Background Art The household chopping board or the commercial chopping board generally used is made of wood, polyethylene-based plastic or glass.

However, since the related art chopping board is not flexible, it has an inconvenience in carrying cooked foods from the chopping board to a dish or the like.

Also, the chopping board made of wood or polyethylene may cause knife-cut or groove due to the use of the chopping knife. The knife-cut or the groove causes foods or pot liquor to be introduced therein, so that harmful bacilli such as mold may be nurtured. However, it is not easy to completely remove the introduced foods remnants or harmful bacilli by using a dishtowel or water. The remnants or harmful bacilli may cause an offensive odor. Further, the related art chopping board is weak in heat and thus has a difficulty in boiling the chopping board for sterilization.

Disclosure of the Invention Accordingly, the present invention has been made to substantially obviate one or more of the problems due to limitations and disadvantages of the related art.

An object of the present invention is to provide a sanitary chopping board molded from a polymer and no having a change in the physical property.

Another object of the present invention is to provide a

sanitary chopping board molded from the polymer and having a superior antifungal property.

A further object of the present invention is to provide a sanitary chopping board molded from the polymer and having superior elasticity and flexibility.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, there is provided a sanitary chopping board molded from a polymer obtained by reacting a hard segment and a soft segment, the hard segment being obtained by reacting a chain extender having a molecular weight ranged from 60 to 400 with diisocyanate and the soft segment being obtained by reacting a polyol having a molecular weight ranged from 600 to 4,000 with diisocyanate.

According to the inventive sanitary chopping board, the physical property is not changed in warm water. The sanitary chopping board has superior antifungal property, elasticity and flexibility.

Brief Description of the Drawings The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

In the drawings: FIG. 1 is a perspective view of a sanitary chopping board according to the present invention; FIG. 2 is a partial detailed view of a hole portion in the sanitary chopping board; and FIG. 3 is a vertical sectional view showing a manufacturing process of the sanitary chopping board.

Best Mode for Carrying Out the Invention Hereinafter, preferred embodiments of the present

invention will be described in detail with reference to accompanying drawings.

Polyol used in the present invention has an average molecular weight ranged from 600 to 4,000, and can use a polyether-based polyol. As the kinds of the polyether-based polyol, there are polyoxypropyleneglycol (PPG) (HO [CH3CHCH2O] nCH2-CH3CHO [CH2CH3CHO] nH), polyoxytetramethylene (PTMG) (HO [CH2CH2CH2CH20] nH) B polyoxyethyleneglycol (PEG) (HO [HC2CH20] nH) and the like.

Also, a chain extender used in the present invention has an average molecular weight ranged from 60 to 400, and can use glycols having a low molecular weight below 500.

Also, the chain extender may use ethylene glycol (EG) (CH20HCH20H), 1,3-prophylene glycol (PG) (HOCH2CH2CH2OH), bisphenol A (C15Hl602), 1,4-buthanediol (HOCH2CH2CH2CH2OH), etc.

Also, the diisocyanate used in the present invention can use 4, 4'-diphenylmethanediisocyanate (MDI) (OCN-Ph-CH2- Ph-NCO), 2, 4- or 2,6-toluenediisocyanate (TDI), etc.

Also, the additive added in the polyethylene of the present invention can use fatty acid derivative and salicylic acid ester group. The fatty acid derivative is used to enhance the release effect and to improve the productivity in a range of 0.1-2 %. The salicylic acid ester group is a stabilizer against ultraviolet, and is used to prevent decoloring of products in field usage.

Hereinafter, synthesis of polyurethane using the aforementioned main components will be described.

The synthesis of the polyurethane according to the present invention can be performed in a temperature range of 80-200 °C. It is desirable that the polyol component and the chain extender component are mixed at a weight ratio of 1 : 0.1 or 1 : 0.05, and has an equivalent ratio (R) of 1.02.

Herein, the equivalent ratio (R=-NCO/-OH) represents a ratio of an equivalent number of diisocyanate with respect to an equivalent number of a sum of the chain extender and the

polyol. In theory, when the equivalent ratio is 1, polyurethane of a high molecular weight having the highest polymerization degree can be obtained. In general, it is suitable that the equivalent ratio is in a range of 0.97- 1.02. If the equivalent ratio is lower than 0.97, it fails to obtain a high molecular weight, so that a good physical property cannot be obtained. To the contrary, if the equivalent ratio is higher than 1.02, gel or the like may be generated through a side reaction during the molding process.

In the meanwhile, the synthesis of the polyurethane according to the present invention can be performed not by the batch type reactor according to the related art but by a continuous type reaction facility. The continuous type reaction facility can decrease a deviation in the physical property and also enhance the general product quality. Also, the continuous type reaction facility may use a conveyor belt type, an extruder type and a composite type of the conveyor belt and the extruder type.

The below reaction formula shows one embodiment corresponding to a reaction mechanism where the polyurethane according to the present invention is obtained. However, it should be noted that the present invention is not limited only to the below embodiment.

In the reaction formula, P is polyol, Q is chain extruder, and R is diisocyanate residual radical respectively. In the present embodiment, the below reaction can be performed at a temperature range of 70-90 °C.

The reaction equation 1 to be described below is for a reaction where the soft segment is obtained, the reaction equation 2 is for a reaction where the hard segment is obtained, and the reaction equation 3 is for a reaction where the polyurethane according to the present invention is obtained.

Reaction equation 1: Reaction equation 2:

Reaction equation 3:

Referring to the above reaction equation 1, the polyol is reacted with the diisocyanate, so that soft segment is obtained, and the-NCO radical is addition-reacted with the- OH radical, so that-OH radical is formed at both ends.

Referring to the above reaction equation 2, the chain extender is reacted with the diisocyanate, so that hard segment is obtained, and the chain extender is addition- reacted with the-NCO radical, so that-NCO radical is formed at both ends.

Also, referring to reaction equation 3, the-OH radical of the soft segment is reacted with the-NCO radical of the hard segment, so that the polyurethane according to the present invention is obtained.

In the meanwhile, the polyurethane used in the sanitary

chopping board of the present invention has a superior tensile strength and percentage of elongation compared with other material such as nylon or PBT resin, and is a friendly- environmental material since a variation in the physical property is small. Also, the polyurethane is excellent in the abrasion-resistant property, bending fatigue-resistant property, hardy property, mechanical strength, weight- resistant property, elasticity and elastic recovery rate.

Further, since the polyurethane has a heat-resistant degree above 100 °C, although the sanitary chopping board of the polyurethane is sterilized in boiling water, the sanitary chopping board is not deformed.

The related art partly uses polyester-based polyurethane as the material of a sanitary chopping board, the present invention preferably uses the polyether-based polyurethane as the material of a sanitary chopping board. As aforementioned, the polyether used as the material of the sanitary chopping board according to the present invention has the following advantages.

In general, polyurethane can be used in water without a large variation in the physical property, but its ester radical is hydrolyzed in hot water of approximately 80 °C, so that the physical property of the polyester-based polyurethane is greatly changed. However, since the polyether-based polyurethane shows no variation in the physical property in hot water, it is suitable as the material of the sanitary chopping board frequently contacting hot water.

Also, when being exposed to an environment having a high humidity, the polyester-based polyurethane is affected by microorganism. However, the polyether-based polyurethane is stable against microorganism although it is exposed to such an environment for a long time. Accordingly, the polyether-based polyurethane is suitable as the material of the sanitary chopping board frequently affected by

microorganism due to its superior antibiosis.

Further, since the polyether-based polyurethane is superior in the elasticity and flexibility compared with the polyester-based polyurethane, it is suitable as the material of the sanitary chopping board frequently bent during cooking.

Furthermore, when being left alone in an air for 12 hours or more, the polyether-based polyurethane has a moisture absorption rate of 0.2-1. 0%, while the polyester- based polyurethane has a moisture absorption rate of 0.4- 1.4%. Accordingly, since the polyether-based polyurethane needs a small dry time during its processing, the working time is shortened and yield rate can be enhanced.

Accordingly, the polyether-based polyurethane is suitable as the material of the sanitary chopping board requiring mass production.

The inventive sanitary chopping board manufactured by using the aforementioned polyurethane will be described hereinafter.

FIG. 1 is a perspective view of a sanitary chopping board according to the present invention.

Referring to FIG. 1, the sanitary chopping board 20 includes a front part 21 functioning as a cooking surface for cutting a food, and a furrow 22 formed lower than the upper surface of the front part 21. The sanitary chopping board 20 further includes a hole 23 formed at an upper side of the front part 21 and serving as an exhaust hole of water flowing through the furrow 22, and a rear part 24 formed at a rear side of the front part 21.

The functions of the sanitary chopping board constructed as above will be described hereinafter.

First, while a user performs a cooking work such as cutting of a food, water or the like is generated from the food. The water or the like flows on the front part 21 and into the furrow 22. After that, the water or the like in the

furrow 22 flows along the furrow 22 and is then exhausted through the hole 23.

Meanwhile, the front part 21 having a surface comprised of fine concave portions and fine convex portions allows the sanitary chopping board 20 to be easily separated from a mold during an injection molding.

Also, the rear part 24 has a surface comprised of fine concave portions and fine convex portions, which allow the sanitary chopping board 20 to be easily fixed to a bottom.

Meanwhile, the sanitary chopping board 20 includes a pigment added during its manufacturing process. Due to the existence of the pigment, the sanitary chopping board 20 is formed in a somewhat opaque state, which is to prevent the user from feeling displeasure when the upper surface of the sanitary chopping board 20 becomes unsanitary during a cooking work.

FIG. 2 is a detailed view of the hole portion of the sanitary chopping board.

Referring to FIG. 2, the sanitary chopping board 20 includes a front part 21 functioning as a cooking face, and a furrow 22 concaved at a predetermined depth from an upper surface of the front part 21 and through which water generated during a cooking work flows, and a hole 23 formed on the furrow 22 and allowing the water flowing into the furrow 22 to be exhausted.

Also, the hole 23 can be used to hang the sanitary chopping board 20 on a projection structure formed on the wall.

Hereinafter, the manufacturing process of the sanitary chopping board using the aforementioned polyurethane will be described.

A general processing method of polyurethane includes an injection molding mainly used in molding of thermoplastic resin, and an extrusion molding mainly used in molding of thermosetting resin. Further, there is a blow molding in

which thermoplastic resin is pre-molded in a tube shape, the pre-molded material is loaded in a mold, air is blown into the mold to expand and cool the material.

The polyurethane used in the sanitary chopping board according to the present invention is a thermoplastic material, and is preferably manufactured by using an injection molding, which will be described with reference to FIG. 3.

FIG. 3 is a vertical sectional view showing an injection molding process of the sanitary chopping board.

Referring to FIG. 3, an injection molder 10 for manufacturing a sanitary chopping board according to the present invention includes a hopper 11 in which resin is stored, and a cylinder 12 for pushing out the resin stored in the hopper 11. The injection molder 10 further includes an inlet 13 through which the resin pushed by the cylinder 12 is injected, and a mold 14 in which the resin injected through the inlet 13 is supplied, and having the shape of the injected sanitary chopping board.

Hereinafter, the manufacturing process of the sanitary chopping board according to the present invention by the injection molder constructed as above will be described.

The moisture content requested in the processing of the polyurethane is approximately 0. 05%, but the polyurethane contains the moisture content above 0.05%. Accordingly, it is essentially necessary to perform a dry process before the injection molding of the polyurethane. The dry process is preferably performed at a temperature of 80 °C for 4-6 hours. Also, the dry process can be performed using forced air circulation dry oven, a dehumidifying drier or the like.

Meanwhile, after the dry process is performed, the injection molding is carried out as follows. First, a compound made in the form of a chip having a few mm size by <BR> <BR> adding pigment, stabilizer, plasticizer, filler, etc. , is loaded into the hopper 11. The compound is melted, then

passes through the inlet 13 by the cylinder, is the injected into the mold 14. After that, the mold 14 is opened and the sanitary chopping board hardened in the mold 14 is unloaded from the mold 14.

For the injection molding, the mold 14 may use a runnerless mold. The runnerless mold is a mold in which when thermoplastic resin is injection-molded, sprue or runner part of the mold is heated such that the molding material is always kept in a melt state, and only the molding product is cooled and unloaded.

Meanwhile, the injection-molded sanitary chopping board is subject to a post-process. This is because when the injection-molded sanitary chopping board is rapidly cooled in room temperature, a preferable phase separation cannot be obtained, and the hard segment and the soft segment are irregularly arranged. Owing to the above reason, it is desirable to perform the heat treatment at a temperature of 120 °C for 15-20 hours. By the heat treatment, the flow of molecules is activated, so that the phase separation of the hard segment and the soft segment is enhanced to obtain a physical crosslink and to approach an optimum physical property.

Meanwhile, since the aforementioned injection molding can be performed repeatedly for mass production, it is suitable as the manufacturing method of the sanitary chopping board according to the present invention.

Industrial Applicability As described previously, the inventive sanitary chopping board constructed as above is stable against the influence of microorganism, thereby providing a superior antifungal effect.

Also, since the sanitary chopping board does not show a variation in the physical property, it can be boiled in boiling water, so that the product reliability of the

sanitary chopping board frequently contacting hot water during a cooking work can be improved.

Further, since the sanitary chopping board has an excellent elasticity and flexibility, it can be bent during a cooling work so that foods can be easily transferred from the sanitary chopping board to a dish or the like.

Furthermore, since the sanitary chopping board has a hole formed on the upper furrow of the front part, it allows moisture or the like generated during the cooking work and flowing into the furrow to be easily exhausted.

Moreover, since the sanitary chopping board has a front part comprised of concave portions and convex portions, it is easily separated from the mold during the injection molding.

Also, since the sanitary chopping board has a rear part comprised of concave portions and convex portions, it can be well fixed to a bottom.