KR20190123705A - Vinylidene chloride based copolymer resin composition - Google Patents

Abstract

The present invention relates to a resin composition containing vinylidene chloride-based copolymer, which solves a bias by not lowering gas barrier properties but lowering a melt viscosity down to the degree of not generating surface non-uniformity even when being processed as a tube or thin film. The resin composition of the present invention comprises: a vinylidene chloride-based copolymer including vinylidene chloride and another monomer copolymerizable with the vinylidene chloride as a monomer component, and having a weight average molecular weight of 50,000 to 200,000; and an acrylic copolymer containing methylmethacrylate and butyl acrylate as a monomer component. According to the present invention, a melt viscosity at 175°C and at a shear rate of 100 (1/s) is 800 to 2,300 (Pa·s), and a plasticizer and a stabilizer are not contained or the sum of both contents is 8 mass% or less.

Description

Vinylidene chloride copolymer resin composition {VINYLIDENE CHLORIDE BASED COPOLYMER RESIN COMPOSITION}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition containing a vinylidene chloride-based copolymer, and in particular, a vinylidene chloride-based resin having low melt viscosity and excellent processability and further maintaining gas barrier properties of the vinylidene chloride-based copolymer. It relates to a copolymer-containing resin composition.

Since a vinylidene chloride type copolymer and the resin composition containing this have gas barrier property, it is used for various uses.

However, the vinylidene chloride copolymer has poor thermal stability in that the melting temperature and the decomposition temperature are close. Therefore, during extrusion, extrusion is carried out without sufficient kneading to shorten the time from melting to extrusion in order to prevent thermal deterioration, so that non-uniformity in the amount of resin occurs in the flow direction. I) There is a problem that occurs.

Moreover, since a vinylidene chloride type copolymer has a high melt viscosity, when it is going to extrude into a thin film or tube, a flow nonuniformity arises in the flow path of a die, As a result, surface roughness falls and thickness precision and transparency are There is also a problem that cannot be secured.

In general, it is known to reduce the extrusion speed or lower the melt viscosity as the knitting removal means.

In this regard, reducing the extrusion speed may lead to a decrease in productivity, and in the case of the vinylidene chloride copolymer, thermal degradation may proceed.

On the other hand, lowering the melt viscosity leads not only to eliminating knitting but also to improving the surface roughness, thickness accuracy, and the like. Therefore, it is preferable to lower the melt viscosity of the vinylidene chloride copolymer.

As a method of lowering the melt viscosity, it is conceivable to increase the processing temperature. However, in the vinylidene chloride-based copolymer, the progress of thermal degradation becomes remarkable, and thus cannot be employed.

In general, in order to lower the melt viscosity of the resin, processing aids such as plasticizers have been added. However, in the case of vinylidene chloride-based copolymers, the effect of lowering the melt viscosity by adding the plasticizer is not sufficient. There is also a problem that the gas barrier property, which is a characteristic thereof, is damaged.

Patent Document 1 discloses blending an acrylic copolymer with vinylidene chloride-methylacrylate copolymer as a processing aid to improve thermal stability. However, in this technique, the melt viscosity and knitting of the resin blend are not examined.

Japanese Patent Publication No. 2947931

In view of the above problems, the present invention melts to the extent that surface unevenness does not occur even when processing into a tube or a thin film in a resin composition containing a vinylidene chloride-based copolymer without lowering the gas barrier property. It is a problem to lower a viscosity and to eliminate knitting.

MEANS TO SOLVE THE PROBLEM As a result of earnestly researching in order to solve the said subject, when selecting the thing which has a specific molecular weight as a vinylidene chloride type copolymer, and adding a specific acryl-type copolymer, melt | dissolution viscosity is fully made, without impairing gas barrier property. It was found out that it could be lowered and the present invention was completed by using such knowledge.

Acrylic copolymers are generally used for the purpose of increasing the melt viscosity of vinyl chloride-based (co) polymers to promote gelation. However, it was unexpected that acrylic copolymers have an effect of lowering the melt viscosity on the contrary. .

That is, this invention is as follows.

[1] a vinylidene chloride copolymer having a weight average molecular weight of 50,000 to 200,000, containing vinylidene chloride and other monomers copolymerizable with vinylidene chloride as monomer components;

Containing an acrylic copolymer containing methyl methacrylate and butyl acrylate as monomer components,

Melt viscosity in 175 degreeC and shear rate 100 (1 / s) is 800-2300 (Pa * s),

The vinylidene chloride copolymer resin composition which does not contain a plasticizer and a stabilizer, or whose sum total of both is 8 mass% or less.

[2] The vinylidene chloride copolymer resin composition according to [1], wherein the weight average molecular weight of the acrylic copolymer is 80,000 to 200,000.

[3] The vinylidene chloride copolymer resin composition according to [1] or [2], in which the vinylidene chloride copolymer contains 70% by mass or more of vinylidene chloride as a monomer component.

[4] The O ₂ TR value (oxygen permeability) of the composition having the same composition as that of the vinylidene chloride copolymer resin composition except for the acrylic copolymer is set to A, and the O ₂ TR of the vinylidene chloride copolymer resin composition. When the value is B, the vinylidene chloride copolymer resin composition in any one of [1]-[3] whose B / A is 1.5 or less.

According to this invention, the vinylidene chloride type copolymer containing resin composition excellent in extrusion processability and transparency can be provided, without impairing gas barrier property.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram of the film forming apparatus used when evaluating the film forming property of a resin composition in an Example.

EMBODIMENT OF THE INVENTION Hereinafter, although the form for implementing this invention (henceforth "this embodiment") is demonstrated in more detail, this invention is not limited to this, A various deformation | transformation is not carried out in the range which does not deviate from the summary. It is possible.

1. Vinylidene chloride copolymer

The vinylidene chloride type copolymer resin composition of this embodiment contains vinylidene chloride type copolymer which contains vinylidene chloride and another monomer copolymerizable with vinylidene chloride as a monomer component. Compared with the vinylidene chloride homopolymer, the vinylidene chloride copolymer has a higher thermal stability, and furthermore, the effect of lowering the melt viscosity when combined with the acrylic copolymer of the present embodiment is remarkably obtained.

Although there is no limitation of the other monomer copolymerizable with vinylidene chloride, if the solubility parameter (SP value) of the homopolymer is 9.0-11.0 (cal / cm 3) ^1/2 , the difference with the SP value of vinylidene chloride is small, and the chloride Since the transparency of the vinylidene-type copolymer itself becomes high, it is preferable. As for SP value, it is more preferable that it is 9.0-10.0 (cal / cm <3>) ^1/2 .

The solubility parameter (SP value) herein means an amount defined by the following formula when the aggregation energy density is ΔE (cal / mol) and the molecular weight is V (cm 3 / mol).

SP value ((cal / cm 3) ^1/2 ) = (ΔE / V) ^1/2

As a method of obtaining a specific SP value, the method of Fedors is known, for example. Moreover, about typical monomers, the SP value is "A Method for Estimating both the Solubility ㎩rameters and molar Volumes of Liquids, POLYMER ENGINEERING AND SCIENCE, FEBRUARY, 1974, vol. 14, Issue 2, p. 147-154 ", and these can also be used in this embodiment.

In this embodiment, as a preferable specific example of the other monomer copolymerizable with vinylidene chloride, vinyl chloride and methyl acrylate are preferable at the point which the difference of the decomposition temperature of a copolymer and melting | fusing point becomes comparatively large, for example.

As another specific example, acrylic acid esters, such as butyl acrylate, methacrylic acid esters, such as methyl methacrylate and butyl methacrylate, acrylonitrile, isobutylene, vinyl acetate, etc. are mentioned, for example. It does not specifically limit to these.

Only one type of these other monomers copolymerizable with vinylidene chloride may be contained (a binary copolymer), or two or more types may be contained (a three or more member copolymer).

Among these, when vinyl chloride is used as another monomer copolymerizable with vinylidene chloride, the molecular weight distribution of the vinylidene chloride-based copolymer tends to be wider, and thus better film forming property is obtained in that the melt tension is increased.

In addition, since the melt viscosity of a vinylidene chloride-vinyl chloride binary copolymer falls remarkably by addition of an MMA-BA copolymer, especially this invention uses a vinylidene chloride-vinyl chloride binary copolymer. It is advantageous if it does.

Although there is no limitation in the copolymerization composition of a vinylidene chloride type copolymer, as long as the target melt viscosity is obtained, for example, content of vinylidene chloride can be 70 mass% or more, and 80 mass% or more may be sufficient as it. , 90 mass% or more may be sufficient.

When a vinylidene chloride type copolymer is a binary copolymer, the binary copolymer of 70-97 mass% of vinylidene chloride and the other monomer 3-30 mass% copolymerizable with vinylidene chloride may be sufficient, for example.

In this embodiment, the weight average molecular weight of a vinylidene chloride type copolymer is 50,000-200,000 from a viewpoint of melt viscosity, and it is preferable that it is 50,000-150,000.

In this embodiment, there is no limitation in the superposition | polymerization form of a vinylidene chloride type copolymer, Any of a random copolymer, a block copolymer, and a graft copolymer may be sufficient.

In this embodiment, it does not specifically limit as a polymerization method of a vinylidene chloride type copolymer, For example, all well-known methods, such as suspension polymerization method, emulsion polymerization method, and solution polymerization method, can be employ | adopted. Among these, the suspension polymerization method is preferable. As the suspension polymerization method, a monomer phase is continuously obtained by adding a monomer directly in water in which a suspending agent is dissolved or by adding water dissolved in a suspending agent to a monomer as described in JP-A-62-280207. The suspension method etc. which make a monomer into the dispersion which discontinuous / water is a continuous phase via the dispersion state where a phase / water is a discontinuous phase are illustrated.

As the oil-soluble initiator that can be used when the vinylidene chloride-based copolymer is prepared by the suspension polymerization method, for example, an organic peroxide (eg, lauroyl peroxide, benzoyl peroxide, tert-butylperoxy-2- Azobis compounds (eg, in addition to ethylhexanoate, tert-butylperoxyisobutylate, tert-butylperoxypivalate, tert-butylperoxyneodecanoate, diisopropylperoxydicarbonate, etc.) Azobisisobutylnitrile etc.) is mentioned.

As a suspending agent which can be used when manufacturing a vinylidene chloride type copolymer by suspension polymerization method, For example, cellulose derivatives, such as methyl cellulose, ethyl cellulose, hydroxypropyl methylcellulose, polyvinyl alcohol, or polyvinyl acetate Partial saponified products; and the like.

As a water-soluble initiator which can be used when manufacturing a vinylidene chloride type copolymer by emulsion polymerization method, organic peroxide (For example, in addition to inorganic peroxide (for example, sodium persulfate, potassium persulfate, ammonium persulfate, etc.), For example, tert- butyl hydroperoxide and the redox system of formaldehyde sodium sulfoxide etc. are mentioned.

As an emulsifier which can be used when manufacturing a vinylidene chloride type copolymer by emulsion polymerization method, it is a nonionic surfactant other than an anionic surfactant (for example, sodium alkyl sulfonate, sodium alkylbenzene sulfonate etc.), for example. (For example, polyoxyethylene alkyl phenyl ether etc.) is mentioned.

When manufacturing a vinylidene chloride type copolymer, you may add chain transfer agents, such as a trichloroethylene, a dodecyl mercaptan, an octyl mercaptan, thioglycolic acid, a thioglycolic acid 2-ethylhexyl, at the time of superposition | polymerization.

Although the polymerization temperature at the time of manufacturing a vinylidene chloride type copolymer is not specifically limited, Generally, 20-100 degreeC is preferable, More preferably, it is 40-90 degreeC. In addition, after superposition | polymerization of a vinylidene chloride type copolymer, well-known post-processing, such as filtration, water washing, and drying, can be performed as needed. For example, when an emulsion is obtained by emulsion polymerization, a powdered or granular vinylidene chloride copolymer can be obtained by salting it with aluminum sulfate, calcium chloride, or the like and then subjecting it to post-treatment.

2. Acrylic Copolymer

The vinylidene chloride-based copolymer resin composition of the present embodiment contains an acrylic copolymer (hereinafter sometimes referred to as "MMA-BA copolymer") containing methyl methacrylate and butyl acrylate as monomer components. do.

In the present embodiment, by coexisting the MMA-BA copolymer with the vinylidene chloride-based copolymer, the melt viscosity of the vinylidene chloride-based copolymer is lowered, thereby eliminating knitting and improving the extrusion workability.

The reason why the melt viscosity of the vinylidene chloride copolymer is lowered by the coexistence of the MMA-BA copolymer is not clear. However, as for the vinylidene chloride copolymer, methyl methacrylate is commercially available and butyl acrylate is incompatible. When a copolymer containing both such commercial and emergency components as a monomer component coexists with a vinylidene chloride copolymer, the MMA- gathered around the vinylidene chloride copolymer molecule by the action of the compatible methyl methacrylate copolymer. The butyl acrylate portion of the BA copolymer inhibits the aggregation of vinylidene chloride-based copolymer molecules, and as a result, it is considered that the entanglement of the polymer chain is reduced and the viscosity is lowered. However, the mechanism does not depend on this.

By the way, generally, when the components contained in this are incompatible for resin compositions, the transparency falls. However, the inventors have studied variously, but the reason is not clear. When butyl acrylate coexists with a vinylidene chloride-based copolymer, butyl acrylate is incompatible with other components that are incompatible with other vinylidene chloride-based copolymers. It was found that not too much the transparency of the resin composition was found.

In particular, in the case where butyl acrylate is used in combination with methyl methacrylate (that is, copolymerized as MMA-BA copolymer), which is commonly used with respect to vinylidene chloride copolymer, the vinylidene chloride copolymer is a main component. Even if it adds in the resin composition to be used, it turned out that the transparency is hardly reduced.

Surprisingly, even when the MMA-BA copolymer is added to the vinylidene chloride-based copolymer, it has been found that the decrease in gas barrier property of the vinylidene chloride-based copolymer is small.

Although the vinylidene chloride type copolymer is used for various uses, paying attention to the characteristic that gas barrier property is high, when the plasticizer etc. which are conventionally used for reducing melt viscosity are added, the gas barrier property fall was inevitable. Therefore, in the vinylidene chloride copolymer resin composition, it is a very advantageous effect that the melt viscosity can be lowered without impairing gas barrier properties.

The MMA-BA copolymer used in this embodiment may contain methyl methacrylate and butyl acrylate as a copolymerization component, these binary copolymers may be sufficient, and also contain the monomer copolymerizable with these as a monomer component. Copolymers of three or more members may be used. As a monomer copolymerizable with these, aromatic vinyl, such as styrene, (alpha) -substituted styrene, divinylbenzene, and allyl methacrylate, is mentioned, for example, It is not limited to this.

As a MMA-BA copolymer used in this embodiment, the binary copolymer which consists only of methyl methacrylate and butyl acrylate is preferable, but a ternary copolymer may be sufficient, In that case, methyl methacrylate, butyl acrylate, and styrene Ternary copolymers of are preferred.

Although there is no limitation in the copolymerization ratio of the MMA-BA copolymer used in this embodiment, It is preferable that content (mol%) of butyl acrylate is smaller than methyl methacrylate, for example, when it is a binary copolymer, It is preferable that both molar ratios (mol%) are MMA / BA = 50-70 / 50-30, and when it is a ternary copolymer, when the sum total of MMA and BA is 100, the molar ratio (mol%) is It is preferable that MMA / BA = 55-70 / 45-30.

Although there is no limitation in the superposition | polymerization form of the MMA-BA copolymer used in this embodiment, Any of a random copolymer, a block copolymer, and a graft copolymer may be sufficient, In the case of a block or a graft copolymer, especially melt viscosity reduction The effect tends to be excellent.

In addition, the MMA-BA copolymer may be particulate.

There is no limitation in the polymerization method of the MMA-BA copolymer used in this embodiment, A well-known method can be employ | adopted.

Although there is no limitation in the weight average molecular weight of the MMA-BA copolymer used in this embodiment, it is preferable that it is 80,000-200,000 from a viewpoint of a melt viscosity reduction effect.

Although the melt viscosity of the MMA-BA copolymer is not limited, it is preferably lower than the value expected for the vinylidene chloride-based copolymer composition, and specifically, melting at 175 ° C and a shear rate of 100 (1 / s) It is preferable that a viscosity is 300-700 (Pa * s).

Melt viscosity in 175 degreeC and shear rate 100 (1 / s) can be measured by the method as described in the Example mentioned later.

In addition, the oxygen permeability (O ₂ TR value) (cc / 15 μm · m 2 · yl · MPa) is preferably a value close to that of the vinylidene chloride-based copolymer, and furthermore, the O ₂ TR value is excessive by addition. It is desirable not to increase it.

Specifically, the increase rate (barrier magnification) when comparing the O ₂ TR values before and after the addition of the MMA-BA copolymer is 1.5 times or less (that is, vinylidene chloride-based air having the same composition except for the MMA-BA copolymer). A vinylidene chloride copolymer resin composition further comprising A and MMA-BA copolymers with an O ₂ TR value of the copolymer composition (vinylidene chloride copolymer alone when no other than the MMA-BA copolymer is added). When the O ₂ TR value of is set to B, it is preferable that B / A is 1.5 or less).

The O ₂ TR value can be measured by the method described in Examples described later.

3. Resin composition

The vinylidene chloride-based copolymer resin composition of the present embodiment contains the vinylidene chloride-based copolymer and the MMA-BA copolymer described above. It is preferable that content of MMA-BA copolymer in a vinylidene chloride-type copolymer resin composition is 0.05-10 mass%, It is more preferable that it is 0.1-5 mass%, It is further more preferable that it is 0.5-3 mass%.

Even if the content is 0.05% by mass, the effect of lowering the melt viscosity is sufficiently obtained, while the gas barrier property decreases as the content increases, so that the content may be 0.05% by mass or more and less than 0.5% by mass when importance is placed on gas barrier properties. .

The vinylidene chloride copolymer resin composition may contain other polymer compounds or other additives in addition to the vinylidene chloride copolymer and the MMA-BA copolymer within a range that does not impair the object of the present invention. Although there is no limitation in these content, From a gas barrier property viewpoint, it is preferable that the sum total does not exceed the mass of a vinylidene chloride type copolymer, It is more preferable that content in a vinylidene chloride type copolymer resin composition is less than 12 mass%. desirable.

Examples of the other additives include plasticizers, nucleating agents, antistatic agents, flame retardants, lubricants, easy agents, stabilizers, colorants such as pigments and dyes, and the like.

A plasticizer generally has the effect of lowering the elastic modulus of the material or lowering the melt viscosity of the resin, and is added to improve workability. For example, dioctyl phthalate, tributyl acetyl citrate, and dibutyl sebacate And carboxylic acid esters such as dioctyl sebacate and acetylated glycerides.

Examples of the lubricant include waxes such as polyethylene oxide wax, paraffin wax, polyethylene wax, montan acid ester wax, and calcium montanate; fatty acid esters such as glycerin monoester; mono or bisamides of fatty acids such as stearamide; have.

A stabilizer is added for the purpose of suppressing various chemical reactions which may occur in a material, For example, antioxidant, a hydrochloric acid collector, a light stabilizer, a dispersing agent, a ultraviolet absorber, surfactant, a pH adjuster, etc. are mentioned. Specifically, vitamin E, thiopropionic acid alkyl ester, sodium pyrophosphate, ethylenediamine tetraacetic acid, sodium ethylenediamine tetraacetic acid, glycerin fatty acid ester, fatty acid amide, etc. are mentioned.

Some of these additives have various functions such as a plasticizer, a dispersing aid, and a lubricant.

In this embodiment, especially about a plasticizer and a stabilizer, even if it contains or does not contain these from a gas barrier property, the sum total of both content (content rate in a vinylidene chloride-type copolymer resin composition) is 8 mass. It is made into% or less.

In addition, in this embodiment, from a gas barrier property viewpoint, it is preferable that the sum total of all content (content ratio in vinylidene chloride-type copolymer resin composition) of the other additive containing a plasticizer and a stabilizer is less than 8 mass%, and 7 It is also preferable that it is less than mass%, it is still more preferable that it is less than 2 mass%, and it is especially preferable that it is less than 1.5 mass%.

Moreover, about a plasticizer, it is preferable that content in a vinylidene chloride type copolymer resin composition is less than 0.2 mass%, It is more preferable that it is less than 0.1 mass%, It is especially preferable that it does not contain at all.

Even if the vinylidene chloride-based copolymer resin composition of the present embodiment does not contain a large amount of a plasticizer or a stabilizer, the melt viscosity is sufficiently low and can exhibit good extrusion processability.

It is preferable to add the additive which has a hydrochloric acid collection effect to the resin composition of this embodiment. When the vinylidene chloride-based copolymer resin composition having a low melt viscosity of the present embodiment contains an additive having a hydrochloric acid trapping effect, it has been found that the thermal stability is remarkably improved.

In the case where the vinylidene chloride copolymer is thermally decomposed, hydrochloric acid is generated, which is considered to be a catalyst and dehydrochloric acid is accelerated. Therefore, an improvement in thermal stability can be expected by adding an additive having a hydrochloric acid trapping effect to the vinylidene chloride copolymer and suppressing acceleration of dehydrochloric acid except for the hydrochloric acid described above. The reason for this is not clear, but the effect is more pronounced.

Here, when the additive which has a hydrochloric acid trapping effect (henceforth a "hydrochloric acid trapping agent") is mixed with 3 g of the said substance with respect to 97 g of vinylidene chloride type copolymers, it heats at 175 degreeC for 15 minutes. It means that the amount of hydrochloric acid (dehydrochloric acid) generated at is 0.05 g (500 ppm) or less.

As this hydrochloric acid collecting agent, an epoxy compound can be used as an organic type collecting agent, for example. Specific examples of the epoxy compound include epoxidized vegetable oil, epoxidized fatty acid ester, bisphenol A type epoxy resin, and the like. Examples of the epoxidized vegetable oils include epoxidized soybean oil, epoxidized linseed oil, epoxidized cottonseed oil, epoxidized safflower oil and the like.

In addition, examples of the inorganic collecting agent include inorganic ion exchangers such as hydrotalcites and zeolites, metal oxides, metal lead compounds, metal hydroxides, fatty acid metal soaps, and the like. For example magnesium oxide, calcium oxide, zinc oxide, lead monoxide, lead tetratrioxide, tribasic lead sulfate, lead dibasic phosphite, calcium hydroxide, sodium stearate, magnesium stearate, calcium stearate, sodium bicarbonate, sodium carbonate, ammonia, hydroxide Magnesium, copper hydroxide, aluminum hydroxide, iron hydroxide, etc. can be used, These can be used individually or in mixture.

Hydrotalcites are represented by the following general formula.

Mg _1-x Al _x (OH) ₂ (CO ₃ ) _{x /} 2mH ₂ O

(Wherein x is a number from 0 to 0.33, m is a number from 0 to 2)

The hydrotalcites shown by the said general formula can be manufactured by a well-known method, and a commercial item is also widely sold. As a specific example of the commercial item which can be used in this embodiment, the brand names "ALCAMIZER", "DHT-4", etc. made by Kyowa Chemical Industry Co., Ltd. are mentioned, for example.

In this embodiment, there is no limitation in the manufacturing method of a vinylidene chloride type copolymer resin composition, What is necessary is just to mix materials suitably according to a conventional method. The timing of mixing the vinylidene chloride copolymer with the MMA-BA copolymer, other additives, and the like is not limited, and is a slurry state after polymerization of the vinylidene chloride copolymer when the vinylidene chloride copolymer is in a monomer state before polymerization. When it is, in the drying process after superposition | polymerization of a vinylidene chloride type copolymer, you may be any timing after a polymer recovery after drying of a vinylidene chloride type copolymer.

At the time of mixing after polymer recovery of the vinylidene chloride copolymer after polymerization, for example, a mixer such as a high speed mixer such as a Henschel mixer, a ribbon blender, a turn blender, or the like can be used.

Moreover, about MMA-BA copolymer, you may add a latex phase at the time of drying.

In this embodiment, melt viscosity at 175 degreeC and a shear rate of 100 (1 / s) of a vinylidene chloride type copolymer resin composition shall be 800-2300 (Pa * s). According to the composition of this embodiment, it becomes possible to lower the melt viscosity of vinylidene chloride type copolymer resin composition to such a low value. It is more preferable that it is 800-2000 (Pa * s), and, as for melt viscosity, it is still more preferable that it is 800-1800 (Pa * s).

If the melt viscosity is in such a range, it is possible to prevent the deviation of the amount of resin in the resin flow direction during extrusion molding, the flow unevenness generated in the flow path of the die, etc., and as a result, the knitting and surface roughness, transparency and Surface glossiness is improved. Moreover, when a molded object is thin, such as a film or a tube, the thickness precision improves.

Moreover, when melt viscosity exists in such a range, the frequency of resin leakage in an extruder becomes low, and also the extrusion amount per unit time can be increased, and there also exists an advantage that productivity improves.

From such an advantage, it shows the outstanding effect also in single layer extrusion molding like a wrap film, or multilayer coextrusion molding containing another resin layer. Moreover, the same effect is exhibited in fiber spinning, such as melt spinning and wet spinning, injection molding, etc., and it is widely useful in various resin processing methods.

In addition, the vinylidene chloride-based copolymer resin composition of the present embodiment may be processed in a state of high melt viscosity which is conventionally employed when molding a vinylidene chloride-based copolymer alone, and in that case, at a lower heating temperature Since it can be set as the melt viscosity, it has an economic effect by energy saving.

The oxygen permeability (O ₂ TR value) (cc / 15 μm · m 2 · day · MPa) of the vinylidene chloride copolymer resin composition is generally determined by the copolymer composition of the vinylidene chloride copolymer contained therein. The value is not limited, and may be a value determined according to the use.

Example

Next, although an Example demonstrates this invention still in detail, this invention is not limited at all by these examples.

In the following example and the comparative example, the characteristic of the resin composition was measured as follows.

(1) melt viscosity (㎩ · s)

Using the Shimadzu Corporation make flow tester CFT-500D (die hole diameter phi 1 mm, die length 5 mm), the shear rate and melt viscosity in each load were measured at the temperature of 175 degreeC, and the melt viscosity curve was obtained.

Melt viscosity in shear rate 100 (1 / s) was obtained from the melt viscosity curve.

(2) oxygen permeability deterioration rate (B / A)

The degree of deterioration (increase) of the oxygen permeability (O ₂ TR value) (cc / 15 μm · m 2 · day · MPa) by addition of the acrylic copolymer was evaluated.

Examples, comparative examples vinylidene chloride that were not added to the copolymer resin composition and the acrylic type copolymer other than the standard value of the oxygen permeability of the extruded film-forming composition having the same composition loaded with a (standard O ₂ TR value A), and this The ratio (B / A) of oxygen permeability (O ₂ TR value: B after addition) of the evaluation film of the vinylidene chloride copolymer resin composition of Examples and Comparative Examples for the above was calculated by the following calculation formula, and the oxygen permeability deteriorated. It was evaluated as a rate (it is also undesirable because the deterioration rate exceeds 1.5, since the commodity value is markedly impaired).

[Oxygen permeability deterioration rate] (B / A) = [O ₂ TR value after addition] / [Standard O ₂ TR value]

The measurement of oxygen permeability was performed about the film of 15 micrometers in thickness on condition of 23 degreeC and 65% RH using the oxygen transmittance | permeability measuring apparatus (Mocon OX-TRAN 2/20).

(3) knitting

The flow direction of the film formed into a film so that thickness might be set to 30 micrometers using Yamabin Electric Co., Ltd. tabletop type off-line contact thickness measuring apparatus TOF-5R, and using the vinylidene chloride-type copolymer resin composition of an Example and a comparative example. The thickness (micrometer) of was measured continuously. It measured about the film of 1 m in length, and evaluated the difference of the maximum value and minimum value of the obtained measured value based on the following criteria.

  Rating symbol Difference between maximum value and minimum value (㎛)

◎ 0 or more and 2.0 or less

○ Greater than 2.0 and less than 5.0

△ Greater than 5.0 and above 6.0

× Greater than 6.0

(4) transparency (HAZE value)

In accordance with ASTM D-1003, the transparency of the 15-micrometer-thick film formed by using the vinylidene chloride-based copolymer resin composition of Examples and Comparative Examples was 23 ° C. and 50% with a turbidimeter (NDH 5000 manufactured by Nippon Denshoku Industries Co., Ltd.). It measured on the conditions of RH.

(5) film forming properties

Using the apparatus of FIG. 1, the film forming property was evaluated as follows about the vinylidene chloride-type copolymer resin composition of an Example and a comparative example.

The vinylidene chloride-based resin composition is supplied from the hopper portion 102 of the extruder 101, propelled by the screw 103, heated and kneaded to melt, and slit of the annular die 104 attached to the tip of the extruder 101. Extrusion was carried out to obtain parison 105 normally. The parison 105 is quenched with cold water of the cooling tank 106, guided to the pinch rolls A and A ', and then preheated in the hot water tank 107, and the pinch roll groups B, B' and C , C ').

Subsequently, normally, air is enclosed in the parison 105, and the operation of stretching by the volume ratio of the air and the speed ratio between the pinch rolls (B, B ', C, C') is repeated 10 times, and all 10 times. ◎, 8 to 9 times out of 10 times, △, 5 to 7 times out of 10 times, △, 0 to 4 times out of 10 times Usually, what was able to hold | maintain a film was made into x.

(6) thermal stability (die disassembly and cleaning interval)

It is to evaluate the thermal stability of the resin with respect to the retention of the resin in the die. If the slipperiness between the wall surface and the molten resin in the die is poor, the retained resin is thermally deteriorated and adheres to the die. When the degree becomes serious, a film thickness nonuniformity and a stripe generate | occur | produce. If streaky contamination occurs continuously or the film thickness unevenness is significantly worsened, it is necessary to stop the extruder, disassemble and clean the die, and the production efficiency is significantly reduced. The length of time of continuous extrusion until it became such a state was evaluated based on the following criteria.

  Rating symbol Time until continuous extrusion is not possible

◎ More than 4000 hours

○ More than 1000 hours, less than 4000 hours

△ More than 100 hours, less than 1000 hours

× Less than 100 hours

(7) weight average molecular weight

It calculated | required by the gel permeation chromatography method which made polystyrene the standard with the following apparatus and conditions.

GPC: Shimazu Corporation manufacture LC-10AD

Column ： Combination of Shodex Asahipak GS-710 7E and GS-310 7E

Measurement temperature: 40 degrees Celsius

Measurement concentration: 0.3 mass% of the sample was dissolved in a solvent of hexamethyl phosphate triamide.

Example 1

As a vinylidene chloride-based copolymer, a binary copolymer of vinylidene chloride and vinyl chloride (SP value: 9.5 (cal / cm 3) ^1/2 ) (vinylidene chloride: 88% by mass, vinyl chloride: 12% by mass, weight average) The molecular weight 90,000) is a ternary copolymer of methyl methacrylate, butyl acrylate and styrene (Methyl methacrylate: 35 mol%, butyl acrylate: 20 mol%, styrene: 45 mol%, weight average) as MMA-BA copolymer (Molecular weight 100,000) (manufactured by Kaneka Corporation, PA-101) was used.

The MMA-BA copolymer, the plasticizer (acetyl butyl citrate (hereinafter ATBC, ATBC manufactured by Asahi Chemical Finechem Co., Ltd.), dibutyl sebaxate (hereinafter referred to as DBS, to the vinylidene chloride copolymer) to the mass% shown in Table 1) DS-80) manufactured by Takaoka Chemical Co., Ltd.) and a hydrochloric acid collecting agent (epoxylated soybean oil (hereinafter ESO, Nichi Oil Co., Ltd., Newizer 510R)) were added, and mixed with a Henschel mixer to obtain a resin composition.

Example 2

The point using the binary copolymer of vinylidene chloride and vinyl chloride (vinylidene chloride: 83 mass%, vinyl chloride: 17 mass%, weight average molecular weight 120,000) as a vinylidene chloride type copolymer, and MMA-BA copolymer, ATBC , The resin composition was obtained like Example 1 except having changed the content rate of DBS and ESO as shown in Table 1.

Example 3

The point using the binary copolymer of vinylidene chloride and vinyl chloride (vinylidene chloride: 88 mass%, vinyl chloride: 12 mass%, weight average molecular weight 110,000) as a vinylidene chloride type copolymer, and MMA-BA copolymer, ATBC , The resin composition was obtained like Example 1 except having changed the content rate of DBS and ESO as shown in Table 1.

[Examples 4 and 7]

Points using a binary copolymer of vinylidene chloride and vinyl chloride (vinylidene chloride: 90 mass%, vinyl chloride: 10 mass%, weight average molecular weight 120,000) as the vinylidene chloride-based copolymer, and MMA-BA copolymer, ATBC , The resin composition was obtained like Example 1 except having changed the content rate of DBS and ESO as shown in Table 1.

Example 5

As MMA-BA copolymer, binary copolymer of methyl methacrylate and butyl acrylate (methyl methacrylate: 55 mol%, butyl acrylate: 45 mol%, weight average molecular weight: 200,000) (Mitsubishi Rayon Corporation make, L- Except having used 1000), it carried out similarly to Example 4 and obtained the resin composition.

Example 6

MMA-BA copolymer and ATBC using the binary copolymer of vinylidene chloride and vinyl chloride (vinylidene chloride: 90 mass%, vinyl chloride: 10 mass%, weight average molecular weight 120,000) as a vinylidene chloride type copolymer , The content ratio of DBS and ESO was changed as shown in Table 1, and the polyethylene wax (High Wax 320P manufactured by Mitsui Chemicals, Inc.) was added in the same manner as in Example 1 except that the amount of mass% shown in Table 1 was added. And the resin composition was obtained.

Comparative Example 1

Containing ATBC, DBS, and ESO as a vinylidene chloride copolymer using a binary copolymer of vinylidene chloride and vinyl chloride (vinylidene chloride: 90 mass%, vinyl chloride: 10 mass%, weight average molecular weight 120,000) The ratio was changed as shown in Table 1, and it carried out similarly to Example 1 except having removed the MMA-BA copolymer, and obtained the resin composition.

Example 8

As a vinylidene chloride-based copolymer, a binary copolymer of vinylidene chloride and methyl acrylate (SP value: 10.0 (cal / cm 3) ^1/2 ) (vinylidene chloride: 95 mass%, methyl acrylate: 5 mass%, weight average) The molecular weight 70,000) was used as the MMA-BA copolymer with respect to the vinylidene chloride copolymer using the same terpolymer (PA-101) of methyl methacrylate, butyl acrylate, and styrene as used in Example 1 , MMA-BA copolymer and the hydrochloric acid collector (ESO) were added so that it might become mass% shown in Table 1, it mixed by the Henschel mixer, and obtained the resin composition.

Example 9

A resin composition was obtained in the same manner as in Example 8 except that the same binary copolymer (L-1000) of methyl methacrylate and butyl acrylate as in Example 5 was used as the MMA-BA copolymer.

Example 10

In addition, the resin composition was obtained like Example 9 except having added hydrotalcite (HT) (made by Kyowa Chemical Industry Co., Ltd., ALCAMIZER2) as the mass% shown in Table 1 as a hydrochloric acid collector.

Comparative Example 2

The resin composition was obtained like Example 8 except having changed the addition amount of MMA-BA copolymer (PA-101) into the quantity used as the mass% shown in Table 1.

Comparative Example 3

A resin composition was obtained in the same manner as in Example 8 except that the MMA-BA copolymer was not contained.

Example 11

As a vinylidene chloride-based copolymer, a binary copolymer of vinylidene chloride and methyl acrylate (SP value: 10.0 (cal / cm 3) ^1/2 ) (vinylidene chloride: 92 mass%, methyl acrylate: 8 mass%, weight average) A molecular weight of 70,000) was used as the MMA-BA copolymer, and the same tertiary copolymer (PA-101) of methyl methacrylate, butyl acrylate and styrene as used in Example 1 was used for the vinylidene chloride copolymer. The MMA-BA copolymer and the hydrochloric acid collector (ESO) of the quantity used as the mass% shown in Table 1 were added, it mixed by the Henschel mixer, and the resin composition was obtained.

[Comparative Example 4]

A resin composition was obtained in the same manner as in Example 11 except that the hydrochloric acid collector (ESO) was not added.

Melt viscosity, thermal stability, film forming property at 175 degreeC and the shear rate 100 (1 / s) of the composition of Examples 1-11 and Comparative Examples 1-4 and the obtained vinylidene chloride type copolymer resin composition below. , Values of knitting, transparency and oxygen permeability deterioration rate (B / A) are shown.

The vinylidene chloride-based copolymer resin composition of the present invention can be used for various applications because the vinylidene chloride-based copolymer resin composition has low melt viscosity, excellent extrusion processability, and film forming property while maintaining transparency and gas barrier properties equivalent to those of the vinylidene chloride-based copolymer alone. .

In particular, it can use suitably as a material of thin molded objects, such as a film and a tube.

Claims (4)

A vinylidene chloride copolymer having a weight average molecular weight of 50,000 to 200,000, containing vinylidene chloride and other monomers copolymerizable with vinylidene chloride as monomer components,
Containing an acrylic copolymer containing methyl methacrylate and butyl acrylate as monomer components,
Melt viscosity in 175 degreeC and shear rate 100 (1 / s) is 800-2300 (Pa * s),
The vinylidene chloride copolymer resin composition which does not contain a plasticizer and a stabilizer, or whose sum total of both is 8 mass% or less. The method of claim 1,
A vinylidene chloride copolymer resin composition having a weight average molecular weight of the acrylic copolymer of 80,000 to 200,000. The method according to claim 1 or 2,
The vinylidene chloride type copolymer resin composition in which the said vinylidene chloride type copolymer contains 70 mass% or more of vinylidene chloride as a monomer component. The method according to any one of claims 1 to 3,
Except for the acrylic copolymer, the O ₂ TR value (oxygen permeability) of the composition having the same composition as the vinylidene chloride copolymer resin composition was defined as A,
When the O ₂ TR values of the vinylidene chloride copolymer resin composition B, B / A is 1.5 or less vinylidene chloride copolymer resin composition.

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