Low-noise tire, tire inner polyurethane foam sound-absorbing lining composition for manufacturing same, and tire inner polyurethane foam sound-absorbing lining method using same

Abstract

The present invention relates to a low-noise tire, a tire inner polyurethane foam sound-absorbing lining composition for manufacturing same, and a tire inner polyurethane foam sound-absorbing lining method using same. More specifically, the present invention relates to a low-noise tire, a tire inner polyurethane foam sound-absorbing lining composition for manufacturing same, and a tire inner polyurethane foam sound-absorbing lining method using same, wherein in order to reduce cavity resonance noise, which occurs as vibration forces generated between the tire tread and road surface are transmitted to the cavity space inside the tire and the axle, leading to interior noise, a liquid foaming polyurethane composition is conveniently, rapidly, and precisely applied in a liquid foam spraying manner to the inner surface of the tire, which corresponds to the tire tread, and cured to form a polyurethane sound-absorbing lining, whereby the low-noise tire exhibits improved low-noise performance.

Description

Low-noise tire, tire inner polyurethane foam sound-absorbing lining composition for manufacturing same, and tire inner polyurethane foam sound-absorbing lining method using same

[0001] The present invention relates to a low-noise tire, a tire internal polyurethane foam sound-absorbing lining composition for manufacturing the same, and a tire internal polyurethane foam sound-absorbing lining method using the same, and more particularly, to a low-noise tire having improved low-noise performance by forming a polyurethane foam sound-absorbing lining by simply, quickly, and precisely spraying a polyurethane foam sound-absorbing lining composition in a liquid form on the inner surface of the tire corresponding to the tire tread and curing the polyurethane foam sound-absorbing lining in order to reduce cavity resonance noise generated as interior noise due to the excitation force generated between the tire tread and the road surface during driving, a tire internal polyurethane foam sound-absorbing lining composition for manufacturing the same, and a tire internal polyurethane foam sound-absorbing lining method using the same.

[0002]

[0003] Recently, with the spread of electric vehicles, there is a growing demand for reducing noise caused by tire patterns as well as interior noise to improve ride comfort and create a more comfortable environment as a way to improve automobile quality.

[0004]

[0005] Among these noises, the 200-250 Hz low-frequency resonance noise (cavity resonance noise) that is generated as interior noise by the excitation force generated between the tire tread and the road surface during driving being transmitted to the tire internal (cavity) space and the axle is generated as a sound with a sharp peak inside the vehicle, causing discomfort to the driver and reducing ride comfort.

[0006]

[0007] In particular, with the advent of electric vehicles with virtually no engine noise and the tire sizes mounted on vehicles becoming flatter and larger, tire resonance noise is emerging as an increasingly important issue.

[0008]

[0009] Looking at the prior art for reducing such tire resonance noise, Korean Patent No. 10-1439558 (registration date September 2, 2014) discloses a noise reduction device for a tire, which is formed by fixing a soft polyurethane foam to a ring-shaped band member, wherein the soft polyurethane foam has a density of 7 to 40 kg / ㎥ and a tear strength (N / cm) per unit density (kg / ㎥) of 0.39 to 0.70, and the noise reduction device is characterized in that it is maintained on the inner surface of the tire and is freely attached to and detached from the tire.

[0010]

[0011] In addition, Korean Patent No. 10-1993303 (registration date: June 20, 2019) discloses a pneumatic tire (2); a body ply (6) forming the skeleton of the tire (2) in parallel with an inner liner (8) on the lower side of the tread (4) in contact with the road surface of the tire (2); a rim (20) mounted on the tire (2) through a bead portion (10) turned up and wrapped by the body ply (6); and a noise reduction member (30) laminated inside between the body ply (6) and the inner liner (8) located on the shoulder portion (16) formed on both the left (L) and right (R) sides in the width direction based on the center line (CL) of the tire (2) to reduce resonance noise generated inside the cavity (12) between the tire (2) and the rim (20) and arranged in an annular shape divided at regular intervals along the circumference; In a pneumatic tire having a noise reduction member, the noise reduction member (30) is formed by overlapping at least one of a noise-prevention tape, a noise-prevention rubber plate, and a noise-prevention fiber tape, or by combining and overlapping a plurality of them. A pneumatic tire having a noise-prevention member is known.

[0012]

[0013] In addition, Korean Patent No. 10-2075314 (registration date February 3, 2020) discloses that 2 to 4 block-shaped porous foam sound absorbers are attached to the inner surface of the tire at a 90-degree angle in the circumferential direction, and the material of the porous foam sound absorbers is porous melamine resin foam.

[0014] The porous foam sound absorber is in the shape of an octahedral block having a horizontal upper length of 10 to 40 mm, a horizontal lower length of 100 to 180 mm, a vertical length of 100 to 180 mm, a height of both ends of 10 to 20 mm, and a center height of 25 to 75 mm, and the porous foam sound absorber includes six rectangular faces and two hexagonal faces, and any one of the six rectangular faces is attached to be in contact with the inner surface of the tire, and the vertical direction of the porous foam sound absorber is consistent with the circumferential direction of the tire, and the porous foam sound absorber has a volume of 36x10 4 A tire for reducing resonance noise is known, characterized in that the porous foam sound absorbing body is attached to the inner surface of the tire using a thermoplastic polyacrylic type adhesive.

[0015]

[0016] In addition, Korean Patent No. 10-2127660 (registration date June 23, 2020) discloses a pneumatic tire comprising a tread portion (100), a sidewall portion (200), and a bead portion (300), wherein the pneumatic tire comprises a sound-absorbing material (350) attached to the inner surface of the tread portion (100) inside the pneumatic tire; and a sound-insulating film (400) fixedly supported by the sound-absorbing material (350) so as to divide the cross-section of the tire together with the sound-absorbing material (350) inside the pneumatic tire, wherein the sound-absorbing material (350) is formed in a pair of ring shapes that are formed in a circular shape in the circumferential direction of the tread portion (100) at a constant interval from each side of the tread portion (100).

[0017]

[0018] In addition, Korean Patent Publication No. 10-2021-0091400 (publication date July 22, 2021) discloses a pneumatic tire including a tread portion (100), a sidewall portion (200), and a bead portion (300), wherein an inner liner (400) is installed on the inner surface of the pneumatic tire, a space portion (500) is formed between the tread portion (100) and the inner liner (400), and a filler (600) is positioned in the space portion (500).

[0019]

[0020] In addition, Korean Patent No. 10-2460711 (registration date: October 25, 2022) discloses a sound-absorbing tire foam tape comprising: a release film; an adhesive layer formed on the lower surface of the release film; a base film formed on the lower surface of the adhesive layer; an adhesive layer formed on the lower surface of the base film; and a sound-absorbing material layer having a porous structure formed on the lower surface of the adhesive layer; wherein the adhesive layer comprises an acrylic adhesive, and the weight average molecular weight of the adhesive included in the adhesive layer is 200,000 to 2,000,000, and the weight average molecular weight of the adhesive included in the adhesive layer is 1,000 to 80,000, and the acrylic adhesive includes an alkyl acrylate having 4 to 17 carbon atoms, and the sound-absorbing material layer includes a polyurethane foam.

[0021]

[0022] However, the above conventional technologies are a method of cutting polyurethane foam, which is a sound-absorbing material, to a size and then attaching it to the inner surface of the tire. In order to attach the polyurethane foam, a primer is applied to the inner surface of the tire and then a worker manually attaches the polyurethane foam.

[0023]

[0024] That is, the step of molding polyurethane foam, the step of applying a primer or adhesive to the inner surface of the tire to strengthen the adhesion of the molded polyurethane foam to the inside of the tire, and the step of attaching the molded polyurethane foam to the inner surface of the tire.

[0025]

[0026] The above method requires multiple production steps, so it takes a long time to produce, increases production costs, and reduces productivity. In addition, if the polyurethane foam is attached incorrectly, there are problems such as imbalance occurring when the tire rotates or the polyurethane foam separating from the tire.

[0027]

[0028] In addition, the polyurethane foam attached to the tire has a narrow and long shape of about 10 cm in width, making it difficult to manually attach it to the inside of the tire, which reduces productivity and increases the possibility of defects due to incorrect attachment.

[0029]

[0030] To improve the above-mentioned problems, a method of foaming the inside of a tire by spraying polyurethane foam in liquid form has been developed.

[0031]

[0032] However, since the main components of tires, rubber, and organic chemical material, polyurethane foam, cannot have strong adhesion with general adhesives, a primer is applied to the inside of the tire and then a foam lining is formed to form the polyurethane foam as a liner. However, if the primer is not sufficiently applied to the interface between the inner surface of the tire and the polyurethane foam, or if the tire rapidly accelerates or decelerates, the tire and polyurethane foam may separate due to differences in inertial force.

[0033]

[0034] In addition, when foaming lining inside a tire by spraying polyurethane foam in liquid form, if the lining overlaps or gaps occur at the start and end points of the lining, there is a problem of the lining falling off due to deviations in weight and distribution, and there is a problem of low-noise performance being reduced due to tire vibration.

[0035]

[0036] In particular, the above-mentioned problems are becoming more prominent in electric vehicles because they have much greater torque and superior rapid acceleration and deceleration performance than conventional diesel or gasoline vehicles.

[0037]

[0038] The present invention, in order to solve the above-mentioned conventional problems, provides a low-noise tire having improved low-noise performance by forming a polyurethane foam sound-absorbing lining by simply, quickly, and precisely spraying a liquid foam composition on the inner surface of the tire corresponding to the tire tread and curing the polyurethane foam sound-absorbing lining, in order to reduce cavity resonance noise generated as interior noise due to the excitation force generated between the tire tread and the road surface during driving, and a tire inner polyurethane foam sound-absorbing lining composition for manufacturing the same and a tire inner polyurethane foam sound-absorbing lining method using the same.

[0039]

[0040] The present invention is intended to solve the above technical problem, and in order to reduce the resonance noise (cavity resonance noise) generated as interior noise by transmitting the excitation force generated between the tire tread and the road surface during driving to the tire internal (cavity) space and the axle, a polyurethane foam sound-absorbing lining is formed by simply, quickly, and precisely spraying a liquid foam composition on the inner surface of the tire corresponding to the tire tread and curing the composition, the polyurethane foam sound-absorbing lining composition comprising 3 to 40 wt% of polyol 1 (glycerol, OH value = 10-30 mgKOH / g), 40 to 70 wt% of polyol 2 (glycerol, OH value = 31 to 40 mgKOH / g), 10 to 40 wt% of polyol 3 (glycerol, OH value = 41 to 50 mgKOH / g), and 10 to 40 wt% of polyol 4 (glycerol, OH value = 51~60 mgKOH / g,) 5~30 wt%, chain extender 1 (diethanolamine, OH value = 1,500-2,500 mgKOH / g) 1~10 wt%, chain extender 2 (1,4-butanediol, OH value = 500-1,500 mgKOH / g) 0.1~1 wt%, crosslinking agent 0.1~5 wt%, blowing agent (water) 1~5 wt%, urethane curing reaction catalyst 0.1~3 wt%, foaming catalyst 0.1~1 wt% and foaming agent 0.1~3 wt%, Monomeric MDI (MMDI) 4~70 wt%, Carbodiimide-containing MDI (CMDI) 4~70 wt% and A technical solution is provided for obtaining a tire inner polyurethane foam sound-absorbing lining composition comprising 50 to 60 parts by weight of a mixed MDI (methylene diphenyl diisocyanate) curing agent composition comprising 10 to 80 wt% of polymeric MDI (PMDI).

[0041]

[0042] The technical solution is that the above crosslinking agent is triethanolamine (OH value = 1,500-2,500 mgKOH / g).

[0043]

[0044] The above urethane curing reaction catalyst is a technical solution that mixes 33 wt% of triethylene diamine and 66 wt% of dipropylene glycol.

[0045]

[0046] The technical solution is that the above foaming catalyst is diethyl toluene diamine (DETDA).

[0047]

[0048] The technical solution is that the above-mentioned stabilizer is polyether modified polysiloxane.

[0049]

[0050] In addition, the present invention comprises 3 to 40 wt% of polyol 1 (glycerol, OH value = 10-30 mgKOH / g), 40 to 70 wt% of polyol 2 (glycerol, OH value = 31 to 40 mgKOH / g), 10 to 40 wt% of polyol 3 (glycerol, OH value = 41 to 50 mgKOH / g), 5 to 30 wt% of polyol 4 (glycerol, OH value = 51 to 60 mgKOH / g), 1 to 10 wt% of chain extender 1 (diethanolamine, OH value = 1,500-2,500 mgKOH / g), 0.1 to 1 wt% of chain extender 2 (1,4-butanediol, OH value = 500-1,500 mgKOH / g), and a crosslinking agent. A step of preparing a polyol premix composition comprising 0.1 to 5 wt% of a polyurethane curing reaction catalyst, 1 to 5 wt% of a foaming agent (water), 0.1 to 3 wt% of a urethane curing reaction catalyst, 0.1 to 1 wt% of a foaming catalyst, and 0.1 to 3 wt% of a foaming agent; A step of preparing a mixed MDI (methylene diphenyl diisocyanate) curing agent composition comprising 4 to 70 wt% of a monomeric MDI (MMDI), 5 to 70 wt% of a carbodiimide-containing MDI (CMDI), and 10 to 80 wt% of a polymeric MDI (PMDI); A step of introducing 50 to 60 parts by weight of the curing agent composition into a foaming mixer chamber and mixing them with respect to 100 parts by weight of the polyol premix composition to prepare a tire inner polyurethane foam sound-absorbing lining composition as a foaming raw material; A technical solution is a tire inner polyurethane foam sound-absorbing lining method comprising the step of forming a polyurethane foam sound-absorbing lining by spraying the inner polyurethane foam sound-absorbing lining composition in liquid form onto the inner surface of the tire corresponding to the tire tread and curing the same.

[0051]

[0052] The above tire inner surface liquid foam spray is a technical solution in which foam is sprayed on the inner surface of a tire rotating at a constant speed by a foam spray nozzle spaced a certain distance from the inner surface of the tire at a constant discharge amount for a certain period of time according to the speed of one rotation.

[0053]

[0054] The above tire inner surface liquid foam spray is a technical solution that marks the start and end points of the liquid foam spray on the inner surface of the tire with a laser pointer to prevent the polyurethane foam sound-absorbing lining from overlapping or spacing out at the start and end points.

[0055]

[0056] A technical solution comprises a step of punching with a needle brush to form pores in a cured film formed on the surface of a polyurethane foam sound-absorbing lining formed by spraying liquid foam on the inner surface of the tire and curing, or punching a logo design with a logo-designed needle brush.

[0057]

[0058] In addition, the present invention provides a technical solution for a low-noise tire manufactured by the method for producing a polyurethane foam sound-absorbing lining inside the tire.

[0059]

[0060] The low-noise tire of the present invention, the tire inner polyurethane foam sound-absorbing lining composition for manufacturing the same, and the tire inner polyurethane foam sound-absorbing lining method using the same have an excellent effect of improving low-noise performance by forming a polyurethane foam sound-absorbing lining by simply, quickly, and precisely spraying a polyurethane foam sound-absorbing lining composition in a liquid form on the inner surface of the tire corresponding to the tire tread and curing the composition to reduce cavity resonance noise generated as interior noise due to the excitation force generated between the tire tread and the road surface during driving and then curing the polyurethane foam sound-absorbing lining.

[0061]

[0062] Figure 1 is a drawing of the starting position of a polyurethane foam sound-absorbing lining method according to the present invention.

[0063] Figure 2 is a rotational state drawing of a polyurethane foam sound-absorbing lining method according to the present invention.

[0064] Figure 3 is a drawing of the end position of the polyurethane foam sound-absorbing lining method according to the present invention.

[0065] Figure 4 is a cross-sectional view of the inside of a low-noise tire according to the present invention.

[0066]

[0067] Hereinafter, the present invention will be described in detail through embodiments and / or drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments and / or drawings described herein.

[0068]

[0069] First, the present invention forms a polyurethane foam sound-absorbing lining by simply, quickly, and precisely spraying a liquid foam composition on the inner surface of a tire corresponding to the tire tread and curing the liquid foam composition to reduce cavity resonance noise generated as interior noise due to the excitation force generated between the tire tread and the road surface during driving being transmitted to the inner space (cavity) of the tire and the axle, and the polyurethane foam sound-absorbing lining composition comprises 3 to 40 wt% of polyol 1 (glycerol, OH value = 10-30 mgKOH / g), 40 to 70 wt% of polyol 2 (glycerol, OH value = 31 to 40 mgKOH / g), 10 to 40 wt% of polyol 3 (glycerol, OH value = 41 to 50 mgKOH / g), and 10 to 40 wt% of polyol 4 (glycerol, OH value = 51~60 mgKOH / g,) 5~30 wt%, chain extender 1 (diethanolamine, OH value = 1,500-2,500 mgKOH / g) 1~10 wt%, chain extender 2 (1,4-butanediol, OH value = 500-1,500 mgKOH / g) 0.1~1 wt%, crosslinking agent 0.1~5 wt%, blowing agent (water) 1~5 wt%, urethane curing reaction catalyst 0.1~3 wt%, foaming catalyst 0.1~1 wt% and foaming agent 0.1~3 wt%, based on 100 parts by weight of a polyol premix composition comprising Monomeric MDI (MMDI) 4~70 wt%, Carbodiimide-containing MDI (CMDI) 4~70 wt% and Polymeric MDI It is composed of 50 to 60 parts by weight of a mixed MDI (methylene diphenyl diisocyanate) curing agent composition containing 10 to 80 wt% of (PMDI).

[0070]

[0071] Here, the polyurethane resin used in the polyurethane foam sound-absorbing lining composition is a soft foam obtained by reacting a urethane foam composition containing a polyol, a polyisocyanate, a catalyst, a crosslinking agent, a foaming agent, and a blowing agent, wherein the polyol has a hydroxyl functional group (-OH) and the polyisocyanate has an isocyanate functional group (-NCO) in its molecule.

[0072]

[0073] Polyols are classified into monols, diols, triols, etc. depending on the number of functional groups in the molecule, and isocyanates can also be classified into monoisocyanates, diisocyanates, etc. depending on the number of functional groups per molecule.

[0074]

[0075] In order to manufacture a polyurethane resin of high molecular weight, a polyol and an isocyanate having two or more functional groups must generally be used. During the reaction, each component forms a urethane group through a reaction between functional groups at the molecular terminal. As described in [Chemical Formula 1] below, a polymer having a large amount of such urethane groups in the molecule is called a polyurethane.

[0076] [Chemical Formula 1]

[0077] R-NCO + R'-OH → [R-NH-COO-R']

[0078]

[0079] Water reacting with isocyanate forms an unstable structure of carbamic acid, which soon decomposes into an amine and carbon dioxide (CO2). ([Chemical Formula 2])

[0080] [Chemical Formula 2]

[0081] R-NCO + H2O →R-NH2+ CO2

[0082]

[0083] The amine reacts again with the isocyanate to form a urea group ([chemical formula 3]), and the carbon dioxide gas released through decomposition creates small bubbles within the polyurethane resin, ultimately creating a cell structure dispersed within the polyurethane.

[0084] [Chemical Formula 3]

[0085] R-NH2+ R'-NCO →[R-NH-CO-NH-R']

[0086]

[0087] These polyurethane foams are widely used as automotive component materials due to their excellent properties such as low density, high mechanical properties, and high heat resistance.

[0088]

[0089] The polyurethane foam sound-absorbing lining composition used in the present invention comprises 3 to 40 wt% of polyol 1 (glycerol, OH value = 10-30 mgKOH / g), 40 to 70 wt% of polyol 2 (glycerol, OH value = 31 to 40 mgKOH / g), 10 to 40 wt% of polyol 3 (glycerol, OH value = 41 to 50 mgKOH / g), 5 to 30 wt% of polyol 4 (glycerol, OH value = 51 to 60 mgKOH / g), 1 to 10 wt% of chain extender 1 (diethanolamine, OH value = 1,500-2,500 mgKOH / g), and 1,4-butanediol, OH value = 500-1,500 mgKOH / g. A polyol premix composition comprising 0.1 to 1 wt% of a crosslinking agent, 0.1 to 5 wt% of a foaming agent (water), 0.1 to 3 wt% of a urethane curing reaction catalyst, 0.1 to 1 wt% of a foaming catalyst, and 0.1 to 3 wt% of a foaming agent.

[0090]

[0091] At this time, the polyol of the polyol premix composition is used at least 60%, and rather than using only a single polyol, various types of polyols are used according to the product characteristics and production site. The polyol is produced through the chemical bonding of an initiator with PO (propylene oxide) and EO (ethylene oxide).

[0092]

[0093] When glycerol (or Glycerine), Trimethylolpropane (TMP), Triethanolamine (TEOA), 1,2,6-hexanetriol, phosphoric acid, and triisopropanolamine are used as initiators, a triol (functionality = 3) with three hydroxyl groups (-OH) is produced.

[0094] At this time, the OH value is determined according to the degree of PO / EO capping, which is related to the molecular weight of the chemically bonded polyol, and polyols with an OH value in the range of 20-60 mgKOH / g are used in the production of polyurethane foam, an automotive component material. Triol products account for the largest portion of mixed polyols, and at least 60% or more must be used to satisfy the required characteristics such as flowability, moldability, and hardness of the raw material.

[0095]

[0096] In addition, the vibration absorption capacity of urethane foam varies depending on the molecular weight of the polyol. In the present invention, a polyol having an OH value of 40 or less was used as the main material, and several additional polyols with adjusted PO and EO contents were used together to induce room temperature curing and prevent foam shrinkage.

[0097]

[0098] According to a preferred embodiment of the present invention, the recommended usage amount of the polyol is a mixture of polyol 1 (glycerol, OH value = 10-30 mgKOH / g) 3 to 40 wt%, polyol 2 (glycerol, OH value = 31 to 40 mgKOH / g) 40 to 70 wt%, polyol 3 (glycerol, OH value = 41 to 50 mgKOH / g) 10 to 40 wt%, and polyol 4 (glycerol, OH value = 51 to 60 mgKOH / g) 5 to 30 wt%.

[0099]

[0100] In the case of polyol 1, 3.0 to 40 wt% is used. If it is less than 3 wt%, the hardness is soft, and if it exceeds 40 wt%, the hardness is hard, resulting in poor vibration absorption.

[0101]

[0102] In particular, polyol 1 is a polyol to which the solid of Stylene Monomer is added, and since the hardness and cell opening characteristics and the viscosity of the raw material are affected depending on the solid content (30 to 50%), it is used at a maximum of 40 wt% or less.

[0103]

[0104] In the case of polyol 2, 40.0 to 70.0 wt% is preferable, and when it is less than 40 wt%, the rebound elasticity is significantly reduced, and when it exceeds 70 wt%, the hardness is reduced.

[0105]

[0106] In the case of polyol 3, 10.0 to 40.0 wt% is preferable. When it is less than 10 wt%, the vibration transmission rate increases, and when it exceeds 40 wt%, the permanent compression set rate decreases.

[0107]

[0108] In the case of polyol 4, 5.0 to 30.0 wt% is preferable. When it is less than 5 wt%, the vibration transmission rate increases, and when it exceeds 30 wt%, the elasticity and permanent compression set rate decrease.

[0109]

[0110] Meanwhile, the chain extender is a mixture of chain extender 1 (diethanolamine, OH value = 1,500-2,500 mgKOH / g) and chain extender 2 (1,4-butanediol, OH value = 500-1,500 mgKOH / g), and the crosslinking agent is triethanolamine (OH value = 1,500-2,500 mgKOH / g).

[0111]

[0112] The reason for using the above chain extender and crosslinking agent is that polyol alone cannot satisfy the required characteristics of the product, so the physical and mechanical properties such as tensile strength and tear strength show different aspects depending on the use of the chain extender and crosslinking agent during product manufacturing, so these are raw materials that must be added.

[0113]

[0114] The use of the above chain extender and crosslinking agent increases the crosslinking strength between molecules, which plays an important role in improving general physical properties such as tensile strength and tearing, and at the same time, improves hydrolysis resistance, allowing the product to maintain its characteristics under high temperature and high humidity conditions.

[0115]

[0116] However, if only the required characteristics of the final product are satisfied, productivity decreases due to problems such as closed cells and flowability. Therefore, chain extender 1 (diethanolamine, OH value = 1,500-2,500 mgKOH / g) is used at 1 to 10 wt%, but if it is less than 1 wt%, tensile and tear properties decrease, and if it exceeds 10 wt%, closed cells occur excessively, rapidly reducing productivity.

[0117]

[0118] The above chain extender 2 (1,4-butanediol, OH value = 500-1,500 mgKOH / g) is used in an amount of 0.1 to 1 wt%, but if it exceeds 1 wt%, the flowability deteriorates.

[0119]

[0120] The above crosslinking agent uses 1 to 5 wt% of triethanolamine (OH value = 1,500-2,500 mgKOH / g). If it exceeds 5 wt%, the flowability deteriorates and the defect rate increases.

[0121]

[0122] Furthermore, the polyurethane reaction involves two liquid substances meeting and forming a solid. It is not simply a reaction between isocyanate and polyol. The catalysts needed to lower the activation energy of these two reactions are urethane curing catalysts and foaming catalysts. Depending on the degree of use of each of these catalysts, stable polyurethane foam production is possible.

[0123]

[0124] The above urethane curing reaction catalyst uses 0.1 to 3 wt% of a mixture of 33 wt% of triethylene diamine and 66 wt% of dipropylene glycol.

[0125]

[0126] The above foaming catalyst uses 0.1 to 2 wt% of diethyl toluene diamine (DETDA).

[0127]

[0128] In order for the polyurethane foam sound-absorbing lining of the present invention to be cured within a limited time, the urethane curing reaction catalyst is used in an amount of up to 3 wt%, and the foaming catalyst is used in an amount of up to 2 wt%.

[0129]

[0130] The recommended usage amounts of the above urethane curing reaction catalyst and foaming catalyst are 0.1 to 3.0 wt% and 0.1 to 2.0 wt%, respectively. If the usage amounts are less than the recommended amounts, curing properties will be reduced, resulting in decreased productivity. If the usage amounts exceed the recommended amounts, flowability will be reduced, resulting in pore defects.

[0131]

[0132] The above-mentioned foaming agents are broadly classified into physical and chemical foaming agents, and here, the chemical foaming agent is referred to. Since the reaction rate, curing property, and free rise density are determined by the amount of foaming agent used, the amount used is determined according to production conditions within a maximum range of 5 wt%. In the present invention, water is used.

[0133]

[0134] Generally, the usage amount is 1.0 to 5.0 wt%. If it is less than 1.0 wt%, the foaming ratio is low and the required density cannot be achieved. If it exceeds 5.0 wt%, all physical properties deteriorate due to excessive foaming.

[0135]

[0136] The above-mentioned foaming agent uses polyether-modified polysiloxane, which acts as an emulsifier to aid the reaction between MDI and polyol, lowers surface tension to create fine bubbles, and stabilizes these fine bubbles. The amount used is determined according to production conditions within a maximum range of 3%.

[0137]

[0138] Generally, the usage amount is 0.1 to 3.0 wt%. If it is less than 0.1 wt%, urethane foam is not formed, and if it exceeds 3.0 wt%, there is a problem of reduced productivity due to excessive occurrence of closed cells.

[0139]

[0140] Meanwhile, in the present invention, the polyisocyanate uses a mixed MDI composed of 4 to 70 wt% of monomeric MDI (MMDI), 4 to 70 wt% of carbodiimide-containing MDI (CMDI), and 10 to 80 wt% of polymeric MDI (PMDI).

[0141]

[0142] Each raw material has its own unique characteristics such as hardness, flowability, and hardening, and by combining these characteristics, the desired chemical bonding structure can be secured.

[0143]

[0144] In particular, to maximize vibration absorption, it is possible to secure it when using a range of 4 to 70 wt% of Monomeric MDI (MMDI), 4 to 70 wt% of Carbodiimide-containing MDI (CMDI), and 10 to 80 wt% of Polymeric MDI (PMDI).

[0145]

[0146] The usage amount of Monomeric MDI (MMDI), M-MDI, and Carbodiimide-containing MDI (CMDI) is in the range of 4 to 70 wt%. If it is less than 4 wt%, closed cells are excessively generated, which hinders productivity, and if it exceeds 70 wt%, on the contrary, open cells are excessive, which prevents foam generation, increasing the defect rate.

[0147]

[0148] For polymeric MDI (PMDI), it is generally used at 10.0 to 80.0 wt%. If it is less than 10 wt%, the tensile and tear strengths decrease rapidly, and if it exceeds 80 wt%, the hardness increases rapidly.

[0149]

[0150] Meanwhile, the present invention, in another aspect, comprises 3 to 40 wt% of polyol 1 (glycerol, OH value = 10-30 mgKOH / g), 40 to 70 wt% of polyol 2 (glycerol, OH value = 31 to 40 mgKOH / g), 10 to 40 wt% of polyol 3 (glycerol, OH value = 41 to 50 mgKOH / g), 5 to 30 wt% of polyol 4 (glycerol, OH value = 51 to 60 mgKOH / g), 1 to 10 wt% of chain extender 1 (diethanolamine, OH value = 1,500-2,500 mgKOH / g), 0.1 to 1 wt% of chain extender 2 (1,4-butanediol, OH value = 500-1,500 mgKOH / g), A step of preparing a polyol premix composition comprising 0.1 to 5 wt% of a crosslinking agent, 1 to 5 wt% of a blowing agent (water), 0.1 to 3 wt% of a urethane curing reaction catalyst, 0.1 to 1 wt% of a foaming catalyst, and 0.1 to 3 wt% of a foaming agent; A step of preparing a mixed MDI (methylene diphenyl diisocyanate) curing agent composition comprising 4 to 70 wt% of a monomeric MDI (MMDI), 5 to 70 wt% of a carbodiimide-containing MDI (CMDI), and 10 to 80 wt% of a polymeric MDI (PMDI); A step of introducing 50 to 60 parts by weight of the curing agent composition into a foaming mixer chamber and mixing them with respect to 100 parts by weight of the polyol premix composition to prepare a tire inner polyurethane foam sound-absorbing lining composition as a foaming raw material; A method for forming an inner tire polyurethane foam sound-absorbing lining includes a step of spraying the inner tire polyurethane foam sound-absorbing lining composition in a liquid foam form on the inner surface of the tire (31) corresponding to the tire tread and curing the spray to form a polyurethane foam sound-absorbing lining (32).

[0151]

[0152] At this time, as shown in [Figure 1] to [Figure 3], the liquid foam spray on the inner surface of the tire (31) is sprayed as foam at a constant discharge amount for a constant time according to the speed of one rotation by the foam spray nozzle (13a) of the foaming head (13) spaced a constant distance from the inner surface of the tire, onto the inner surface of the tire rotating at a constant speed.

[0153]

[0154] In particular, it is important to mark the starting point (32a) and the end point (32b) of the liquid foam spray on the inner surface of the tire with a laser pointer (13b) so that the polyurethane foam sound-absorbing lining (32) does not overlap or separate from the starting point and the end point.

[0155]

[0156] Optionally, a step of punching with a needle brush to form pores in the cured film formed on the surface of the polyurethane foam sound-absorbing lining (32) formed by spraying liquid foam on the inner surface of the tire and curing it, or punching a logo design with a logo-designed needle brush may be included.

[0157]

[0158] In addition, the present invention, in another aspect, features a low-noise tire (30) having a polyurethane foam sound-absorbing lining lined with the tire internal polyurethane foam sound-absorbing lining composition as shown in [Figure 4], or manufactured by the tire internal polyurethane foam sound-absorbing lining method.

[0159]

[0160] The above description is merely an example of the technical idea of ​​the present invention, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential characteristics of the present invention. Therefore, the embodiments and / or drawings disclosed in the present invention are not intended to limit the technical idea of ​​the present invention, but rather to explain it, and the scope of the technical idea of ​​the present invention is not limited by these embodiments and / or drawings. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

[0161]

[0162] The low-noise tire of the present invention, the tire inner polyurethane foam sound-absorbing lining composition for manufacturing the same, and the tire inner polyurethane foam sound-absorbing lining method using the same have an excellent effect of improving low-noise performance by forming a polyurethane foam sound-absorbing lining by simply, quickly, and precisely spraying a liquid foam composition on the inner surface of the tire corresponding to the tire tread and curing the composition to reduce cavity resonance noise generated as interior noise due to the excitation force generated between the tire tread and the road surface during driving and then curing the polyurethane foam sound-absorbing lining, and thus have industrial applicability.

Claims

1. In order to reduce cavity resonance noise generated as interior noise due to the force generated between the tire tread and the road surface during driving being transmitted to the tire internal (cavity) space and the axle, a polyurethane foam sound-absorbing lining is formed by simply, quickly, and precisely spraying a liquid foam composition on the inner surface of the tire corresponding to the tire tread and curing the composition, wherein the polyurethane foam sound-absorbing lining composition comprises 3 to 40 wt% of polyol 1 (glycerol, OH value = 10-30 mgKOH / g), 40 to 70 wt% of polyol 2 (glycerol, OH value = 31 to 40 mgKOH / g), 10 to 40 wt% of polyol 3 (glycerol, OH value = 41 to 50 mgKOH / g), and 10 to 40 wt% of polyol 4 (glycerol, OH value = A polyol premix composition comprising 5 to 30 wt% of a chain extender 1 (diethanolamine, OH value = 1,500-2,500 mgKOH / g), 1 to 10 wt% of a chain extender 1 (diethanolamine, OH value = 1,500-2,500 mgKOH / g), 0.1 to 1 wt% of a chain extender 2 (1,4-butanediol, OH value = 500-1,500 mgKOH / g), 0.1 to 5 wt% of a crosslinking agent, 1 to 5 wt% of a blowing agent (water), 0.1 to 3 wt% of a urethane curing reaction catalyst, 0.1 to 1 wt% of a blowing catalyst, and 0.1 to 3 wt% of a foaming agent, wherein, based on 100 parts by weight of the polyol premix composition, 4 to 70 wt% of a monomeric MDI (MMDI), 4 to 70 wt% of a carbodiimide-containing MDI (CMDI), and 100 parts by weight of the monomeric MDI (MMDI) are included, and the monomeric MDI is included. A tire inner polyurethane foam sound-absorbing lining composition characterized by comprising 50 to 60 parts by weight of a mixed MDI (methylene diphenyl diisocyanate) curing agent composition comprising 10 to 80 wt% of (PMDI) 2. In paragraph 1, A tire inner polyurethane foam sound-absorbing lining composition characterized in that the cross-linking agent is triethanolamine (OH value = 1,500-2,500 mgKOH / g).

3. In paragraph 1, The above urethane curing reaction catalyst is a tire inner polyurethane foam sound-absorbing lining composition characterized by mixing 33 wt% of triethylene diamine and 66 wt% of dipropylene glycol.

4. In paragraph 1, A tire inner polyurethane foam sound-absorbing lining composition characterized in that the above-mentioned foaming catalyst is diethyl toluene diamine (DETDA).

5. In paragraph 1, A tire inner polyurethane foam sound-absorbing lining composition characterized in that the above-mentioned foaming agent is polyether modified polysiloxane.

6. Polyol 1 (glycerol, OH value = 10-30 mgKOH / g) 3~40 wt%, polyol 2 (glycerol, OH value = 31~40 mgKOH / g) 40~70 wt%, polyol 3 (glycerol, OH value = 41~50 mgKOH / g) 10~40 wt%, polyol 4 (glycerol, OH value = 51~60 mgKOH / g) 5~30 wt%, chain extender 1 (diethanolamine, OH value = 1,500-2,500 mgKOH / g) 1~10 wt%, chain extender 2 (1,4-butanediol, OH value = 500-1,500 mgKOH / g) 0.1~1 wt%, crosslinker A step for preparing a polyol premix composition comprising 0.1 to 5 wt% of a polyurethane curing reaction catalyst, 1 to 5 wt% of a blowing agent (water), 0.1 to 3 wt% of a urethane curing reaction catalyst, 0.1 to 1 wt% of a foaming catalyst, and 0.1 to 3 wt% of a foaming agent; A step for preparing a mixed MDI (methylene diphenyl diisocyanate) curing agent composition comprising 4 to 70 wt% of a monomeric MDI (MMDI), 5 to 70 wt% of a carbodiimide-containing MDI (CMDI), and 10 to 80 wt% of a polymeric MDI (PMDI); A step for introducing 50 to 60 parts by weight of the curing agent composition relative to 100 parts by weight of the polyol premix composition into a foaming mixer chamber and mixing the mixture to produce a tire interior polyurethane foam sound-absorbing lining composition as a foaming solution; A method for forming an internal tire polyurethane foam sound-absorbing lining using a tire internal polyurethane foam sound-absorbing lining composition according to any one of claims 1 to 5, comprising the step of forming a polyurethane foam sound-absorbing lining by spraying the tire internal polyurethane foam sound-absorbing lining composition in a liquid foam form on the inner surface of the tire corresponding to the tire tread and curing the same; 7. In paragraph 6, The tire inner surface liquid foam spray is sprayed at a constant discharge amount for a constant time according to the speed of one rotation on the inner surface of the tire by a foam spray nozzle spaced a constant distance from the inner surface of the tire, and a tire inner surface polyurethane foam sound-absorbing lining method using a tire inner surface polyurethane foam sound-absorbing lining composition.

8. In paragraph 7, The above tire inner surface liquid foam spray is a tire inner surface liquid foam spray, and the starting and ending points of the liquid foam spray are marked on the tire inner surface with a laser pointer so that the polyurethane foam sound-absorbing lining does not overlap or separate at the starting and ending points, using a tire inner surface polyurethane foam sound-absorbing lining composition.

9. In paragraph 6, A method for producing a tire interior polyurethane foam sound-absorbing lining using a tire interior polyurethane foam sound-absorbing lining composition, comprising a step of forming pores in a cured film formed on the surface of a polyurethane foam sound-absorbing lining formed by spraying liquid foam on the inner surface of the tire and curing the same, by punching with a needle brush or punching with a logo design using a logo-designed needle brush.

10. A low-noise tire having a polyurethane foam sound-absorbing lining lined with a tire inner polyurethane foam sound-absorbing lining composition according to any one of clauses 1 to 5.

11. A low-noise tire manufactured by a tire inner polyurethane foam sound-absorbing lining method according to any one of clauses 6 to 9.

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