KR20210112556A - Eco Expanded Polypropylene a buoy and manufacturing method - Google Patents

Abstract

The present invention relates to an eco-friendly expanded polypropylene buoy and a manufacturing method thereof capable of providing buoyancy by using being used in a fish farm or an offshore structure. Since the present invention provides corrosion resistance which does not decompose even when exposed to seawater for a long time and is an eco-friendly material which is recycled, the present invention is manufactured with expanded polypropylene (EPP) which is physically foamed without using a chemical foaming agent and minimizes a problem of losing the buoyancy due to water absorption. The present invention comprises: a first buoyant body which is molded by the EPP which is physically foamed without using the chemical foaming agent; a coating layer which is coated on the outside of the first buoyant body and is formed by a polymer, a pigment, and a solvent to block absorption of the water from the first buoyant body; and a second buoyant body which is molded with EPP which is physically foamed without using the chemical foaming agent to be positioned on the outside of the coating layer. The present invention has a volume of 65-500 L.

Description

Eco-Expanded Polypropylene a buoy and manufacturing method

The present invention relates to an eco-friendly expanded polypropylene float that provides buoyancy by using it in aquaculture farms or offshore structures, and a method for manufacturing the same. Eco-friendly expanded polypropylene float and its manufacturing method to minimize the problem of loss of buoyancy due to water absorption while manufacturing with expanded polypropylene (EPP) that is physically expanded without using chemical foaming agents as an eco-friendly material is intended to provide.

In addition to installing fishing nets in aquaculture farms, floaters are mainly used to install various structures in freshwater lakes.

Commonly used rich polystyrene (foamed polyethylene (EPS); Styrofoam) is mainly used. However, in the case of Styrofoam rich material, it has the advantage of being able to manufacture at a low price, but there is a problem in that durability is weak, and when exposed to seawater for a long time, hydrolysis is severe and is damaged and pollutes the environment.

As a means to solve this problem, various configurations of rich plants are being developed, and representative examples include improved fish and shellfish culture improvement plants and registered patent publications (B1) in Republic of Korea Patent Publication (B1) 10-0615435 (2006.08.29.) 10-0903073 (2009.06.18.) There is a sealed float with an improved structure for rational production, and it is composed of a semi-cylindrical float cover on the outside of a general styrofoam float to prevent corrosion and damage to the Styrofoam inside. Although it is possible to prevent it, there is a problem such as having to separately manufacture and assemble the sub-cover.

Meanwhile, expanded polypropylene (EPP), an eco-friendly material that can be recycled, is widely used as a cushioning material in the automobile industry. However, in the case of expanded polypropylene, its formability at 100 mm or more was inferior compared to its excellent buoyancy and usability, so it was mostly applied to thin plates or single products of 100 mm or less.

Recently, using the eco-friendly material as described above, expanded polypropylene (EPP) is being provided to provide wealth.

As a prior art of using expanded polypropylene (EPP), an eco-friendly material, the expanded polypropylene float and its manufacturing method are provided in Republic of Korea Patent Publication No. (B1)10-1246931 (2013.03.25.). , this provides the vapor pressure supplied through the steam supply hole formed at regular intervals on the inner surface of the cavity of the mold at the same time as the pressing pressure while the polypropylene particles are physically foamed and put into the open mold to melt the surface of the particles and paste the polypropylene In manufacturing the float, it is formed to protrude from the cavity of the mold and provides vapor pressure to the vicinity of the center of the axis of the float through the steam supply pipe in which the vapor supply hole is formed at regular intervals so that the surfaces of the central particles of the float can be melted and glued together. After taking out from the mold, it was dried for 48 hours in a drying room under dry conditions at 80°C to manufacture.

In the case of such prior art, it is very advantageous for environmental pollution because it can be recycled while providing corrosion resistance that does not hydrolyze even when exposed to seawater for a long time.

However, the above-mentioned eco-friendly material, foamed polypropylene composition, has a problem in that buoyancy decreases due to water absorption when submerged for a long time. is frequent, and the cover is damaged by external force even during use, so the problem caused by water absorption cannot be solved.

KR 100615435 B1 2006.08.29. KR 100903073 B1 2009.06.18. KR 101246931 B1 2013.03.25.

Accordingly, the present inventor has researched and developed the present invention to solve the various problems of the conventional expanded polypropylene member as described above.

That is, in the present invention, it is an eco-friendly material that can be recycled while providing corrosion resistance that does not hydrolyze even when exposed to seawater for a long time. A coating layer is formed by applying a paint formed of a polymer, pigment, and solvent to the outside of the first buoyant body, and a second buoyant body molded from expanded polypropylene is formed outside the buoyant body, and the coating layer is damaged by external force. The present invention has been completed with the technical problem of the invention in providing an eco-friendly expanded polypropylene float and a method for manufacturing the same, which can simultaneously solve the problem that the foam-molded buoyancy agent absorbs water and loses buoyancy ability.

In the present invention as a means to solve the problem, first, a first buoyant body molded from Expanded Polypropylene (EPP) that is physically foamed without using a chemical foaming agent; a coating layer formed by applying a paint coated on the outside of the first buoyancy body to block water absorption into the first buoyancy body; It is characterized in that the volume including the second buoyancy body molded with expanded polypropylene that is physically foamed without using a chemical foaming agent to be located outside the coating layer is 65 to 500L.

Second, the paint is characterized in that it is composed of a mixture of a synthetic resin (polymer), a pigment and a solvent.

Third, the second buoyancy body is characterized in that it is composed of a thickness of 60 ~ 120mm.

Fourth, the first buoyancy force is applied by melting the surfaces of the particles by providing the vapor pressure supplied through the vapor supply holes formed at regular intervals on the inner surface of the cavity of the mold at the same time as the pressing pressure while the polypropylene particles are physically foamed and put into the open mold. a first step of forming a sieve; a second step of forming a coating layer by applying a paint composed by mixing a synthetic resin, a pigment, and a solvent to the outside of the first buoyant body molded in the first step; A small amount of physically foamed polypropylene particles are put into the open mold, and the first buoyant body formed with the coating layer in the second process is put inside the upper side, and then the physically foamed polypropylene particles are put into the open mold so that they are located outside the first buoyant body. It is manufactured through the third process of forming the second buoyant body by melting the surface of the particles by providing the vapor pressure supplied through the vapor supply hole formed at regular intervals on the inner surface of the cavity of the mold at the same time as the pressing force in one state. do it with

According to the eco-friendly expanded polypropylene member and its manufacturing method provided in the present invention, there are the following effects.

- Corrosion resistance that does not hydrolyze even when exposed to seawater for a long time is provided, so the service life of the rich can be prolonged.

-Environmental pollution can be minimized by using expanded polypropylene, an eco-friendly material.

- Since the coating layer is formed by mixing a synthetic resin (polymer), pigment and solvent between the first and second buoyancy bodies, damage to the coating layer can be prevented during transportation and installation.

- The first buoyancy body prevents water absorption, so the buoyancy of the rich person can be maintained for a long time.

-Since the paint constituting the coating layer located between the first and second buoyancy bodies is a synthetic resin (polymer) of the same quality as the first and second buoyancy bodies, it can be crushed and used without separate separation during recycling. It works.

1 is a partially fractured external perspective view showing a preferred embodiment of the eco-friendly expanded polypropylene member provided by the present invention;
Figure 2 is an enlarged cross-sectional view of the main part of the eco-friendly expanded polypropylene member provided by the present invention;
3 is a block diagram of the eco-friendly expanded polypropylene member manufacturing process provided by the present invention

Hereinafter, a preferred embodiment of the eco-friendly expanded polypropylene member provided by the present invention will be described based on the accompanying drawings.

1 is a partially fractured external perspective view showing a preferred embodiment of the eco-friendly expanded polypropylene member provided by the present invention, and FIG. 2 is an enlarged cross-sectional view of the main part of the eco-friendly expanded polypropylene member provided by the present invention. will be.

The eco-friendly expanded polypropylene member (1) provided in the present invention is an eco-friendly material that can be recycled while providing corrosion resistance that does not hydrolyze even when exposed to seawater for a long time. It is molded with Expanded Polypropylene, EPP), and is applied when making medium-to-large floats with a size of 65-500L.

Buoyancy in the present invention is preferably a first buoyancy body (2) on the inside, a coating layer (3) coated on the outside of the first buoyancy body (2), and a second buoyancy force formed on the outside of the coating layer (3) It is configured to include a sieve (4).

The first buoyancy body 2 and the second buoyancy body 4 are provided by molding with expanded polypropylene that is physically foamed as described above.

And the coating layer 3 that is coated on the outside of the first buoyancy body 2 to block water absorption into the first buoyancy body 2 is provided by a paint composed of a mixture of a synthetic resin (polymer), a pigment and a solvent. .

The main physical properties of the paint constituting the coating layer required in the present invention are excellent adhesion with the first and second buoyancy agents that are physically foamed without using a chemical foaming agent, and a hiding power for the material is required, and the place where it is used Due to the nature of the product, a paint with excellent salt water resistance, water resistance, and weather resistance is required.

To this end, in the present invention, a paint composed of a combination of a synthetic resin (polymer), a pigment, and a solvent is used. In addition, a small amount of dispersant is mixed.

The synthetic resin has a similar chemical structure to the first and second buoyancy bodies, so it has excellent adhesion, and excellent salt water resistance, water resistance and weather resistance. Polypropylene Elastomer, maleic acid modified polypropylene elastomer, acrylate modified polypropylene Elastomer, ethylene-modified polypropylene elastomer, isoprene-modified polypropylene elastomer, butadiene-modified polypropylene elastomer, chlorinated polypropylene elastomer, and rubber-modified polypropylene elastomer can be used alone or in combination of two or more. In addition, since the synthetic resin has a chemical structure similar to that of the first and second buoyancy bodies, it can be crushed and used without separate separation during recycling.

The synthetic resin may be used in an amount of 5 to 50% by weight in the composition of the paint, and the optimal ratio suitable for the present invention is 10 to 30% by weight.

If the proportion of the synthetic resin is less than 5% by weight, the adhesion to the material is significantly reduced, and if it is more than 50% by weight, the workability for painting the material becomes difficult.

In addition, the pigment used can be used in various ways depending on the color, and titanium oxide (TiO2) can be used in the composition of the paint in an amount of 1 to 30% by weight, and the optimum ratio is 5 to 20% by weight as a white standard. Suitable.

If the proportion of the pigment is 1 wt% or less, the hiding power with the material is reduced, and if it is 30 wt% or more, the adhesion to the material is reduced.

In addition, in the present invention, various solvents can be used to dissolve the polymer and adjust the viscosity of the paint to facilitate workability during painting.

The solvents used include aromatics such as toluene and xylene, acetates such as ethyl acetate and butyl acetate, propyl acetate, ketones such as methyl ethyl ketone, methyl isobutyl ketone, and diisobutyl ketone, and alcohols such as methanol, ethanol, and propanol. Solvents such as alcohol, cyclohexane, and methylene chloride can be used alone or in combination of two or more.

In addition, as the dispersant, Disper BYK P104 may be used, and 0.3 wt% may be used in the composition of the paint.

Hereinafter, Examples and Comparative Examples of the paint used in the present invention will be described in detail in Table 1.

Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 profit polypropylene elastomer 20 Maleic acid modified polypropylene elastomer 20 Acrylate-modified polypropylene elastomer 20 Ethylene-modified polypropylene elastomer 20 Butadiene-modified polypropylene elastomer 20 Chlorinated Modified Polypropylene 20 pigment TiO2 R-902 10 10 10 10 10 10 dispersant Disper BYK P104 0.3 0.3 0.3 0.3 0.3 0.3 solvent Toluene 40 40 40 40 40 40 Cyclo hexane 15 15 15 15 15 15 Methyl ethyl ketone 14.7 14.7 14.7 14.7 14.7 14.7 Sum 100 100 100 100 100 100

Table 2 shows a comparison of the physical properties of the paint obtained in the above example and the paint using the chlorinated-modified polypropylene resin, which is currently the most used for a bumper paint made of polypropylene for automobiles and a case paint for cosmetics.

paint composition Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 dry dry to the touch ◎ ◎ ◎ ◎ ○ ◎ solidified dry ◎ ◎ ◎ ◎ ◎ ○ material adhesion 100 95 95 95 100 40 water resistance ◎ ○ ◎ ◎ ◎ △ alkali resistance ◎ ○ ○ ◎ ◎ △ boiling water resistance ◎ ○ ◎ ○ ○ △ corrosion resistance ◎ ○ ◎ ○ ◎ △ paint storage ○ ◎ ◎ ○ ○ ◎

In Table 2 above, the evaluation items indicating the characteristics of each paint mean the following. ◎ means very good, ○ means good, △ means average, and X means bad.

In addition, each characteristic in Table 2 was measured in the following way. First, the drying conditions were natural drying, and dry to touch was confirmed to the extent that stickiness remained on the hand within 10 to 30 minutes after painting. It was evaluated as normal or poor.

And the material adhesion was judged by the amount that remained attached to the material by cross-cutting according to ASTM D3359 standard, and the water resistance was solidified and dried, and the degree of change in the coating film was confirmed after immersion in water for a week, and the alkali resistance was ASTM D1308. As a method, the boiling water resistance was measured by immersion in boiling water for 24 hours, and the degree of change in the coating was determined. was evaluated by confirming the occurrence of

In addition, in the case of corrosion resistance, the coating film was scratched by cross-cutting, and after 200 hours of testing in a salt spray tester (35 °C, 5% sodium chloride aqueous solution), the results according to the degree of adhesion to the material were visually determined.

The storability of the paint was evaluated by diluting each diluent twice in the paint obtained in Table 1, putting it in a test tube, and observing the degree of separation of the pigment and the resin or the pigment and the diluent at room temperature for 30 days.

The molding of the first buoyancy body 2 and the second buoyancy body 4 is made by a mold, and is preferably supplied through a steam inlet hole formed at regular intervals on the inner surface of the cavity of an open mold that can provide a pressing force. It is provided according to a method of melting the surface of the physically foamed polypropylene particles by the vapor pressure to be adhered to the neighboring ones.

On the other hand, the second buoyancy body 4 made of the same material as the first buoyancy body 2 provides a function of preventing the coating layer 3 from being damaged during an external impact or installation process.

The second buoyancy body 4 surrounding the coating layer 3 has a thickness of about 60 to 120 mm.

For example, in the case of a medium-sized float with a size of 65L, the second buoyancy body 4 has a thickness of about 60mm, and in the case of a large float with a size of 500L, the second buoyancy body 4 has a thickness of about 120mm to protect the coating layer 3 make it possible

When the thickness of the second buoyancy body 4 is formed as thin as 60 mm or less, the first buoyancy body 2 becomes large, so there is a low risk of loss of buoyancy due to water absorption, but the ability to prevent damage to the coating layer 3 due to external force is reduced. , When the thickness of the second buoyancy body 4 is thicker than 120mm, the first buoyancy body 2 is relatively small and water absorption is increased by the second buoyancy body 4, resulting in a problem that the buoyancy is lowered. can

Unexplained reference numeral 5 in the drawing shows a fixing groove used when installing the eco-friendly expanded polypropylene member (1).

Figure 3 shows a block diagram of the eco-friendly expanded polypropylene member manufacturing process provided by the present invention.

The manufacturing process of the eco-friendly expanded polypropylene float (1) provided by the present invention is 1) a first process (S10) of manufacturing the first buoyancy body (2), 2) a coating layer (3) on the outside of the first buoyancy body (2) ) is made through a second process (S20) of forming, 3) a third process (S30) of forming the second buoyancy body 4 on the outside of the coating layer 3, and each process will be described in detail below. .

1) A first process (S10) of manufacturing the first buoyancy body (2)

After the polypropylene particles are physically foamed and put into an open mold, the first buoyant body melts the surface of the particles by providing the vapor pressure supplied through the steam supply holes formed at regular intervals on the inner surface of the cavity of the mold at the same time as the pressing pressure. (2) is a molding process.

2) A second process of forming the coating layer 3 on the outside of the first buoyancy body 2 (S20)

This is a process of forming the coating layer 3 by applying a paint composed by mixing a polymer, a pigment, and a solvent to the outside of the first buoyant body 2 molded in the first step (S10).

3) A third process of forming the second buoyancy body 4 on the outside of the coating layer 3 (S30)

A small amount of physically foamed polypropylene particles are put into an open mold, and the first buoyant body 2 on which the coating layer 3 is formed in the second step (S20) is put in the upper side, and then the physically foamed polypropylene particles are first The second buoyancy force is applied by melting the surface of the particles by providing the vapor pressure supplied through the steam supply hole formed at regular intervals on the inner surface of the cavity of the mold at the same time as the pressing pressure while the buoyant body 2 is placed in the open mold to be positioned outside. It is a process of shaping|molding the sieve 4.

The specific method of the first process (S10) and the third process (S30) is the same as the manufacturing process of Patent No. 1246931, which is the prior art, and is specifically as follows.

a) physical foaming

For physical foaming, polypropylene particles are put into a closed foaming tank and then heated at a temperature of 40 to 60° C. for 12 hours to foam the particles in a desired state. Foaming does not occur at 40°C or lower, and foaming is possible at 60°C or higher, but the economical efficiency is low due to large heat loss.

b) input of material

Physically foamed particles are put into an open mold.

The mold is for producing products with a diameter of 200mm (65L) to 3000mm (500L), and a steam supply pipe formed to protrude near the center of the cavity can be formed. It may be possible to provide vapor pressure to the vicinity of the center of the cavity.

c) Forming and cooling

In a state in which particles with physical foaming are put into the open mold, steam is supplied through the steam supply hole formed in the cavity and at the same time pressurized so that the mold in the open state is molded. At this time, steam of 180~190℃ is supplied into the cavity and the mold is pressed for 400~500 seconds at a pressure of 6~9kgf/cm2. In this process, the surfaces of the particles that have been physically foamed melt and combine with neighboring particles This is made, and the vapor pressure is provided to the vicinity of the shaft center of the float through the vapor supply hole, so that the vapor pressure can be provided evenly to the entire expanded polypropylene particles filled in the cavity.

After molding, the formed float is cooled by water cooling.

d) take out

Open the mold and take out the finished float.

e) drying

Since the expanded polypropylene member 1 is configured to mold a product using vapor pressure, it contains a significant amount of moisture therein.

The moisture content causes the weight increase and buoyancy decrease of the product in the future, so it must be removed. Since the products for floaters with a diameter of 200mm (65L) or more cannot evaporate the moisture inside without artificial drying, put the molded floaters in a drying room that maintains a dry state of 80℃ and dry them for 40 hours.

As described above, when the eco-friendly expanded polypropylene float (1) provided in the present invention and the float are provided by the manufacturing method thereof, corrosion resistance that does not hydrolyze even when exposed to seawater for a long time is provided, so that the service life can be prolonged. , environmental pollution can be minimized, and the effect of preventing damage to the coating layer 3 during transportation and installation can be expected.

In the detailed description of the present invention, although specific embodiments are described, various modifications are possible without departing from the scope of the present invention. Therefore, the protection scope of the present invention should not be limited to the described embodiments, and should be defined by the following claims as well as equivalents.

1: (eco-friendly) polypropylene foam
2: 1st buoyant body
3: coating layer
4: 2nd buoyant body
S10: first process
S20: second process
S30: 3rd process

Claims (4)

A first buoyant body 2 molded from expanded polypropylene (EPP) that is physically foamed without using a chemical foaming agent;
a coating layer (3) coated on the outside of the first buoyancy body (2) and formed by applying a paint to block water absorption into the first buoyancy body (2);
Eco-friendly expanded polypropylene, characterized in that the volume including the second buoyancy body (4) molded with expanded polypropylene that is physically foamed without using a chemical foaming agent to be located outside the coating layer (3) is 65 to 500L Wealthy.
The method of claim 1 ;
The paint forming the coating layer is an eco-friendly expanded polypropylene material, characterized in that a synthetic resin (polymer), a pigment, and a solvent are mixed.
The method of claim 1 ;
The second buoyancy body (4) is an eco-friendly expanded polypropylene float, characterized in that it is composed of a thickness of 60 ~ 120mm.
After the polypropylene particles are physically foamed and put into an open mold, the first buoyant body melts and pastes the surfaces of the particles by providing the vapor pressure supplied through the steam supply holes formed at regular intervals on the inner surface of the cavity of the mold at the same time as the pressing force. (2) a first step (S10) of molding;
a second process (S20) of forming a coating layer (3) by applying a paint composed by mixing a polymer, a pigment, and a solvent to the outside of the first buoyancy body (2) molded in the first process (S10);
A small amount of physically foamed polypropylene particles are put into an open mold, and the first buoyant body 2 having the coating layer 3 formed thereon in the second step (S20) is put inside, and then the physically foamed polypropylene particles are first The second buoyancy force is applied by melting the surface of the particles by providing the vapor pressure supplied through the steam supply hole formed at regular intervals on the inner surface of the cavity of the mold at the same time as the pressing force while the buoyant body 2 is placed in the open mold to be positioned outside. Eco-friendly expanded polypropylene member manufacturing method, characterized in that manufactured by the third step (S30) of molding the sieve (4).

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