WO2011118910A2 - Surface coating compound and coating method for a pallet - Google Patents

Abstract

The present invention discloses a surface coating compound and coating method for an EPS, urethane foam, PP, and PE pallet for loading and transporting goods. The surface coating compound and coating method can prevent damage, such as cracks formed from loads during loading or unloading of goods onto and from pallets generally made of wood or iron and used to transport goods, and dents from handling goods. In order to prevent corrosion of a pallet, the pallet is first immersed in a liquid compound of a liquid polymer resin (polyurethane, polyurea, or polyurethane-polyurea) mixed with a solvent, and then the coating is hardened to provide durability to the pallet.

Description

Surface coating mixture and coating method for pallet

The present invention relates to a composition and coating method of a pallet surface coating mixture consisting of a pallet, wood, steel, etc., which are made of substances such as EPS (Expanded Polystyrene), urethane foam, PP (polypropylene), PE (polyethylene) having a chemical composition, In detail, the surface of the pallet may be formed of a liquid polymer resin so as to prevent damages such as cracking and scratches caused by handling when loading or unloading items on a pallet surface made of EPS, urethane foam, PP, and PE having high density properties. Polyurethane, polyurea, polyurethane-polyurea) applied to the cured or applied to the surface coating mixture and coating method for transporting the article to secure durability by immersing in a solution using the polymer resin and solvents (Solvents) It is about.

Pallets made of high-density EPS, urethane foam, PP, and PE may cause cracks due to load when loading or unloading items. Pallets made of wood are vulnerable to moisture and cannot be used for a long time due to corrosion due to moisture absorption. Do. In addition, in Korea, timber production is absolutely insufficient, and timber is imported and used in foreign countries. For the lamination pallets used for export goods, in accordance with the inspection regulations of imported countries and other countries, In order to avoid the transmission of pathogens, high-temperature heat treatment or the regulation of difficult hygiene and disinfection tests were carried out. Therefore, it was necessary to replace other substances with new chemical composition to avoid such strict regulations. . Even in the case of steel pallets, although they were manufactured at high prices due to the decrease in the durability life due to corrosion and the like, they were limited to use.

Currently used transport and lamination pallets have been mainly made of wood, but their use has been used for a short period of time. As a limiting factor for long-term use, corrosion factors due to moisture function and damages during loading of goods are greatly affected. It is known to do. In addition, the import and export customs were severely restricted by risk factors such as environmental destruction caused by the inflow of living organisms parasitic on wood.

In addition, such a wooden pallet may cause damage to the product because the moisture content of the wood (containing up to about 30%) is changed depending on the surrounding environment when laminating moisture sensitive products.

As the alternative material, plastic lamination pallets and steel pallets are manufactured, but the disadvantages thereof are bulky, heavy weights, high manufacturing costs, and the weight of pallets in actual transportation. The cost of the part is high.

In this regard, although the PCT publication WO2007 / 056821 discloses that the pallet body is composed of EPS in the related art, the coating composition for improving the durability and strength of the EPS pallet as in the present invention is not disclosed.

The present invention is to solve the problems of the prior art as described above in the loading and unloading load on the pallet surface consisting of wood or steel or on the pallet surface made of EPS, urethane foam, PP, PE having a high density and high strength In order to prevent cracks and damage caused by cracks and handling, and to prevent corrosion of the pallet itself, it is hardened by applying a liquid polymer resin (polyurethane, polyurea, polyurethane-polyurea) or mixing the polymer resin and a solvent. It is an object of the present invention to provide a surface coating mixture and coating method for transporting wood, steel, EPS, urethane foam, PP, PE pallets, which is hardened by immersing a pallet in a mixed solution and hardening it.

Still another object of the present invention is to provide a light and cushioning pallet having a weight of about 1/10 to 1/2 of that of wood, steel, and plastic pallets.

Still another object of the present invention is to provide a pallet that is excellent in terms of environment and cost by not corrosive and does not require control against pests or molds.

Another object of the present invention is to provide a pallet imparted with the non-slip effect in order to prevent damage to the product.

The present invention to solve the above problems;

A surface coating composition for pallets, the surface coating composition for pallets comprising 30 to 70% by weight of a urethane prepolymer and 70 to 30% by weight of at least one mixture selected from polyamines, polyhydric alcohols and chain extenders. .

The present invention also provides a surface coating composition for a pallet, comprising: a material (A) containing 70 to 99% by weight of a urethane prepolymer and 1 to 30% by weight of a solvent;

Provided is a surface coating composition for pallets, in which a substance (B) containing at least one 70-99% by weight and a solvent 1-30% by weight selected from polyamines, polyhydric alcohols and chain extenders is 1: 1 mixed.

In the above urethane prepolymer may be used that includes at least one polyisocyanate which may be aliphatic or aromatic, the aliphatic polyisocyanate is hexamethylene diisocyanate (HDI), tetraalkyl xylene diisocyanate, cyclo hexane diisocyanate, 1,12-dodecane diisocyanate, 1,4-tetramethylene diisocyanate, 1,3- and 1,4-cyclohexane diisocyanate, 1-isocyanate-3,3,5-trimethyl-5-isocyanatemethyl-cyclo Preference is given to using at least one selected from hexane (isophorone diisocyanate), 4,4'-, 2,2'- and 2,4'-dicyclohexyl-methane diisocyanate.

In addition, the aromatic polyisocyanate is selected from 2,4- or 2,6-toluene diisocyanate, 2,4- or 4,4-diphenylmethane diisocyanate, P-phenyline diisosanate and polymethylene polyphenyl isocyanate. One or more selected may be used, and the polyamine is preferably a polyoxyalkylene polyamine.

In addition, the polyhydric alcohol may be used at least one selected from polyether polyol, polyester polyol, polycarbonate polyol and polycaprolactone polyol, the chain extender is 1-methyl-3,5-diethyl -2,4- or 2,6-diaminobenzene (also referred to as diethyltoluene diamine or DETDA: US Alberta, Swiss Lonza); 1,3,5-triethyl-2,6-diaminobenzene; 3,5,3 ', 5'-tetraethyl-4,4'-diaminodiphenylmethane; Di (methylthio) -toluene diamine including 3,5-di (methylthio) -2,4 and 2,6-toluene diamine; N, N'-bis (t-butyl) ethylene diamine; 4,4'-methylenebis (2-isopropyl-6-methylaniline); 4,4'-methylenebis (2,6-diisopropylaniline), Clearlink 1000 (UOP); One or more kinds selected from Polyclear 136 (Basf) may be used.

In the present invention, the coating composition may further comprise a catalyst, in which case the catalyst is dibutyltin dilaurate, dibutyltin diacetate, diethyltin diacetate, dihexyltin diacetate, di-2-ethyl Hexyltin oxide, dioctyltin dioxide, stannous octoate, stannous oleate, trialkylamine (trimethylamine, triethylamine); N-alkylmorpholine (N-methylmorpholine, N-ethylmorpholine), 2,2′-dimorpholinodiethyl ether, 1,4-dimethylpiperazine, N, N, N ′, M′-tetra One or more types selected from methyl-1,3-butanediamine, dimethyldiaminodiethyl ether and triethylenediamine can be used.

In addition, the solvent in the above uses at least one selected from DMA (N, N-dimethylacetamide), DMF (dimethylformamide), THF (Tetrahydrofuran), DMSO (dimethylsulfoxide) and propylene carbonate (Propylene carbonate).

According to the present invention, the pallet coated with the coating composition of the present invention has a tensile strength, hardness, etc. required for the pallet during transportation, loading or unloading of the article, and prevents cracking and provides a pallet that is light in weight and economical. In particular, since it can solve the corrosiveness of wooden pallets or steel pallets, the durability of these pallets can be improved, and the occurrence of pests and molds can be suppressed. It can be provided.

The component A urethane prepolymer applied to the polyurea system of the present invention comprises at least one polyisocyanate which may be aliphatic or aromatic.

As said aromatic isocyanate type, 2, 4- or 2, 6-toluene diisocyanate, 2, 4- or 4, 4- diphenylmethane diisocyanate, P-phenyline diisosanate, polymethylene polyphenyl isocyanate, or mixtures thereof, etc. It includes, but is not limited to.

Aliphatic isocyanates include hexamethylene diisocyanate (HDI), tetraalkyl xylene diisocyanate, cyclohexane diisocyanate, 1,12-dodecane diisocyanate, 1,4-tetramethylene diisocyanate, 1,3- and 1,4- Cyclohexane diisocyanate, 1-isocyanate-3,3,5-trimethyl-5-isocyanatemethyl-cyclohexane (isophorone diisocyanate), 4,4 '-, 2,2'- and 2,4'-dicyclo Hexyl-methane diisocyanate, and the corresponding isomer mixtures and the like.

Aliphatic / aromatic diisocyanates can here be used in combination or alone or in combination. Examples of suitable polyhydric alcohols include polyetherpolyols, polyesterpolyols, polycarbonate polyols, polycaprolactone polyols, and other polyols. These polyols can be used independently or in combination of two or more.

Preferred aromatic and aliphatic isocyanate NCO (%) to meet the required physical properties has an isocyanate content of 18 to 25%.

In addition, the component B of the present invention may use one or more selected from polyamines, polyhydric alcohols, and amine chain extenders.

The polyamine is preferably a polyoxyalkylene polyamine. Polyoxyalkylene polyamines typically have a weight average molecular weight of about 200 to about 5000; It has 2-6, preferably 2-3 functional groups.

The total amount of polyamine in the total polyurea system of the present invention may range from about 50 to about 90 wt%, preferably from about 70 to about 90 wt%.

The reason for the content is that the elongation is 150% or more in the above range, the Shore D hardness is 50 or more and does not produce defective products such as cracks. In general, if the Shore D hardness is 70 or more, the elongation is high, and no problems such as cracks occur, a large area may be applied with a small amount of material.

Examples of commonly used chain extenders are 1-methyl-3,5-diethyl-2,4- or 2,6-diaminobenzene (also referred to as diethyltoluene diamine or DETDA: US Alberta, Switzerland Lonza) ); 1,3,5-triethyl-2,6-diaminobenzene; 3,5,3 ', 5'-tetraethyl-4,4,' diaminodiphenylmethane; Di (methyllio) -toluenediamine containing 3,5-di (methylthio) -2,4 and 2,6-toluene diamine; N, N'-bis (t-butyl) ethylenediamine; 4,4'-methylenebis (2-isopropyl-6-methylaniline); 4,4'-methylenebis (2,6-diisopropylaniline) and the like are used, and Clearlink 1000 (Clearlink 1000, UOP); Polyclear 136 (Basp).

The total amount of chain extender in the total polyurea system of the present invention may range from about 20 to about 40 wt%, preferably from about 25 to about 35 wt%.

The reason for this is that it is possible to maintain the elongation rate without making defects such as cracks as described above, and because it is the optimum content range for maintaining Shore D hardness.

In pure polyurea systems, no catalyst was used.

It preferably contains some polyurethane groups comprising at least one polyamine and a chain extender, optionally blended with at least one polyhydric alcohol so as to produce a polyurethane-polyurea (aka hybrid) system of the mixture of the present invention. Polyurethane-polyurea systems are made. The polyamines and chain extenders used therein are described in the pure polyureas above.

Generally, the amount of polyhydric alcohol is less than 50 wt%, preferably 10 to 30 wt%, based on the total polyfunctional isocyanate-reactive compound. The advantage of such polyhydric alcohol addition has the smoothness and economical part of the surface according to the control of the curing rate.

The reason for the content is that such a hybrid system can complement each other's advantages as well as economic effects. When the polyurea is hybridized, the elongation may be slightly reduced, but it may facilitate adjustment of Shore D hardness and gelation time. For this reason, polyhydric alcohol can be used in the above range.

Preferably, a system comprising at least 70% of a polyurethane group comprising at least one polyhydric alcohol and optionally comprising at least one polyhydric alcohol and at least one amine as a chain extender so as to produce a polyurethane system of the mixture of the invention Is made. The polyamines and chain extenders used therein are described in pure polyureas above.

Generally the amount of polyhydric alcohol is at least 40 wt%, preferably 40 to 50 wt%, based on the total polyfunctional isocyanate-reactive compound. The advantage of such polyhydric alcohol addition is that it is economical and flexible in coating.

Examples of suitable polyhydric alcohols include polyetherpolyols, polyesterpolyols, polycarbonate polyols, polycaprolactone polyols, and other polyols. These polyols can be used independently or in combination of two or more.

Catalysts are used in the urethane system, and the catalysts used are Pb-based, cobalt-based, bismuth-based, and tertiary amine or organic tin compounds. The organic group in the organic portion may be a hydrocarbon group containing 1 to 8 carbon atoms.

For example, dibutyl tin dilaurate, dibutyl tin diacetate, diethyl tin diacetate, dihexyl tin diacetate, di-2-ethylhexyl tin oxide, dioctyl tin dioxide, stanox octoate, stano oleate Trialkylamines (trimethylamine, triethylamine); N-alkylmorpholine (N-methylmorpholine, N-ethylmorpholine), 2,2'-dimorpholinodiethyl ether, 1,4-dimethylpiperazine, N, N, N ', M'-tetra Methyl-1,3-butanediamine, dimethyldiaminodiethylether and triethylenediamine.

The amount used to accelerate the chemical reaction is used less than 5% during the formulation, preferably less than 3wt%.

Of the mixtures (polyamines / polyols and chain extender (s)) which are the components required for preparing the polyurethane, polyurea, polyurethane-polyurea elastomer systems of the invention, (A) 'polyisocyanates and (B)' components. Typical proportions are from about 30 to 70 wt% of component (A) 'to about 70 to 30 wt% of component (B)', most preferably from 50 to 50% mixture of components (A) 'and (B)' It shows the best physical properties.

In order to easily apply the polyurea and polyurethane-polyurea elastomer systems, a mechanical device is required. The condition of the equipment is a two-component spray device with a static mixer or a two-component high pressure direct collision spraying machine. The minimum pressure of the equipment used for this is at least 500 psi and preferably should be able to work under high pressure of about 1500 to about 3500 psi. In addition, a device for heating and using the product may be installed as needed.

Example 1 Pure Polyurea System

Table 1 Synthesis No. One 2 3 4 5 A component (urethane prepolymer) A-1 100 80 70 60 50 A-2 20 20 30 40 A-3 10 10 10 B component (amine mixture) DETDA 40 25 20 20 20 Polyclear 136 5 D2000 58 58 58 50 50 T5000 20 18 10 Unilink 4200 10 10 18 Absorbent 2 2 2 2 2 Gelation time (sec, 100g) <One 〈6 〈10 〈15 〈15 Tensile Strength (Mpa) 23 22 20 20 18 Tear strength (N / m) 70 65 65 63 58 Elongation (%) 40 170 230 320 330 Shore D 75 70 65 54 50 Crack generation (with or without) [static load 700kg / ㎠] U radish radish radish radish Pallet Applications incongruity fitness fitness fitness fitness

Example 2 Polyurethane-polyurea system, hybrid

TABLE 2 Synthesis No. One 2 3 4 5 A component (urethane prepolymer) AA-1 100 80 70 60 50 AA-2 20 30 40 50 B component (amine + polyol mixture) DETDA 20 23 25 25 20 Polyclear 136 5 D2000 40 50 50 45 45 T5000 5 Polyol (amine base) 40 22 20 15 20 Ester polyol 5 5 10 10 Gelation time (sec, 100g) 〈15 <8 〈6 〈13 <4 Tensile Strength (Mpa) 19 21 20 19 18 Tear strength (N / m) 60 65 63 54 46 Elongation (%) 370 310 260 310 200 Shore D 38 42 48 48 42 Crack occurrence (with or without) [static load 700kg / ㎠] U radish radish radish radish Pallet use incongruity fitness fitness fitness fitness

Example 3 Polyurethane System

TABLE 3 Synthesis No. One 2 3 A component (urethane prepolymer) AAA-1 100 AAA-2 100 50 AAA-3 50 B component (amine + polyol mixture) DETDA 20 25 25 D2000 20 40 40 Polyol (amine base) 50 22 20 Ester polyol 8 10 12 Curing catalyst (Sn type) 2 3 3 Gelation time (sec, 100g) 〈30 〈15 〈18 Tensile Strength (Mpa) 15 18 16 Tear strength (N / m) 45 53 49 Elongation (%) 380 250 220 Shore D 31 42 41 Crack occurrence (with or without) [static load 700kg / ㎠] radish radish radish Pallet use Not suitable (hardness) fitness fitness

In the above table, D2000 and T5000 are trade names of polyethylamine.

* work method

Coating: 0.7 mm

Mechanism Name: GUSMER H-3500 tkdyd

Spray Gun: 100 GX-7 Guns

Hose Heater Temperature: 70 ℃ for both A and B components

Static pressure: 2,400psi

In the case of coating by the dipping method of the present invention, the solid content after curing of the A and B agents is possible up to 70 ~ 99% and the solvent may be used up to 1 ~ 30%. However, after the preparation of agent A and agent B, a solvent may be added and mixed with each other. This is because, when a solvent is added to and mixed with one of the agents A and B, the reaction may be partially progressed to prevent uniform surface coating.

The solvent used in the present invention uses 1 to 30% by weight of at least one selected from DMA, DMF, THF, DMSO, and propylene carbonate.

If the solvent is less than 1%, other materials are not dissolved, and if it exceeds 30%, it is hard to be cured after coating, so the above range is used.

The coating method using the A agent and the B agent which does not use the solvent of the present invention as described above is a time when the A and B agent is mixed with the A spraying agent and the curing time is a time that does not matter when the finger is touched. Since it is about 20 seconds, the pallet cannot be dipped and coated. However, if the solvent is added to A component and 10% of the solvent is mixed with B component, the drying time is increased to 2 hours, 4 hours using 20% by weight, and 8 hours using 30% by weight. This makes it easier to dip and coat rather than spraying the pallets one by one.

EXAMPLE 4 The following Table 4 shows the case where 10 weight% of solvents were used when a solvent is contained in both A component and B component.

Table 4 number Solvents usage EXAMPLE Drying (hours) One N, N-dimethylacetamide (DMA) 1-30% 10% use 2 2 Dimethylformamide (MDF) 1-30% 10% use 2 3 Tetrahydrofuran (THF) 1-30% 10% use 2 4 Dimethylsulfoxide (DMSO) 1-30% 10% use 2 5 Propylene carbonate 1-30% 10% use 2

10% use is included in both agents A and B.

As can be seen in the above embodiment, when the mixture according to the present invention is used, the drying time is increased, so that the pallet can be sufficiently immersed to provide a desired pallet economically while saving time than the spraying method.

Claims (15)

As a surface coating composition for EPS, a urethane foam, a PP, PE pallet, 30-70 weight% of urethane prepolymers; Surface coating composition for EPS, urethane foam, PP, PE pallet, characterized in that it comprises 70 to 30% by weight of at least one mixture selected from polyamines, polyhydric alcohols and chain extenders. A component which is a urethane prepolymer; 1 to 30% by weight of one or more solvents selected from DMA, DMF, THF, DMSO and propylene carbonate to 70 to 99% by weight of each of component B, which is one or more mixtures selected from polyamines, polyhydric alcohols and chain extenders Surface coating mixture for pallets. A material containing 70 to 99% by weight of a urethane prepolymer and 1 to 30% by weight of at least one solvent selected from DMA, DMF, THF, DMSO, and propylene carbonate; Material containing 1 to 70% by weight of at least one selected from polyamines, polyhydric alcohols and chain extenders and 1 to 30% by weight of at least one solvent selected from DMA, DMF, THF, DMSO and propylene carbonate Surface coating mixture for a pallet, characterized in that the mixture. The surface coating composition according to any one of claims 1 to 3, wherein the urethane prepolymer comprises at least one polyisocyanate system which may be aliphatic or aromatic. The method of claim 4, wherein the aliphatic polyisocyanate is hexamethylene diisocyanate (HDI), tetraalkyl xylene diisocyanate, cyclohexane diisocyanate, 1,12-dodecane diisocyanate, 1,4-tetramethylene diisocyanate, 1 , 3- and 1,4-cyclohexane diisocyanate, 1-isocyanate-3,3,5-trimethyl-5-isocyanatemethyl-cyclohexane (isophorone diisocyanate), 4,4'-, 2,2'- And 2,4′-dicyclohexyl-methane diisocyanate, the surface coating composition for EPS, urethane foam, PP, PE pallets characterized in that at least one selected from. The method of claim 4, wherein the aromatic polyisocyanate is 2,4- or 2,6-toluene diisocyanate, 2,4- or 4,4-diphenylmethane diisocyanate, P-phenyline diisosanate and polymethylene Surface coating composition for EPS, urethane foam, PP, PE pallet, characterized in that at least one selected from polyphenyl isocyanate. The surface coating composition according to any one of claims 1 to 3, wherein the polyamine is a polyoxyalkylene polyamine. 8. The surface coating composition of claim 7, wherein the polyamine contains 70 to 90 wt% of the mixture. The method according to any one of claims 1 to 3, wherein the polyhydric alcohol is EPS, urethane foam, characterized in that at least one selected from polyether polyol, polyester polyol, polycarbonate polyol and polycaprolactone polyol Surface coating composition for PP, PE pallets. 10. The surface coating composition of claim 9, wherein the polyhydric alcohol contains 10 to 30% by weight of the mixture. The method according to any one of claims 1 to 3, wherein the chain extender is 1-methyl-3,5-diethyl-2,4- or 2,6-diaminobenzene (also referred to as diethyltoluenediamine or DETDA). Referred to as: US Albertal, Swiss Lon); 1,3,5-triethyl-2,6-diaminobenzene; 3,5,3 ', 5'-tetraethyl-4,4'-diaminodiphenylmethane; Di (methylthio) -toluenediamine, including 3,5-di (methylthio) -2,4 and 2,6-toluenediamine; N, N'-bis (t-butyl) ethylenediamine; 4,4'-methylenebis (20isopropyl-6-methylaniline); 4,4'-methylenebis (2,6-diisopropylaniline), Clearlink 1000 (UOP); Surface coating composition for EPS, urethane foam, PP, PE pallet, characterized in that at least one selected from polyclear 136 (Polyclear 136, BASF). The surface coating composition for EPS, urethane foam, PP, PE pallets according to any one of claims 1 to 3, wherein the chain extender contains 25 to 35% by weight of the mixture. The surface coating composition of claim 1, wherein the coating composition further comprises a catalyst. 13. The surface coating composition of claim 12, wherein the catalyst contains 5 parts by weight or less of the total coating composition. The method of claim 13 wherein the catalyst is dibutyltin dilaurate, dibutyltin diacetate, diethyltin diacetate, dihexyltin diacetate, di-2-ethylhexyltin oxide, dioctyltin dioxide, stanno Us octoate, stanous oleate, trialkylamine (trimethylamine, triethylamine); N-alkylmorpholine (N-methylmorpholine, N-ethylmorpholine), 2,2′-dimorpholinodiethyl ether, 1,4-dimethylpiperazine, N, N, N ′, M′-tetra Surface coating composition for EPS, urethane foam, PP, PE pallet, characterized in that at least one selected from methyl-1,3-butanediamine, dimethyldiaminodiethyl ether, triethylenediamine.