KR100872542B1 - A high cell elastic body and manufacturing method thereof - Google Patents

Abstract

A high cell elastomer, and a method for preparing the high cell elastomer are provided to reduce volume change and abrasion by improving recovering force even though excellent impact absorption and the extreme compression, to decrease operation noise and to enhance the overall durability of the constitution line. A high cell elastomer comprises 100 parts by weight of a polyester polyol and polyether polyol; 20~40 parts by weight of 1,5-diisocyanate-naphthalene; 1.0~3.0 parts by weight of a crosslinking agent; 0.01~0.05 parts by weight of N,N-dimethylcyclohexylamine; 0.1~0.5 parts by weight of an amine salt containing an alkylbenzene sulfonate or a fatty acid polyglycol ester; 0.001~0.03 parts by weight of a retarder; 0.1~3.0 parts by weight of an anti-hydrolysis agent; and 1.0~10 parts by weight of a lubricant.

Description

High-Cell Elastomer and Its Manufacturing Method {A HIGH CELL ELASTIC BODY AND MANUFACTURING METHOD THEREOF}

The present invention relates to a high-cell elastic body and a method for manufacturing the same, and in particular, provides a stable gap in the hydraulic breaker chisel with extremely low strain rate and excellent wear resistance, thereby improving accuracy in the selection of the hitting portion and reducing the impact vibration applied to the chisel through the piston. It relates to a high-cell elastic body that absorbs noise and improves the durability of the chisel and its components, as well as its manufacturing method.

Impregnating a suitable amount of lubricant inside the processed open cell on the skin of high-cell elastomer products that come into contact with sliding parts of various mechanical devices to improve the durability of moving part accessories, prevent oil leakage from inside, and introduce foreign substances from outside. An elastic body is used for the purpose of preventing this. Hereinafter, a bushing applied to a hydraulic breaker as an example of an elastic body will be described.

Hydraulic breakers used for crushing large concrete structures and natural stones at construction sites and civil engineering sites include rod-shaped pistons that move in the longitudinal direction by the hydraulic pressure provided by the hydraulic pump, and press the crushing targets with the tips thereof. The rear end portion is hit in the longitudinal direction by the piston in a state to have a chisel that breaks the object.

As shown in FIG. 1, a conventional hydraulic breaker 1 includes a valve unit (not shown) that receives hydraulic oil supplied through an external hydraulic pump and has a plurality of oil passages formed therein, and the valve unit. An accumulator (not shown) installed at an upper portion of the valve unit to store pressure by partially receiving hydraulic oil passing through the valve unit, and a cylindrical cylinder positioned at a lower portion of the valve unit and having a piston 11 therein. And a front head 14 in the form of a square pillar, which is installed at the lower part of the cylinder 12 and accommodates the lower end of the cylinder 12 and partially accommodates the chisel 13 therein.

The chisel 13 is a steel member extending below the front head 14 with the upper side supported by the chisel pin inside the front head 14.

While the chisel 13 moves up and down, it is equipped with a chisel bush that prevents external foreign matter from entering the inside of the operating unit and mitigates the noise caused by the vibration of the chisel 13.

The chisel bushing is mounted on the contact surface of the chisel 13 and the front head 14. The chisel bushing 15 supports the upper end of the chisel 13, and the chisel 13 is mounted on the lower end of the front head 14. It consists of a lower chisel bushing (16) to support the middle portion of the) to prevent foreign matter from flowing in from the outside.

However, the conventional chisel bushings 15 and 16 are made of a simple P / U, general industrial resin, steel, or the like, and the bushings 15 and 16 and the chisel 130 and the front head 14 are made of materials. Abrasion gap due to driving friction is generated between the two and the gap has difficulty in precise positioning as the chisel 13 is shaken.

Since the chisel 13 and the front head 14 are inserted in the space between the chisel 13 and the front head 14, the wear of the chisel bushings 15 and 16 occurs due to the friction generated while the chisel 13 reciprocates. Since a space is generated between the front heads 14, oil leakage from the inside and foreign substances are introduced to the outside, which hinders the smooth hydraulic circuit flow and causes severe wear and noise of the parts.

The present invention has been made to solve the above problems, and excellent shock absorption and resilience even in the extreme compression, the volume change and wear is less, so that the shake of the hydraulic breaker chisel can be prevented, the impact position can be precisely adjusted, open cell and closed The structure of the cell provides a high-cell elastic body and its manufacturing method that can absorb the vibration caused by the shock applied to the chisel through the piston and improve the overall operation durability of the device by absorbing the vibration caused by the piston. There is a purpose.

The high-cell elastomer according to the present invention for achieving the above object, 1.5-diisocyanate-naphthalene based on 100 parts by weight of polyester polyol and polyether polyol (1.5-diisocyanate-naphthalene) 20 to 40 parts by weight, crosslinking agent 1.0 to 3.0, NN-dimethylcyclohexylamine 0.01 to 0.05 parts by weight, amine salts such as alkylbenzene sulphonate or fatty acid polyglycol ester 0.1 to 0.5 parts by weight, retardant 0.001 to 0.03 parts by weight, 0.1 to 3.0 parts by weight of the hydrolysis agent, 1.0 to 10 parts by weight of the lubricant is mixed and characterized in that the foam molding process.

According to the high-cell elastic body and the manufacturing method of the present invention, since the volume change and the wear are small, the shake of the chisel of the hydraulic breaker is prevented, and the striking position can be adjusted accurately.

In addition, by absorbing the vibration caused by the shock applied to the chisel through the piston, the operation noise of the device can be reduced, and since dust does not penetrate into the inside of the device, dust malfunction, friction, and wear can be reduced. There is.

The high cell elastomer according to the present invention comprises a polyester polyol and a polyether polyol (hereinafter referred to as 'polyol'), an isocyanate, a crosslinking agent, a catalyst, a hydrolysis agent, and a lubricant. It is done.

1.Polyol is a mixture of adipic acid and ethylene glycol, adipic acid and butane diol-1.4 / ethane diol glycol mixture, adipic acid (Adipic acid) and hexane diol (hexane diol) -1.6 / neopentyl glycol (neopentyl glycol) of any one is selected and used, each characteristic is as follows.

end. Mixture of Adipic Acid and Ethylene Glycol

Average molecular weight: 1000 ~ 5000

Appearance: Wax, liquid, flake

Specific gravity: 20 ℃ * 1.27 g / cm 3 ± 30%

                     : 100 ° C * 1.14 g / cm 3 ± 30%

       OH: 20 ~ 90 mg KOH / g

       Acid value: up to 1.0

Viscosity: 100 ~ 1000 mPas (75 ℃)

Moisture: about 0.3%

I. Adipic acid and butane diol-1.4 / ethane diol glycol mixtures

Average molecular weight: 1000 ~ 5000

Appearance: Wax, Liquid, Flakes

Specific gravity: 20 ℃ * 1.20 g / cmcm 3 ± 30%

: 100 ° C * 1.09 g / cm 3 ± 30%

OH: 20 ~ 90 mg KOH / g

Acid value: up to 1,0

Viscosity: 100 ~ 1000 mPas (75 ℃)

Moisture: about 0.1%

All. Adipic acid and hexane diol-1.6 / neopentyl glycol

Average molecular weight: 1000 ~ 5000

Appearance: Wax, Liquid, Flakes

Specific gravity: 75 ℃ * 1.04 g / cm 3 ± 30%

OH: 20 ~ 90 mg KOH / g

Acid value: up to 1,0

Viscosity: 100 ~ 1000 mPas (75 ℃)

Moisture: about 0.1%

2. The characteristics of isocyanate are as follows.

Chemical Composition: 1.5-diisocyanate-naphthalene

NCO content: 20 ~ 50%

Molecular Weight: 190 ~ 220

Specific gravity: 20 ℃ * 1.30 ~ 1.50 g / cm 3

: 130 ℃ * 1.10 ~ 1.30 g / cm 3

Effective content (purity): 90% or more

Condensation Point: 125 ℃ ~ 130 ℃

Total chlorine: up to 0.2%

Hydrolysable chlorine: up to 0.05%

Flash point: 180 ℃ ~ 210 ℃

Flash Point: 600 ℃ ~ 700 ℃

Average Specific Heat: 20 ℃ ~ 60 ℃ (Solid) 1.0 ~ 1.3 J / g.k

                  60 ° C to 120 ° C (solid) 1.2 to 1.5 J / g.k

                 140 ℃ ~ 150 ℃ (liquid) 2.0 ~ 2.3 J / g.k

In the production of the present invention, a prepolymer, which is a high molecular weight network-structured compound produced by polymerization between a polyol compound having at least two —OH groups and an isocyanate having a polyfunctional group, is used.

This can improve the storage stability problems such as viscosity increase caused by the high reactivity of the isocyanate because it can be properly controlled production of the final product requirements at a relatively low vapor pressure. Experience has shown that content combinations other than 20 to 40 parts by weight fall short of the basic physical properties of the final product.

3. Crosslinking agents

The crosslinking agent provides mechanical strength and chemical stability, such as hardness and elasticity, to the final mixture between polyol and isocyanate. 1.0 to 3.0 parts by weight is mixed with respect to 100 parts by weight of polyol, but less than 1.0 part by weight or 3.0 parts by weight or more. Mixing does not improve basic physical properties.

4. Catalyst.

end. N.N-dimethylcyclohexylamine is mixed with 0.01 to 0.05 parts by weight based on 100 parts by weight of polyol, and is used as a standard accelerator for controlling the activity of the reaction rate.

I. Emulsifier

It is used to extend the foaming reaction and 0.1 to 0.5 parts by weight of amine salts such as alkylbenzene sulphonate or fatty acid polyglycol ester are mixed with 100 parts by weight of polyol. Control of the amount of use takes precedence over the volume of the product and the volume of the product.

All. Retardant: For example, 2-Hydroxy-1,2,3-propanetricarboxylic acid is used, and as a stabilizer of the prepolymer, it is aimed at smooth process progress by expanding water stability, lowering viscosity and increasing pot life. It can be used as a mixture with 1 mol of crystallized water and should have a purity of at least 99% and mix 0.001 parts by weight to 0.03 parts by weight with respect to 100 parts by weight of polyol.

5. Antihydrolysis agent

When the final product comes into contact with hot water, saturated steam, acid, alkali, etc., 0.1 to 3.0 parts by weight of 100 parts by weight of polyol is mixed for the purpose of preventing the physical properties of the chain linkage from being gradually broken.

Chemical structure: Polysubstituted diaryl carbodiimide (N = C = N) content min. 10%

Density: 20 ℃ * 0.97g / cm 3 ± 30%

                   : 50 ° C * 0.94g / cm 3 ± 30%

Melting Point: Room Temperature ~ 70 ℃

Viscosity: 50 ℃ * 20 ~ 100 cps

Solubility: Soluble in organic solvents such as acetone, benzene, methylene chloride, carbon tetrachloride, insoluble in water.

6. Lubricant: Used for the purpose of facilitating cleaning of prepolymer handling container and molding machine piping line. Vegetable oil is mixed with 1.0 ~ 10 parts by weight based on 100 parts by weight of polyol.

The manufacturing method of the high cell elastic body by this invention is demonstrated with reference to FIG.

(S10) Polyol Preparation.

Preheat; Completely melt the entire polyol package in an oven where hot air circulates between 60 and 110 ° C.

dehydration; It is a process to remove the water contained in polyol and requires condition within 0.01 ~ 0.05% of water content. It takes about 2 ~ 5 hours depending on the amount of contents and the shape of the container, and the proper vacuum pressure is at least 40mm bar. Consider using a thin film evaporator to save time when a large amount of polyol is needed. Heat and stir the polyol's temperature to 120 ~ 150 ℃ in the dehydration vessel and remove the moisture by vacuum pump.

100~120℃ 중합기내에서 30분간 진공 교반 다시 한번 150℃까지 가열한 뒤 적정 시발 온도(Starting temperature)에서 이소시아네이트(Isocyanate)를 혼합 교반한 뒤 프리폴리머(Prepolymer)가 우유빛처럼 맑고 투명하지 못하면 폴리올 내 과다한 수분의 영향으로 간주하고 탈수 공정의 점검과 Karl Fisher방법에 의한 정밀 분석을 시행한다.The time required for heating / dehydration depends on the structure of the dehydration vessel and the amount of polyol. However, the recommended dehydration time of 10 Kg of polyol is about 2 hours and 90 Kg takes about 4 hours. Clean the inside of the dehydration container by boiling it with distilled water or drinking water in about 2 ~ 3 weeks, regardless of the frequency of use. If in doubt, first heat 500g of polyol to about 150 ℃

30 minutes vacuum stirring in 100 ~ 120 ℃ polymerizer Heat up to 150 ℃ once more, and mix and stir the isocyanate at the proper starting temperature. If the prepolymer is not milky and transparent, consider the effect of excess moisture in the polyol and check the dehydration process. And precise analysis by Karl Fisher method.

(S20) Prepolymer Polymerization

The prepolymer is a sticky syrup-like reactant with isocyanate that forms chemically reactive NCO groups at the end and is ready to react with the crosslinking agent with polyester isocyanate with isocyanate groups at the end of the reaction.

The polymerization process is mixed with a retardant (2-Hyrroxy-1,2,3-Propanetricarboxylic Acid) and a lubricant (Lubricant) adjusted according to the amount of raw materials, and the isocyanate is added after setting the starting temperature (125 ~ 150 ℃) When the temperature rises due to exothermic reaction, the maximum temperature is based on 125 ℃ ~ 130 ℃ regardless of the amount of raw materials. The purpose of this temperature control is that the isocyanate does not melt at 117 ° C or lower and the side reaction occurs due to the rapid rise in viscosity at 130 ° C or higher. Since the air contained during the process acts as a nucleus for forming the foam structure, it is not necessary to remove bubbles using a vacuum device.

(S30) Hydrolyzate mixture.

5시간 내 사용을 기본으로 한다. 만약 폴리올에 혼합하면 발생되는 기포들에 의해 거품(foam)이 형성될 수도 있으므로 주의를 요한다.A propeller-type stirrer is used to allow complete mixing in one to three minutes and may be added at the end of the polymerization process. At this time, since the viscosity of the prepolymer rises sharply,

Based on use within 5 hours. Care should be taken as bubbles may form due to the bubbles generated when mixed with the polyol.

(S40) cooling.

It is forced to cool within 30 minutes below the mixing temperature of the crosslinking agent at 100 ° C. and is cooled by using a propeller-type stirrer or by circulating the cooling water in a prepolymer vessel.

(S50) Crosslinking agent mixture.

The crosslinking agent may be mixed with the prepolymer, and the mixture may be placed in a closed stirred mixing container and stored for about 10 hours at a temperature of less than 70 ° C.

(S60) primary aging.

(S50) Molding the mixture (prepolymer and crosslinking agent) to the mold to proceed with product molding and primary aging, the mixture is heated in the mold (heated to 70 ~ 100 ℃ and the release agent is treated) time that can be separated after separation ( 20 to 120 minutes) to stay in the mold for the first aging. At this time, if the mold temperature is low, the surface of the product becomes thick, and if it is high, a rough and thin surface is formed, but it is not related to the density inside.

(S70) secondary aging.

After the first matured product is separated from the mold and then aged for 8 to 24 hours at 100 ~ 130 ℃ temperature.

(S80) room temperature aging.

The second aged product is aged at a temperature of 10 ~ 50 ℃ for 1 to 10 days to complete the product.

(S90) lubrication.

By lubricating the product processed in the closed cell epidermis in the open cell form by lubricating oil in about 10 minutes, the friction coefficient with the chisel can be lowered, resulting in improved durability.

The density range of the high-cell elastomer produced by this method is about 100 ~ 700Kg / ㎥, which is manufactured at the ideal ratio between the open and closed cells (preferably 80 ~ 90: 20 ~ 10), resulting in very low Young's modulus. It features high quality properties such as high mechanical strength, excellent dynamic stability and low permanent strain compared to general urethane foam.

In addition, the shock absorbency can be adjusted according to the specific gravity and the design of the product, and the load resistance and shock absorbency can be reduced to 60% of the original size when applied for spring applications because the greater the specific gravity. In addition, it is an excellent material that can solve the problems caused by vibration due to its excellent load resistance and less damping effect. In the fatigue test results, the deformation rate of 20% to 40% in the 2H _Z 10 ⁶ test is less than 5%, and it is not comparable with other elastomers that destroy the material itself under the same conditions.The impact is 150Kg / Even in m3, it absorbs shock without damage. In addition, it is excellent in compression resistance, wear resistance, elasticity, tensile strength, oil resistance, ozone resistance, and the like.

<Mixing example>

division Polyol Retardant slush Isocyanate Hydrolysis agent Crosslinking agent catalyst Amine salt Weight ratio 100 0.015 5 30 1.5 1.5 0.3 0.3

The compounding ratio is based on polyol, and the catalyst is a mixture of 0.05 N.N-dimethylcyclohexylamine and 0.25 emulsifier. Amine salts are fatty acid polyglycol esters.

The high-cell elastic body produced by this method has a density range of about 100-700Kg / m 3, which is manufactured at an ideal ratio between the open and closed cells (preferably 80-90: 20-10) and is very low. The modulus is characterized by high quality properties such as high mechanical strength, excellent dynamic stability and low permanent strain compared to ordinary urethane foams.

In addition, the shock absorbency can be adjusted according to the specific gravity and the design of the product, and the load resistance and shock absorbency can be reduced to 60% of the original size when applied for spring applications because the greater the specific gravity. In addition, it is an excellent material that can solve the problems caused by vibration due to its excellent load resistance and less damping effect. In a variation of the fatigue test to 20% ~ 40% 2H _Z The permanent compression reduction rate is less than 5% in 10 ⁶ tests. It is not comparable to other elastomers that destroy the material itself under the same conditions, and absorbs shocks without damage even when the impact is 150Kg / ㎥. In addition, it is excellent in compression resistance, wear resistance, elasticity, tensile strength, oil resistance, ozone resistance, and the like. In fact, as shown in FIG. 3 to FIG. 7, the results show excellent results in tensile strength by density, tear strength by density, elongation by density, compression strength by density, and permanent compression reduction by density. Of course, the graph is not compared with the existing elastomer, but the results of the above items will be confirmed through this graph.

1 is a block diagram of a hydraulic breaker.

2 is a manufacturing process diagram of the high cell elastic body according to the present invention.

3 to 7 is a graph showing the characteristics of the high-cell elastic body according to the present invention.

Claims (6)

20 to 40 parts by weight of 1.5-diisocyanate-naphthalene, crosslinking agent 1.0 to 3.0, NN-dimethylcyclohexylamine (100 parts by weight of polyester polyol and polyether polyol) NN-dimethylcyclohexylamine) 0.01 to 0.05 parts by weight, 0.1 to 0.5 parts by weight of amine salt containing alkylbenzene sulphonate or fatty acid polyglycol ester, 0.001 to 0.03 parts by weight of delaying agent, 0.1 hydrolysis agent -3.0 parts by weight, 1.0-10 parts by weight of a lubricant is mixed, characterized in that the high-cell elastic body. delete delete Preparing a polyol by dehydrating the polyol at 60 to 110 ° C .; Polymerizing the prepolymer by mixing 1.5-diisocyanate naphthalene in a state in which the retarder and the lubricant are mixed with the polyol at 125 to 150 ° C .; Cooling the prepolymer mixed with the hydrolysis agent to 100 ° C. or less; Mixing a crosslinker with the cooled prepolymer; And injecting the prepolymer mixed with the crosslinking agent into a mold for aging. The method according to claim 4, wherein the aging step, Injecting the prepolymer mixed with the crosslinking agent into a mold for aging; Separating the first matured product from the mold and staying at 100 to 30 ° C. for 8 to 4 hours; And, A method for producing a high cell elastic body comprising the step of aging the product for 1 to 10 days at a temperature of 10 ~ 50 ℃. The method of claim 5, further comprising impregnating the aged bushing through the aging step in lubricating oil to increase the lubrication of the chisel and reduce the coefficient of friction.

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