CA1275564C - Mat consisting of filament loop aggregations, and method and apparatus for producing the same - Google Patents

Abstract

Abstract of the Disclosure In this mat consisting of filament loop aggregations, the filament loop aggregations wherein irregular form loops are formed in the upright direction by respectively winding to be coil-like many filaments coarse in the arranging intervals and made of a thermo-plastic synthetic resin and are fused in the intersect-ing parts are overlapped above and below an intermediate filament loop aggregation layer high in the filament density and formed of coiled loops in the partly or all laterally fallen direction.

Description

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5P~CIFICAlION

~itle of the Invention:
MAT CONSISTING OF FI~AMENT ~OOP AGGREGA~IONS
AND M~THOD AND APPARATUS ~OR PRODUCING ~HE
SAME

Background of the Invention:
This invention relates to a coarse net-like developed resilient mat made by complicatedly entangling synthetic resin monofilaments and more particularly to a mat consisting of filament loop àggregations and adapted to a porch mat o~ fixed dimensions or a floox mat formed and laid in a long sheet and a method and apparatus for producing the ~ame.
Ins~ead of a conventional carpet mat or synthetic resin mat, there is recently proYided a three-dimensional net-like mat consisting of synthetic resin monofilaments high in the water permeability and quick dryability. Due to such characteristics as the resili-ency and weather-prsofness, such three-dimensional net-like mat is uRed in many indoor and outdoor fields;
is applied particularly to such water using place as, for example, an inlet and outlet of a bath room or a pool side and is appreciated because it is simple ( 1 ) - :

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to wash and dry.
Also, as this kind of three-dimensional mat is open, the ~and and gravels brought when it i8 trod will drop down and will not remain on the surface.
As water or the like also will drop down, the surface can be always kept dry. It is thus convenient.
In addition, when such elastic sheet as a synthetic resin sheet, foaming sheet or rubber sheet i8 pasted to the lower surface of such mat, the cushion-ing property as of a mat will be able to be increased, the sand and water dropping ~rom the surface will be able to be r~ceived by this sheet pasted to the lower surface and the M oor will be able to be prevented from being made dirty directly by the dropping sand and the like.
Description of the ~rior Art:
As disclosed in the gazette of a Japanese patent publication No.14347/1972, such three-dimensional net-like mat is formed a~ a non-woven fabric wherein many monofilaments made of a thermoplastic synthetic resin are laminated while being rubbed and bend, are fused at their contact points and are cooled to be solidified.
- The formation of upright loops disclosed in the gazette of a Japanese patent publication No.31222/

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1980 and a Japanese patent laid open No.85061/1987 is known as a web forming mean~ of the above mentioned filaments in such non-woven fabric.
Now9 in the non woYen fabric formation by the above described conventional means, in ~uch rubbed and bent web formation, the re~iliency of the indivi-dual rubber and bent filament form part it~elf i9 low, the rubbed and bent filaments by this producing means overlap on each other to fall down and, as a result, as the entangled density of the filaments becomes higher, the resiliency of the sheet will be 109t.
Thus, when the mat i~ used, the treading touch will be obstructed and, when the mat is stored or carried, it will be difficult to wind in the ~heet-like mat, much to the inconvenience.
On the other hand, when the web formation is made loop-like, the resiliency of the filament itself in each loop-like part will be developed but, in the web made of arcuate loop~ arranged in a ~ubstantially fixed form, the respective loops are only fused at their inter~ecting points and the contact points between the adjacent loops, are high in the independency and are therefore low in the re~iliency against treading and, as a re~ult, no favorable treading tocu will be o~tained.

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Summar,y of the Invention:
~ herefore, the pre~ent invention has it a~
an object to provide a mat wherein a filament web i~
formed of positively closed loops to develop a filamen-t resiliency in each loop part and the degree of the contact fusing between the respective loop~ is made high to be able to develop a strong sheet resiliency and a method and apparatus for producing the same~
Description of the Drawing~:
The many advantages and features of the present invention can be best understood and appreciated by reference to the accompanying drawings wherein:
~ ig, 1 is a side view of an essential part showing an embodiment of the apparatus of the present invention; and Fig. 2 is a side view showing an example of the mat of the present invention.
Detailed Description of the Invention:
In order to attain such object) according to the present invention, a mat consists of upright disarranged loop-like synthetic resin filament -three-dimensional aggregations and has many spaces within it to develop a cushioning property.
~ here i~ suggested a mat o~ a multilayer structure wherein are overlapped aggregations each ( 4 ) : ' :. . .

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each having coiled loops formed in the upright direc-tion on both front and back sides by intermediately holding a high filament density aggregation layer of coiled loops overlapped in the laterally fallen dlrec-tion.
In order to form such mat, several hot fila-ments of a thermoplastic ~ynthetic resin are pressed and extruded through T-die orifices and are made to fall toward a water surface~
~ pair of guide rollers are set as opposed to each other below a water surface and a bundle of the above mentioned filaments is lowered so as to drop between these rollers.
The falling hot filaments are heated by such heat sources as ceramic far infrared ray heaters so as not to be cooled by the atmosphere.
Such hot filaments are easy to make coiled loops on the water surface, Unless the filament~ are hot, the loops will become large, Further, in the filaments of a reduced temperature, no coiled loop will be formed but only a channeled rubbed and bent form will be able to be made.
The height from the die mouth end to the water surface is 5 to 100 cm. and the heat reduction of the filaments is prevented by making -the die mouth '~, ' . ' ' " , ~ 2'~$~4 .

end approach the water surface as much as possible.
The orifice diameter of the T-die i9 O. 3 to 1.5 mm. a~ an element determining the filament diameter, retains the resiliency and durability of the fQrmed filaments and prevent~ the permanent set.
A mat sheet consisting of filament aggrega-tions of respective widths can be made by arranging the numbers of orlfices corresponding to the widths of 90, 120 and 150 cm. of intended mat sheets with an orifice arrangement of a T-die of 3 to6 longitudinal rows at the interval~ of 3 to5 mm, and a pi-tch of 3to 5 mm. in the lateral row.
That is to say, a hot filament bundle extruded out of the l-die of ~uch orifice arrangement is made -to fall upright toward cooling water and is received by submerged rolls of a rotary peripheral speed well ~lower than the falling speed to limit the falling speed in water and to give the filament~ a resistance toward the water surface from the above mentioned rolls.
~oops having a perlpheral length of a filament length corresponding to the difference between the extruding speed of the re~pective filaments and the falling speed in water will be sequentially continuously formed to be coil-like on the water surface by thi~ re~istance, At this time, in order to make it easy to form ( 6 ) : , - - . . .
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loops and to make bent irregular loops~ it i~ effective to keep boiling the cooling water surface between the inclined panels.
This boiling ~tate vibrates the respective filaments wound on the water surface. Aq a result, entangled disarranged coiled loop~ are induced on the water sruface.
In order to make the boiling state on the water surface between the inclined guide panels, it i9 important to keep the filaments coming out of the T-die at a high temp~rature until the liquid level.
Generally, when the filament~ are in contact with the atmosphere, the filament temperature will quickly reduce.
The water ~urface heated by the falling in water of the filament bundle kept at a filament extruding molding temperature of 200 to 150C. by the above mentioned heating treatment to prevent air cooling in the filament~
coming out of the T-die will be in the boiling state.
lherefore, when the cooling water ifl kept at a high temperature of ~0 to 80C~, this boiling will be made positive.
When the filaments are molded to be coiled loops while kept at a high temperature, the fusing between the loops will be acceleratedO Further, when the cooling water is at a high temperature, in case the molded loops are pulled out into the atmosphere by the guide rolls and ( 7 ) . . .

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are sent to the secondary process, they will be able to be easily dried with cool or hot air.
A filament -loop aggregation in which the coil den~ity i9 made coar~e by increasing the rotation (pulling speed in water) of the roll~ in water and is made high by reducing the pulling speed i~ formed.
On the other hand 9 even if the thickness width of the hanging filament bundle i~ ~ot regulated, a three-dimensional formation of a coiled loop will be able to be made However, the size of the loop formed on the liquid surface is not fixed. Therefore, a means of regulating the thickness width of the filament bundle functions effectively to make uniform coiled loop aggregati~ns of an in~tended thickness.
As the pair of guide rollers are just below the water surface and regulate the positions of the filaments having sunk while describing loops, the thickness width of the filament bundle in the water surface position just above them will be regulated a~
related with the regulation below the water surface.
Such filament loop aggregations are made in two parallel place~ and the other aggregation is formed along one~ide surface of one aggregation.
In such formation, when the above mentioned one aggregation is heated on the side surface to be ( 8 ) 'I

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about -the fusing temperature~ the filaments of the side surface will soften and will form an aggregation layer high in the filament density by the laterall fall of loops.
In molding synthetic resin~, the general temperature as of the cooling bath is a~out 50C. for PE (polyethylene) and PP (polypropylene), about 10 to 40C. for PVC (polyvinyl chloride) and about 85C. for PS (polystyrene).
~ he surface tension of water on Pva (poly-vinyl chloride) is so high as to be about 60 to 70 dym~/cm. that fine filaments of an outside diameter less than 1 mm. will be overlapped in turn above the water surface, the coiled loops formed here will be laminated in several step~ and will be cooled in water and therefore the object aggregations coarse in the loop clearances will not be obtained. Therefore) in order to sequentially sin~ the coiled loop~ on the surface, it i~ effective to add a surface active agent reducing the surface ten~ion of the cooling bath.
Embodiments:
-Fig. 1 is a side view showing component parts -in an optimum apparatus for embodying the present invention. Respectively two filament~ 2a and 2b are to lower vertically toward cooling water 5 while being ( 9 ) . . ~ . . .

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molded in the thickness direction (longitudinal direc-tion) in separate positions from a T-die 1 extruding a thermoplastic synthetic resin material under pressure.
In the lateral direction (front to back direction on the paper surface) of the ~-die in this case, many ~ilaments 2a and 2b are to be molded as arranged at predetermined lntervals ~pitch of 3 to 5 mm.) in a length range corresponding to the lateral width of an intended molding.
In the falling zone of these filaments 2a and 2b, bar-like ceramic far infrared ray heaters 3a and 3b are arranged on both sides of the respective filament bundles so as to be heating heat sources.
In the filament 2a falling zone, just below the water surface, a pair of guide rollers 4a and 4b are arranged at a predetermined spacing so that the bundle of the above mentioned filament~ 2a may fall on the water surface in this clearance and may be led by these rollers 4a and 4b to sink.
Also, a feeding roller 6 rotated and driven at a constant speed is arranged in watex so that the bundle of the filaments 2a having sunk in the above mentioned water may be moved in the cooling water 5 as held between it and the above mentioned guide roller 4b. As many engaging pins 8 are erected at intervals ( 10 ) .. . ~ .
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on the yerlpheral surface of this roller 6 in w~ter and the rotary peripheral speed of the roller 6 rotating at a constant speed i~ set at a speed lower than the falling speed Df the filaments 2a, the filaments 2a falling from the ~-die 1 at a high speed will be dece-lerated in sinking in water by the above mentioned roller 6 in the water and will be, as a result, relaxed by the filament length corresponding to the difference between these falling speed and sinking speed. r~he~e relaxations will concentrate in the water surface zone due to the buoyancy of the filaments 2 of a small speci-fic gravity. As a result, the filament~ 2a will form loop~ on the water surface.
That is to say, the filaments 2a extruded out of the l-die will reach the water surface of the cooling water 5 while being kept near the temperature at the time of molding by heating by the above mentioned hea-ters 3a in the falling zone in air. The fil~ments 2a having sunk in th~ cooling water 5 will qulckly lower in the temperature and will be hardened. However, these hardened filaments 2a will be regulated in-the pulling amounts by the submerged rollers 6 stopped in sliding by the engaging pins 8, therefore the hardene~ part~ in water will be subjected to resistances from the submerged roller 6 and thereby the soft filaments 2a still at a ( 11 ) .'' ' ` ' - , , ' . ' ~.
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high temperature just before reaching the water surface will be curved and will be gradually pulled into water while describing loops to form coil-like loops.
When the temperature within the bath of this cooling water 5 is kept at 60 to 80~., the cooling water 5 in the falling position will be locally boiled by heating by the filaments 2a reaching the water surface while at a high temperature. By thi~ boiling, the water surface of that part will be waved and greatly rocked and therefore the filament~ 2 describing loops on this water surface will be waved and disarranged in response to the rocking of the water surface.
Therefore, the di~turbed form loops will be prevented by the concavo-convexes by the disarrangement from the total surface contact between the adjacent loops overlapped on the water surface and will have comparatively many contact point parts.
In such contact part, the loops will be fused with each other between them and will be cooled to be hardened, Therefore, coiled loops having comparatively many fused parts between the adjacent loops will be continuously formed in turn and a filament loop aggre-gation A in which coiled loops are crosq-linked longitudi-nally and latqrally with the loop edges overlapping between the adjacent filament~ 2 will be foxmed.

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With the above formation as a first filament loop aggregation forming step, the aggregation A moving in the above mentioned cooling wa-ter 5 will be engaged with a guide roller 7b of a pair of guide rollers 7a and 7b arranged just below the water surface in the falling zone of the other filament 2b and will be pulled up so as to be exposed at least on one surface above the water surface.
A ceramic far infrared ray heater 9a i9 arranged in the exposed position of this aggregation A so tha-t -the aggregation A may be dried and heated on the surface to be near the fusing temperature while moving. There-fore, the loops near this heated surface will soften in the filaments and will overlap as laterally fallen to form a filament loop layer C high in the filament density and will be further softened and fused on the surface.
This aggregation A wlll detour the guide roller 7b and will be again pulled into the cooling water 5. Filaments 2b hang down between the above mentioned heated surface and the other gu~de roller 7a in this pulling zone.
~ urther, another submerged roller 10 is arranged in the water sinking zone of the filaments 2b. ~he filament bundle is moved at a low speed while engaged with the engaging pins 8 on the peripheral surface of the rollex 10, As the moving speed of the filament - ~ -~ ' ' -1.;2~S~

bundle in water is made lower than the falling speed of the filaments 2b falling down from the T-die, the same a~ in the above described first filament loop aggregation forming step, an aggregation B in which irregular loops on the water surface are formed to be coil-like will be obtained. 9b represents a heating ceramic far infrared ray heater present in the falling zone of the filaments 2b. 11 represents a reflecting pla-te.
When this aggregation B molding step is made a second filament loop aggregation molding step, in this second step, the aggregation B will be fused and connected on one side with the heated surface of the above mentioned aggregation A
lherefore, the product formed under cooling in water through the above mentioned step is a mat of an overlapped structure of the aggregations A and B
consisting of vertically upright loops holding in the center between them an aggregation layer C of laterally fallen direction loops as shown in Fig. 2 By the w~y, the means of forming the above mentioned aggregation layer C is not limlted to be as in the above illustrated embodiment. ~or example, a separately formed aggregation layer C consisting of laterally fallen loop~ may be bonded to the aggregation ( 14 ) . -.

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A or B formed of loops in the uprlght direction. Eachof the guide rollers 4a, 4b and 9a, 9b may be arranged so as to be exposed on a part of the peripheral sur~ace above the water surface, By the way, in order to pull the coiled loops formed on the cooling water surface into water without di~turbing their form, a surface active agent is added into cooling water 4.
Amounts of addition of the surface active agents per 100 parts of water:
Anionic system: Alkylbenzenesulfonate: I to 0.2 part Dialkylsulfosuccinate: 1 to 0005 "
Noninonic sy~tem: Polyoxyethylene nonylphenol ether:
1 to 0,1 It is effective to add 0.05 to 0.2% dialkyl-sulfosuccinate which i9 high in the capacity of reducing the surface tension and in the connecting effect with a slight amount.
Now, in this kind of apparatu~, in order to keep the cooling bath level constant, cooling water i~
circulated with a pump while being overflowed. In such case, many bubbles will be generated in an auxiliary tank level detecting electrode and cooling bath and will be disadvantageous in molding. In thi~ respect~ at the above mentioned effective component concentratlon of ( 15 ~

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the dialkylsulfosuccinate, many bubbleq tend to be gene-rated. Therefore~ lt can be said to be optimum to add and use preferably 0.05 to 0.?~ dialkylsulfosuc-cinate.
~ he mat material consi~ting of -the thus formed filament loop aggregatlons A and B may be coated with a plastisol made of the same material mixture as of the filament to prevent the bonding 3trength reduction and permanent set of the filament loops, A back sheet B consisting of a resin sheet, foamed sheet or rubber sheet may be used as bonded to the back surface of the mat material in response to the ob~ect of use of the product.
(Formation Example 1) Polyvinyl chloride (PVC) (P-1300) 100 part~
Plasticizer DOP Dioctyl phthalate 50 "
Stabilizer Dibutyl tin laurate 2 "
" Cadmium stearate 0.6 part " Barium stearate 0.4 "
Coloring agent 0.1 "
A compound material of the above mentioned mixture i9 molded to be filaments by an extruding molder.
~ he distance between the guide rollers 4a and ~b below the cooling water surface iq set to be 8 mm.
The distance between the guide roller 4b and submerged ( 16 ) -- : - , ~ ' I , ' ~

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~oller 6 i9 9 mm. The distance between the other guide rollers 7a and 7b is 16 mm. The filament molding orifice diamet~r i~ 0.8 mm. The T-die orifice arrangement is of two longitudinal rows at the intervals of 5 mm.
and a lateral orifice pitch of 5 mm.
The distance between the T-die and cool~ng water surface is 5 cm. The die temperature is 185C.
The-cooling water temperature i9 60 to 80C. Four ceramic far infrared ray heaters of 1,5 KW each are used. At a molding linear speed of 2 m. per minute, loops at a speed of 40 cm~ per minute can be made.
In this formation, by only holding the fila-ment bundle in its thickness width directio~ with the guide rollers, the front and back surfaces of the aggre-gations can be uniformed and the mat shown in Fig. Z
is obtained and i~ made a produc-t through drying and bonding steps.
As the extruder die pres~ure i9 applied and hot filaments are extruded into air, the finished dimension of the filament is 0.2 mm. thicker than the filament orifice of a diameter of 0.8 mm. of the T-die and a filament coil structure of a diameter of 1 mm is made. Even if the distance between the guide rollers 7a and 7b is set to be 16 mm " the aggregation molded under the width regulation by this distance will shrink ( 17 ) - . ~ . . .

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i4 when the filament is hardened and will be therefore 13.S to 14 mm~ thick.
(Effects of the Invention~
Thus, according to the mat of the present invention, as an aggregation i~ formed of irregular form loops by winding filaments to be coil-like, the individual closed loops well develop the filament resi-liency, are of such irregular form as a wavy for~ and are therefore high in the degree of contact fusing between the adjacent continuous coiled loops and between the filament forming loops arranged longitudinally and laterally and thu~ a mat high in -the bonded degree as a whole can be obtained. In the aggregation part in which such loops are formed in the upright direction, in addition to the resiliency of the above mentioned loops themselves, a stiff mat resiliency can be obtained by the strength of the bonded degree between..these loops The aggregation layer high in the filament density is high in the strength, particularly, in the tensile strength, is so high in the clogged degree as to allow sand or water to drop from the upper part of the mat and, on the other hand, to prevent it from springing up from-the lower surface. Therefore, the mat of the present .
invention of doubly overlapped filament loop aggregations with such aggregation layer held between them i8 80 high ( 18 ) ',: . :, - I
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When the diameter of the filament in this case i9 set to be in the range mentioned in claim 2, the prac-tical ~trength of the filament loop can be obtained and, on the other hand, the mat can be ~ade high in the sheet weight convenient to the setting work and in the treading touch.
When the major diameter o~ the loop of an irregular form is adjusted to be in the rage mentioned in claim ~, lt will be effective ln keeping the mat elasticity but, on the other hand, if the major diameter of the loop is too large, a shoe tip or like will catch on and cut the loop and such danger as falling down will he likely to be caused. Thus, it is not preferable.
In the method of forming a mat or sheet consisting of such f~lament loop aggregatlons, the filaments are lowered onto the water surface while near the moldlng temperature and, when this water sur--face is waved by boiling, the loop~ formed on the water -surface will be able to be in such irregular form~ as wavy forms and to be contact-fused in the loop intersecting parts and between the loops.
In addition, there are auxiliary effect that ( 19 ) - ' 1 : "' - ', ' ~' :

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when the filament bundle falling toward the cooling water surface is regulated in the direction of cont-racting from outside the width of the thickness direc-tion of the bundle, the si~es of the respective loops formed of these filaments will be able to be uniformed and, when the contracted width is controlled, -the forma-tion of combining the above de~cribed upright direction loops and laterally fallen loops will be able to be freely made.
If the distance from the T-die to the cooling water surface is long, the filament temperature will be reduced by air cooling between them. ~herefore, it is desirable to set the di~tance to be as short as possible.
However, if they are too adjacent~ the loop formation on the water surface will be di~turbed. Therefore, this distance of 5 to 10 cm. i9 effective.
By keeping the temperature of the cooling water at a comparatively high temperature of 60 to 80C., a local boiling qtate in which the water surface on which the filaments fall is properly waved by heating by the filaments submerging lnto water can be automatically obtained In order to ~moothly sink the filaments to prevent the loop forms from being disturbed, it is effective to add a surface active agent.

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Claims (7)

1. A mat consisting of filament loop aggregations wherein the filament loop aggregations in which irregular form loops are formed in the upright direction by res-pectively winding to be coil-like many filaments coarse in the arranging intervals and made of a thermoplastic synthetic resin and are fused in the intersecting parts are overlapped above and below an intermediate filament loop aggregation layer high in the filament density and formed of coiled loops in the partly or all late-rally fallen direction.

2. A mat consisting of filament loop aggregations according to claim 1 wherein the diameter of said filament is in the range of 0.3 to 1.5 mm.

3. A mat consisting of filament loop aggregations according to claim 1 wherein the major diameter of said loop is in the range of 3 to 15mm.

4. A method of producing a mat consisting of filament loop aggregations characterized in that, between the first filament loop aggregation forming step wherein many filaments arranged at intervals longitudinally and laterally are continuously molded by extruding a thermoplastic synthetic resin out of a T-die, are present on a cooling water surface boiling as kept by heating at a filament temperature close to the temperature at the time of molding while this filament bundle is vertically lowered toward the cooling water surface and are sunk in the vertical direction as controlled to be at a speed lower than the extruding molding speed of these filaments and the second filament loop aggregation forming step progressing simultaneously with the first step, the aggregation processed in said first step is once pulled up on the water surface, is fed into the filament bundle falling water surface zone in said second step while being heated on one side surface near to the fusing temperature and is formed by making said heated surface a loop forming surface on one side of the filament bundle in said second step.

5. A method of producing a mat consisting of filament loop aggregations according to claim 4 wherein the distance from the lower surface of the T-die to the water surface is in the range of 5 to 10 cm.

6. A method of producing a mat consisting of filament loop aggregations according to claim 4 wherein cooling water held at a temperature of 60 to 80°C. is locally boiled by heating by sinking loops just below the fall of said filaments.

7. A method of producing a mat consisting of filament loop aggregations according to claim 4, 5 or 6 wherein about 0.05 to 0.2% surface active agent dialkyl-sulfosuccinate is added into cooling water.