Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/42—Polycondensates having carboxylic or carbonic ester groups in the main chain
  • C08G18/4266—Polycondensates having carboxylic or carbonic ester groups in the main chain prepared from hydroxycarboxylic acids and/or lactones
  • C08G18/4269—Lactones
  • C08G18/4277—Caprolactone and/or substituted caprolactone
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
  • B32B27/26—Layered products comprising a layer of synthetic resin characterised by the use of special additives using curing agents
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/40—Layered products comprising a layer of synthetic resin comprising polyurethanes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/30—Low-molecular-weight compounds
  • C08G18/32—Polyhydroxy compounds; Polyamines; Hydroxyamines
  • C08G18/3203—Polyhydroxy compounds
  • C08G18/3206—Polyhydroxy compounds aliphatic
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/65—Low-molecular-weight compounds having active hydrogen with high-molecular-weight compounds having active hydrogen
  • C08G18/66—Compounds of groups C08G18/42, C08G18/48, or C08G18/52
  • C08G18/6633—Compounds of group C08G18/42
  • C08G18/6637—Compounds of group C08G18/42 with compounds of group C08G18/32 or polyamines of C08G18/38
  • C08G18/664—Compounds of group C08G18/42 with compounds of group C08G18/32 or polyamines of C08G18/38 with compounds of group C08G18/3203
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
  • C08G18/72—Polyisocyanates or polyisothiocyanates
  • C08G18/74—Polyisocyanates or polyisothiocyanates cyclic
  • C08G18/76—Polyisocyanates or polyisothiocyanates cyclic aromatic
  • C08G18/7657—Polyisocyanates or polyisothiocyanates cyclic aromatic containing two or more aromatic rings
  • C08G18/7664—Polyisocyanates or polyisothiocyanates cyclic aromatic containing two or more aromatic rings containing alkylene polyphenyl groups
  • C08G18/7671—Polyisocyanates or polyisothiocyanates cyclic aromatic containing two or more aromatic rings containing alkylene polyphenyl groups containing only one alkylene bisphenyl group
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G2110/00—Foam properties
  • C08G2110/0083—Foam properties prepared using water as the sole blowing agent
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G2150/00—Compositions for coatings
  • C08G2150/60—Compositions for foaming; Foamed or intumescent coatings
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2203/00—Foams characterized by the expanding agent
  • C08J2203/22—Expandable microspheres, e.g. Expancel®
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2375/00—Characterised by the use of polyureas or polyurethanes; Derivatives of such polymers
  • C08J2375/04—Polyurethanes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
  • C08J9/32—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof from compositions containing microballoons, e.g. syntactic foams

Definitions

• the present disclosure relates to coating materials, coating layers, and springs.
• Patent Document 1 discloses a method for forming a coating on a coil spring, which is characterized in that "at least a portion of the axial direction of a coil spring that has been preheated to a predetermined surface temperature is rolled in a trough-shaped container that contains thermoplastic resin powder having a melting point of 250°C or less, and the resin powder that has adhered to the spring wire of the coil spring is heated and melted, and then solidified.”
• Patent Document 2 also discloses "a highly durable spring having a single coating film with a thickness of 450 ⁇ m or less, the coating film containing epoxy resin, phenolic resin, and zinc.” Patent Document 2 also discloses that "the coating film is a cured product of an epoxy resin-based powder paint containing epoxy resin, phenolic resin, and zinc.”
• Patent Document 3 discloses "a chip-resistant powder topcoat on a steel substrate having thereon a corrosion-resistant powder coating basecoat, the chip-resistant powder topcoat comprising a cured or fused product of a coating powder of one or more resin components of one or more toughened epoxy resins, 0.1 to 5 parts per hundred parts of resin (phr) of one or more waxes, and optionally up to 200 phr of one or more extenders.”
• Patent document 4 also discloses a coil spring used in vehicle suspension, characterized in that the coating is made thicker in a portion of the spring that satisfies at least one of the following conditions: the stress during use is higher than in other portions, and the probability of the coating being damaged by flying stones is higher than in other portions.
• a coating material for springs when a spring having a cured layer (coating layer) after coating is contacted between the spring and another object or between parts of the spring (for example, between wires of a coil spring when the spring is a coil spring), abnormal noise may be generated even if the contact is via the coating layer.
• the coating layer is also required to have mechanical strength (wear resistance, tear strength, adhesive shear stress, etc.).
• mechanical strength wear resistance, tear strength, adhesive shear stress, etc.
• the objective of this disclosure is to provide a coating material capable of forming a hardened layer that can suppress the generation of abnormal noise while ensuring mechanical strength, a coating layer that can suppress the generation of abnormal noise, and a spring that utilizes the same.
• ⁇ 4> ⁇ 4> The coating material according to any one of ⁇ 1> to ⁇ 3>, wherein the cured layer after curing has a tear strength of 40 N/mm or more after being exposed to an environment of a temperature of 85° C. and a humidity of 85% for 240 hours.
• ⁇ 5> ⁇ 4> The coating material according to any one of ⁇ 1> to ⁇ 4>, wherein the cured product layer after curing has a urethane bond.
• ⁇ 6> The coating material according to any one of ⁇ 1> to ⁇ 5>, which is used for a spring.
• the coating layer according to any one of ⁇ 7> to ⁇ 9> which is made of a cured product having a urethane bond.
• the coating layer according to any one of ⁇ 7> to ⁇ 10> which is used for a spring.
• the present disclosure provides a coating material capable of forming a hardened layer that can suppress the generation of abnormal noise while maintaining mechanical strength, a coating layer that can suppress the generation of abnormal noise, and a spring that utilizes the same.
• the numerical range indicated using “to” indicates a range that includes the numerical values before and after "to” as the minimum and maximum values, respectively.
• the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in another stepwise manner.
• the upper or lower limit value of the numerical range may be replaced with a value shown in the examples.
• each component may contain multiple types of corresponding substances.
• the amount of each component in this specification if there are multiple substances corresponding to each component, the total amount of those multiple substances is meant unless otherwise specified.
• the cured layer (i.e., the coating layer) has a higher air bubble rate in the inner layer on the side facing the surface to be coated than in the surface layer on the opposite side to the surface to be coated.
• the surface layer refers to the layer on the opposite side to the surface to be coated, with the boundary being half the thickness of the cured layer (coating layer)
• the inner layer refers to the layer on the side of the surface to be coated, with the boundary being half the thickness of the cured layer (coating layer).
• air bubbles in the cured layer (coating layer) after curing reflect and attenuate the sound generated upon contact, thereby reducing the sound pressure of the generated sound.
• the air bubble rate of the inner layer on the side of the surface to be coated is made higher than the air bubble rate of the surface layer on the opposite side to the side of the surface to be coated, thereby reducing the presence of air bubbles in the surface layer, which are the starting point for reducing mechanical strength. Therefore, it is possible to form a cured material layer that can suppress the generation of abnormal noise while ensuring mechanical strength.
• the coating layer according to this embodiment can suppress the generation of abnormal noise while ensuring mechanical strength.
• the coating material and coating layer according to this embodiment will be described in detail below.
• the cured layer of the coating material according to this embodiment after curing is also referred to as a "coating layer.”
• the air bubble ratio of the inner layer on the surface to be coated is preferably 3 to 70%, and more preferably 3 to 50%.
• the air bubble ratio of the surface layer on the side opposite to the surface to be coated is preferably 0 to 30%, and more preferably 0 to 15%.
• the difference in the air bubble ratio between the inner layer and the surface layer is preferably from 3 to 70%, and more preferably from 3 to 40%.
• the formation of recesses due to air bubbles on the surface of the cured layer (coating layer) is suppressed.
• hard granular matter such as sand grains
• vibration is applied to the hardened layer (coating layer)
• accelerated wear of the surface with which the hardened layer (coating layer) comes into contact e.g., the surface of another article, the surface of a painted layer of another article
• the promotion of hydrolysis caused by an increase in the specific surface area due to the formation of depressions on the surface of the cured layer (coating layer) is suppressed, and as a result, the decrease in mechanical strength (wear resistance, tear strength, adhesive shear stress, etc.) can be suppressed.
• the air bubble ratio of the entire cured layer is preferably 1.5 to 50%, more preferably 1.5 to 35%, and even more preferably 5 to 35%.
• the void ratio of the entire cured layer (entire coating layer) and the inner layer increases, the tear strength decreases and the durability of the coating layer tends to decrease. Therefore, it is preferable that the void ratio of the entire cured layer (entire coating layer) and the inner layer be in the above range.
• a method for forming a cured layer (coating layer) after curing for example, a method of adding an antifoaming agent to the coating material while adopting the coating material preparation method shown in the following (1) to (3) can be mentioned.
• a method of adding an antifoaming agent to the coating material while adopting the coating material preparation method shown in the following (1) to (3) can be mentioned.
• a method of incorporating a foaming agent into the coating material that expands when heated. A method in which the raw materials are premixed to dissolve gas into the coating material, and then these gases act as nuclei for the growth of bubbles when the coating layer is formed.
• water is added to the coating layer to generate carbon dioxide through a reaction with isocyanate, thereby causing foaming.
• a method for forming the cured product layer (coating layer) after curing for example, a method may be adopted in which a coating material for an inner layer in which bubbles are easily generated is prepared by the above methods (1) to (3), and a coating material for a surface layer in which bubbles are not easily generated is prepared by the above methods (1) to (3), and the inner layer and the surface layer are formed using these coating materials.
• the cured layer (coating layer) may be formed using a coating material of three or more liquids, that is, the cured layer (coating layer) may be composed of a plurality of layers.
• the air bubble content of the surface layer and the inner layer is measured as follows. First, samples of the surface layer and inner layer are taken from the cured layer (coating layer) after curing (that is, samples obtained by cutting and separating the coating layer at the boundary of 1/2 of the thickness). Using these samples, the air bubble ratios of the surface layer and the inner layer are measured by the underwater specific gravity method using A&D Co., Ltd.'s "Specific Gravity Measurement Kit AD-1654.” The air void content of the entire cured layer (entire coating layer) after curing is defined as the arithmetic mean value of the air void content of the surface layer and the inner layer.
• the average diameter of air bubbles in the cured layer (coating layer) after curing is preferably from 30 to 2000 ⁇ m, more preferably from 30 to 1200 ⁇ m, and even more preferably from 30 to 700 ⁇ m, from the viewpoints of mechanical strength and suppression of abnormal noise.
• the average diameter of the cured layer (coating layer) is within the above range, the increase in the bubble diameter suppresses the local decrease in the layer thickness and tear strength.
• the direct transmission of sound vibration from the surface of the cured layer (coating layer) to the interface with the article is suppressed, enhancing the effect of suppressing abnormal noise.
• the surface of the cured layer (coating layer) is less likely to become uneven.
• the average bubble diameter can be adjusted, for example, by the methods shown in (11) to (13) below.
• (11) In the above method (1) of incorporating a foaming agent that expands when heated into the coating material, a foam stabilizer is added to the coating material together with the foaming agent.
• (12) In the method of (2) above, in which the raw materials are premixed to dissolve gas in the coating material, and when the coating layer is formed, the gas is used as a nucleus to grow bubbles, a foam stabilizer is added to the coating material.
• the average bubble diameter in the cured layer (coating layer) after curing is measured as follows. First, the cured layer (coating layer) to be measured is sliced parallel to the thickness direction to obtain a sample. The cut surface of the sample is observed as the observation surface using an optical microscope (Keyence Corporation, "One-shot 3D Shape Measuring Machine Head VR-3100"). In the observed image, the maximum diameter of any 10 bubbles is measured in each of the surface layer and inner layer regions, and the arithmetic mean value of the total 20 maximum diameters is regarded as the average bubble diameter.
• the abrasion loss of the cured layer (coating layer) after curing, as measured with a Taber abrasion tester, is preferably 150 mg or less, and more preferably 100 mg or less.
• the amount of wear is measured using a Taber abrasion tester in accordance with JIS K 7204: 1999. The measurement conditions are as follows: Wear wheel: Taber type H22 wear wheel Wear wheel load: 1000gf Rotation speed of the wear wheel: 60 rpm ⁇ Rotation speed: 1000 rpm
• the tear strength of the cured layer (coating layer) after exposure for 240 hours to an environment of a temperature of 85° C. and a humidity of 85% is preferably 40 N/mm or more, more preferably 45 N/mm or more, and even more preferably 60 N/mm or more.
• the tear strength is measured in accordance with the tear test specified in JIS K 7311:1995.
• a 2 mm-thick cured layer (coating layer) was formed on an SPCC steel plate (thickness 1.6 mm, width 70 mm, length 150 mm) with a release film attached, and the deterioration test was performed. After that, the cured layer (coating layer) was peeled off from the release film and torn, and punched out into the shape of the test specimen, and a tear test was performed.
• the coating material of the present embodiment may be either a thermoplastic resin composition or a composition for forming a thermosetting resin, so long as it can form a cured layer that satisfies the above-mentioned characteristics.
• thermoplastic resin include acrylic resin, polystyrene resin, polyethylene resin, polypropylene resin, polyamide resin, nylon resin, vinyl chloride resin, polyacetal resin, polycarbonate resin, polyphenylene ether resin, polybutylene terephthalate resin, polyphenylene sulfone resin, polysulfone resin, polyarylate resin, and polyetherimide resin.
• thermosetting resin examples include urethane resin, epoxy resin, cyanate resin, melamine resin, and phenol resin.
• Other examples of the rubber material include natural rubber, butadiene rubber, chloroprene rubber, nitrile butadiene rubber, and styrene butadiene rubber.
• the cured layer after curing is preferably a cured layer having a urethane bond, and specifically, is preferably a urethane resin layer.
• the coating material of the present embodiment is preferably a composition containing (A) a polymer polyol, (B) an isocyanate, and (C) a chain extender, or a composition containing (D) a prepolymer obtained by reacting a polyol with an isocyanate.
• the (A) polymer polyol preferably contains at least one selected from the group consisting of (A1) polycarbonate-based polyols, (A2) polyether-based polyols having a bisphenol structure, (A3) lactone-based polyols, (A4) polyester-based polyols, and (A5) copolymers of polycarbonate-based polyols and lactone-based polyols.
• polycarbonate-based polyol (A1) examples include polyols obtained by reacting glycol with alkylene carbonate, polyols obtained by reacting glycol with diaryl carbonate, and polyols obtained by reacting glycol with dialkyl carbonate.
• alkylene carbonate examples include ethylene carbonate, 1,2-propylene carbonate, and 1,2-butylene carbonate.
• diaryl carbonates include diphenyl carbonate, 4-methyldiphenyl carbonate, 4-ethyldiphenyl carbonate, 4-propyldiphenyl carbonate, 4,4'-dimethyldiphenyl carbonate, 2-tolyl-4-tolyl carbonate, 4,4'-diethyldiphenyl carbonate, 4,4'-dipropyldiphenyl carbonate, phenyltoluyl carbonate, bischlorophenyl carbonate, phenylchlorophenyl carbonate, phenylnaphthyl carbonate, and dinaphthyl carbonate.
• dialkyl carbonates include dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, di-n-butyl carbonate, diisobutyl carbonate, di-t-butyl carbonate, di-n-amyl carbonate, and diisoamyl carbonate.
• polyether polyols having a bisphenol structure examples include polyether polyols obtained by adding polyethylene oxide and/or polypropylene oxide to a cyclic diol (such as bisphenol A, hydrogenated bisphenol A, bisphenol S, or bisphenol P), a propylene oxide adduct of bisphenol A, an ethylene oxide adduct of bisphenol A, an ethylene oxide adduct of hydrogenated bisphenol A, and a propylene oxide adduct of hydrogenated bisphenol A.
• the polyether polyol is preferably a propylene oxide adduct of bisphenol A.
• lactone polyol (A3) examples include ring-opening polymers of lactones (such as ⁇ -caprolactone and ⁇ -methyl- ⁇ -valerolactone). Among these, the ring-opening polymer of caprolactone (caprolactone-based polyol) is preferable.
• the polyester polyol (A4) may be a condensation type polyester polyol of a polybasic acid and a polyhydric alcohol other than a lactone polyol.
• the polybasic acid include polyvalent carboxylic acids.
• Specific examples of the polybasic acid include phthalic acid, isophthalic acid, tetrahydrophthalic acid, tetrahydroisophthalic acid, hexahydrophthalic acid, hexahydroterephthalic acid, trimellitic acid, adipic acid, sebacic acid, succinic acid, azelaic acid, fumaric acid, maleic acid, itaconic acid, pyromellitic acid, and acid anhydrides thereof.
• polyhydric alcohols examples include glycols and trihydric or higher polyhydric alcohols.
• glycols include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, neopentyl glycol, hexylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, methylpropanediol, cyclohexanedimethanol, and 3,3-diethyl-1,5-pentanediol.
• trihydric or higher polyhydric alcohols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and dipentaery
• a copolymer of a polycarbonate-based polyol and a lactone-based polyol includes the above-mentioned (A1) polycarbonate-based polyol and the above-mentioned (A3) lactone-based polyol.
• each of the polymer polyols (A) may be used alone or in combination of two or more types.
• the number average molecular weight of the high molecular weight polyol (A) is preferably from 300 to 12,000, and more preferably from 800 to 4,000.
• the number average molecular weight is the molecular weight calculated from the measured value of the hydroxyl value and the number of functional groups according to JIS K 0070.
• the number average molecular weights of other components are also measured in the same manner.
• (B) isocyanate examples include well-known polyisocyanates such as aromatic diisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, xylene-1,4-diisocyanate, 1,5-naphthylene diisocyanate, 1,4-naphthylene diisocyanate, and 3,3'-dichloro-4,4'-diphenylmethane diisocyanate; aliphatic diisocyanates such as hexamethylene diisocyanate, propylene-1,2-diisocyanate, and butylene-1,2-diisocyanate; and alicyclic diisocyanates such as isophorone diisocyanate, 4,4'-dicyclohexy
• chain extender (C) examples include difunctional to tetrafunctional polyols having a molecular weight of 60 to 300.
• Examples of bifunctional polyols include aliphatic diols such as ethylene glycol, propylene glycol, butanediol, pentanediol, neopentyl glycol, methylpentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, and dodecanediol; alicyclic diols such as cyclohexanediol and hydrogenated xylylene glycol; aromatic diols such as xylylene glycol; and polyether polyols obtained by addition polymerization of alkylene oxides (ethylene oxide, propylene oxide, etc.) to dihydric alcohols.
• the addition polymerization of multiple types of alkylene oxides may be random addition polymerization or block addition polymerization.
• trifunctional polyols include trihydric alcohols having 3 to 10 carbon atoms, such as glycerin and trimethylolpropane.
• trifunctional polyols include polyether polyols obtained by addition polymerization of alkylene oxides (ethylene oxide, propylene oxide, etc.) to trihydric alcohols.
• the addition polymerization of multiple types of alkylene oxides may be random addition polymerization or block addition polymerization.
• tetrafunctional polyols include polyether polyols obtained by addition polymerization of alkylene oxide with ethylenediamine, pentaerythritol, or the like.
• low molecular weight polyols include ester-based polyols obtained by condensation of adipic acid and a short chain diol such as ethylene glycol or 1.4-butanediol with a polyfunctional triol such as glycerin.
• the chain extender (C) may be used alone or in combination of two or more kinds. It may be reacted in advance with the polyisocyanate to form a prepolymer.
• preferred chain extenders (C) are ethylene glycol, 1,4-butanediol, 1,6-hexanediol, trimethylolpropane, and glycerin, with 1,4-butanediol and 1,6-hexanediol being more preferred.
• the prepolymer is a prepolymer obtained by reacting a polyol with an isocyanate.
• the polyol include the above-mentioned (A) high molecular weight polyol and the above-mentioned (C) low molecular weight polyol as examples of the chain extender.
• the isocyanate includes the above-mentioned (B) isocyanate.
• composition containing the (D) prepolymer may contain, in addition to the (D) prepolymer, at least one selected from the group consisting of (A) high molecular weight polyol, (B) isocyanate, and (C) chain extender.
• the coating material of the present embodiment may contain other components.
• other components include well-known additives such as catalysts, thickeners, antioxidants, colorants, ultraviolet absorbers, inorganic fillers (calcium carbonate, etc.), water, foam stabilizers, and antifoaming agents.
• additives such as catalysts, thickeners, antioxidants, colorants, ultraviolet absorbers, inorganic fillers (calcium carbonate, etc.), water, foam stabilizers, and antifoaming agents.
• the structure of the resin itself can be made highly heat resistant, and crosslinking agents and reinforcing agents (CNT, etc.) can also be added to increase heat resistance.
• CNT crosslinking agents and reinforcing agents
• the equivalent ratio ((A+C)/(B+D)) of the (A) high molecular weight polyol and (C) chain extender to the (B) isocyanate and (D) prepolymer obtained by reacting a polyol with an isocyanate is preferably 0.5 to 1.5, or 0.8 to 1.2.
• the mass ratio (A/C) of the high molecular weight polyol (A) to the chain extender (C) is preferably 1.0 to 35.0, or 1.5 to 10.0.
• the mass ratio (D/C) of the prepolymer obtained by reacting (D) a polyol with an isocyanate to the chain extender (C) is preferably 1.0 to 15.0, or 5.0 to 10.0.
• the coating material of the present embodiment can be suitably used as a coating material for forming a protective layer for articles such as springs, stabilizers, bumpers, and building materials (wall tiles, etc.).
• the article may be a painted article.
• the coating material of the present embodiment may alternatively be a coating material for springs.
• the article of the present embodiment has a cured layer (i.e., a coating layer) of the coating material for springs of the present embodiment on at least a portion of the surface.
• the spring of this embodiment has a hardened layer of the coating material for a spring of this embodiment on at least a part of its surface.
• the spring may be either a coil spring or a leaf spring.
• the embodiment in which the cured layer of the coating material is provided is, for example, as follows. 1) The surface of the coil spring where the spring wires come into contact with each other, for the purpose of preventing abnormal noise caused by contact between the spring wires. 2) The surface of the seat winding part of the coil spring, or part or the entire coil spring, for the purpose of protecting the paint. 3) Part or the entire FRP leaf spring, for the purpose of absorbing shock and preventing fraying.
• the method for applying the coating material of the present embodiment is not particularly limited, and any of a variety of application methods, including dip coating, spray coating, roller coating, brush coating, and flow coater methods, can be used.
• the thickness of the cured layer to be formed is 1 mm or more (particularly, 1 to 2 mm), and therefore there is a concern about the problem of sagging of the coating film. Therefore, it is also preferable to add a thickener to the coating material of this embodiment to increase the viscosity.
• a surface layer coating material (1) was prepared using the components shown in the "CO material (1)” column of Table 1, and an inner layer coating material (2) was prepared using the components shown in the "CO material (2)” column of Table 1.
• the preparation conditions for the coating material were the same as those in Example 1, except for the components used.
• Example 1 The coating materials of Examples 1 to 11 and Comparative Example 1 were applied to an SPCC steel plate having a width of 12.5 mm, a length of 70 mm, and a thickness of 3.2 mm, and then cured under conditions of 180°C and 10 minutes to form a hardened layer (coating layer) having a thickness of 2 mm to prepare a test specimen (1).
• the surface layer coating material (1) and the inner layer coating material (2) of Examples 12 to 14 were each applied to an SPCC steel plate having a width of 12.5 mm, a length of 70 mm, and a thickness of 3.2 mm, and after application, the material was cured under conditions of 180°C and 10 minutes to prepare a test piece (2) having a hardened layer (coating layer) with a total thickness of 2 mm, i.e., a surface layer of 1 mm and an inner layer of 1 mm.
• the test pieces were then used to carry out the following evaluations.
• bubble rate average bubble diameter
• the coating layer was exposed to an environment of a temperature of 85° C. and a humidity of 85% for 240 hours, and then the tear strength was measured.
• Weight amount 2 The amount of wear at the contact portion with the coating layer was evaluated using a fatigue tester (linear-torsion type dynamic fatigue tester "E10000") manufactured by Instron Corporation. Specifically, the following procedure was performed. Silica sand was laid on the test piece, and the coating layer was then sandwiched between a ⁇ 15 round rod with a 100 ⁇ m thick epoxy powder coating. The round rod was then vibrated 100,000 times under conditions of a minimum load of 10 N and a maximum load of 3,000 N, and the remaining thickness of the epoxy powder coating on the round rod was then measured.
• a fatigue tester linear-torsion type dynamic fatigue tester "E10000”
• the adhesive shear strength of the coating layer was measured as follows. A 100 ⁇ m thick epoxy powder coating was applied to an SPCC steel plate with a thickness of 3.2 mm, width of 25 mm, and length of 70 mm, and the coating film was subjected to a pretreatment for adhesion before applying a coating material. The coating material was then sandwiched between SPCC steel plates that had been similarly painted and pretreated for adhesion, and cured by heating while maintaining the adhesive film thickness at 2 mm. In other words, the surface layer coating material was adhered to one side of the SPCC steel plate, and the inner layer coating material was adhered to the other side. The adhesive area of the test specimen was 25 mm wide and 12.5 mm long. The thus prepared tensile shear test pieces were subjected to a tensile test under conditions in accordance with JIS K6850-1999, and the tensile shear strength was calculated.
• the coating material of this example can suppress the generation of abnormal noise. It is clear that the coating material of this example, in which the air void ratio of the surface layer and the inner layer is controlled, is capable of forming a coating layer with high mechanical strength.

Landscapes

• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Paints Or Removers (AREA)
• Springs (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=91379381

Family Applications (1)

Country Status (5)

Citations (8)

Family Cites Families (4)

• 2023
  • 2023-12-11 JP JP2024563016A patent/JPWO2024122655A1/ja active Pending
  • 2023-12-11 EP EP23900764.4A patent/EP4632027A4/en active Pending
  • 2023-12-11 WO PCT/JP2023/044302 patent/WO2024122655A1/ja not_active Ceased
  • 2023-12-11 CN CN202380084142.8A patent/CN120344626A/zh active Pending
• 2025
  • 2025-06-06 MX MX2025006674A patent/MX2025006674A/es unknown

Patent Citations (8)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events