JP2017007690A - Resin container lid and resin container using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin container lid which prevents packing from coming off even when the lid has been repeatedly opened and closed, and can secure such sealability causing no liquid leakage, and to provide a resin container using the same.SOLUTION: A resin container has a lid body 10A which has a surface subjected to a surface treatment and is made from a polyolefin resin, and a packing 14 formed by applying a reaction curable polyurethane resin composition onto a surface subjected to the surface treatment and curing the resin composition. The surface treatment is, for instance, any one selected from corona discharge treatment, plasma treatment and flame treatment.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a resin container lid and a resin container using the same.

  Conventionally, resin containers often do not use packing, depending on the contents. In recent contents, paints and the like have shifted from a solvent type to an aqueous type, and packing for resin container lids has become necessary.

  In the case of an open pail that contains contents such as paint, the sealing property of the resin container lid is required, and opening and closing may be repeated many times. Therefore, it was an urgent task to develop a packing that can withstand this.

  Traditionally, metal pail cans with lids have been used, but plastic pail cans made of plastic do not rust, do not dent, are lighter, and save space when stored than metal ones. There is an advantage that can be realized.

  When the contents of the pail can are liquid, in order to prevent liquid leakage, generally a packing is attached to the lid to ensure a sealing property with the container body. Rubber, elastomer, etc. are used for the packing material.

  As a general technique for attaching the packing to the lid, for example, in the case where the lid is mainly made of resin, a string-like packing is produced by thermoforming, and a protrusion or a claw is formed on the lid, and molding is performed. Sometimes there is a technique of attaching a packing to a mold and molding it integrally. However, in the former, the mold is undercut and it is difficult to form a sufficient mounting shape, and the mold cost tends to be high, and there is room for improvement in productivity. In the latter case, the molding cost tends to be high. In addition, there is a method of packing a resin such as a thermoplastic elastomer by injection molding, but expensive capital investment is required.

  In addition, when the lid is mainly made of metal, there is a technique for bonding the packing and the lid with an adhesive or a pressure-sensitive adhesive. However, there is a problem that if the frequency of use increases, it tends to peel off and an adhesive or the like oozes out from the contents.

  In particular, when the lid is made of resin, if the lid is repeatedly opened and closed, the packing is removed, and liquid leakage due to contamination of the packing, dropping into the liquid, loss, crushing of the packing, etc. is likely to occur. When a room temperature curing type two-component urethane elastomer or two-component silicone is used, the packing is dropped because it does not adhere to the resin lid. For example, a polyurethane elastomer has been proposed as a packing for a pail can with a lid (Patent Document 1), but even if this polyurethane elastomer is applied to a lid made of polyethylene resin, it falls off as the lid is opened and closed. . When the lid is made of metal, it can be improved to some extent by sticking the packing by increasing the stickiness of the surface of the polyurethane resin. However, if it is used repeatedly, dirt such as dropping or dust adhesion will occur.

  In addition, large cans such as resin pail cans and resin drum cans are required to have strength as a whole. Sealing also requires certainty of sealing and strength against impacts, and resistance to various contents such as water-based paints is also required. Is done.

JP-A-61-9481

  The present invention has been made in view of the circumstances as described above, and uses a resin container lid that can prevent the packing from dropping off even when the lid is repeatedly opened and closed, and can also secure a sealing property without liquid leakage. It is an object to provide a resin container.

  In order to solve the above-mentioned problems, a resin container lid according to the present invention includes a polyolefin resin lid body having a surface-treated surface, and a reaction-curable polyurethane resin on the surface-treated surface. And a packing formed by applying and curing the composition.

  The resin container lid of the present invention includes a lid body made of a modified polyolefin resin obtained by modification with an unsaturated carboxylic acid or a derivative thereof or a blend of this modified polyolefin resin and a polyolefin resin as a resin material. And a packing formed by applying and curing a reaction-curable polyurethane resin composition.

  The resin container of the present invention includes the resin container lid and a resin container body.

  According to the present invention, the packing can be formed by a relatively inexpensive nozzle lining method, and even when the lid is repeatedly opened and closed, the packing is difficult to drop off, and a sealing property with no liquid leakage can be secured.

It is a perspective view which shows embodiment of the resin container lid of this invention, and the resin container using the same, and shows the back surface side and container main body of the resin container lid. It is a perspective view which shows the state which closed the resin-made container lids to the container main body of FIG. It is a fragmentary sectional view of the fitting part of the resin container lid and the container main body in the resin container of FIG. 1 and FIG.

Embodiments of the present invention will be described below with reference to the drawings.
<First Embodiment>
As shown in FIGS. 1 to 3, the resin container 1 of the present embodiment includes a resin container lid 10 and a resin container body 20.

  The resin container 1 is a pail having a vine handle 25 attached to the container body 20, and the resin container lid 10 is locked with a metal band 30 and closed as shown in FIG. In addition, liquids such as paints and cleaning agents are stored without leaking. In addition to liquids, it can also be used to store powders such as bleached powder.

  The resin container lid 1 of FIG. 1 is a view seen from the back side. As shown in FIGS. 1 and 3, the resin container lid 10 is made of resin and forms a lid body. A packing 14 is provided inside the outer peripheral portion 11 of the main body 10A and the lid main body 10A.

  The lid body 10A is a molded product made of polyolefin resin. Examples of the polyolefin resin include polyolefin resins, modified polyolefin resins, and blends thereof as described later.

  The lid body 10 </ b> A is attached to the opening 22 of FIG. 1 of the container body 20, and is formed in a disk shape with substantially the same size as the opening 22.

  As shown in FIG. 3, the lid body 10A has an annular groove 12 in the outer peripheral portion 11 of the back surface 10b among the top surface 10a of FIG. 2 and the back surface 10b of FIG. A packing 14 is formed in the annular groove 12 by applying and curing a reaction-curable polyurethane resin composition. Further, a cylindrical peripheral wall 13 extending from the inner peripheral side of the annular groove 12 to the bottom surface side of the container body 20 is formed over the entire periphery of the lid main body 10A at a portion located on the radially inner side of the annular groove 12. Yes.

  The container body 20 is a molded product of the same material as the lid body 10A, and as shown in FIGS. 1 and 2, the peripheral wall 21 has a cylindrical shape that gradually increases in diameter from the bottom toward the opening 22. Yes.

  As shown in FIGS. 1 and 3, a flange-like seal portion 24 is formed in the opening 22 along the upper end outer peripheral portion 23 of the container main body 20 so as to spread outward in the radial direction over the entire circumference.

  When the resin container lid 10 is attached to the container main body 20, the cylindrical peripheral wall 13 on the back surface 10 b of the resin container lid 10 enters the opening 22 of the container main body 20, so that the resin container lid 10 The 10 packings 14 are brought into contact with the seal portion 24 of the container body 20 to close the entire opening 22, and the outer periphery thereof is locked by the metal band 30 shown in FIG. As a result, the resin container lid 10 and the container main body 20 come into close contact with each other through the packing 14 at the outer periphery of the opening 22.

  In the present embodiment, the back surface 10b of the lid main body 10A is subjected to any surface treatment selected from corona discharge treatment, plasma treatment, and flame treatment in a range including at least the annular groove 12. The surface of the annular groove 12 is a surface treatment portion 12a, and a packing 14 is formed by applying and curing a reaction curable polyurethane resin composition thereon.

  As a result, the adhesiveness of the packing 14 to the lid body 10A is enhanced, and even when the lid is repeatedly opened and closed, the packing is difficult to drop off and a sealing property with no liquid leakage can be secured. Specifically, by these surface treatments, the surface layer of the lid body 10A made of polyolefin resin is oxidized and modified, polar groups such as hydroxyl groups are introduced, and a cured product of the reaction curable polyurethane resin composition is used. Adhesiveness with a certain packing 14 can be improved.

  In the corona discharge treatment, air is ionized by the high frequency generated from the corona treatment machine to generate charged particles. When such particles collide with the surface of the object to be treated, the surface is oxidized and the surface is It can be modified. Such a corona discharge treatment can be performed, for example, by performing corona discharge irradiation at normal pressure in an air or oxygen atmosphere.

  The plasma discharge treatment activates the surface by bringing plasma generated under atmospheric pressure or the like into contact with the surface of the object to be treated. Examples of the gas for generating plasma include rare gases such as helium and argon, nitrogen gas, and air. As a method of plasma discharge treatment under atmospheric pressure, an object to be treated is held in a plasma generated by applying a high voltage at a high frequency between parallel plate electrodes, at least one of which is coated with a dielectric, or in the plasma. A discharge space is formed by facing a pair of electrodes with at least one electrode surface coated with a dielectric material, and a plasma gas is pumped by applying a high frequency high voltage there. Examples include a method of ejecting outside the discharge space and bringing it into contact with the object to be treated.

  The flame treatment can be performed by, for example, treatment with an oxidizing flame (temperature 1000 to 2700 ° C.) such as city gas or propane gas. When exposed to fire for several seconds, the surface is oxidized and polar groups can be introduced.

  As the reaction curable polyurethane resin composition as the material of the packing 14, a two-component type of a first liquid mainly composed of polyisocyanate and a second liquid mainly composed of polyol can be suitably used. .

  As polyisocyanate used for the first liquid, aromatic polyisocyanate, aliphatic polyisocyanate, alicyclic polyisocyanate, araliphatic polyisocyanate, modified products thereof (for example, urethane group, carbodiimide group, allophanate group, Urea group, burette group, isocyanurate group, modified product containing oxazolidone group, etc.). These may be used alone or in combination of two or more.

  Aromatic polyisocyanates include 6 to 16 aromatic diisocyanates, 6 to 20 aromatic triisocyanates, and crude products of these isocyanates (except for the number of carbons in the NCO group, and the following polyisocyanates). Thing etc. are mentioned. Specific examples include 1,3- and 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, crude TDI, 2,4'- and 4,4'-diphenylmethane diisocyanate (MDI), polymethylene polyphenylene poly. Examples include isocyanate (crude MDI), naphthylene-1,5-diisocyanate, triphenylmethane-4,4 ′, 4 ″ -triisocyanate and the like.

  Examples of the aliphatic polyisocyanate include aliphatic diisocyanates having 2 to 18 carbon atoms. Specific examples include 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, and the like.

  Examples of the alicyclic polyisocyanate include alicyclic diisocyanates having 6 to 16 carbon atoms. Specific examples include isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, norbornane diisocyanate, and the like.

  Examples of the araliphatic polyisocyanate include araliphatic diisocyanates having 8 to 16 carbon atoms. Specific examples include xylylene diisocyanate, α, α, α ′, α′-tetramethylxylylene diisocyanate, and the like.

  Specific examples of the modified polyisocyanate include urethane-modified MDI, carbodiimide-modified MDI, sucrose-modified MDI, sucrose-modified TDI, castor oil-modified MDI, and the like.

  Among these polyisocyanates, aromatic polyisocyanates and modified products thereof are preferably used.

  The isocyanate group content of the first liquid is preferably 5 to 38% by mass from the viewpoint of easy handling of viscosity and the concentration of free raw material isocyanate. The isocyanate group content here is the content when reacting with the second liquid.

  In the first liquid, an isocyanate group-terminated prepolymer is blended as a polyisocyanate. The isocyanate group-terminated prepolymer is obtained by adding a polyisocyanate such as a mixture of 2,4- and 2,6-tolylene diisocyanate or diphenylmethane diisocyanate to a polyol having 2 to 3 hydroxyl groups in the molecule. Things.

  The polyol having 2 to 3 hydroxyl groups is, for example, a compound obtained by adding alkylene oxide to a compound having 2 to 3 active hydrogen groups (hereinafter referred to as an active hydrogen group-containing compound), and preferably has a molecular weight of 200 to 6000. Can be mentioned.

  Examples of the active hydrogen group-containing compound include compounds having two active hydrogen groups such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, and 1,4-butanediol, and active hydrogen groups such as glycerin and trimethylolpropane. The compound which has three is mentioned.

  Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, and the like.

  The polyol that can be used in the second liquid is specifically a high-molecular polyol, a low-molecular polyol, or a mixture thereof, and a mixture of a high-molecular polyol and a low-molecular polyol is preferable from the viewpoint of easy selection of physical properties. Each of the high molecular polyol and the low molecular polyol may be used alone or in combination of two or more.

  The polymer polyol is a polyol having a number average molecular weight of 500 or more, preferably 1000 to 3000.

  Specific examples thereof include polypropylene glycol (PPG) -based polyether polyol, polytetramethylene ether glycol (PTMG), abibate polyester polyol, polycaprolactone-based polyester polyol, and polycarbonate-based polyol.

  Examples of the low molecular polyol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5- Pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8-octanediol, 1,9-nonanediol, diethylene glycol, cyclohexane-1,4-diol, cyclohexane -1,4-dimethanol, dimethylol heptane, dimer acid diol, trimethylol propane, glycerin, hexanetriol, quadrol, bisphenol A, hydrogenated bisphenol A, and ethylene oxide or propylene oxide added to these compounds The compounds of the number average molecular weight of less than 500 obtained can be mentioned.

  The amount of the low-molecular polyol used is not particularly limited and is appropriately selected according to the hardness to be imparted to the target packing 14, but is 5 mol or less, particularly 0.1 to 3 per mol of the polymer polyol. It is preferably used in the molar range.

  The polyol suitably used in the present invention has a hydroxyl value of 20 to 350 (mgKOH / g), preferably 100 to 350 (mgKOH / g). If the hydroxyl value is too small, the resulting polyurethane elastomer is too soft and the compression set becomes too large. If the hydroxyl value is too large, the polyurethane elastomer is too hard and unsuitable for the packing 14.

  The average number of functional groups of the polyol is preferably 2 to 3 from the viewpoint that an appropriate amount of a crosslinked structure is preferably introduced into the cured product of the reaction curable polyurethane resin composition.

  Further, when synthesizing the polyurethane cured product by reacting the first liquid and the second liquid, the first liquid is used with respect to the total amount of active hydrogen atoms contained in the polyol and other components of the second liquid. It is preferable to use it in a proportion that the number of moles of isocyanate groups per mole of active hydrogen atoms is 0.9 to 1.5 moles.

  In the reaction curable polyurethane resin composition, various additives can be blended together with the above essential components within a range not impairing the effects of the present invention. Specific examples of such additives include plasticizers, inorganic fillers, curing accelerators, dyes and pigments, inorganic fibers, flame retardants, antioxidants, ultraviolet absorbers, light stabilizers, fungicides, and the like. It is done.

  In a preferred embodiment, the reaction-curable polyurethane resin composition contains a benzoate plasticizer and an epoxidized fatty acid ester plasticizer. These are mainly blended in the first liquid.

  In order to adjust the hardness of the cured product of the reaction curable polyurethane resin composition, a benzoic acid plasticizer that has good compatibility with organic isocyanate is blended to create a flexible sealing surface without being affected by working conditions or the environment. A cured product can be obtained. And in order to reduce surface tackiness (stickiness), it becomes possible to reduce tackiness, suppressing bleeding, by mix | blending an epoxidized fatty acid ester plasticizer.

  The benzoate ester plasticizer has good compatibility with the isocyanate component, and even if an epoxidized fatty acid ester plasticizer is used, bleeding of the cured product (packing 14) of the reaction curable polyurethane resin composition can be suppressed.

  Examples of the benzoate ester plasticizer include ethylene glycol benzoate, diethylene glycol dibenzoate, triethylene glycol dibenzoate, polyethylene glycol dibenzoate, propylene glycol dibenzoate, dipropylene glycol dibenzoate. Ester, tripropylene glycol dibenzoate, 1,3-butanediol dibenzoate, 1,4-butanediol dibenzoate, 1,6-hexanediol dibenzoate, 3-methyl-1,5 -Pentanediol dibenzoate, 1,8-octanediol dibenzoate and the like. Examples include 2-ethylhexyl benzoate, isononyl benzoate, dodecyl benzoate, diethylene glycol benzoate, dipropylene glycol bisbenzoate. These may be used alone or in combination of two or more.

  The blending amount of the benzoate ester plasticizer is preferably 15% by mass or less, more preferably 11% by mass or less, based on the total amount of the reaction curable polyurethane resin composition.

  The epoxidized fatty acid ester plasticizer can suppress the surface tackiness of the cured product (packing 14) of the reaction curable polyurethane resin composition. By using together with a benzoate plasticizer, compatibility with the isocyanate component is also improved, and bleeding can be suppressed.

  Epoxidized fatty acid ester plasticizers include epoxidized animal and vegetable oils such as naturally produced epoxidized oil, epoxidized soybean oil (ESO), epoxidized propylene glycol dioleate, epoxidized corn oil, and epoxidized sunflower oil , Epoxidized palm oil, epoxidized linseed oil, epoxidized canola oil, epoxidized rapeseed oil, epoxidized safflower oil, epoxidized tall oil, epoxidized tung oil, epoxidized fish oil, epoxidized beef tallow oil, epoxidized castor oil, Epoxidized methyl stearate, epoxidized butyl stearate, epoxidized 2-ethylhexyl stearate, epoxidized stearyl stearate, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate epoxidized soybean oil, Epoxy Fatty acid methyl ester, and the like each of the epoxidized derivatives of the foregoing. These may be used alone or in combination of two or more.

  Among these, epoxidized soybean oil and epoxidized linseed oil are preferable.

  Epoxidized soybean oil can be produced, for example, as follows. Transesterification of soybean oil with methanol synthesizes methyl esters of fatty acids in the soybean oil and removes insoluble glycerin from the reaction product. Next, a double bond of fatty acid is epoxidized using a peracetic acid solution using ethyl acetate as a solvent. The ethyl acetate and acetic acid product are then removed by vacuum stripping.

  The blending amount of the epoxidized fatty acid ester plasticizer is preferably 15% by mass or less, more preferably 11% by mass or less, based on the total amount of the reaction curable polyurethane resin composition.

  Examples of components to be blended with the polyol as necessary in the second liquid of the reaction curable polyurethane resin composition include polyamines, urethanization catalysts, inorganic fillers, and the like.

  Examples of the polyamine include methylenebisorthochloroaniline (MOCA) and diphenylmethanediamine (DAM).

  Examples of the urethanization catalyst include tertiary amine catalysts such as triethylenediamine and triethylamine, and organometallic catalysts such as lead octylate, dibutyltin dilaurate, and butyltin diacetate.

  Examples of the inorganic filler include calcium carbonate, talc, my strength powder, silica powder, magnesium carbonate, and carbon black.

  In a preferred embodiment, the reaction curable polyurethane resin composition contains an antistatic agent.

  When an antistatic agent is blended, it is expected to have an effect of preventing static electricity and preventing the adhesion of dust.

  Antistatic agents include (polyoxyethylene alkyl ethers, polyoxylethylene derivatives, sorbitan acid fatty acid esters, polyoxyethylene sorbitan acid fatty acid esters, polyoxyethylene sorbitol fatty acid esters, glycerin fatty acid esters, polyoxyethylene hydrogenated castor oil, poly Nonionic antistatic agents such as oxyethylene alkylamines and alkylalkanolamides, cationic antistatic agents such as alkylamine salts and quaternary ammonium salts, alkyl sulfate esters, polyoxyethylene alkyl ether sulfates, alkylbenzene sulfonates And anionic antistatic agents such as sodium dialkylsulfosuccinate and sodium alkyldiphenyl ether disulfonate).

  The blending amount of the antistatic agent is preferably 1.5% by mass or less, more preferably 0.1 to 1.0% by mass with respect to 100 parts by mass of the total amount of the reaction curable polyurethane resin composition.

  In addition, you may mix | blend the said antistatic agent with the resin material of 10 A of lid | cover main bodies of the resin container lid | covers 10. FIG.

  The reaction curable polyurethane resin composition can form the packing 14 by applying and curing the annular groove 12 of the lid body 10A according to a conventional method. When hardening, you may heat as needed.

  For example, the reaction-curable polyurethane resin composition is discharged to the lid body 10A by discharging the reaction-curable polyurethane resin composition pressurized to the rotating lid body 10A from the nozzle and performing one or several times overcoating. The packing 14 can be formed by (lining) and then heat-curing at room temperature or, if necessary, using a baking drying heating furnace or the like. In the case of a pail can lid, a reaction curing type polyurethane resin composition is pumped by a two-component mixing system, and about 18 g is discharged from a 3φ nozzle onto a rotating lid, and applied once or twice. The resin container lid 10 is obtained by curing.

  The packing 14 has a JIS K6253 A hardness of 5 to 40, a specific gravity of 0.2 to 1.5, and a compression set (JIS 7213) of 0.1 to 60%.

  By satisfying such physical properties, it is possible to obtain a cured product having physical properties that achieve both a level of restoration and strength at a practical level, and it is easy to bite into the seal surface 24 of the packing 14 to increase the coating surface area and increase the content of the contents. Sealing performance can be ensured by preventing liquid leakage, and adhesion to the seal portion 24 can be secured by giving the packing 14 a certain rebound resilience.

In addition, the packing 14 preferably has a tensile strength of 0.2 kg / cm ² or more in terms of mechanical strength, and an elongation of 50 to 5000%.

  According to this embodiment described above, the back surface 10b of the lid body 10A made of polyolefin resin is previously subjected to any surface treatment selected from corona discharge treatment, plasma treatment, and flame treatment, and this surface treatment is performed. Since the reaction curing polyurethane resin composition is applied to the annular groove 12 of the back surface 10b and cured to form the packing 14, the resin container lid 10 releases the lock by the metal band 30 and the lid body 10A. Further, by locking and attaching the lid main body 10A with the metal band 30, even when the lid main body 10A is repeatedly opened and closed, the packing 14 is less likely to drop off and a sealing property with no liquid leakage can be secured.

<Second Embodiment>
In the first embodiment, the lid body 10A made of polyolefin resin is subjected to any surface treatment selected from corona discharge treatment, plasma treatment, and flame treatment to ensure the adhesion between the lid body 10A and the packing 14. However, in this embodiment, the lid body 10A is not subjected to these surface treatments, but as a resin material of the lid body 10A, a modified polyolefin resin obtained by modifying with an unsaturated carboxylic acid or a derivative thereof or the modified polyolefin resin. By using a blend of olefin and polyolefin resin, the adhesion between the lid main body 10A and the packing 14 is improved.

  That is, by modifying the polyolefin resin with an unsaturated carboxylic acid or a derivative thereof, a polar group such as a carboxy group is introduced into the polyolefin resin, and the adhesion to the packing 14 that is a cured product of the reaction-curable polyurethane resin composition is improved. be able to. As a result, the adhesiveness of the packing 14 to the lid body 10A is enhanced, and even when the lid is repeatedly opened and closed, the packing is difficult to drop off and a sealing property with no liquid leakage can be secured.

  Examples of the polyolefin resin used as a raw material for the modified polyolefin resin include ethylene homopolymer (polyethylene resin), propylene homopolymer (polypropylene resin), ethylene-propylene random copolymer, ethylene-α-olefin random copolymer, Propylene-α-olefin random copolymer, ethylene-propylene-α-olefin random copolymer, ethylene homopolymerized to produce an ethylene homopolymer, and then ethylene and propylene in the presence of the ethylene homopolymer An ethylene block copolymer obtained by copolymerizing propylene, and propylene obtained by homopolymerizing propylene to produce a propylene homopolymer and then copolymerizing ethylene and propylene in the presence of the propylene homopolymer Examples thereof include a system block copolymer.

  Examples of the α-olefin include 1-butene, 2-methyl-1-propene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, 2-ethyl-1-butene, 2 , 3-dimethyl-1-butene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3,3-dimethyl-1-butene, 1-heptene, methyl-1 -Hexene, dimethyl-1-pentene, ethyl-1-pentene, trimethyl-1-butene, methylethyl-1-butene, 1-octene, methyl-1-pentene, ethyl-1-hexene, dimethyl-1-hexene, Propyl-1-heptene, methylethyl-1-heptene, trimethyl-1-pentene, propyl-1-pentene, diethyl-1-butene, 1-nonene, 1-decene, 1-u Decene, 1-dodecene, and the like. Preferred are α-olefins having 4 to 8 carbon atoms (for example, 1-butene, 1-pentene, 1-hexene, 1-octene).

  The modified polyolefin resin is obtained, for example, by graft polymerization of an unsaturated carboxylic acid or derivative thereof to a polyolefin resin. Graft modification of the polyolefin resin can be performed by a known method, for example, a polyolefin resin such as a polyethylene resin is dissolved in an organic solvent, and then an unsaturated carboxylic acid or a derivative thereof and a radical initiator are added to the obtained solution. Usually, the reaction is performed at a temperature of 60 to 350 ° C., preferably 80 to 190 ° C., for 0.5 to 15 hours, preferably 1 to 10 hours. Here, the organic solvent can be used without particular limitation as long as it is an organic solvent capable of dissolving a polyolefin resin such as a polyethylene resin. Examples of such an organic solvent include aromatic hydrocarbon solvents such as benzene, toluene, and xylene, and aliphatic hydrocarbon solvents such as pentane, hexane, and heptane.

  As another graft modification method, a modified polyolefin resin can be prepared by reacting a polyolefin resin such as a polyethylene resin with an unsaturated carboxylic acid or a derivative thereof in the absence of solvent using an extruder or the like. The reaction conditions in this case are such that the reaction temperature is usually not lower than the melting point of the polyolefin resin, specifically 120 to 350 ° C. in the case of polyethylene resin, and the reaction time is usually 0.5 to 10 minutes.

  When any known graft modification method is applied, the reaction is preferably performed in the presence of a radical initiator in order to efficiently graft copolymerize the unsaturated carboxylic acid or derivative thereof as the graft monomer.

  The graft amount (graft modification rate) of the graft group derived from the unsaturated carboxylic acid or derivative thereof in the modified polyolefin resin used in the present embodiment is preferably 0.05 to 10% by mass, and 0.05 to 5% by mass. More preferred.

  Examples of the unsaturated carboxylic acid include maleic acid, fumaric acid, itaconic acid, acrylic acid, and methacrylic acid. These may be used alone or in combination of two or more.

  Examples of unsaturated carboxylic acid derivatives include unsaturated carboxylic acid anhydrides, ester compounds, amide compounds, imide compounds, and metal salts. Specific examples of the unsaturated carboxylic acid derivative include maleic anhydride, itaconic anhydride, methyl acrylate, ethyl acrylate, butyl acrylate, glycidyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methacrylic acid 2 -Hydroxyethyl, glycidyl methacrylate, maleic acid monoethyl ester, maleic acid diethyl ester, fumaric acid monomethyl ester, fumaric acid dimethyl ester, acrylamide, methacrylamide, maleic acid monoamide, maleic acid diamide, fumaric acid monoamide, maleimide, N- Examples thereof include butyl maleimide and sodium methacrylate. These may be used alone or in combination of two or more. As these unsaturated carboxylic acids or derivatives thereof, acrylic acid, glycidyl methacrylate, maleic anhydride, and 2-hydroxyethyl methacrylate are preferable.

  When a blend of a modified polyolefin resin and an (unmodified) polyolefin resin is used, the graft amount (graft modification rate) of the graft group derived from the unsaturated carboxylic acid or its derivative in the modified polyolefin resin is the total amount of the blend. On the other hand, 0.05-10 mass% is preferable, and 0.05-5 mass% is more preferable.

  The resin material of this modified polyolefin resin or a blend of this modified polyolefin resin and polyolefin resin can be added with components that are usually added to such a resin material, if necessary. Examples of such additional components include inorganic fillers, light stabilizers, ultraviolet absorbers, dispersants, lubricants, decomposition agents, metal deactivators, flame retardants, crystal nucleating agents, pigments, organic fillers, antibacterial agents, and the like. Can be mentioned. Examples of the inorganic filler include talc, mica, clay, calcium carbonate, aluminum hydroxide, magnesium hydroxide, wollastonite, barium sulfate, silica, calcium silicate, and potassium titanate. Examples of the antioxidant include phenol-based antioxidants, thioether-based antioxidants, and organic phosphorus-based antioxidants. Examples of the light stabilizer include hindered amine light stabilizers. Examples of the ultraviolet absorber include benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers, and benzoate ultraviolet absorbers. Examples of the dispersant include a bisamide dispersant, a wax dispersant, and an organic metal salt dispersant. Examples of the lubricant include an amide lubricant, a wax lubricant, an organometallic salt lubricant, an ester lubricant, and the like. Examples of the decomposing agent include an oxide decomposing agent and a hydrotalcite decomposing agent. Examples of metal deactivators include hydrazine-based metal deactivators and amine-based metal deactivators. Examples of the flame retardant include bromine-containing organic flame retardant, phosphoric acid flame retardant, antimony trioxide, magnesium hydroxide, red phosphorus and the like. Examples of the crystal nucleating agent include organophosphate crystal nucleating agents and sorbitol crystal nucleating agents. Examples of the pigment include organic pigments and inorganic pigments. Examples of the antibacterial agent include inorganic antibacterial agents and organic antibacterial agents.

  The present invention has been described above based on the embodiment. However, the present invention is not limited to this embodiment, and various modifications and changes can be made without departing from the scope of the present invention. For example, although the container lid of the pail can has been described in the present embodiment, the present invention can be applied to various types of resin containers including large cans such as a pail can and a drum can.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

<Example 1>
Preparation of liquid A: 100 parts by weight of polyol (hydroxyl value 55.4, molecular weight 2000, functional group number 2) and 0.1 part of catalyst (TEDA) are added and blended with a stirrer.

  Adjustment of B liquid: Isocyanate prepolymer A (MDI type, latent isocyanate average functional group number = 2, latent isocyanate group content = 15.23%, molecular weight 550) 10.9 parts by mass, isocyanate prepolymer B (MDI type, latent isocyanate average functional group number) = 2.9, latent isocyanate group content = 31.00%, molecular weight 390) 8 parts by weight, epoxidized soybean oil 10 parts by weight (7.2% of the blending amount), benzoic acid plasticizer 10 parts by weight (7.2% in the blending) ) Was mixed and stirred with a stirrer. Liquid A and liquid B were blended to prepare a reaction curable polyurethane resin composition (sealing compound), and the following evaluation was performed.

[hardness]
Using a type A rubber hardness tester based on JIS K 6253, the hardness at 25 ° C. was measured and evaluated based on the following criteria.
A: JIS A hardness is 10-40
B: JIS A hardness is 5 to 9, or 41 to 60
C: JIS A hardness is less than 5 or more than 60

[Compression set]
The compression set (%) was measured based on JIS K 7312 and evaluated based on the following criteria.
A: 60% or less B: Over 60%

[Tensile strength]
Apply 18g of sealing compound to the annular groove (no surface treatment) of the lid body for 300φ plastic open pail can, and cure for 3 days to form packing. The packing was peeled off from the lid body, and a dumbbell No. 3 was used as a punched specimen. The tensile strength of the test piece was measured at a speed of 200 mm / min based on JIS K7312 using a tensile tester manufactured by Toyo Seiki Co., Ltd. The tensile strength was evaluated based on the following criteria.
A: Tensile strength is 0.6 kg / cm ² or more B: Tensile strength is 0.1 kg / cm ² or more and less than 0.6 kg / cm ² C: Tensile strength is less than 0.1 kg / cm ²

[Growth rate]
Apply 18g of sealing compound to the annular groove (no surface treatment) of the lid body for 300φ plastic open pail can, and cure for 3 days to form packing. The packing was peeled off from the lid body, and a dumbbell No. 3 was used as a punched specimen. The test piece was pulled at a speed of 200 mm / min based on JIS K7312 using a tensile tester manufactured by Toyo Seiki Co., Ltd., and the elongation was measured. The elongation was evaluated based on the following criteria.
A: Elongation rate is 150% or more B: Elongation rate is 50% or more and less than 150% C: Elongation rate is less than 50%

[Surface tackiness]
Apply 18g of sealing compound to the annular groove (no surface treatment) of the lid body for 300φ plastic open pail can, and cure for 3 days to form packing. The packing was peeled off from the lid body, the packing was folded in two and pulled in the direction of 180 degrees, the strength (gf) per 1 cm width of the test piece was measured, and the surface tackiness was evaluated based on the following criteria.
A: Tensile strength is 10gf / 1cm width or less B: Tensile strength is 11-30gf / 1cm width C: Tensile strength is 31gf / 1cm width or more

[Bleed]
Apply 18g of sealing compound to the annular groove (no surface treatment) of the lid body for 300φ plastic open pail can, and cure for 3 days to form packing. The packing was peeled off from the lid body, the packing was attached to paper with double-sided tape, stored at room temperature for 1 week, and the bleeding property was evaluated based on the following criteria.
A: No migration of plasticizer to the paper surface.
B: The plasticizer is slightly transferred to the paper surface.
C: Migration of the plasticizer to the paper surface is observed.

[Adhesion between lid and packing]
Surface treatment is performed by burning the annular groove of the lid body of a 300φ plastic open pail can. Thereto, 18 g of sealing compound was applied and the packing formed by curing for 3 days was peeled off, and the adhesiveness between the lid body and the packing was evaluated based on the following criteria.

A: The packing is difficult to peel off from the lid body surface, and if it is pulled forcibly, the base material is destroyed and continuous peeling is not seen.
C: The packing was peeled off continuously from the lid body surface. Easily falls off.

[Sealability]
Fill a plastic open pail can with a lid with a sealing compound and lining it, fill it with water, tighten the lid with a band, invert (below the lid), store 4 cans in a cool and dark place, 1 can It was installed so that it weighed about 200 kg per week, and one week later, the presence or absence of leakage was investigated. And the sealing performance was evaluated based on the following criteria.
A: There is no leakage of water from the pail can and no abnormality is observed.
C: Leakage of water from the pail can occurs, or generation of blurring is observed in the sealed portion.

<Example 2>
In Example 1, 0.1 part of an antistatic agent was added, and a sealing compound was prepared under the same conditions as in Example 1 except that. This sealing compound was evaluated in the same manner as in Example 1.

<Example 3>
In Example 1, 1 part of an antistatic agent was added, and a sealing compound was prepared under the same conditions as in Example 1 except that. This sealing compound was evaluated in the same manner as in Example 1.

<Example 4>
In Example 1, 2 parts of an antistatic agent was added, and a sealing compound was prepared under the same conditions as in Example 1 except that. This sealing compound was evaluated in the same manner as in Example 1.

<Example 5>
In Example 1, a sealing compound was prepared under the same conditions as in Example 1 except that the surface treatment of the lid body annular groove was not performed, and a modified polyethylene resin (modified PE) was used as the material of the lid body. This sealing compound was evaluated in the same manner as in Example 1.

<Example 6>
In Example 1, a sealing compound was prepared under the same conditions as in Example 1 except that 20 parts by mass of epoxidized soybean oil and 0 parts by mass of a benzoic acid plasticizer were used. This sealing compound was evaluated in the same manner as in Example 1.

<Example 7>
In Example 1, a sealing compound was prepared under the same conditions as in Example 1 except that 0 part by mass of epoxidized soybean oil and 20 parts by mass of a benzoic acid plasticizer were used. This sealing compound was evaluated in the same manner as in Example 1.

<Example 8>
In Example 1, a sealing compound was prepared under the same conditions as in Example 1 except that 0 part by mass of epoxidized soybean oil and 0 part by mass of a benzoic acid plasticizer were used. This sealing compound was evaluated in the same manner as in Example 1.

<Example 9>
In Example 1, a sealing compound was prepared under the same conditions as in Example 1 except that isocyanate prepolymer A was 0 parts by mass and isocyanate prepolymer B was 13.4 parts by mass. This sealing compound was evaluated in the same manner as in Example 1.

<Example 10>
In Example 1, 0 parts by mass of isocyanate prepolymer A, 13.4 parts by mass of isocyanate prepolymer B, 0 parts by mass of epoxidized soybean oil, 0 parts by mass of benzoic acid plasticizer, and the same conditions as in Example 1 A sealing compound was prepared. This sealing compound was evaluated in the same manner as in Example 1.

<Example 11>
In Example 1, a sealing compound was prepared under the same conditions as in Example 1 except that 10 parts by mass of epoxidized soybean oil and 0 parts by mass of a benzoic acid plasticizer were used. This sealing compound was evaluated in the same manner as in Example 1.

<Example 12>
In Example 1, a sealing compound was prepared under the same conditions as in Example 1 except that 0 part by mass of epoxidized soybean oil and 10 parts by mass of a benzoic acid plasticizer were used. This sealing compound was evaluated in the same manner as in Example 1.

<Example 13>
In Example 1, a sealing compound was prepared under the same conditions as in Example 1 except that the polyol was 80 parts by mass. This sealing compound was evaluated in the same manner as in Example 1.

<Example 14>
In Example 1, a sealing compound was prepared under the same conditions as in Example 1 except that 10 parts by mass of epoxidized soybean oil and 30 parts by mass of a benzoic acid plasticizer were used. This sealing compound was evaluated in the same manner as in Example 1.

<Example 15>
In Example 1, a sealing compound was prepared under the same conditions as in Example 1 except that 30 parts by mass of epoxidized soybean oil and 10 parts by mass of a benzoic acid plasticizer were used. This sealing compound was evaluated in the same manner as in Example 1.

<Example 16>
In Example 1, a sealing compound was prepared under the same conditions as in Example 1 except that the polyol was 70 parts by mass. This sealing compound was evaluated in the same manner as in Example 1.

<Example 17>
In Example 1, a sealing compound was prepared under the same conditions as in Example 1 except that the polyol was 50 parts by mass. This sealing compound was evaluated in the same manner as in Example 1.

<Example 18>
In Example 1, a sealing compound was prepared under the same conditions as in Example 1 except that the polyol was 30 parts by mass. This sealing compound was evaluated in the same manner as in Example 1.

<Reference Example 1>
In Example 1, 3 parts of an antistatic agent was added, and a sealing compound was prepared under the same conditions as in Example 1 except that. This sealing compound was evaluated in the same manner as in Example 1.

<Reference Example 2>
In Example 1, a sealing compound was prepared under the same conditions as in Example 1 except that 27.2 parts by mass of isocyanate prepolymer A and 0 part by mass of isocyanate prepolymer B were used. This sealing compound was evaluated in the same manner as in Example 1.

<Reference Example 3>
In Example 1, 27.2 parts by mass of isocyanate prepolymer A, 0 part by mass of isocyanate prepolymer B, 0 part by mass of epoxidized soybean oil, 0 part by mass of benzoic acid plasticizer, and the same conditions as in Example 1 A sealing compound was prepared. This sealing compound was evaluated in the same manner as in Example 1.

<Reference Example 4>
In Example 1, a sealing compound was prepared under the same conditions as in Example 1 except for 120 parts by mass of polyol. This sealing compound was evaluated in the same manner as in Example 1.

<Reference Example 5>
In Example 1, a sealing compound was prepared under the same conditions as in Example 1 except that the polyol was 110 parts by mass. This sealing compound was evaluated in the same manner as in Example 1.

<Reference Example 6>
In Example 1, a sealing compound was prepared under the same conditions as in Example 1 except that the polyol was 100 parts by mass, the epoxidized soybean oil was 40 parts by mass, and the benzoic acid plasticizer was 0 part by mass. This sealing compound was evaluated in the same manner as in Example 1.

<Reference Example 7>
In Example 1, a sealing compound was prepared under the same conditions as in Example 1, except that the polyol was 100 parts by mass, the epoxidized soybean oil was 0 parts by mass, and the benzoic acid plasticizer was 40 parts by mass. This sealing compound was evaluated in the same manner as in Example 1.

<Comparative Example 1>
In Example 1, a sealing compound was prepared under the same conditions as in Example 1 except that the surface treatment of the lid body annular groove was not performed. This sealing compound was evaluated in the same manner as in Example 1.

<Comparative example 2>
In Example 1, a sealing compound was prepared under the same conditions as in Example 1 except that the polyol was 0 parts by mass. This sealing compound was evaluated in the same manner as in Example 1.

<Comparative Example 3>
When the sealability of the unpacked container was investigated, the contents leaked.

  The results of Examples and Comparative Examples are shown in Table 1 and Table 2.

表１および表２より、エポキシ化大豆油を20％以下で添加した実施例１〜６、９、１１、１３〜１８は表面タックが少なく、その他の物性も良好であった。

From Table 1 and Table 2, Examples 1-6, 9, 11, 13-18 which added epoxidized soybean oil at 20% or less had little surface tack, and other physical properties were also favorable.

  In Example 6, 14.3% (20 parts by mass) of epoxidized soybean oil was added, but the tackiness was good, but there was a tendency to slightly bleed, but it was within an acceptable range, and other physical properties were also good. there were. However, when 25% (40 parts by mass) of epoxidized soybean oil was added as in Reference Example 6, there was no problem with surface tackiness, but a tendency to bleed was observed.

  In Example 15, 20% (30 parts by mass) of epoxidized soybean oil was added, the hardness decreased, and the surface tack tended to increase, but was within an acceptable range.

  When 14.3% (20 parts by mass) of a benzoic acid plasticizer is added as in Example 7, the bleed product does not appear because of good compatibility with urethane, but the surface tackiness tends to deteriorate as the addition amount increases. .

  When 20% (30 parts by mass) of a benzoic acid plasticizer was added as in Example 14, a decrease in hardness and an increase in surface tackiness were observed, but were within an acceptable range. When 25% (40 parts by mass) of a benzoic acid plasticizer was added as in Reference Example 7, a decrease in hardness and an increase in surface tackiness were observed, which exceeded the allowable range.

  When blending without a plasticizer as in Example 8, the surface tack was slightly inferior, but was within an acceptable range.

  Examples 9 to 10 are blends using the isocyanate prepolymer B (isocyanate content 31.00%, molecular weight 390, functional group number 2.9) alone, but the physical properties were within an acceptable range.

  80 parts by mass, 70 parts by mass and 50 parts by mass of polyol A (reaction product of 3 methyl 1,5 pentanediol and adipic acid, hydroxyl value 55.4, molecular weight 2000, functional group 2) as in Examples 13 and 16-18 Even when the content was reduced to 30 parts by mass, the physical properties were good and within an allowable range. However, when polyol A was not added as in Comparative Example 2, the hardness was increased and the tendency to become brittle was observed, and the physical properties exceeded the allowable range.

  As in Reference Examples 4 to 5, when the amount of polyol A was increased to 120 to 110, the hardness decreased, the surface tack increased, the compression set also increased, and exceeded the allowable range.

  As in Reference Examples 2-3, when the isocyanate prepolymer A (isocyanate content 15.23%, molecular weight 550, functional group number 2) was used alone, the compression set increased and exceeded the allowable range.

  In Examples 2 to 4 in which 0.1 to 2 parts by mass of the antistatic agent was added, the surface tack was small and other physical properties were good, but as in Reference Example 1, the addition of 3 parts of the antistatic agent increased the surface tack. However, it was beyond the allowable range.

DESCRIPTION OF SYMBOLS 1 Resin container 10 Resin container lid 10A Cover body 10a Upper surface 10b Back surface 11 Outer peripheral part 12 Annular groove 12a Surface treatment part 13 Perimeter wall 14 Packing 20 Container main body 21 Perimeter wall 22 Opening part 23 Upper end outer peripheral part 24 Seal part 25 Handle 30 Metal band

Claims (7)

A lid body made of polyolefin resin having a surface treated with a surface treatment;
A resin container lid provided with a packing formed by applying and curing a reaction-curable polyurethane resin composition on the surface-treated surface. A lid body using a modified polyolefin resin obtained by modification with an unsaturated carboxylic acid or a derivative thereof or a blend of this modified polyolefin resin and a polyolefin resin as a resin material;
A resin container lid provided with a packing formed by applying and curing a reaction-curable polyurethane resin composition on the lid body.   The resin container lid according to claim 1 or 2, wherein the surface treatment is performed by any one selected from corona discharge treatment, plasma treatment, and flame treatment.   4. The resin container lid according to claim 1, wherein the reaction-curable polyurethane resin composition contains a benzoate ester plasticizer and an epoxidized fatty acid ester plasticizer. 5. 5. The packing according to claim 1, wherein the packing has a JIS K6253 A hardness of 5 to 40, a tensile strength of 0.2 kg / cm ² or more, and a compression set (JIS 7213) of 0.1 to 60%. Resin container lid.   The resin container lid according to any one of claims 1 to 5, wherein an antistatic agent is contained in at least one of the reaction curable polyurethane resin composition and the resin material of the lid body.   A resin container comprising the resin container lid according to claim 1 and a resin container main body.

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