KR20050030306A - Biodegradble composition having improved water resistance and release property - Google Patents

Abstract

Provided is a biodegradable composition which is improved in releasing property and water fastness and can be used to produce a molded product such as a container having depth massively. The biodegradable composition comprises 100 parts by weight of a natural polymer; 20-60 parts by weight of a fiber powder; 10-40 parts by weight of an acrylate copolymer; and 1-10 parts by weight of a releasing agent. Preferably the acrylate copolymer is represented by the formula 1, wherein R1 and R2 are independently a C1-C12 alkyl group, an alkoxyalkyl group, a hydroxyalkyl group, a glycidyl group or a 2-(dimethylamino)ethyl group; R3 and R4 are independently a repeating unit derived from (meth)acrylic acid, N-methylol acrylamide, styrene, vinyl acetate, vinyl alcohol, acrylonitrile, acrylamide, maleic anhydride, maleic acid, 1,3-butadiene, diallyl phthalate, itaconic acid or neopentyl glycol; l is 0.2-0.6; m is 0.1-0.6; n is 0.05-0.5; and x is 0.05-0.5.

Description

Biodegradable composition with improved water resistance and releasability {BIODEGRADBLE COMPOSITION HAVING IMPROVED WATER RESISTANCE AND RELEASE PROPERTY}

The present invention relates to a biodegradable composition having improved water resistance and releasability, and more particularly, to a biodegradable composition which can easily fall out of a mold when forming a product such as a container using a heat press molding machine and has excellent water resistance.

Many studies have been conducted to develop environmentally friendly disposable containers using biodegradable natural polymer and starch. For example, Japanese Patent Laid-Open No. 8-311243 discloses a biodegradable molding composition prepared by blending starch-based polymers, vegetable fibers, metal ions, blowing agents and aliphatic polyesters. In Japanese Patent Laid-Open No. 7-97545, in order to improve the water resistance of a biodegradable polymer composition, a coating agent in which poly L-lactic acid, a biodegradable aliphatic polyester, is dissolved in CFC 123, a halogenated hydrocarbon, is adopted. In addition, U. S. Patent No. 6,361, 827 discloses a method of chemically bonding prolamin such as zein to the surface of a polysaccharide molded body to impart water resistance.

Such biodegradable compositions are molded into containers of various shapes and used for packaging and containers such as disposable dishes. However, when the depth of the article is 5cm or more, the article does not easily fall out of the mold and is stuck, so that it is not only inconvenient to interrupt the process and remove them manually by hand, but also causes a decrease in production efficiency.

In order to improve the releasability of the biodegradable composition, Korean Patent Registration No. 376000 discloses a method of mixing magnesium stearate with dry cellulose in advance, and Patent No. 354867 discloses calcium stearate, magnesium stearate, polyethylene Wax is added to the composition and used. However, they have no problem in releasing the molded article from the mold when molding a low depth article, but lack of releasability from the mold when forming a deep article such as a cup noodle container, and also with liquid contents such as ramen. It is not suitable for use as a disposable container to be cooked due to lack of water resistance. In particular, there is no mention of a composition that can improve the water resistance and releasability at the same time.

Therefore, the technical problem to be achieved by the present invention is to improve the water resistance and releasability of the biodegradable composition together, to provide a biodegradable composition that can mass-produce biodegradable containers used in cup noodles, udon, instant cooked food with high production efficiency It is.

In order to achieve the above object, the present invention provides a biodegradable composition comprising 20 to 60 parts by weight of fiber powder, 10 to 40 parts by weight of acrylate copolymer and 1 to 10 parts by weight of release agent, based on 100 parts by weight of natural polymer. .

According to a preferred embodiment of the present invention, the acrylate copolymer is represented by the following formula (1):

Wherein R 1 and R 2 are independently C _1-12 alkyl, alkoxyalkyl, hydroxyalkyl, glycidyl or 2- (dimethylamino) ethyl;

R3 and R4 are independently (meth) acrylic acid, N-methylol acrylamide, styrene, vinyl acetate, vinyl alcohol, acrylonitrile, acrylamide, maleic anhydride, maleic acid, 1,3-butadiene, diallyl phthalate, Repeat units derived from itaconic acid or neopentyl glycol;

1, m, n and x are 0.2 to 0.6, 0.1 to 0.6, 0.05 to 0.5 to 0.05 to 0.5 as molar fractions, respectively.

According to a preferred embodiment of the present invention, the release agent is magnesium stearate, calcium stearate, monostearyl citrate or mixtures thereof.

According to a preferred embodiment of the present invention, the natural polymer is an anionic starch which is not substituted with a functional group, and may be starch derived from corn, potato, wheat, rice, tapioca and sweet potato.

According to a preferred embodiment of the present invention, the fiber powder has a fiber length of 10 to 90 ㎛, at least one selected from wood, straw, sugar cane, reed, bamboo, wood stem, bast fiber, leaf fiber and seedling fiber It may be derived from pulp fibers.

According to an embodiment of the present invention, based on 100 parts by weight of natural polymer may further comprise 0.01 to 1 parts by weight of a long-term preservative, long-term preservatives sorbic acid, potassium sorbate, sodium benzoate, sodium propionate, calcium propionate, sodium dehydroacetate And one or more selected from the group consisting of butyl paraoxybenzoate.

Hereinafter, the present invention will be described in more detail.

The present invention not only can distribute and store processed foods and instant cooked foods for a long time, but also has sufficient water resistance for cooking foods using hot water, and is an environmentally friendly container that is completely decomposed by microorganisms when used in landfilling. Provided are compositions that can be mass produced with high production efficiency.

That is, the biodegradable composition according to the present invention is an acrylate after pulverizing natural cellulose fibers, molten pulp fibers used in the manufacture of natural polymers, such as sweet potatoes, potatoes, corn, rice, tapioca, hemp and the like, which are sold and used for food. Fiber powder treated with a copolymer and a release agent.

The biodegradable composition according to the present invention preferably contains 20 to 60 parts by weight of the fiber powder, 10 to 40 parts by weight of the acrylate copolymer and 1 to 10 parts by weight of the release agent based on 100 parts by weight of the natural polymer.

The types of fibers that can be obtained from natural resources include conifers, hardwoods, straw and grass, sugarcane, reeds, bamboo, wood stems, bast fibers, leaf fibers, and seedling fibers. It depends on. In particular, the hydrophilicity of the cellulose fibers plays a very important role in the production of the molded article of the present invention, since water is used as a medium in the grinding, decomposition and beating of the fibers. That is because the fibers readily absorb water and are easily dispersed in the suspension. When the fibers wet and adhere to each other, polar attraction occurs between the water molecules and the hydroxyl groups on the surface of the cellulose to form hydrogen bonds. Due to these chemical properties, fibers and starch are ionic bonds using the ion energy potential.

In general, pulp cellulose fibers have an anion (-) charge, and in the case of modified starch, the cationic (+), the natural polymer starch has an anion (-). In the case of pulp fibers, since they generally have an anion (-) charge of 500 meq or more, they are agglomerated with each other, and even when mixed with natural polymers, they are mutually anion (-) charges, resulting in weak intermolecular binding energy. Water resistance is weakened.

The fine powder of the fiber increases the apparent density, decreases the volume, and reduces the agglomeration of each other. In the present invention, by finely powdering the fiber, the ion energy charge of the fiber is reduced from 150 meq to 250 meq. It is characteristic to have. In addition, the acrylate copolymer used for improving the water resistance was synthesized to have a potential difference of 50 meq ~ 300 meq of the cationic (+) charge. Therefore, the biodegradable shaped article according to the present invention is a natural polymer having a fiber powder having an anion (-) charge formed thereon and coated with an acrylate copolymer having a cation (+) charge and having an anion (-) charge. Has a structure in which is dispersed. As such, when different ion energy charges are used, intermolecular binding energy is increased to increase the burst strength of the container and to improve the water resistance.

The term 'fiber powder' as used herein means that the fiber length is the same as the fiber diameter or in the range of 10 ~ 90 ㎛, powdered into a solid phase. The apparent density is preferably 60 ~ 70g / ℓ, outside this range it is difficult to absorb the surrounding moisture to aggregate with each other or to expect a uniform dispersion in the composition.

The fiber powder treated in this way is easy to mix with natural polymers, to obtain a uniform dispersing effect in the production of the molded body, and to maintain the molded body strength at each site. In addition, it is excellent in formability and easy to maintain color due to the uniform dispersion effect. The content of the natural polymer and the fiber powder used in the composition of the present invention is preferably 20 to 60 parts by weight of fiber powder based on 100 parts by weight of natural polymer. If the content of the fiber powder is less than 20 parts by weight, the moldability and impact strength is relatively excellent, but the production cost of the molded product is increased, and if the content exceeds 60 parts by weight, the molded product is insufficient due to the lack of natural polymer that acts as a binder for the fiber powder and inorganic filler. There is a drawback that the impact strength of is significantly lowered.

The basic chemical formula of the copolymer derived from acrylate used as a water-resistant agent in the biodegradable composition of the present invention is as follows.

<Formula 1>

Wherein R 1 and R 2 may be the same or different from each other and are selected from C _1-12 alkyl, alkoxyalkyl, hydroxyalkyl, glycidyl and 2- (dimethylamino) ethyl;

R3 and R4 are independently acrylic acid, N-methylol acrylamide, styrene, vinyl acetate, vinyl alcohol, acrylonitrile, methacrylic acid, acrylamide, maleic anhydride, maleic acid, 1,3-butadiene, diallyl phthalate , Repeating units derived from itaconic acid and neopentyl glycol.

Preferably R 1 and R 2 are independently methyl, ethyl, isopropyl, n-butyl, isobutyl, tert-butyl, 2-hydroxyethyl, 2-ethoxyethyl, decyl, 2-ethylhexyl, 2-hydroxy Propyl, glycidyl, lauryl and 2- (dimethylamino) ethyl.

As molar fraction, l is 0.2-0.6, m is 0.1-0.6, n is 0.05-0.5, x is 0.05-0.5. The amount of the acrylate copolymer is preferably 10 to 40 parts by weight based on 100 parts by weight of natural polymer, but if the content is less than 10 parts by weight, it is difficult to expect sufficient water resistance. Deterioration causes color browning.

The biodegradable composition of the present invention comprises 1 to 10 parts by weight of a release agent selected from magnesium stearate, monostearyl citrate or a mixture thereof based on 100 parts by weight of natural polymer.

The molded article is removed from the mold when sufficient form stability is obtained, and the normally shaped article must remain in the lower mold when separated from the mold. Release material such as Teflon is coated on the inside of the lower mold and the outside of the upper mold to facilitate the release of the container. However, in the case of mass production of biodegradable articles based on sticky starch under heating and pressing conditions, there are about 20 to 80 molds which can be molded at one time in one molding unit. If a few stick to the upper mold and the process is stopped and then removed manually, the continuous operation is possible again. Therefore, the design and material of the mold is also important, but above all, if the mold release function is imparted to the molded article itself, the productivity in the continuous process can be further increased and the cost of the article itself can be expected to be reduced.

Magnesium stearate or monostearyl citrate used in the present invention is preferable because of its excellent releasability with the mold after molding, and if the content is less than 1 part by weight based on 100 parts by weight of natural polymer, sufficient releasability cannot be expected. Exceeding the weight part is undesirable because the natural polymer in the composition kneading process interferes with the role of the organic binder and the release force is no longer improved.

The molded article according to the present invention may optionally further include a long-term preservative that serves to inhibit the growth of microorganisms such as molds. As long-term preservatives that can be used in the present invention, it is preferable to use those which are mainly allowed to be used in food, and should not be leached by a high temperature liquid phase. The content of the long-term preservative is preferably 0.01 to 1% by weight based on 100 parts by weight of natural polymer.

Examples of additives that can be used as compounds having long-term storage properties include sorbic acid, potassium sorbate, sodium benzoate, sodium propionate, calcium propionate, and dehydroacetic acid. Sodium dehydroacetate and butyl ρ-hydroxybenzoate.

The biodegradable compositions according to the invention can be molded into shaped bodies of the desired shape by methods known in the art. For example, a predetermined amount is injected into a mold molding machine heated to 100 to 250 ° C., preferably 140 to 220 ° C., for 10 seconds to 5 minutes at a pressure of 0.5 to 8 kgf / cm 2, preferably 1 to 3 kgf / cm 2, Preferably, the molded product of a desired shape can be obtained by molding for 60 seconds to 5 minutes. The present invention provides a biodegradable molded article having excellent moldability and excellent water resistance.

The present invention will be described in more detail with reference to the following Examples. The following examples are merely examples to aid the understanding of the present invention and do not limit the scope of the present invention.

<Comparative Example 1-6>

Unmodified anionic corn starch, fiber powder from coniferous wood, acrylate copolymer of formula 1 (R1 is dimethylamino, R2 is n-butyl, R3 is acrylonitrile, R4 is styrene, l is 0.4, m Silver 0.3, n is 0.1, x is 0.2), oleamide (AKZO NOBEL AMIDES CO., ARMOSLIP CP), long-term preservative (potassium sorbate) and water as a release agent in a double jacket heating stirrer with a composition as shown in Table 1 Mixing and kneading for 20 minutes to prepare a molding composition. The acrylate copolymer was a milky white liquid having a physical property of 20 to 24% solids, a pH of 4 to 6, and a viscosity of 80 to 100 cps at a temperature of 25 ° C.

Ingredient Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Natural polymer (corn starch) 35.0 35.0 35.0 35.0 35.0 35.0 Fiber powder 14.0 14.0 14.0 14.0 14.0 14.0 Polyacrylate copolymer 9.0 9.0 9.0 9.0 9.0 9.0 Preservative 0.1 0.1 0.1 0.1 0.1 0.1 Release Agent (Oleamide) - 0.4 0.8 1.2 1.6 2.0 water 41.9 41.5 41.1 40.7 40.3 39.9 Sum 100 100 100 100 100 100

<Comparative Example 7-11>

A biodegradable composition was prepared in the same manner as in Comparative Example 1 except that stearamide (AKZO NOBEL AMIDES CO., ARMOSLIP HT) was used as a release agent. The composition is shown in Table 2.

Ingredient Comparative Example 7 Comparative Example 8 Comparative Example 9 Comparative Example 10 Comparative Example 11 Natural polymer (corn starch) 35.0 35.0 35.0 35.0 35.0 Fiber powder 14.0 14.0 14.0 14.0 14.0 Polyacrylate copolymer 9.0 9.0 9.0 9.0 9.0 Preservative (Potassium Sorbate) 0.1 0.1 0.1 0.1 0.1 Moldamide 0.4 0.8 1.2 1.6 2.0 water 41.5 41.1 40.7 40.3 39.9 Sum 100 100 100 100 100

<Comparative Example 12-16>

A biodegradable composition was prepared in the same manner as in Comparative Example 1 except that liquid paraffin (original air medicine) was used as a release agent. The composition is shown in Table 3.

Ingredient Comparative Example 12 Comparative Example 13 Comparative Example 14 Comparative Example 15 Comparative Example 16 Natural polymer (corn starch) 35.0 35.0 35.0 35.0 35.0 Fiber powder 14.0 14.0 14.0 14.0 14.0 Polyacrylate copolymer 9.0 9.0 9.0 9.0 9.0 Preservative (Potassium Sorbate) 0.1 0.1 0.1 0.1 0.1 Release Agent (Fluid Paraffin) 0.4 0.8 1.2 1.6 2.0 water 41.5 41.1 40.7 40.3 39.9 Sum 100 100 100 100 100

<Comparative Example 17-21>

A biodegradable composition was prepared in the same manner as in Comparative Example 1 except that zinc stearate (monolithic industry) was used as the release agent. The composition is shown in Table 4.

Ingredient Comparative Example 17 Comparative Example 18 Comparative Example 19 Comparative Example 20 Comparative Example 21 Natural polymer (corn starch) 35.0 35.0 35.0 35.0 35.0 Fiber powder 14.0 14.0 14.0 14.0 14.0 Polyacrylate copolymer 9.0 9.0 9.0 9.0 9.0 Preservative (Potassium Sorbate) 0.1 0.1 0.1 0.1 0.1 Zn Stearate 0.4 0.8 1.2 1.6 2.0 water 41.5 41.1 40.7 40.3 39.9 Sum 100 100 100 100 100

<Comparative Example 22-25>

A biodegradable composition was prepared in the same manner as in Example 1 except that zinc stearate (Danseok Industry) and magnesium stearate (Dubon Fine Chemical) were used together as a release agent. The composition is shown in Table 5.

Ingredient Comparative Example 22 Comparative Example 23 Comparative Example 24 Comparative Example 25 Natural polymer (corn starch) 35.0 35.0 35.0 35.0 Fiber powder 14.0 14.0 14.0 14.0 Polyacrylate copolymer 9.0 9.0 9.0 9.0 Preservative (Potassium Sorbate) 0.1 0.1 0.1 0.1 Zn Stearate 0.4 0.8 1.2 1.6 Mg Stearate 1.6 1.2 0.8 0.4 water 41.5 41.1 40.7 40.3 Sum 100 100 100 100

<Examples 1-5>

Biodegradable compositions were prepared in the same manner as in Example 1, except that magnesium stearate (Dubon Fine Chemical) was used as a release agent. The composition is shown in Table 6.

Ingredient Example 1 Example 2 Example 3 Example 4 Example 5 Natural polymer (corn starch) 35.0 35.0 35.0 35.0 35.0 Fiber powder 14.0 14.0 14.0 14.0 14.0 Polyacrylate copolymer 9.0 9.0 9.0 9.0 9.0 Preservative (Potassium Sorbate) 0.1 0.1 0.1 0.1 0.1 Mg Stearate 0.4 0.8 1.2 1.6 2.0 water 41.5 41.1 40.7 40.3 39.9 Sum 100 100 100 100 100

<Example 6-10>

A biodegradable composition was prepared in the same manner as in Example 1 except that monostearyl citrate (MORFLEX INC.) Was used as a release agent. The composition is shown in Table 7.

Ingredient Example 6 Example 7 Example 8 Example 9 Example 10 Natural polymer (corn starch) 35.0 35.0 35.0 35.0 35.0 Fiber powder 14.0 14.0 14.0 14.0 14.0 Polyacrylate copolymer 9.0 9.0 9.0 9.0 9.0 Preservative (Potassium Sorbate) 0.1 0.1 0.1 0.1 0.1 Monostearyl Citrate 0.4 0.8 1.2 1.6 2.0 water 41.5 41.1 40.7 40.3 39.9 Sum 100 100 100 100 100

<Example 11-14>

Biodegradable compositions were prepared in the same manner as in Example 1, except that monostearyl citrate (MORFLEX INC.) And magnesium stearate (Dubon Fine Chemical) were used together as a release agent. The composition is shown in Table 8.

Ingredient Example 11 Example 12 Example 13 Example 14 Natural polymer (corn starch) 35.0 35.0 35.0 35.0 Fiber powder 14.0 14.0 14.0 14.0 Polyacrylate copolymer 9.0 9.0 9.0 9.0 Preservative (Potassium Sorbate) 0.1 0.1 0.1 0.1 Monostearyl Citrate 0.4 0.8 1.2 1.6 Mg Stearate 1.6 1.2 0.8 0.4 water 41.5 41.1 40.7 40.3 Sum 100 100 100 100

<Production and Evaluation of Physical Properties>

The compositions prepared in Comparative Examples 1 to 26 and Examples 1 to 14 were molded in a mold molding machine having a temperature of 180 ° C. and a pressure of 3 kgf / cm 3 for 150 seconds to prepare a molded article having a container shape. Evaluation of the physical properties of the molded product was carried out in the following manner and the results are summarized in Table 9 and Table 10.

(1) water resistance

Water of 25 ° C room temperature and high temperature was filled in the molded article in the form of a container and the leakage of water was measured at each time.

A: No leakage occurs after 30 minutes

B: Leakage occurs within 15 to 30 minutes

C: Leakage occurs within 1 to 15 minutes

D: Leakage occurs within 1 minute

(2) formability

◎: smooth surface, no wrinkles or pinholes

O: The surface is relatively rough, but there are no wrinkles or pinholes

X: The surface has wrinkles or pinholes or is difficult to shape.

(3) particle dispersibility

The composition was stirred at 45 rpm for 10 minutes and then magnified 20 times to observe the surface.

◎: uniformly dispersed

O: 5 or less agglomerated parts

X: 5 or more agglomerated parts

(4) compressive strength

Both sides of the container were compressed using a load cell at a speed of 2 mm / s to measure the strength when the container was broken.

◎: 5 kgm / s ² or more

O: 3-5kgm / s ²

×: less than 3kgm / s ²

(5) flexibility

In measuring the compressive strength, the distance that the load cell moved until the container was destroyed was measured.

◎: 20 mm or more

O: 15-20mm

×: less than 15mm

(6) off-flavor

Three researchers examined the container for an unpleasant odor other than starch.

N: none

Y: Yes

(7) browning phenomenon

The color of the container was compared to the color of the standard composition (34% corn starch, 14% fiber powder and 42% water).

N: none

Y: Yes

(8) release

The number of containers attached to the male mold was measured while forming 100 container samples using the composition of the example.

In Comparative Example 1, which did not use a release agent, and Comparative Examples 2-6 and 7-11, which used oleamide and stearamide, respectively, severe odor (odor) was generated and the mold release property was not excellent.

Since the liquid paraffin used in Comparative Example 12-16 had a high boiling point, not only the foaming ratio of the molded article was suppressed but also the appearance after molding was not beautiful. Zinc stearate of Comparative Examples 17-21 also caused moldability defects and foaming rate was suppressed. In Comparative Examples 22-26 using a mixture of zinc stearate and magnesium stearate, the release force was increased, but the moldability was poor.

When the magnesium stearate of Example 1-5 is added at 0.5% or more (1.4 parts by weight based on 100 parts by weight of natural polymer), the dough is easily formed because there is no phenomenon that the dough adheres to the inner wall of the stirrer due to the increase in the amount added. After sticking to the upper mold was also improved. In addition, when magnesium stearate is added about 2% (about 5.7 parts by weight based on 100 parts by weight of natural polymer), the foaming rate is increased, and thus cost reduction of raw materials can be expected. The monostearyl citrate used in Example 6-10 not only gave better release force than magnesium stearate, but also contributed to gloss on the surface of the molded article. Example 12, which used a mixture of magnesium stearate and monostearyl citrate in a ratio of 1.5: 1, showed particularly good releasability.

As described above, the biodegradable composition according to the present invention can be mass-produced with a high production efficiency of a molded article such as a container having a deep water resistance and improved releasability by adding an acrylate copolymer.

Claims (10)

A biodegradable composition comprising 20 to 60 parts by weight of fiber powder, 10 to 40 parts by weight of acrylate copolymer, and 1 to 10 parts by weight of release agent, based on 100 parts by weight of natural polymer. The biodegradable composition according to claim 1, wherein the acrylate copolymer is represented by the following Chemical Formula 1: <Formula 1> Wherein R 1 and R 2 are independently C _1-12 alkyl, alkoxyalkyl, hydroxyalkyl, glycidyl or 2- (dimethylamino) ethyl; R3 and R4 are independently (meth) acrylic acid, N-methylol acrylamide, styrene, vinyl acetate, vinyl alcohol, acrylonitrile, acrylamide, maleic anhydride, maleic acid, 1,3-butadiene, diallyl phthalate, Repeat units derived from itaconic acid or neopentyl glycol; 1, m, n and x are 0.2 to 0.6, 0.1 to 0.6, 0.05 to 0.5 to 0.05 to 0.5 as molar fractions, respectively. The compound of claim 2, wherein R 1 and R 2 are independently methyl, ethyl, isopropyl, n-butyl, isobutyl, tert-butyl, 2-hydroxyethyl, 2-ethoxyethyl, decyl, 2-ethylhexyl, 2 -A biodegradable composition, which is selected from hydroxypropyl, glycidyl, lauryl and 2- (dimethylamino) ethyl. The biodegradable composition of claim 1, wherein the release agent is magnesium stearate, monostearyl citrate, or a mixture thereof. The biodegradable composition according to claim 1, wherein the natural polymer is an anionic starch with no functional group substituted. The biodegradable composition of claim 1, wherein the natural polymer is starch derived from corn, potato, wheat, rice, tapioca, and sweet potato. The biodegradable composition according to claim 1, wherein the fiber powder has a fiber length of 10 to 90 μm. The biodegradable composition according to claim 1, wherein the fiber powder is derived from at least one pulp fiber selected from wood, straw, sugarcane, reed, bamboo, wood stem, bast fiber, leaf fiber and seedling fiber. The biodegradable composition according to claim 1, further comprising 0.01 to 1 part by weight of a long term preservative based on 100 parts by weight of natural polymer. 10. The biodegradable agent according to claim 9, wherein the long-term preservative comprises at least one selected from the group consisting of sorbic acid, potassium sorbate, sodium benzoate, sodium propionate, calcium propionate, sodium dehydroacetate and butyl paraoxybenzoate. Composition.