KR101157112B1 - Soft foam composition and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a flexible foam composition and a method for manufacturing the same. Specifically, in the addition of the processing oil to improve the soft characteristics of the foam, the processing oil is impregnated with a high molecular weight polystyrene-based material having a large specific surface area. By increasing the amount of use, and mixing it with the polymer material for plastic foam, to prepare a foam composition, the adsorption characteristics of the processing oil is improved by the large specific surface area of the polystyrene-based material as described above can not only increase the amount of processing oil used but also foam The process oil does not migrate to the surface of the foam even after molding, and the soft properties of the foam can be improved, but the physical properties such as specific gravity, hardness, and permanent compression ratio and thermal shrinkage can be maintained by the high molecular weight of the polystyrene-based polymer. Flexible foam composition And it relates to a method of manufacturing the same.

Description

Soft foam composition and manufacturing method thereof

The present invention relates to a flexible foam composition and a method for manufacturing the same, and more particularly, to adding a processing oil to improve the soft characteristics of the foam, by impregnating the processing oil in a high molecular weight polystyrene-based material having a large specific surface area, In addition to improving the adsorption characteristics of the process oil, the amount of the process oil can be increased, and the process oil is mixed with the surface of the foam even after molding. Soft foam that does not migrate and can maintain the physical properties such as specific gravity, hardness, and permanent compression ratio and thermal properties such as heat shrinkage by the high molecular weight of the polystyrene-based polymer while improving the soft properties of the foam Concerning the composition and its preparation method Will.

In general, as a method of implementing soft nitriding of a foam, a method using a polymer material having a soft property and a method of introducing an additive such as a processing oil or a plasticizer that can be softened are used.

In the method using the polymer material of the soft properties, mainly used as a polymer material of the soft properties, PU (polyurethane) or the Republic of Korea published in the Republic of Korea Patent Publication Nos. 10-2007-0057943 and 10-2007-0084023 Ethylene-based or styrene-based polymer material proposed in Patent Publication No. 10-2007-0119642.

The PU foam has excellent soft properties compared to ethylene-based or styrene-based polymer materials and is used throughout the industry as a garment and an industrial foam. However, the PU foam has a fundamental problem of hydrolysis and discoloration characteristics. Due to this, there is a problem that the use environment is very limited.

In addition, in the case of the ethylene-based or styrene-based copolymer material, the hydrolysis and discoloration characteristics, which are problems of the PU, can be compensated for, but due to the limitations of the fundamental hardness characteristics of the components constituting the ethylene-based or styrene-based copolymer. Compared with the PU described above, there is a problem in that the soft property that can be represented is limited.

Meanwhile, among the ethylene-based and styrene-based copolymers, a copolymer having a high soft segment content may implement soft properties, but the soft segment is weak in mechanical properties and thermal properties, and thus foams using the same. Also mechanical and thermal properties appear to be a problem.

Therefore, by introducing an additive capable of improving soft properties such as processed oil and plasticizer in ethylene or styrene copolymers, the researchers have attempted to improve the soft properties while solving the hydrolysis and discoloration characteristics of the PU. Progressed.

However, in the case of the processing oil or plasticizer, a liquid material capable of imparting a free volume in the polymer chain is used. In the case of the liquid material as described above, compatibility with ethylene-based or styrene-based polymer materials Vulnerable to limit the amount of use, and there was a problem because of the limitation in the soft foam.

Although the amount is limited as described above, when a large amount of the processing oil or plasticizer is used, the process becomes very long due to the lubrication of the liquid material, and the processing oil or plasticizer migrates to the surface of the compound or molded product manufactured therewith. .

Therefore, there is a case where a large amount of filler is used to prevent the migration phenomenon, in which case there is a problem that the specific gravity of the foam increases and the foaming characteristics become unstable.

On the other hand, in the case of the rubber foam having a relatively free use of the processing oil or plasticizer, but has a soft property in itself, it is possible to manufacture a soft foam, but the heat shrinkage characteristics are weak, and to solve this problem, complex molding process must be accompanied. However, since the manufactured foam has an open cell structure, physical properties such as permanent compression strain are weak.

The present invention, in order to solve the above problems, in adding the processing oil to improve the soft properties of the foam, by improving the adsorption characteristics of the processing oil by impregnating the processing oil in a high molecular weight polystyrene-based material having a large specific surface area Not only can the amount of oil be increased, but it is mixed with a polymer material for plastic foam to prepare a foam composition, so that processing oil does not migrate to the surface of the foam even after molding the foam, and even though the soft property of the foam is improved, It is an object of the present invention to provide a flexible foam composition and a method for producing the same, in which physical properties such as specific gravity, hardness, and permanent compression ratio and thermal properties such as heat shrinkage can be maintained by high molecular weight.

The present invention provides a flexible foam composition comprising various additives, wherein the flexible foam composition comprises a high molecular weight polystyrene-based material impregnated with processing oil and a polymer material for plastic foam.

In addition, the present invention provides a method for producing a flexible foam composition,

5 to 15 parts by weight of calcium carbonate, 1 to 10 parts by weight of zinc oxide, and 1 to 5 parts by weight of stearic acid based on 100 parts by weight of the base material consisting of a polymer material for plastic foam and a high molecular weight polystyrene material impregnated with processing oil. After kneading for 10 to 15 minutes to uniformly disperse the solution, and dumping under conditions of 100 to 120 ℃,

1 to 10 parts by weight of azodicarbonamide-based blowing agent, 0.1 to 5 parts by weight of peroxide-based crosslinking agent, and 0.1 to 5 parts by weight of crosslinking aid are added and dispersed in a roll mill at 90 to 100 ° C based on 100 parts by weight of the base material. To prepare the compound,

 The manufacturing method of the flexible characteristic foam composition characterized by press-molding or injection-molding the sheet-like compound manufactured above is made into another problem solving means.

On the other hand, the processing oil may be impregnated with 100 to 500 parts by weight based on 100 parts by weight of a high molecular weight polystyrene-based material.

In addition, the high molecular weight polystyrene-based material is polystyrene (styrene-ethylene-butylene-styrene), SEPS (poly- (styrene-ethylene-propylene-styrene)) or SEEPS (poly- (styrene-ethylene-ethylene) -propylene-styrene)).

In addition, the processing oil is a white oil (White oil). Paraffin oil, Naphthene oil or Aromatic oil may be used.

In addition, the polymer material for the plastic foam is one or more of EVA (ethylene-vinyl acetate copolymer), ethylene-α-olefin resin (ethylene-α-olefin copolymer), polyethylene (polyethylene), hydrogenated polymer, rubber Can be selected and used.

In addition, the high molecular weight polystyrene-based material, MI (Melt Index) may be 1 or less under the condition of a load of 200 ℃, 10kg.

In addition, the high molecular weight polystyrene-based material impregnated with the processing oil may be impregnated with the high-molecular weight polystyrene-based material by using a super mixer or a hand mix method.

According to the present invention, when adding the processing oil to improve the soft properties of the foam, by impregnating the processing oil in a high molecular weight polystyrene-based material having a large specific surface area can improve the adsorption characteristics of the processing oil to increase the amount of processing oil used In addition, by mixing this in the polymer material for plastic foam to prepare a foam composition, the processing oil does not migrate to the surface of the foam even after the foam molding, while the soft properties of the foam is improved, the specific gravity, hardness due to the high molecular weight of the polystyrene-based polymer Physical properties such as permanent compression rate and thermal properties such as heat shrinkage can be maintained, there is an advantage that can be easily utilized as shoes, clothing, etc. that require soft properties.

Hereinafter, preferred embodiments of the present invention will be described in detail. It should be noted that in the following description, only parts necessary for understanding the manufacturing method of the present invention will be described, and descriptions of other parts will be omitted so as not to distract from the gist of the present invention.

The present invention relates to a flexible foam composition and a method for manufacturing the same, and more particularly, to a high molecular weight polystyrene-based material having a large specific surface area, impregnated with processing oil, and mixed with a high-molecular foam material for general plastic foam to soften the foam. By providing the characteristics, the adsorption characteristics of the processing oil introduced for soft nitriding are improved due to the large specific surface area of the high molecular weight material, so that the amount of processing oil can be increased, and the processing oil does not migrate to the foam surface even after molding. The present invention relates to a flexible foam composition in which physical and thermal properties can be maintained by a high molecular weight of a polystyrene-based polymer and a method for producing the same.

The polystyrene-based polymer material used for impregnating the processing oil is SEBS (Poly- (styrene-ethylene-butylene-styrene)), SEPS (Poly- (styrene-ethylene-propylene-styrene)), SEEPS (Poly- (styrene-ethylene) -ethylene-propylene-styrene)), and among them, the MI (Melt Index) corresponding to the molecular weight is applied at a temperature of 200 ° C. under a load of 10 kg or less.

In this case, when MI is applied to 1 or more, the specific surface area of the polymer is small, so that the amount of process oil that can be impregnated is limited.

The processing oil used for decreasing the hardness is typically white oil used in rubber products. Paraffin oil, Naphthene oil. Aromatic oils can be used, but plasticizers that function similarly to processed oils are excluded from use due to environmental concerns.

The amount of the processing oil applied to the high molecular weight polystyrene-based material is preferably in the range of 100 to 500 parts by weight based on 100 parts by weight of the high-molecular weight polystyrene-based material.

At this time, when the amount of the processing oil is less than 100 parts by weight, the soft nitriding effect is less than 500 parts by weight, the migration of the processing oil to the foam surface after the foam molding occurs.

In addition, a method of impregnating the processing oil into the high molecular weight polystyrene-based material may use a super mixer or a hand mix method using a zipper bag or the like.

On the other hand, high molecular weight polystyrene-based material impregnated with processing oil is used as a base material for foaming by applying together with a high-molecular plastic material for general plastic foam. In this case, the general plastic foam material applied is EVA (ethylene-vinyl acetate copolymer), ethylene -α-olefin resin (ethylene-α-olefin copolymer), polyethylene (polyethylene), hydrogenated polymer, rubber and the like can be used.

As the above-described mixed base material for foam, zinc oxide, stearic acid, calcium carbonate, tackifying resin, lubricant, pigment, etc. which are additives used in ordinary foams can be used. The crosslinking agent may be a peroxide, sulfur, or the like used in a conventional foam, and the blowing agent may be an azo, OBSH, DPT, TSH, urea, or the like used in a conventional foam.

Foam compound manufacturing process and the molding process introduce | transduce a normal plastic foam manufacturing process, and press molding or injection molding is carried out to manufacture foam.

Hereinafter, the present invention will be described in detail based on the examples produced in the configuration of [Table 1], but the present invention is not limited to the examples.

Example 1

Carbonic acid based on 100 parts by weight of a base material consisting of 70% by weight of a vinyl acetate content of 40% EVA and 30% by weight of oil-extended SEBS impregnated with 300 parts by weight of processing oil relative to 100 parts by weight of SEBS, 10 parts by weight of calcium, 5 parts by weight of zinc oxide, and 1 part by weight of stearic acid are added to a sealed mixer, kneaded for 10 to 15 minutes to be uniformly dispersed, and dumped under conditions of 100 to 120 ° C. In a roll-mill, 2.9 parts by weight of azodicarbonamide-based blowing agent, 1.0 part by weight of peroxide-based crosslinking agent, and 0.4 part by weight of crosslinking aid are dispersed and dispersed to prepare a compound in a sheet form.

The sheet-like compound thus prepared is left at room temperature and then charged into a 25 mm thick press mold, pressurized for 40 minutes at a temperature of 155 ° C. and a pressure of 150 kgf / cm ² , and then the mold is opened to prepare a foam.

The physical properties of the prepared foam is shown in Table 2 below.

[Example 2]

10 parts by weight of calcium carbonate and 5 parts by weight of zinc oxide based on 100 parts by weight of a substrate composed of 70% by weight of EVA having 28% vinyl acetate and 300 parts by weight of processed oil impregnated with 300 parts by weight of SEEPS. 1 part by weight of stearic acid was introduced into a hermetic mixer, kneaded for 10 to 15 minutes to be uniformly dispersed, dumped under conditions of 100 to 120 ° C, and azodicarbonamide based on 100 parts by weight of the substrate in a roll mill at 90 to 100 ° C. 3.1 parts by weight of blowing agent, 1.0 parts by weight of peroxide-based crosslinking agent and 0.4 parts by weight of crosslinking aid are added to disperse the compound to prepare a sheet.

The sheet-like compound thus prepared is left at room temperature and then charged into a 25 mm thick press mold, pressurized for 40 minutes at a temperature of 155 ° C. and a pressure of 150 kgf / cm ² , and then the mold is opened to prepare a foam.

The physical properties of the prepared foam is shown in Table 2 below.

Comparative Example 1

10 parts by weight of calcium carbonate, 5 parts by weight of zinc oxide, and 1 part by weight of stearic acid are added to a sealed mixer with respect to 100 parts by weight of EVA having a vinyl acetate content of 40%, and kneaded for 10 to 15 minutes to uniformly disperse the mixture at 100 to 120 ° C. Dumped under the conditions of, and poured into a sheet by dispersing 2.6 parts by weight of azodicarbonamide-based blowing agent, 0.8 parts by weight of peroxide-based crosslinking agent, and 0.2 parts by weight of crosslinking aid with respect to 100 parts by weight of the substrate in a roll mill at 90 to 100 ° C. Prepare the compound.

The sheet-like compound thus prepared is left at room temperature and then charged into a 25 mm thick press mold, pressurized for 40 minutes at a temperature of 155 ° C. and a pressure of 150 kgf / cm ² , and then the mold is opened to prepare a foam.

The physical properties of the prepared foam is shown in Table 2 below.

Comparative Example 2

10 parts by weight of calcium carbonate, 5 parts by weight of zinc oxide, and 1 part by weight of stearic acid are added to an airtight mixer for 100 parts by weight of EVA having a vinyl acetate content of 28%, and then kneaded for 10 to 15 minutes to uniformly disperse 100 to 120 ° C. Dumped under the conditions of, and 2.8 parts by weight of azodicarbonamide-based blowing agent, 0.8 parts by weight of peroxide-based crosslinking agent, and 0.2 parts by weight of crosslinking aid were dispersed with respect to 100 parts by weight of the substrate in a roll mill at 90 to 100 ° C. To prepare the compound.

The sheet-like compound thus prepared is left at room temperature and then charged into a 25 mm thick press mold, pressurized for 40 minutes at a temperature of 155 ° C. and a pressure of 150 kgf / cm ² , and then the mold is opened to prepare a foam.

The physical properties of the prepared foam is shown in Table 2 below.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 EVA 1 (VA 40%) ¹⁾ 70 - 100 - EVA 2 (VA 28%) ²⁾ - 70 - 100 300% process oil impregnation SEBS ³⁾ 30 - - 300% processing oil impregnation SEEPS ⁴⁾ 30 Zinc oxide ⁵⁾ 5 5 5 5 Stearic acid ⁶⁾ One One One One Light calcium carbonate ⁷⁾ 10 10 10 10 Peroxide ⁸⁾ 1.0 1.0 0.8 0.8 Crosslinking aid ⁹⁾ 0.4 0.4 0.2 0.2 Blowing agent ¹⁰⁾ 2.9 3.2 2.6 2.8 week)
1) Dupont 2) Hanwha Chemical 3) Ashhi-Kasei Chemicals, Michang Petroleum
4) Kuraray, Michang Petroleum 5) PJ Comtech 6) Keeping Peace
7) Eugene Industries 8) Akzo Novel 9) Akzo Novel
10) Geumyang

Example and Comparative Example is a foam composition for showing the change in the soft properties when the high molecular weight styrene-based material impregnated with the processing oil is applied when the same EVA is used.

Example 1 is a foam composition applied with the most excellent EVA properties of the current EVA foam material for foam, and a high molecular weight styrene-based material impregnated with processing oil, Comparative Example 1 is a foam composition applying only EVA applied in Example 1 Example 2 is a foam composition which exhibits hardness characteristics similar to those of Comparative Example 1 by applying a harder EVA than EVA applied to Comparative Example 1 and applying a high molecular weight styrene-based material impregnated with processing oil thereto. Example 2 is a foam composition to which only EVA applied in Example 2 was applied.

In addition, the foams shown in Examples and Comparative Examples were prepared with similar specific gravity for a more accurate comparison of the physical and thermal properties of the foams.

[Test Example]

The properties of the foam compositions prepared by Examples 1 and 2 and Comparative Examples 1 and 2 are shown in the following [Table 2].

Example 1 Example 2 Comparative Example 1 Comparative Example 2 importance 0.338 0.321 0.326 0.337 Hardness (C type) 34 43 44 55 Permanent Compression Decrease (%) 45 43 52 46 Heat shrinkage (%) 1.8 1.5 3.2 2.3

1) Specific gravity

The specific gravity of the foam was measured five times using an automatic specific gravity measuring device at the surface portion of the foam and the average value was taken.

2) hardness

The hardness of the foam was measured according to ASTM D 2240 with an Escer C hardness tester on the surface of the foam.

3) permanent compression rate

The foam was turned up to have a thickness of 10 mm, and the test piece produced in the form of a cylinder, now 30 ± 0.05 mm, was measured according to ASTM D 3574. Insert the test piece between two parallel metal plates, insert the spacer corresponding to 50% of the test piece thickness, compress it, heat treatment for 6 hours in the open maintained at 50 ± 0.1 ℃, release the compressed state, and leave at room temperature for 30 minutes. The thickness of the test piece was measured. Three specimens were used in the same test and the permanent compression ratio was calculated by the following equation.

t ₀ : Initial thickness of the test piece

t _f : thickness of specimen when cooled after heat treatment

t _x : thickness of spacer

4) Heat Shrinkage

The foam was turned up to have a thickness of 6 mm, left for 40 minutes in an open maintained at 70 ± 0.1 ℃, taken out and left for 30 minutes at room temperature and the change in the length of the foam was measured. Two specimens were used in the same test and the heat shrinkage was calculated by the following equation.

L ₀ : Foam length before heat treatment

L _f : Foam length after heat treatment

Looking at Examples 1 and 2 and Comparative Examples 1 and 2, when the same EVA is used, the high-density styrene-based material impregnated with the processing oil is softened to about 10 and the permanent compression corresponds to the physical properties. It can be seen that the heat shrinkage characteristics corresponding to the reduced rate and the thermal characteristics are improved.

Comparative Example 1 is the case of applying the softest EVA among the current EVA material for the foam, it is impossible to represent the hardness characteristics under the specific gravity below 40 but as shown in Example 1 high molecular weight styrene-based impregnated processing oil When the material is applied, it can be seen that softness of 40 or less is possible.

Example 2 was prepared by applying a harder EVA than EVA applied in Comparative Example 1 and applying a high molecular weight styrene-based material impregnated with processing oil thereto to produce a foam having similar hardness characteristics as Comparative Example 1. Under the characteristics, it can be seen that the permanent compression ratio corresponding to the physical characteristics and the heat shrinkage characteristics corresponding to the thermal characteristics are excellent.

That is, the soft foam composition according to the present invention and a method for producing the same are used to impregnate the processing oil in a high molecular weight polystyrene material having a large specific surface area in order to add the processing oil to improve the soft properties of the foam. By increasing the amount and mixing the same into the polymer material for plastic foam, the foam composition is prepared. As a result, the adsorption characteristics of the processing oil can be improved by the large specific surface area of the polystyrene-based material, thereby increasing the amount of processing oil used, and even after foam molding. Process oil does not migrate to the surface of the foam, and the high molecular weight of the polystyrene-based polymer can maintain physical properties such as specific gravity, hardness, and permanent compression ratio and thermal properties such as heat shrinkage.

As described above, the soft foam composition according to the present invention and a method for producing the same have been confirmed through the above examples, and the present invention can be applied to those skilled in the art. It will be understood that various modifications and variations can be made in the present invention without departing from the spirit and scope.

Claims (11)

In the flexible foam composition comprising a variety of additives,
With respect to 100 parts by weight of the base material consisting of a high molecular weight polystyrene-based material impregnated with processing oil and a polymer material for plastic foam, as an additive, 5 to 15 parts by weight of calcium carbonate, 1 to 10 parts by weight of zinc oxide, and 1 to 5 parts by weight of stearic acid 1 to 10 parts by weight of azodicarbonamide-based blowing agent, 0.1 to 5 parts by weight of peroxide-based crosslinking agent and 0.1 to 5 parts by weight of crosslinking aid,
The processed oil is a white oil. Select one or more of paraffin oil, naphthene oil, or aromatic oil, and impregnate 100 to 500 parts by weight based on 100 parts by weight of high molecular weight polystyrene-based material. ,
The high molecular weight polystyrene-based material, the MI (Melt Index) of 200 ℃, 10kg or less under the conditions of 1 or less SEBS (Poly- (styrene-ethylene-butylene-styrene)), SEPS (Poly- (styrene-ethylene-propylene) -styrene) or SEEPS (Poly- (styrene-ethylene-ethylene-propylene-styrene))
The polymer material for the plastic foam is selected from one or more of EVA (ethylene-vinyl acetate copolymer), ethylene-α-olefin resin (ethylene-α-olefin copolymer), polyethylene (polyethylene), hydrogenated polymer, rubber Flexible foam composition, characterized in that to use
delete delete delete delete delete In the method for producing a soft property foam composition,
5 to 15 parts by weight of calcium carbonate and 1 to 10 parts by weight of zinc oxide, based on 100 parts by weight of a substrate made of a polymer material for plastic foam and a high molecular weight polystyrene material impregnated with processing oil using a super mixer or hand mix method. , 1 to 5 parts by weight of stearic acid was introduced into a hermetic mixer, kneaded for 10 to 15 minutes to be uniformly dispersed, and after dumping under conditions of 100 to 120 ° C,
1 to 10 parts by weight of azodicarbonamide-based blowing agent, 0.1 to 5 parts by weight of peroxide-based crosslinking agent, and 0.1 to 5 parts by weight of crosslinking aid are added and dispersed in a roll mill at 90 to 100 ° C based on 100 parts by weight of the base material. To prepare the compound,
The compound on the sheet prepared is press-molded or injection-molded,
The processed oil is a white oil. Select one or more of paraffin oil, naphthene oil, or aromatic oil, and impregnate 100 to 500 parts by weight based on 100 parts by weight of high molecular weight polystyrene-based material. ,
The high molecular weight polystyrene-based material, the MI (Melt Index) of 200 ℃, 10kg or less under the conditions of 1 or less SEBS (Poly- (styrene-ethylene-butylene-styrene)), SEPS (Poly- (styrene-ethylene-propylene) -styrene) or SEEPS (Poly- (styrene-ethylene-ethylene-propylene-styrene))
The polymer material for the plastic foam is selected from one or more of EVA (ethylene-vinyl acetate copolymer), ethylene-α-olefin resin (ethylene-α-olefin copolymer), polyethylene (polyethylene), hydrogenated polymer, rubber Method for producing a flexible foam composition, characterized in that to use delete delete delete delete