KR102003207B1 - A discoloration delay material for using citric acid and manufacturing method thereof - Google Patents

Abstract

The color retardation retarding material using citric acid according to the present invention is characterized by comprising an acidity adjusting agent in which 0.3 to 1 part by weight of citric acid is mixed with 100 parts by weight of water, a polyurethane foam comprising a polyol and a diisocyanate compound, And a fiber fabric attached to at least one of the surfaces of the polyurethane foam, wherein the method comprises a foam forming step of forming an alkaline polyurethane foam containing a polyol and a diisocyanate compound, 0.3 to 1 part by weight of the acidic polyurethane foam is mixed with the acidic polyurethane foam to prepare an aqueous citric acid solution, and the alkaline polyurethane foam obtained through the foam-forming step is immersed in the citric acid aqueous solution to change into acidic polyurethane. A duct including activated carbon is provided, And a drying step of flowing into the chamber where the heat of high temperature and the wind are discharged to form an acidic polyurethane foam in a dry state.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discotic retardation material using citric acid,

More particularly, the present invention relates to a discoloration retarding material having a polyurethane foam treated with citric acid to delay discoloration due to ultraviolet rays, and a method for producing the same.

Synthetic rubber and polyurethane are generally used for shoes. Neoprene, which is a representative synthetic rubber with excellent stretchability and warmth, is made from chloroprene as a raw material and has excellent elasticity, warmth, water resistance, flame retardancy, It is widely used in industrial fields, and it is widely used as wet suit and shoe material due to excellent elasticity and warmth.

However, in the case of neoprene as a shoe material, it has disadvantages that the odor is insufficient due to its waterproofness due to its non-breathability, and it has a high density (200 kg / m ³ ) There is no problem.

In order to solve the problems of neoprene, which is one kind of synthetic rubber, it is necessary to use a porous polyurethane resin having a high elasticity, durability and warmth, Although a polyurethane having fine pores has been proposed using a sheet manufacturing technique, there has been a problem that yellowing which is discolored by ultraviolet rays occurs.

In the case of the polyurethane used as a shoe material, toluene diisocyanate (TDI) or diphenylmethane diisocyanate (MDI), which is an aromatic compound, is used. This is because, due to the chemical structure of the aromatic compound, N-quinone forms a mid structure and is prone to discoloration. This is different from the cleavage of the polymer chain, and acts as a factor for lowering the aesthetic property, resulting in a problem of significantly lowering the value of the product.

In order to solve such a problem, a method for producing a soft yellowish flexible polyurethane foam of Patent Application No. 10-2003-0040129 (filed on June 20, 2003) filed by the Korean Intellectual Property Office has been proposed to solve the above problems , There is a problem that it is difficult to ensure stable foam formability due to excessive use of the catalyst for discoloration retardation.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems occurring in the prior art, and it is an object of the present invention to provide an improved coloring retarding effect without using an excessive amount of catalyst, Which can prevent the deterioration of the mechanical properties of the polyurethane foam, can provide a discoloration retarding material using citric acid containing polyurethane foam and can remove the volatile organic compounds (VOCs) The present invention provides a method for producing a discoloration retarding material using the same.

The color retardation retarding material using citric acid according to the present invention is characterized by comprising an acidity adjusting agent in which 0.3 to 1 part by weight of citric acid is mixed with 100 parts by weight of water and fine pores are formed in the inside of the mixture and polyol and diisocyanate compound, A polyurethane foam which is immersed in the acidity regulating agent and whose acidity is changed into an acidic state by penetrating the surface and the acidity regulator into the pores, and a polyurethane foam in which at least the upper surface and the lower surface of the polyurethane foam to maintain the acidity of the polyurethane foam And a fiber fabric adhered to one surface.

The polyurethane foam has a density of 80 to 150 kg / m ³ .

The acidity adjusting agent has a pH concentration equal to that of the fiber fabric.

In addition, the method for producing a discoloration retardation material may include a foaming step of forming an alkaline polyurethane foam containing a polyol and a diisocyanate compound, and a citric acid aqueous solution containing 0.3 to 1 part by weight of citric acid per 100 parts by weight of water, A step of immersing the alkaline polyurethane foam in the aqueous citric acid solution into an acidic polyurethane, and a step of immersing the acidic polyurethane foam in the chamber containing the activated carbon, To form an acidic polyurethane foam in a dry state.

Lastly, the drying step is characterized in that, when the acidic polyurethane foam is moved in the chamber, the odor of the acidic polyurethane foam and the volatile organic compounds (VOCs) are adsorbed on the activated carbon and removed.

The present invention can not only provide an effect of preventing discoloration due to ultraviolet rays or nitrogen oxides by increasing the acidity of the polyurethane foam by immersing the polyurethane foam in which the air holes are formed in a citric acid aqueous solution used as an acidity regulator, In the step of forming the polyurethane foam, the acidity control agent composed of the citric acid aqueous solution is not added, so that the mechanical properties of the polyurethane foam are not reduced, and the time required for the production of the discoloration retardant material for shoes of the present invention It is possible to give an effect to shorten the time.

In addition, it is possible to provide an effect of removing volatile organic compounds and odors which may occur in the production of the polyurethane foam contained in the discoloration retarding material.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view schematically showing a discoloration retarding material of the present invention. FIG.
2 is a flowchart sequentially showing the steps of manufacturing the discoloration retarding material of the present invention.
3 is an odor test report of a polyurethane foam containing an acidity adjusting agent used in the discoloration retarding material of the present invention.
4 is a VOC emission test and a discoloration test report of a polyurethane foam containing an acidity controlling agent used in the discoloration retarding material of the present invention.

Hereinafter, the technical spirit of the present invention will be described in more detail with reference to preferred embodiments and drawings.

It is to be understood that the technical spirit of the present invention is not limited to the embodiments and the accompanying drawings.

The discoloration retarding material using citric acid of the present invention has a structure as shown in FIG. 1 and includes a polyurethane foam 1, an acidity adjusting agent 2, and a fiber fabric 3.

First, the polyurethane foam (1) uses a not-friendly (ezyprene) having flexibility was prepared by mixing the polyol, diisocyanate compound, blowing agent, catalyst, other additives, and the density was a 80Kg / m ³ to about 150Kg / m ³ However, fine pores may be formed inside the polyurethane foam 1 to impart breathability to the discoloration retarding material.

 Next, the acidity controlling agent 2 is used as the acidity controlling agent 2 based on citric acid, and the citric acid is mixed with water to have an aqueous citric acid solution. More specifically, 100 parts by weight of water 0.3 to 1 part by weight of citric acid is mixed to prepare the acidity controlling agent (2).

Further, when citric acid is used in an amount of less than 0.3 part by weight based on 100 parts by weight of water in the preparation of the acidity controlling agent (2), the polyurethane foam (1) can not impart a discoloration retarding effect to the acidity controlling agent (2) , And when more than 1 part by weight of citric acid is used with respect to 100 parts by weight of water, the mechanical properties of the polyurethane foam (1) may be drastically lowered, and its use may be discarded.

The polyurethane foam (1) is made of an alkaline polyurethane foam whose surface is alkaline in appearance before being dipped in the acidity control agent (1).

The present invention also provides a method of preparing a polyurethane foam 1 by immersing the polyurethane foam 1 in the pH adjusting agent 2 so that the pH of the surface of the polyurethane foam 1 can be maintained at 6 to 7, In addition, the polyurethane foam 1 is sufficiently immersed in the acidity adjusting agent 2 so that the polyurethane foam 1 can be penetrated into fine pores formed therein.

The fiber fabric 3 is attached to the upper and lower surfaces of the polyurethane foam 1 so that the pH of the polyurethane foam 1 can be maintained for a long period of time. As a result, The material of the fabric 3 may be not only synthetic fibers made of various polymers but also materials such as leather.

Further, when the difference between the pH concentration of the fiber fabric 3 and the pH concentration of the polyurethane foam 1 is large, the pH concentration favorable for the discoloration retarding effect of the polyurethane foam 1 may be changed, The pH value of the fiber fabric 3 is maintained at 6 to 7 so as to be adhered to the polyurethane foam 1 so that the pH concentration of the polyurethane foam 1 is not changed.

Next, as shown in FIG. 2, the method for producing a discoloration retardant material using citric acid according to the present invention includes a foam forming step (S10), an immersion step (S20), and a drying step (S30).

First, the foam forming step (S10) is a step of forming an alkaline polyurethane foam containing a polyol and a diisocyanate compound. The alkaline polyurethane foam has an acidity of alkaline, and is flexible in the inside of the alkaline polyurethane foam to form a plurality of fine pores, To thereby produce an alkaline polyurethane foam.

The alkaline polyurethane foam may be used for shoes, and at least one additive such as a polyol, a diisocyanate compound, a foaming agent, a catalyst, and the like may be added.

Since the alkaline polyurethane foam formed through the foam forming step (S10) is not yet given a discoloration retarding effect, it may be simply stacked in a block form to prevent contact between ultraviolet rays and nitrogen oxides, Roll. In case of mass production of the alkaline polyurethane foam, the length of the alkaline polyurethane foam is required to be 50 m or more. In this case, the sheet may be wrapped and stored in a plurality of rolls.

Thereafter, through the immersion step (S20), a process of completely immersing the surface of the alkaline polyurethane and the fine pores formed in the alkaline polyurethane so that the acidity regulator can permeate is performed, so that the acidity of the alkaline polyurethane And the alkaline polyurethane foam formed in the foam forming step S10 is wound and stored in the form of a plurality of rolls so as to proceed smoothly the smooth immersion step S20, The end of the roll may be joined using a welding mechanism, and then the immersion step S20 may be performed.

Particularly, in the immersion step (S20), as described above, the acidity of the alkaline polyurethane is increased to change the acidic polyurethane to acidic polyurethane. The acidity adjusting agent comprising the citric acid aqueous solution is prepared, The alkaline polyurethane foam formed through the foam forming step (S10) is introduced into the water tank, so that the alkaline polyurethane foam can be sufficiently immersed in the acidity adjusting agent so as to be immersed therein.

The citric acid aqueous solution used as the acidity regulator is prepared by mixing 0.3 to 1 part by weight of citric acid with respect to 100 parts by weight of water.

Particularly, when the citric acid is used in an amount of less than 0.3 part by weight based on 100 parts by weight of water in the preparation of the acidity adjusting agent, the alkaline polyurethane foam can not impart a discoloration retarding effect by the acidity controlling agent. When used in an amount exceeding 1 part by weight, the mechanical properties of the alkaline polyurethane foam may be drastically reduced, and the use of the alkaline polyurethane foam may be discolored.

In addition, at the time of forming the alkaline polyurethane in the foam forming step (S10), the acidity controlling agent is prevented from being injected so that the mechanical property of the alkaline polyurethane foam is prevented from being lowered, and the reaction time is prevented from being increased do.

Thereafter, a compression roller is provided, and the acid polyurethane foam produced through the immersion step (S20) is compressed to perform a dehydration process for primarily removing moisture.

Next, a drying step (S30) is performed. Through the drying step (S30), not only the removal of moisture remaining in the acidic polyurethane foam but also the removal of volatile organic compounds (VOCs) and odors can proceed .

In order to proceed with the drying step S30, a chamber including a heat emitter for emitting high-temperature heat and a conveyor belt for conveying the acidic polyurethane foam in an unfolded state is provided. The temperature of the acidic polyurethane is controlled by the heating pipe, and a duct facility including an adsorbent such as activated carbon is provided, so that volatile organic compounds (VOCs) and odors are adsorbed on the activated carbon to be removed .

Particularly, when the temperature of the heat discharged from the chamber is in the range of 100 ° C to 150 ° C, and the temperature of the heat discharged from the chamber is 150 ° C, the drying time is not exceeded for 4 minutes, so that the acidic polyurethane foam Do not allow deformation to occur.

Further, when the acidic polyurethane foam is transported through the chamber through the conveyor belt in the unfolded state, the thickness of the acidic polyurethane foam is limited to within 150 mm in order to prevent the acidic polyurethane foam from being damaged.

In addition, as the thickness of the acidic polyurethane foam increases, the working efficiency decreases, and the temperature of the heating pipe and the operating speed of the conveyor belt can be changed to adapt to the thickness of the polyurethane foam.

In addition, after the drying step (S30), the heat of the acidic polyurethane foam and the remaining foreign matters may be removed by using the wind blown from the cooling fan separately provided outside the chamber.

In addition, the acidic polyurethane foam is kept in a flat shape. In order to prevent deformation of the acidic polyurethane foam during storage, the left and right sides of the polyurethane foam can be maintained at regular intervals and then rolled in a roll form to be stored.

Thereafter, in order to prevent the acidic polyurethane foam from being damaged and prevent the acidity from changing, a fiber fabric is attached to at least one of the upper and lower surfaces of the acidic polyurethane foam, wherein the acidity of the fiber fabric is The acidic polyurethane foam having a similar range to the acidity of the acidic polyurethane foam may be used to prevent the acidity of the acidic polyurethane foam from changing.

Hereinafter, the operation and effect of the present invention will be described in more detail through preferred embodiments of the present invention. It should be understood, however, that the invention is not limited to the disclosed embodiments.

3 is an odor test result of a polyurethane foam containing an acidity adjusting agent used in the discoloration retarding material of the present invention. Through Example 1 and Comparative Example 1, it was confirmed that the polyurethane foam obtained by immersing an acidity adjusting agent containing an aqueous citric acid solution And the degree of smell reduction.

An alkaline polyurethane foam having a fine pore size of 150 kg / m < ³ > was prepared and cut to have a length of 10 cm and a length of 10 cm, followed by mixing 0.3 to 1 part by weight of citric acid with respect to 100 parts by weight of water The acidic polyurethane foam was prepared by immersing the acidic polyurethane foam in an acidic solution containing citric acid aqueous solution, and then the acidic polyurethane foam was stored in a glass bottle having a capacity of 4 L and dried at (80 ± 2) ° C for 2 hours to measure the odor The results are shown in Table 1.

[Comparative Example 1]

An alkaline polyurethane foam having a density of 150 kg / m ³ was formed, and the alkali polyurethane foam was cut to have a length of 10 cm and a length of 10 cm. The alkaline polyurethane foam was stored in a glass bottle having a capacity of 4 L (80 2 < [deg.] ≫ C for 2 hours to measure the odor. The results are shown in Table 1.

division
smell MS 300-34 division 1 rating Odorless Wet deflation 2 ratings Odor detection Example 1 1.5 rating 3.0 rating
3 ranks Normal smell 4 ratings A strong smell Comparative Example 1
3.0 rating 4.5 rating 5 ratings An extreme odor 6 ratings Unpleasant smell

As shown in Table 1, it was found that the odor of Example 1 and Comparative Example 1 was significantly reduced in Example 1, which was prepared by immersing a polyurethane foam in an acidity regulator regardless of whether it was wet or dry there was.

Next, the detection degree of the volatile organic compounds (VOCs) of the polyurethane foam by immersing the acidity adjusting agent including the citric acid aqueous solution will be examined through the Example 2 and the Comparative Example 2.

After the alkali polyurethane foam having a density of 150 kg / m ^{3 and} having a length of 4 cm and a length of 9 cm was cut out, the alkaline polyurethane foam was added to 100 parts by weight of water, And 1 part by weight of a citric acid aqueous solution to prepare an acidic polyurethane foam. The acidic polyurethane foam was dried at 65 DEG C for 2 hours for pretreatment, and then treated with the acidity modifier In order to measure the volatile organic compounds (VOCs) detected in the acidic polyurethane foam, it was stored in a Tedlar bag having a capacity of 3 L, and then 3 L of nitrogen was injected into the Tedlar bag. Volatile organic compounds (VOCs) detected in the acidic polyurethane foam were measured using the method described in Table 2, and the results are shown in Table 2.

[Comparative Example 2]

After the alkali polyurethane foam having a density of 150 kg / m < ³ > was formed to have fine pores and cut to have a length of 4 cm and a length of 9 cm, the resultant was pre-treated by drying at 65 ° C for 2 hours, To measure the volatile organic compounds (VOCs) detected in the polyurethane foam, the alkaline polyurethane foam was stored in a Tedlar bag having a capacity of 3 L, and then 3 L of nitrogen was injected into the Tedlar bag. (VOCs) detected in the alkaline polyurethane foam were measured using the -55 simple measurement technique, and the results are shown in Table 2.

division VOCs MS 300-55 Simplified measurement technique

Detection limit: 0.01ppm Example 2 1.92 ppm Comparative Example 2 5.21 ppm

As shown in Table 2, the amount of volatile organic compounds (VOCs) detected in Example 2 was 1.92 ppm, and in Comparative Example 2, 5.21 ppm was detected. By immersing a polyurethane foam in an aqueous citric acid solution, (VOCs) can be greatly reduced.

4 is a VOC emission test and a color change test result of a polyurethane foam containing an acidity adjusting agent used in the discoloration retarding material of the present invention. Through Example 3 and Comparative Example 3, it was confirmed that the polyurethane foam Let us examine the discoloration delay effect.

After forming an alkaline polyurethane foam having fine pores and a density of 150 kg / m ³ , the alkaline polyurethane foam is immersed in an aqueous citric acid solution prepared by mixing 0.3 to 1 part by weight of citric acid with respect to 100 parts by weight of water, An acidic polyurethane foam is prepared.

As a UV tester for measuring the color change degree (QUV) of the polyurethane foam treated with the citric acid aqueous solution, an ATLAS UV TESTER is used and a UVA 340 lamp having a light amount of 0.78 W / m ² is provided. Subsequently, the acidic polyurethane foam prepared by immersing in an acidity control agent composed of an aqueous citric acid solution was exposed to UV light for 24 hours at a temperature of (45 ± 5) ° C., and the discoloration results are shown in Table 3.

[Comparative Example 3]

A UV tester for measuring the discoloration degree (QUV) of the alkaline polyurethane foam by preparing an alkaline polyurethane foam having a density of 150 kg / m < ³ >, using ATLAS UV TESTER, lt; RTI ID = 0.0 &^gt; UVA 340 < / RTI > Subsequently, the alkaline polyurethane foam not immersed in an acidity regulator composed of an aqueous citric acid solution was exposed to UV light for 24 hours at a temperature of (45 ± 5) ° C., and the discoloration results are shown in Table 3.

division Discoloration (QUV) NIKE TEST # G37
Equipment used: ATLAS, UV Test® Fluorescent / UV Instrument Example 3 2.0 Comparative Example 3 3.0

As shown in Table 3, the degree of discoloration (QUV) of Example 4 was 2.0, and that of Comparative Example 3 was 3.0. As a result, the polyurethane foam was immersed in an acidity control agent composed of an aqueous citric acid solution, The effect of retarding the discoloration of the foam could be significantly increased.

As shown in Tables 1 to 3, the acidity changes of Examples 1 to 3, the odor of the polyurethane foam, which is a chronic problem, the emission of VOCs, and the yellowing phenomenon have shown favorable results.

As described above, the present invention provides a discoloration delay material using citric acid as a main technical idea, and since the above-described embodiments are only one example with reference to the drawings, the true scope of the present invention is not limited to the claims .

1: polyurethane foam
2: acidity regulator
3: Textile Fabric
S10: Foam forming step
S20: Immersion step
S30: drying step

Claims (5)

0.3 to 1 part by weight of citric acid is mixed with 100 parts by weight of water;
A polyurethane foam in which fine pores are formed in the interior of the pores, the polyurethane foam having an alkaline property including a polyol and a diisocyanate compound, the polyurethane foam being immersed in the acidity adjusting agent and having the acidity controlling agent penetrated into the surface and the pores, And
And a fiber fabric adhered to at least one of a top surface and a bottom surface of the polyurethane foam so as to maintain the acidity of the polyurethane foam. The method according to claim 1,
The polyurethane foam,
And a density of 80 to 150 kg / m < ³ >. The method according to claim 1,
The acid-
Wherein the colorant has a pH concentration equal to the pH of the fiber fabric. A foam forming step of forming an alkaline polyurethane foam comprising a polyol and a diisocyanate compound;
Preparing an aqueous citric acid solution containing 0.3 to 1 part by weight of citric acid mixed with 100 parts by weight of water; immersing the alkaline polyurethane foam after the foam-forming step in an aqueous solution of citric acid to convert it into acidic polyurethane; And
And a drying step of introducing the acidic polyurethane foam, which has been changed through the immersion step, into a chamber having a duct including activated carbon, wherein the porous polyurethane foam has a high temperature and discharges heat to form an acidic polyurethane foam in a dry state. A method for manufacturing a discoloration retarding material using the method. 5. The method of claim 4,
The drying step comprises:
Wherein the acidic polyurethane foam is adsorbed on the activated carbon and removed when the acidic polyurethane foam is moved in the chamber, and the odor of the acidic polyurethane foam and the volatile organic compounds (VOCs) are removed by the activated carbon.

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