle composition according to item 3 to item 3. 5. A film or sheet obtained from the bi-lidene chloride-based copolymer particle composition according to any one of claims 1 to 3. 6. Vinylidene chloride copolymer particles having a weight average particle diameter in the range of 200 to 500 m and a particle diameter of less than 150 // m is 3 wt% or less. Composition (A) 100 parts by mass, ethylene monoacetate butyl copolymer (B1) 0.05 to 2.95 parts by mass and a; two kinds selected from unsaturated carboxylic acid ester monomers A composition comprising 0.05 to 2.95 parts by mass of the copolymer (B 2) comprising the above monomers, and the total of the compounding mass of (B 1) and the compounding mass of (B 2) Is 3 parts by mass or less, a vinylidene chloride-based copolymer composition. 7. bulk density of vinylidene copolymer particles composition chloride (A) is, 0. 80 ~1. 0 cm ³ a is claims paragraph 6 vinylidene chloride copolymer sets composition as described. 8. The ratio (Wa) of the vinyl acetate component in the ethylene-vinyl acetate copolymer (B1) is 10 to 4 wt. /. 8. The vinylidene chloride copolymer composition according to claim 6, wherein the composition is: 9. The claim 6, wherein the a, i3 unsaturated carboxylic acid ester monomer is at least one selected from butyl acrylate, methyl acrylate, 21-ethylhexyl acrylate, butyl methacrylate, and methyl methacrylate. Item 9. The copolymer composition according to any one of Items 7 and 8. 10. A film or sheet obtained from the vinylidene chloride copolymer composition according to any one of claims 8 and 9.