JP2022048611A - Resin composition, wrap film and wrap film case - Google Patents

Abstract

To provide a resin composition that has excellent thermal stability and can reduce the amount of additive eluted from a wrap film, a wrap film formed from the resin composition, and a wrap film case containing the wrap film.SOLUTION: A resin composition according to one aspect of the present invention includes a polyvinyl chloride resin, an epoxidized vegetable oil, and a compound having an epoxy group with an ester compound induced from glycerol and/or a derivative thereof. The total content of the epoxidized vegetable oil and the compound is 1-13 pts.mass relative to 100 pts.mass of the polyvinyl chloride resin.SELECTED DRAWING: None

Description

The present invention relates to a resin composition, a wrap film and a wrap film container.

Wrap films are widely used for business purposes in hotels, restaurants, etc., or at home for food preservation, cooking, and the like. Additives such as a plasticizer, an anti-fog agent, and a stabilizer are generally added to the wrap film for the purpose of imparting functions such as flexibility to the film and facilitating the production of the film. As a plasticizer used in the wrap film, for example, a polyester compound (polyester plasticizer) is known (see Patent Document 1).

In recent years, in the study of matching the standards and standards of the Food Sanitation Law with other countries, it is required to suppress the amount of additives transferred from the wrap film to food. For example, in Patent Document 2, it is studied to reduce the amount of the additive eluted from the wrap film.

Japanese Unexamined Patent Publication No. 2013-119624 Japanese Unexamined Patent Publication No. 2018-184617

If an attempt is made to reduce the amount of the additive eluted from the wrap film, the thermal stability of the resin composition is inferior and the productivity tends to be lowered. It is desired that the resin composition for producing a wrap film has both low elution property and thermal stability.

INDUSTRIAL APPLICABILITY The present invention includes a resin composition having excellent thermal stability and capable of reducing the amount of additives eluted from the wrap film, a wrap film formed from the resin composition, and a wrap film containing the wrap film. The purpose is to provide the body.

One aspect of the present invention contains a polyvinyl chloride resin, an epoxidized vegetable oil, and a compound having a partial structure and an epoxy group represented by the following formula (1), and contains the epoxidized vegetable oil and the above compound. The amount is 1 to 13 parts by mass with respect to 100 parts by mass of the polyvinyl chloride resin, which is a resin composition. In formula (1), R ¹ represents an alkylene group.

Another aspect of the present invention is a wrap film comprising a layer containing the above resin composition. Another aspect of the present invention is a wrap film accommodating body including a winding core, the above-mentioned wrap film wound around the winding core, and a box body for accommodating the winding core and the film.

According to the present invention, a resin composition having excellent thermal stability and capable of reducing the amount of additives eluted from the wrap film, a wrap film formed from the resin composition, and a wrap provided with the wrap film. A film container can be provided.

It is a perspective view which shows the wrap film accommodating body which concerns on one Embodiment.

An embodiment of the present invention will be described with reference to the drawings as necessary. However, the present invention is not limited to the following embodiments.

[Resin composition]
The resin composition according to one embodiment is a polyvinyl chloride resin (hereinafter, may be referred to as “(A) component”) and an epoxidized vegetable oil (hereinafter, may be referred to as “(B) component”). And a compound having a partial structure represented by the following formula (1) and an epoxy group (hereinafter, may be referred to as “component (C)”). The content of the epoxidized vegetable oil and the above compound in the resin composition is 1 to 13 parts by mass with respect to 100 parts by mass of the polyvinyl chloride resin. Such a resin composition is excellent in thermal stability and can reduce the amount of the additive eluted from the wrap film. The elution amount of the additive can be determined by immersing the wrap film in heptane and measuring the amount of the component extracted in heptane (hereinafter, may be referred to as "heptane extraction amount").

(Component (A): polyvinyl chloride resin)
The resin composition according to one embodiment contains a polyvinyl chloride-based resin as a main component. The polyvinyl chloride resin as the component (A) preferably contains a polyvinyl chloride resin having an average degree of polymerization of 700 to 1300 from the viewpoint of excellent moldability, thermal stability and fluidity during wrap film molding. The average degree of polymerization in the present specification means the average degree of polymerization measured according to JIS K6720-2.

The polyvinyl chloride-based resin may be a vinyl chloride homopolymer (polyvinyl chloride resin) from the viewpoint of excellent mechanical properties, and may be copolymerized with vinyl chloride for the purpose of imparting other properties. It may be a copolymer with a monomer. The copolymer may be a graft copolymer, a block copolymer or a random copolymer. Examples of other monomers include olefins such as ethylene, propylene and butene; vinyl esters of saturated acids such as vinyl acetate and vinyl laurate; alkyl esters of unsaturated acids such as acrylic acid methyl ester and methacrylic acid methyl ester; lauryl. Alkyl vinyl ethers such as vinyl ethers; maleic acid, acrylonitrile, styrene, methylstyrene, vinylidene fluoride; and the like can be mentioned.

When the polyvinyl chloride resin is a copolymer, the content of the vinyl chloride unit in the copolymer may be 10% by mass or more based on the total amount of the monomer units, and is preferably 30 from the viewpoint of excellent mechanical properties. By mass or more, more preferably 50% by mass or more. The upper limit of the content of the vinyl chloride unit in the copolymer is not particularly limited, and may be, for example, 99% by mass or less based on the total amount of the monomer units.

The polyvinyl chloride resin may be, for example, a polymer blend with a three-dimensional polymer of acrylonitrile-butadiene-styrene, a post-treated product with alcohol or the like, or a post-treated product with a chlorine-containing compound. In these cases, the content of the vinyl chloride unit in the polyvinyl chloride resin may be 10% by mass or more based on the total amount of the resin.

The content of the component (A) may be 60% by mass or more, 70% by mass or more, or 75% by mass or more, and 90% by mass or less, 85% by mass, based on the total amount of the resin composition, from the viewpoint of excellent productivity. % Or less, or 80% by mass or less.

((B) component: epoxidized vegetable oil)
The resin composition according to the present embodiment can improve the thermal stability by containing the epoxidized vegetable oil as the component (B). Examples of the epoxidized vegetable oil include epoxidized soybean oil and epoxidized linseed oil. The component (B) preferably contains epoxidized soybean oil.

(Component (C): a compound having a partial structure represented by the formula (1) and an epoxy group)
The resin composition according to the present embodiment can improve the thermal stability of the resin composition by containing a compound having a partial structure represented by the following formula (1) and an epoxy group as the component (C). can.

In formula (1), R ¹ represents an alkylene group. The alkylene group may be linear or branched. The carbon number of the alkylene group may be 2 or more, 3 or more, or 4 or more, 8 or less, 7 or less, 6 or less, 5 or less, or 4 or less, and 2 to 8, 2 to 7, 2 ~ 6, 2 ~ 5, 2 ~ 4, 3 ~ 8, 3 ~ 7, 3 ~ 6, 3 ~ 5, 3 ~ 4, 4 ~ 8, 4 ~ 7, 4 ~ 6, or 4 ~ 5. good. The alkylene group may be an alkylene group having 4 carbon atoms (butylene group) or a linear alkylene group having 4 carbon atoms (n-butylene group).

The component (C) preferably contains a compound represented by the following formula (2).

In formula (2), R ¹ is synonymous with R ¹ in formula (1), R ² to R ⁵ each independently represent an alkylene group, and R ⁶ to R ⁹ each independently represent an alkyl group. m1 and m2 are independently integers of 1 or more, and n1 and n2 are independently integers of 0 or more. The alkylene groups represented by ^R2 to ^R5 may be linear or branched independently of each other. The alkyl groups represented by R ⁶ to R ⁹ may be linear or branched independently of each other.

The carbon number of the alkylene group represented by R ² , R ³ , R ⁴ , or R ⁵ may be 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, or 7 or more, and 12 or less, 11 or less. It may be 10 or less, 9 or less, 8 or less, or 7 or less, 2 to 12, 2 to 11, 2 to 10, 2 to 9, 2 to 8, 2 to 7, 3 to 12, 3 to 11, 3-10, 3-9, 3-8, 3-7, 4-12, 4-11, 4-10, 4-9, 4-8, 4-7, 5-12, 5-11, 5- 10, 5-9, 5-8, 5-7, 6-12, 6-11, 6-10, 6-9, 6-8, 6-7, 7-12, 7-11, 7-10, It may be 7 to 9 or 7 to 8. The alkylene group may be an alkylene group having 7 carbon atoms (heptene group) or a linear alkylene group having 7 carbon atoms (n-heptene group).

m1 and m2 may be independently integers of 2 or more, 3 or more, or 4 or more, and may be integers of 4 or less, 3 or less, or 2 or less, 1 to 4, 1 to 3, 1 It may be an integer of ~ 2, 2-4, or 2-3. m1 and m2 may be 1.

n1 and n2 may be independently integers of 1 or more, 2 or more, or 3 or more, and may be integers of 3 or less, 2 or less, or 1 or less, and may be 0 to 3, 0 to 2, 0. It may be an integer of ~ 1, 1 ~ 3, or ~ 1 ~ 2. n1 and n2 may be 0.

When m1, n1, m2 and n2 are integers of 2 or more, a plurality of R ^2s may be the same or different from each other, and a plurality of R ^3s may be the same or different from each other, and a plurality of R ^4s may exist. ^May be the same or different from each other, and a plurality of R5s may be the same or different from each other.

The number of carbon atoms of the alkyl group represented by R ⁶ or R ⁹ may be 4 or more, 5 or more, 6 or more, 7 or more, or 8 or more, and is 12 or less, 11 or less, 10 or less, 9 or less, or 8 or less. It may be 4 to 12, 4 to 11, 4 to 10, 4 to 9, 4 to 8, 5 to 12, 5 to 11, 5 to 10, 5 to 9, 5 to 8, 6 to 12, 6 It may be ~ 11, 6-10, 6-9, 6-8, 6-7, 7-12, 7-11, 7-10, 7-9, or 7-8. The alkylene group may be an alkyl group having 8 carbon atoms (octyl group) or a linear alkyl group having 8 carbon atoms (n-octyl group).

The number of carbon atoms of the alkyl group represented by R ⁷ or R ⁸ may be 1 to 8, 1 to 7, 1 to 6, 1 to 5, 1 to 4, 1 to 3, or 1 to 2. The alkyl group may be an alkyl group (methyl group) having 1 carbon atom.

The component (C) may contain a compound represented by the following formula (3). The compound represented by the formula (3) is a compound in which m1 and m2 are 1 and n1 and n2 are 0 in the formula (2). In formula (3), R ¹ , R ² and R ⁵ to R ⁹ are synonymous with R ¹ , R ² and R ⁵ to R ⁹ in formula (2), respectively.

The component (C) is a compound represented by the following formula (4) (in the formula (2), m1 and m2 are 1, n1 and n2 are 0, ^R1 is an n ^- butylene group, and ^R2 and R5 are n. -A compound in which a heptylene group, R ⁶ and R ⁹ are n-octyl groups, and R ⁷ and R ⁸ are methyl groups) may be contained. In the formula (2), the compound represented by the formula (4) has m1 and m2 of 1, n1 and n2 of 0, ^R1 of an n ^- butylene group, ^R2 and R5 of an n ^- heptylene group, and R6. And R ⁹ are n-octyl groups, and R ⁷ and R ⁸ are methyl groups.

The molecular weight of the component (C) is preferably 500 to 5000, preferably 600 or more, 700 or more, 800 or more, or 900 or more, from the viewpoint of further excellent thermal stability, and may be 3000 or less, 2500 or less, 2000. It may be less than or equal to 1500 or less than 1500.

The contents of the component (B) and the component (C) are 1 part by mass or more with respect to 100 parts by mass of the component (A) from the viewpoint of thermal stability, required characteristics of the wrap film and productivity, and 3 It may be 3 parts by mass or more, 5 parts by mass or more, or 7 parts by mass or more, and from the viewpoint of reducing the amount of heptane extracted, it may be 13 parts by mass or less, 12 parts by mass or less, or 11 parts by mass or less.

The content of the component (C) is preferably 50 to 70% by mass, preferably 53 to 68% based on the total amount of the component (B) and the component (C) from the viewpoint of further enhancing the thermal stability of the resin composition. It may be% by mass or 55 to 65% by mass.

The component (C) can be synthesized, for example, by the following method. First, glycerol-3-phosphate is acylated with an unsaturated fatty acid, and the obtained product is desorbed from the phosphate group to synthesize diacylglycerol. The diacetylglycerol is then epoxidized and the resulting product is reacted with a dicarboxylic acid to dehydrate it.

(Component (D): Polyester-based plasticizer)
The resin composition according to one embodiment may further contain a polyester-based plasticizer as the component (D). Examples of the polyester-based plasticizer include aliphatic polybasic acid-based polyesters.

The aliphatic polybasic acid-based polyester may be, for example, a polyester resin containing an aliphatic polybasic acid such as adipic acid or sebacic acid and a polyhydric alcohol such as ethylene glycol, propylene glycol or butanediol. Examples of the aliphatic polybasic acid polyester include poly (ethylene glycol / adipate) ester, poly (1,3-butanediol / adipate) ester, and poly (1,4-butanediol / adipate) ester. Examples thereof include poly (propylene glycol / sebacic acid) esters. These polyester-based plasticizers may be used alone or in combination of two or more.

The weight average molecular weight (Mw) of the component (D) is preferably 1000 to 3000. The Mw of the component (D) may be 1500 or more, 1800 or more, or 2000 or more from the viewpoint of reducing the elution of the plasticizer from the wrap film, and the compatibility with other components is improved to improve the compatibility of the resin composition. From the viewpoint of lowering the viscosity of the above, it may be 2800 or less, 2600 or less, or 2400 or less. Mw can be determined by gel permeation chromatography (GPC) method.

(Component (E): Aliphatic polybasic acid-based ester plasticizer)
The resin composition according to one embodiment is a fat having a plasticization efficiency of 0.90 or less as the component (E) from the viewpoint of reducing the amount of the additive eluted from the wrap film and further improving the thermal stability. A group polybasic acid-based ester plasticizer may be further contained. The plasticization efficiency is a numerical value of the amount of plasticizer required to obtain the same degree of plasticization effect when the plasticization efficiency of DOP (dioctyl phthalate) is 1.00. The smaller the value, the more plastic the product. Excellent efficiency. When the plasticization efficiency of the component (E) is 0.90 or less, the amount of heptane extracted from the wrap film can be easily reduced, and the thermal stability and productivity can be easily improved.

The component (E) is a compound different from the component (D). Examples of the component (E) include aliphatic dibasic acid esters and acetylated monoglyceride. The aliphatic dibasic acid ester may be an ester of an aliphatic dicarboxylic acid and an aliphatic alcohol, and examples thereof include dialkyl adipate, which is an ester of adipic acid and an aliphatic alcohol having 1 to 10 carbon atoms. .. The acetylated monoglyceride may be, for example, a compound in which two of the hydroxyl groups of glycerin are acetylated and the remaining one is esterified with a fatty acid. The fatty acid may be, for example, a fatty acid having 3 to 8 carbon atoms. Examples of the acetylated monoglyceride include glycerin diacet monolaurate.

The content of the component (E) may be 1 part by mass or more, 2 parts by mass or more, or 5 parts by mass or more, and 15 parts by mass or less and 12 parts by mass or less with respect to 100 parts by mass of the polyvinyl chloride resin. , Or 10 parts by mass or less.

The resin composition may further contain other additives in addition to the above-mentioned components. Other additives include, for example, antifogging agents, heat stabilizers, light stabilizers, colorants, plasticizers, lubricants, fillers, antistatic agents, antioxidants, mold release agents, viscosity reducing agents, and surfactants. Examples thereof include activators, fluorescent agents, surface treatment agents, cross-linking agents, processing aids, pressure-sensitive adhesives, antistatic agents, ultraviolet absorbers, and anti-blocking agents. When the resin composition contains other additives, the content (total content) of the other additives may be, for example, 1 part by mass or more with respect to 100 parts by mass of the polyvinyl chloride resin. , 30 parts by mass or less.

The colorant may be, for example, a blue colorant, a red colorant, a yellow colorant, a green colorant, a purple colorant, or the like. The colorant may be used alone or in combination of two or more.

The blue colorant may be, for example, a colorant having a maximum absorption wavelength of 600 to 750 nm in the visible light region (wavelength: the entire range of 380 to 750 nm). The absorbance of the blue colorant at the maximum absorption wavelength in the visible light region is preferably 2 times or more, more preferably 3 times or more the absorbance at a wavelength of 470 nm. Specifically, the blue colorant may be copper phthalocyanine (copper phthalocyanine blue), iron (II) hexacyanoferrate (III), a mixture of primary cobalt oxide and aluminum oxide, indigo or ultramarine. The blue colorant is preferably a blue pigment from the viewpoint of further improving the strength, dispersibility and solvent resistance.

The stabilizer may be calcium / zinc-based metal soap or hydrotalcite.

[Wrap film]
The resin composition according to this embodiment is preferably used for a wrap film. One embodiment of the present invention is a wrap film comprising a layer containing the above-mentioned resin composition. The wrap film according to the present embodiment is particularly preferably used for packaging foods because the amount of the additive eluted into the food can be reduced.

The wrap film may consist of only one layer containing the components (A) to (C), or may consist of a plurality of layers. When the wrap film is composed of a plurality of layers, the wrap film may include, for example, a first surface layer, an intermediate layer, and a second surface layer in this order. In this case, for example, the first and second surface layers contain the components (A) to (C) and additives added as needed, and the intermediate layer contains the components (A) and added as needed. May contain additives. The wrap film may be further provided with an adhesive layer containing an acid-modified polyolefin resin or the like in order to improve the adhesiveness between the layers, and the polyamide resin may be further provided in order to improve the thermal stability of the wrap film. A heat-resistant layer containing the above may be further provided.

The thickness of the wrap film may be preferably 5 μm or more, more preferably 6 μm or more from the viewpoint of efficiently blocking food from the outside air, and preferably 20 μm or less, more preferably 20 μm or less from the viewpoint of excellent handleability. It may be 18 μm or less, more preferably 12 μm or less.

The total light transmittance of the wrap film is preferably 75% or more, more preferably 80% or more, and may be, for example, 90% or less from the viewpoint of excellent visibility. The total light transmittance can be calculated by measuring the incident light amount and the total transmitted light amount according to JIS K7361-1 and setting the total light transmittance = (total transmitted light amount) / (incident light amount) × 100.

In the wrap film, for example, the components (A) to (C) and, if necessary, the above-mentioned additives are mixed by a mixer such as a V-type blender, a ribbon blender, a henschel mixer, a super mixer, and further, if necessary. The composition is obtained by kneading with a kneader such as a mixing roll, a Banbury mixer, or a kneader, and then produced by, for example, extrusion molding. Specifically, the composition is supplied to the hopper of the extruder to obtain a target wrap film by an inflation method, a plastomill T-die method, or the like.

The wrap film may be composed of one layer or may be composed of a plurality of layers. When the wrap film is composed of a plurality of layers, the wrap film is obtained by putting the constituent raw materials of each layer into separate extruders, melt-extruding them, and co-extruding each layer by an inflation method, a T-die method, or the like to laminate them. Be done. At this time, it is preferable to form a wrap film by taking the melt extruded from the T-die as it is while quenching it with a casting roll or the like.

With respect to the wrap film thus obtained, vertical stretching between heating rolls, various heat fixing, etc. are performed according to the purpose of reducing the heat shrinkage rate, the natural shrinkage rate, etc., and suppressing the occurrence of width shrinkage. Heat treatment such as aging may be performed, and for the purpose of improving antifogging property, antistatic property, adhesiveness and the like, corona treatment, aging treatment, printing, surface treatment such as coating, surface treatment and the like may be performed.

[Wrap film container]
For example, a wrap film is formed into a product by being formed on a long length, wound, and then further rewound (wound) into a desired length such as 20 m or 50 m and packed in a box. To. The wrap film in the present embodiment may be in the form of a wrap film wound around a winding core, or may be in the form of a wrap film housed in a box body.

FIG. 1 is a perspective view showing a wrap film accommodating body according to an embodiment. As shown in FIG. 1, the wrap film accommodating body 1 according to the embodiment includes a wrap film 2, a winding core 3 around which the wrap film is wound, and a box body 4 accommodating the wrap film 2 and the winding core 3. It is equipped with. The box body 4 may be provided with a blade portion 5 for cutting the wrap film 2. The materials of the winding core 3 and the box body 4 are not particularly limited. From the viewpoint of making it easy to recognize the color of the wrap film from the outside, at least a part of the box body 4 is preferably transparent or has holes to the extent that the function as a box is not impaired so that the inside can be visually recognized from the outside. It has become.

In general, a "film" is a thin, flat product that is extremely small in thickness and width relative to its length and width, and whose maximum thickness is arbitrarily limited, and can be supplied in the form of rolls (if necessary). (For example, Japanese Industrial Standards JIS K6900 can be referred to), generally, "sheet" means a product that is thin by definition in JIS and whose thickness is generally small and flat for its length and width. However, since the boundary between the sheet and the film is not fixed and it is not necessary to distinguish between the two in the present embodiment, even if the term "film" is used in the present specification, the "sheet" is included and the "sheet" is used. Even if it is referred to as "film", it shall be included. Further, "film" is a concept including a wrap film in particular in the above definition.

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to Examples.

[Resin composition]
The following components were mixed in the blending amounts (parts by mass) shown in Table 1 to prepare resin compositions of Examples and Comparative Examples.
(A) Component: Vinyl chloride resin (Average degree of polymerization: 1050)
(B) Ingredient: Epoxidized soybean oil (manufactured by Sanwa Synthetic Chemical Co., Ltd., "Chemisizer SE-100")
Component (C): Di (2-acetate, 3-epoxyoleate) glyceryl adipate (compound of formula (4))
(D) Ingredient: Adipic acid polyester (Mw: 2300)
(E) Ingredient: Dioctyl adipate (Plasticization efficiency: 0.85)
Antifogging agent: Mixture stabilizer of polyglycerin fatty acid ester, glycerin fatty acid, and sorbitan fatty acid ester Stabilizer: Ca—Zn-based stabilizer (manufactured by ADEKA Co., Ltd., “SC-308E”)

(Evaluation of thermal stability)
60 g of each resin composition is put into a roller mixer R60 type attached to a lab plast mill (manufactured by Toyo Seiki Seisakusho Co., Ltd., "4C150-01") and kneaded at 210 ° C. and 60 rpm to dynamically heat the resin composition. Stability was evaluated. The dynamic thermal stability time was defined as the time required to reach a torque value of 150% from the value of the steady torque. It can be said that the longer the dynamic thermal stability time, the better the thermal stability.

(Evaluation of additive elution amount (heptane extraction amount))
Each resin composition was extruded at a resin temperature of 200 ° C. with a Plast Mill T-die extruder to prepare a wrap film having a thickness of 8.0 μm. A sample of a certain area is cut from the wrap film, immersed in a heptane solution of 2 mL per 1 cm ² of the surface area at a temperature of 25 ° C. for 1 hour, the solution is evaporated to dryness, and the weight is measured from the wrap film to the heptane solution. The amount of migration was calculated. It can be said that the smaller the transfer amount, the more the elution amount of the additive can be suppressed.

1 ... Wrap film housing, 2 ... Wrap film, 3 ... Core, 4 ... Box, 5 ... Blade.

Claims (8)

It contains a polyvinyl chloride resin, an epoxidized vegetable oil, and a compound having a partial structure represented by the following formula (1) and an epoxy group.
A resin composition in which the contents of the epoxidized vegetable oil and the compound are 1 to 13 parts by mass with respect to 100 parts by mass of the polyvinyl chloride resin.

[In formula (1), R ¹ represents an alkylene group. ] The resin composition according to claim 1, wherein the compound has a molecular weight of 500 to 5000. The resin composition according to claim 1 or 2, further containing a polyester-based plasticizer. The resin composition according to claim 3, wherein the polyester-based plasticizer has a weight average molecular weight of 1000 to 3000. The resin composition according to any one of claims 1 to 4, wherein the content of the compound is 50 to 70% by mass based on the total amount of the epoxidized vegetable oil and the compound. A wrap film comprising a layer containing the resin composition according to any one of claims 1 to 5. The wrap film according to claim 6, which is used for packaging foods. With the core and
The wrap film according to claim 6 or 7, which is wound around the core.
A wrap film accommodating body comprising the winding core and a box body accommodating the wrap film.

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