Lining material for pipe lines

A lining material utilizable for a pipe-lining method, which comprises a tubular textile jacket woven or knitted with synthetic fiber yarns provided on the exterior surface thereof with a laminated two or three layer film of the following resinous materials: (1) in case of two layers: PA0 the outer layer: a synthetic resin of polyolefin series having a stress-crack resisting property of at least 1000 hours the inner layer: (1) a resin wherein an ethylenically unsaturated carboxylic acid has been grafted to an ethylene-vinyl acetate copolymer or (2) a resin comprised of 30-70% of a resin wherein an ethylenically unsaturated carboxylic acid has been grafted to a polymer of an .alpha.-olefin and 70-30% of a styrene-ethylene butylene-styrene resin composition. (2) in case of three layers: PA0 between the above described outer layer and inner layer is interposed an intermediate layer of the following resinous material: the intermediate layer: a styrene-ethylene butylene-styrene resin composition.

BACKGROUND OF THE INVENTION 
1. Technical Field: 
The present invention relates to a lining material for lining pipe lines, 
especially gas conduits, city water pipe lines and pipe lines for 
construction of power transmission wires or telecommunication cables, 
chiefly those buried in the ground, for the purpose of repair or 
reinforcement of the pipe lines. 
2. Background Art: 
In recent years, a method of applying a lining material onto the inner 
surface of city water pipe lines, gas conduits and construction pipe lines 
for power transmission wires or telecommunication cables is carried out 
for the purpose of repair or reinforcement of the pipe lines when 
superannuated. The method of applying a lining material is carried out in 
such manner that a flexible lining material in the form of a tube 
previously provided on the inner surface thereof with a binder is inserted 
into a pipe line and allowed to advance therein while turning the lining 
material inside out and pressing it against the inner surface of the pipe 
line under fluid pressure whereby the inner surface of the lining material 
is bonded onto the inner surface of the pipe line by the aid of the 
binder. According to this method, it is unnecessary to dig up a pipe line 
over its full length. The method has such merits that the lining work can 
be done within a short period of time for a long pipe line and is operable 
for a pipe line having a number of bends, thus being watched especially in 
recent years as a very excellent method. 
As a lining material utilizable for this method should be flexible and 
air-impervious and is required to possess satisfactory strength in 
lengthwise and diametrical directions of the pipe line in consideration of 
any influence of creeping or earthquake occurring after lining, a tubular 
textile jacket having a film of a synthetic resin on the exterior surface 
thereof has hitherto been used as the lining material. 
The filmy layer of the lining material is required to possess various 
characteristics such as flexibility, stretchability of a moderate degree 
and strength as well as good heat-resistance, abrasion-resistance and 
scratch-resistance. 
In case of a lining material to be applied to city water pipe lines, a 
synthetic resin constituting the filmy layer should particularly be safe 
to the quality of water. A material utilizable for city water pipe lines 
is required to satisfy the specifications defined in individual countries, 
for example, those defined by the Japan Water Works Association (JWWA) in 
case of Japan. According to the specifications defined by JWWA, the 
material is required to satisfy the test for quality of water defined by 
("Tar Epoxy Resin Paints for Water Works and Method of Coating " (K-115) 
wherein the specifications are defined in detail for turbidity, color 
scale, the amount of consumption of potassium permanganate, the amount of 
consumption of chlorine, etc. A synthetic resin of polyolefin series as 
well as a synthetic resin of fluorine series is specified as a resinous 
material forming the filmy layer of a lining material satisfying these 
specifications. 
Of these synthetic resins, the fluorine resin is very expensive and 
inferior in extrusion characteristics so that it is not suited as a 
resinous material forming the filmy layer of a lining material for the 
pipe lines. Accordingly, the resinous materials for this application are 
substantially restricted to a synthetic resin of polyolefin series. 
The synthetic resin of polyolefin series includes high density 
polyethylene-resin, medium density polyethylene resin, low density 
polyethylene resin, polypropylene resin, polybutene resin, etc. However, 
the resins other than low density polyethylene are inferior in 
flexibility, while the low density polyethylene is inferior in durability. 
Thus, these resins were not necessarily suitable as a material 
constituting the filmy layer of a lining material for pipe lines. 
3. Prior Art: 
The present inventors already devised as a lining material for city water 
pipe lines a material using a linear low density polyethylene resin or a 
material using a blend of polyethylene resin and pure styrene-ethylene 
butylene-styrene resin free from polypropylene resin and an oily substance 
for the filmy layer (Japanese Utility Model Applns. Nos. Sho. 58-176565 
and 59-44499). 
The linear low density polyethylene resin used in the lining material of 
the above mentioned Japanese Utility Model Appln. No. Sho. 58-176565 is a 
synthetic resin of polyolefin series comprised predominantly of ethylene, 
which is obtained by copolymerizing ethylene with an .alpha.-olefin. The 
resin having a density of about 0.910-0.940 g/cm.sup.3 belongs to a low 
density polyethylene resin and has a molecular structure similar to a 
linear high density polyethylene resin almost devoid of branched chains. 
This linear low density polyethylene resin is of such characteristics that 
the tensile strength is as high as about 330 kg/cm.sup.2 and equals to 
that of a high density polyethylene resin and that the stress-crack 
resisting property is longer than 1000 hours to show excellent durability 
while possessing softness as seen in a low density polyethylene resin. 
In general, polyethylene has good chemicals-resisting property. In case 
polyethylene is put in the state of receiving stress or retains stress at 
the time of being processed, however, polyethylene may form cracks when 
brought into contact with a certain kind of liquid or vapor. This 
phenomenon is called stress-crack. The stress-crack resisting property 
referred to herein is measured according to a testing method specified in 
ASTM-D-1693 wherein a polyethylene resin is allowed in the state of 
receiving a definite amount of stress to stand in a given environment and 
the resisting property is given in terms of a period of time elapsing 
until cracks are formed. This property is one of the standards for 
durability of polyethylene resins and is very important as a 
characteristic property required for pipe lines for passing water 
therethrough, especially in the event the lining material is smaller in 
diameter than the pipe lines and is pressed against them by expansion of 
the diameter of the lining material for lining. 
The styrene-ethylene butylene-styrene resin used for the lining material of 
the above mentioned Japanese Utility Model Appln. No. Sho. 59-44499 is 
generally called an elastomer of styrene series and is a resin which is 
most excellent in rubbery elasticity among the thermoplastic elastomers 
substituted for vulcanized rubber. This styrene-ethylene butylene-styrene 
resin is characterized in that the residual double bond has been 
hydrogenated which exists in the central rubber block of a 
styrene-isoprene-ethylene block copolymer and that insufficient stability 
of the copolymer against heat and weathering action has remarkably been 
improved. The styrene-ethylene butylene-styrene resin is stable against 
heat and extremely flexible so that the resin has properties most 
desirable as a material for the film in the lining method. 
However, it is rare that this styrene-ethylene butylene-styrene resin is 
used singly. In general, a commercially available "styrene-ethylene 
butylene-styrene resin" is inferior in stress-crack resisting property and 
fluidity so that the resin is incorporated with polypropylene having good 
compatibility therewith to improve stress-crack resisting property and 
with an oily substance to improve water-flowability and flexibility. As a 
result of tests on the quality of water, however, it has been found that a 
stabilizer in the polypropylene and the oily substance in the above 
mentioned commercially available "styrene-ethylene butylene-styrene resin" 
ooze out on the surface of the resin to increase the amount of consumption 
of chlorine in an undesirable manner. This commercially available 
"styrene-ethylene butylene-styrene resin" will be referred to hereinafter 
as the styrene-ethylene butylene-styrene resin composition. 
SUMMARY OF THE INVENTION 
Although the above described various new technical means were hitherto 
proposed by the present inventors, such technical means were still 
unsatisfactory as a material constituting a film of lining materials for 
city water pipe lines and involves problems as will be described 
hereinafter. A linear low density polyethylene resin used in the lining 
material disclosed in Japanese Utility Model Appln. No. Sho. 58-176565 is 
flexible as compared with high density polyethylene resin or medium 
density polyethylene resin but is not a satisfactorily flexible synthetic 
resin because of its Shore D hardness being about 50. This resin is not 
satisfactory in flexibility as a material used as a film of a lining 
material for lining pipe line according to the above mentioned method and 
makes it harder to evaginate the lining material as the diameter thereof 
becomes smaller so that the fluid pressure has to be elevated 
significantly to effect evagination. 
A blend of a styrene-ethylene butylene-styrene resin and a linear low 
density polyethylene resin, etc. used in the lining material disclosed in 
Japanese Utility Model Appln. No. Sho. 59-44499 has a Shore D hardness of 
40, for example, at a blend ratio of 50:50 and is flexible in comparison 
with the above described linear low density polyethylene resin alone but 
is still unsatisfactory. A blend wherein the content of the 
styrene-ethylene butylene-styrene resin is 70% is inferior in 
scratch-resistance and stress-crack resisting property. 
Further, a synthetic resin of polyolefin series has such a generic 
characteristic property that it is inferior in bonding power and cannot be 
bonded sufficiently to a tubular textile jacket. 
The present invention has been accomplished to solve these various problems 
and its object is to provide a lining material which meets the standard 
for the quality of water without any fear of pollution of water especially 
when applied to city water pipe lines and which is so flexible and easy to 
effect evagination as to facilitate lining works and is excellent in 
adhesion to a tubular textile jacket. 
DETAILED DESCRIPTION OF THE INVENTION 
The present invention is to attain the above mentioned subject according to 
a means as will be detailed hereinafter. The first lining material 
provided by the present invention comprises a tubular textile jacket 
provided on the exterior surface with a laminated two layer resinous film 
and is characterized in that the outer layer of the film is composed of a 
synthetic resin of polyolefin series having a stress-crack resisting 
property of at least 1000 hours and the inner layer of the film is 
composed of (1) a resin wherein an ethylenically unsaturated carboxylic 
acid has been grafted to an ethylene-vinyl acetate copolymer or (2) a 
resin comprised of 30-70% of a resin wherein an ethylenically unsaturated 
carboxylic acid has been grafted to a polymer of an .alpha.-olefin and 
70-30% of a styrene-ethylene butylene-styrene resin composition. The 
second lining material provided by the present invention comprises a 
tubular textile jacket provided on the exterior surface thereof with a 
laminated three layer resinous film and is characterized in that the outer 
layer of the film is of a synthetic resin of polyolefin series having a 
stress-crack resisting property of at least 1000 hours, the intermediate 
layer of the film is composed of a styrene-ethylene butylene-styrene resin 
composition and the inner layer of the film is composed of (1) a resin 
wherein an ethylenically unsaturated carboxylic acid has been grafted to 
an ethylene-vinyl acetate copolymer or (2) a resin comprised of 30-70% of 
a resin wherein an ethylenically unsaturated carboxylic acid has been 
grafted to a polymer of an .alpha.-olefin and 70-30% of a styrene-ethylene 
butylene-styrene resin composition. 
The tubular textile jacket used in the lining material of the present 
invention is a material used in the above mentioned known conventional 
arts. The manufacture of the lining material is carried out according to 
an extrusion molding method adapted for products of this kind. The 
thickness of the film of a resinous material laminated on the exterior 
surface of the tubular textile jacket is properly determined in 
consideration of the diameter of pipe lines and flexibility and mechanical 
strength of the resinous material. No particular limitation exists in the 
numerical ranges but those skilled in the art will easily understand the 
ranges in view of the numerical values illustrated in Examples given 
hereinafter.

EMBODIMENT FOR CARRYING OUT THE INVENTION 
As schematically shown in FIG. 1, the first lining material of the present 
invention utilizable in the above mentioned lining method is characterized 
in that on the exterior surface of a tubular textile jacket 1 woven or 
knitted with synthetic fibers yarns, a synthetic resin of polyolefin 
series having a stress-crack resisting property of at least 1000 hours is 
formed as an outer layer 2 and the above mentioned resin (1) wherein an 
ethylenically unsaturated carboxylic acid has been grafted to an 
ethylene-vinyl acetate copolymer or the above mentioned mixture (2) 
comprised of 30-70% of a resin wherein an ethylenically unsaturated 
carboxylic acid has been grafted to a polymer of an .alpha.-olefin and 
30-70% of the styrene-ethylene butylene-styrene resin composition is 
formed as an inner layer 3 to form a laminated two layer film 4. The 
second lining material of the present invention is, as schematically shown 
in FIG. 2, characterized in that a three layer laminate is formed by 
interposing an intermediate layer of the styrene-ethylene butylene-styrene 
resin composition between the outer layer 2 and the inner layer 3 of the 
above described first lining material 1. 
In the lining material of the present invention, the synthetic resin of an 
.alpha.-olefin used as the outer layer 2 of the film 4 should have a 
stress-crack resisting property of at least 1000 hours as described above. 
The synthetic resins satisfying this criterion include a high density 
polyethylene resin having a density of at least 0.941 g/cm.sup.3, a linear 
low density polyethylene resin having a density of 0.910-0.940 g/cm.sup.3, 
a crosslinked polyethylene resin having a density of 0.910-0.940 
g/cm.sup.3, 1-polybutene resin, etc. 
The ethylene-vinyl acetate copolymer constituting a skeleton of the above 
described resin (1) used for the inner layer 3 is preferably of a vinyl 
acetate content of about 7-30% since such copolymer has a lower melting 
point and is flexible and excellent in adhesibity. The above described 
resin (1) is made by grafting an ethylenically unsaturated carboxylic acid 
such as acrylic acid, methacrylic acid, maleic anhydride or a derivative 
thereof to the skeleton of the ethylene-vinyl acetate copolymer. The 
adhesivity of the resin is enhanced by imparting carboxyl groups to the 
ethylene-vinyl acetate copolymer. 
The polymers of an .alpha.-olefin in the resin (2) used in the inner layer 
3 are those of at least 3 carbon atoms, for example, polypropylene, 
1-polybutene, etc. To this polymer of an .alpha.-olefin is grafted an 
ethylenically unsaturated carboxylic acid, for example, acrylic acid, 
methacrylic acid, maleic anhydride or a derivative thereof. The adhesivity 
of the resin is enhanced by imparting carboxylic groups to the 
.alpha.-olefin. 
The above described polymer of an .alpha.-olefin is softened by blending 
with the styrene-ethylene butylene-styrene resin composition whereby its 
adhesivity is improved and at the same time the styrene-ethylene 
butylene-styrene composition is improved in its stress-crack resisting 
property to have durability. 
On blending of the above resins, the blending ratio is such that the resin 
wherein the ethylenically unsaturated carboxylic acid has been grafted to 
the polymer of an .alpha.-olefin is 30-70% while the modified 
styrene-ethylene butylene-styrene resin composition is 70-30%. If the 
modified styrene-ethylene butylene-styrene resin composition is more than 
70%, the resulting blend will be flexible but its adhesibity will be 
reduced to be inferior. On the other hand, if the resin composition is 
less than 30%, the resulting blend will be inferior in flexibility and 
adhesive power. In the lining material of the present invention, the 
blending ratio is adjusted to 50:50 whereby a resin having a Shore D 
hardness of about 70 is obtained, showing excellent adhesive power. 
The styrene-ethylene butylene-styrene resin composition used for the 
intermediate layer 5 in the second lining material preferably is so 
flexible as to have a Shore D hardness of 30-80. 
The production of a lining material is carried out, in case of the prior 
art lining materials, by forming a filmy layer directly on the exterior 
surface of the tubular textile jacket by extrusion molding of a synthetic 
resinous material and allowing the synthetic resinous material to intrude 
into the texture of the tubular textile jacket for bonding to form an 
integral filmy layer on the tubular textile jacket. It is advantageous 
that a laminated two or three layer tube of synthetic resins is formed on 
the outside of the tubular textile jacket 1 by extrusion molding and the 
interior of the tubular textile jacket is then evacuated to bond the tube 
of synthetic resins in closely attached state to the exterior surface of 
the tubular textile jacket 1 thereby forming the filmy layer 4. 
According to the present invention, the outer layer 2 which is brought, 
after pipe-lining, into contact directly with a fluid flowing through the 
pipe line is comprised of a synthetic resin of polyolefin series which is 
excellent in stress-crack resisting property. Thus, the outer layer 
obtained does not give any influence on the quality of water even in case 
of using the lining material for city water pipe lines and excels in 
hydrolysis-resistance, heat-resistance and scratch-resistance. Thus, the 
use of the outer layer 2 can effectively prevent not only pollution of 
water but also any damage of the lining material when it is passed through 
a pipe line while being evaginated. 
In the second lining material, an extremely flexible styrene-ethylene 
butylene-styrene resin composition is used as the intermediate layer 5 of 
the filmy layer 4 so that the whole filmy layer 4 is not damaged in 
flexibility but is rather improved in heat-resistance even if the resin 
blend is reduced in hardness but is especially excellent in adhesive power 
is used as the inner layer 3. 
Specific embodiments of the lining material utilizable for city water pipe 
lines having a diameter of 200 mm.phi. will be illustrated as Examples of 
the present invention together with Comparative Examples. In each Example 
and each Comparative Example, a tubular textile jacket 1 was made by 
weaving warps and a weft in a tubular form in such manner that 2 groups of 
638 yarns each of which was made by twisting four 1,100 d. polyester 
filament yarns were used as the warps and a yarn made by intertwisting two 
1,100 d. polyester filament yarns with four 20S polyester spun yarns at a 
twisting time of 2.0-2.5/inch was used as the weft and picked up at 62 
pick count/10 cm of the warps. 
In order to maintain adhesivity to the filmy layer 4 while maintaining the 
strength of the lining material, it is preferable to use a spun yarn as a 
part of yarns constituting the tubular textile jacket 1 as in this 
example. 
A specific construction of the filmy layer 4 to be formed on the exterior 
surface of the tubular textile jacket 1 is illustrated in each Example and 
each Comparative Example. 
EXAMPLE 1 
The outer layer : A high density polyethylene resin (Hi-zex 500H 
manufactured by Mitsui Petrochemical Co., Ltd., density: 0.950 g/cm.sup.3, 
Shore D hardness: 60, melting point: 132.degree. C., tensile strength: 370 
kg/cm.sup.2, elongation on break: 900%, and stress-crack resisting 
property: &gt;1000 hours) 
The inner layer: A resin wherein an ethylenically unsaturated carboxylic 
acid has been grafted to an ethylene-vinyl acetate copolymer (Modic 300S 
manufactured by Mitsubishi Petrochemical Co., Ltd., content of vinyl 
acetate: 25%, density: 0.950 g/cm.sup.3, Shore D hardness: 54, melting 
point: 88.degree. C., tensile strength: 110 kg/cm.sup.2 and elongation on 
break: 850%) 
The thickness of the filmy layer: 0.7 mm 
The ratio in thickness of the outer layer to the inner layer: The outer 
layer/the inner layer=1/1. 
EXAMPLE 2 
The outer layer: A linear low density polyethylene resin (Ultzex 2021L 
manufactured by Mitsui Petrochemical Co., Ltd., density: 0.918 g/cm.sup.3, 
Shore D hardness: 50, melting point: 120.degree. C., tensile strength: 330 
kg/cm.sup.2, elongation on break: 740% and stress-crack resisting 
property: &gt;1000 hours) 
The inner layer: The resin wherein an ethylenically unsaturated carboxylic 
acid has been grafted to an ethylene-vinyl acetate copolymer (as described 
above) 
The thickness of the filmy layer: 0.7 mm 
The ratio in thickness of the outer layer to the inner layer: the outer 
layer/the inner layer=1/1. 
EXAMPLE 3 
The outer layer: A crosslinked low density polyethylene resin (Linklon 
XLE700A manufactured by Mitsubishi Petrochemical Co., Ltd., density: 0.928 
g/cm.sup.3, Shore D hardness: 53, tensile strength: 200 kg/cm.sup.2, 
elongation on break: 500% and stress-crack resisting property: &gt;1000 
hours) 
The inner layer: The resin wherein an ethylenically unsaturated carboxylic 
acid has been grafted to an ethylene-vinyl acetate copolymer (as described 
above) 
The thickness of the filmy layer: 0.7 mm 
The ratio in thickness of the outer layer to the inner layer: the outer 
layer/the inner layer=1/1. 
EXAMPLE 4 
The outer layer: A 1-polybutene resin (Witron 1210A manufactured by Adeka 
Argus Chemical Co., Ltd., density: 0.905 g/cm.sup.3, Shore D hardness: 52, 
melting point: 115.degree. C., tensile strength: 288 kg/cm.sup.2, 
elongation on break: 350% and stress-crack resisting property: &gt;5000 
hours) 
The inner layer: The resin wherein an ethylenically unsaturated carboxylic 
acid has been grafted to an ethylene-vinyl acetate copolymer (as described 
above) 
The thickness of the filmy layer: 0.7 mm 
The ratio in thickness of the outer layer to the inner layer: the outer 
layer/the inner layer=1/1. 
EXAMPLE 5 
The outer layer: The high density polyethylene (as described above) 
The intermediate layer: a styrene-ethylene butylene-styrene resin (Rabalon 
ME6302 manufactured by Mitsubishi Petrochemical Co., Ltd., density: 0.90 
g/cm.sup.3, Shore A hardness: 68, melting point: 130.degree. C., tensile 
strength: 161 kg/cm.sup.2 and elongation on break: 850%) 
The inner layer: The resin wherein an ethylenically unsaturated carboxylic 
acid has been grafted to an ethylene-vinyl acetat copolymer (as described 
above) 
The thickness of the filmy layer: 0.7 mm 
The ratio in thickness of the outer layer/the intermediate layer/the inner 
layer=1/1/1. 
EXAMPLE 6 
The outer layer: The linear low density polyethylene resin (as described 
above) 
The intermediate layer: The styrene-ethylene butylene-styrene resin (as 
described above) 
The inner layer: The resin wherein an ethylenically unsaturated carboxylic 
acid has been grafted to an ethylene-vinyl acetate copolymer (as described 
above) 
The thickness of the filmy layer: 0.7 mm 
The ratio in thickness of the outer layer/the intermediate layer/the inner 
layer=1/1/1. 
COMATIVE EXAMPLE 1 
A single layer of the high density polyethylene resin (as described above) 
COMATIVE EXAMPLE 2 
A single layer of the linear low density polyethylene resin (as described 
above) 
COMATIVE EXAMPLE 3 
A single layer of a resin comprised of a 50:50 blend of a linear low 
density polyethylene resin and a styrene-ethylene butylene-styrene resin 
(Rabalon 9200.degree. C. manufactured by Mitsubishi Petrochemical Co., 
Ltd., density: 0.92 g/cm.sup.3, Shore D hardness: 40, melting point: 
130.degree. C., tensile strength: 270 kg/cm.sup.2, elongation on break: 
750% and stress-crack resisting property: at least 1000 hours) 
EXAMPLE 7 
The outer layer: A high density polyethylene resin (Hi-zex 500H 
manufactured by Mitsui Petrochemical Co., Ltd., density: 0.950 g/cm.sup.3, 
Shore D hardness: 60, melting point: 132.degree. C., tensile strength: 370 
kg/cm.sup.2, elongation on break: 900% and stress-crack resisting 
property: at least 1000 hours). 
The inner layer: A resin comprised of a 50:50 blend of a resin wherein an 
ethylenically unsaturated carboxylic acid has been grafted to 
polypropylene and the styrene-ethylene butylene-styrene resin composition 
(Modic F-300V manufactured by Mitsubishi Petrochemical Co., Ltd., 
molecular weight of the polypropylene: several ten thousands to two 
hundred thousands, rate of imparting the carboxylic acid: 1-15%, density: 
0.89 g/cm.sup.3, Shore A hardness: 70, melting point: 130.degree. C., 
tensile strength: 65 kg/cm.sup.2 and elongation on break: 500%) 
The total thickness of the film: 0.7 mm 
The ratio in thickness of the outer layer to the inner layer: the outer 
layer/the inner layer=1/1. 
EXAMPLE 8 
The outer layer: A linear low density polyethylene resin (Ultzex 2021L 
manufactured by Mitsui Petrochemical Co., Ltd., density: 0.918 g/cm.sup.3, 
Shore D hardness: 50, melting point: 120.degree. C., tensile strength: 330 
kg/cm.sup.2, elongation on break: 740% and stress-crack resisting 
property: at least 1000 hours). 
The inner layer: The resin comprised of a 50:50 blend of the resin wherein 
an ethylenically unsaturated carboxylic acid has been grafted to 
polypropylene and the styrene-ethylene butylene-styrene resin composition 
(same as in the foregoing Example 7). 
The total thickness of the film: 0.7 mm 
The ratio in thickness of the outer layer to the inner layer: the outer 
layer/the inner layer=1/1. 
EXAMPLE 9 
The outer layer: A crosslinked low density polyethylene resin (Linklon XLE 
700A manufactured by Mitsubishi Petrochemical Co., Ltd., density: 0.928 
g/cm.sup.3, Shore D hardness: 50 and stress-crack resisting property: at 
least 1000 hours). 
The inner layer: The resin comprised of a 50:50 blend of the resin wherein 
an ethylenically unsaturated carboxylic acid has been grafted to 
polypropylene and the styrene-ethylene butylene-styrene resin composition 
(same as in the foregoing Example 7). 
The total thickness of the film: 0.7 mm 
The ratio in thickness of the outer layer to the inner layer: the outer 
layer/the inner layer=1/1. 
EXAMPLE 10 
The outer layer: A 1-polybutene resin (Witron 1210A manufactured by Adeka 
Argus Chemical Co., Ltd., density: 0.905 g/cm.sup.3, Shore D hardness: 52, 
melting point: 115.degree. C., tensile strength: 288 kg/cm.sup.2, 
elongation on break: 350% and stress-crack resisting property: at least 
5000 hours) 
The inner layer: The resin comprised of a 50:50 blend of the resin wherein 
an ethylenically unsaturated carboxylic acid has been grafted to 
polypropylene and the styrene-ethylene butylene-styrene resin composition 
(same as in the foregoing Example 7). 
The total thickness of the film: 0.7 mm 
The ratio in thickness of the outer layer to the inner layer: the outer 
layer/the inner layer=1/1. 
EXAMPLE 11 
The outer layer: The high density polyethylene resin (same as in the 
foregoing Example 7) 
The intermediate layer: The styrene-ethylene butylene-styrene resin 
composition (Rabalon ME 6302 manufactured by Mitsubishi Petrochemical Co., 
Ltd., density: 0.90 g/cm.sup.3, Shore A hardness: 68, melting point: 
130.degree. C., tensile strength: 161 kg/cm.sup.2 and elongation on break: 
850%) 
The inner layer: The resin comprised of a 50:50 blend of the resin wherein 
an ethylenically unsaturated carboxylic acid has been grafted to 
polypropylene and the styrene-ethylene butylene-styrene resin composition 
(same as in the foregoing Example 7). 
The total thickness of the film: 0.7 mm 
The ratio in thickness of each layer: The outer layer/the intermediate 
layer/the inner layer=1/1/1. 
EXAMPLE 12 
The outer layer: The linear low density polyethylene resin (same as in the 
foregoing Example 8) 
The intermediate layer: The styrene-ethylene butylene-styrene resin 
composition (same as in the foregoing Example 11). 
The inner layer: The resin comprised of a 50:50 blend of the resin wherein 
an ethylenically unsaturated carboxylic acid has been grafted to 
polypropylene and the styrene-ethylen butylene-styrene resin composition 
(same as in the foregoing Example 7). 
The total thickness of the film: 0.7 mm 
The ratio in thickness of each layer: The outer layer/the intermediate 
layer/the inner layer=1/1/1/ 
Performance Test 
(a) Characteristic properties of each resin 
Hardness: In accordance with ASTM-D-2240, Shore D hardness or Shore A 
hardness of each resin was measured. 
Density: The measurement was made in accordance with JIS-K-7112 
(g/cm.sup.3). 
Tensile strength and elongation on break: The measurement was made in 
accordance with ASTM-D-638l (kg/cm.sup.2, %) 
Stress-crack resisting property of the resin constituting the outer layer: 
The measurement was made in accordance with ASTM-D-1693 (hour) 
Softening point (Vicat softening point): The measurement was made in 
accordance with ASTM-D-1525 (.degree.C.) 
(b) Characteristic properties of the laminate 
A laminate was made by extrusion molding of only the filmy layer in each 
Example under the same condition as in the case of manufacturing lining 
materials. The tensile strength and elongation on break of the laminate 
was then measured in accordance with ASTM-D-6381 (kg/cm.sup.2, %). 
(c) Characteristic properties of the lining material 
The lining material provided with the filmy layer illustrated in each 
Example and each Comparative Example was manufactured and tested to 
measure its characteristic properties. In case of Examples, the tubular 
textile jacket was evacuated immediately after extrusion of the laminate 
tube so that the laminate might be brought in tight contac with the 
exterior surface of the tubular textile jacket and bonded thereto. In case 
of Comparative Examples, the synthetic resin was allowed to intrude into 
the tubular textile jacket from the exterior surface thereof to form a 
filmy layer thereon thereby obtaining each lining material. 
Temperature used for heat-resistance: Steam vapor was introduced into the 
lining material and the temperature (.degree.C.) to which the filmy layer 
torelated was measured. 
Amount of consumption of potassium permanganate: The measurement was made 
in accordance with the specification of JWWA-K-115 (mg/1). 
Amount of consumption of residual chlorine: The measurement was made in 
accordance with the specification of JWWA-K-115 (ppm). 
Peeling strength: The peeling power (kg/25 mm in width) between the tubular 
lining material and the filmy layer was measured by 180.degree. peeling. 
Scratch-resisting property: The lining material was applied onto the 
surface of an iron pipe having a diameter of 400-500 mm and a fabric belt 
having a load of 500 kg was applied onto the lining material in such 
manner that the belt was brought into contact with the lining material 
over the length within the range of 5-10 cm. The belt was then allowed to 
slide over 50 m at a speed of 10 m/min. to examine the degree of damage on 
the filmy layer. 
Pressure for self-running evagination: The lining material was evaginated 
over 5 m under fluid pressure whereby the minimum fluid pressure 
(kg/cm.sup.2) necessary for evagination was measured. 
A result of the measurements made above is shown in Tables 1 and 2. 
TABLE 1 
__________________________________________________________________________ 
Item Example 1 Example 2 
Example 3 
Example 4 
Example 5 
Example 
__________________________________________________________________________ 
6 
Construction of lining material 
Material for the outer layer 
High density 
Linear Crosslinked 
Polybutene 
High density 
Linear 
polyethylene 
low density 
low density polyethylene 
low density 
polyethylene 
polyethylene polyethylene 
Material for the 
-- -- -- -- Styrene-ethylene 
Same as 
intermediate layer butylene-styrene 
the left 
resin composition 
Material for the inner layer 
Ethylene-vinyl 
Same as 
Same as 
Same as 
Same as Same as 
acetate copolymer* 
the left 
the left 
the left 
the left the left 
Ratio in thichness of the resin 
1/1 1/1 1/1 1/1 1/1/1 1/1/1 
Thickness of the filmy layer 
0.7 0.7 0.7 0.7 0.7 0.7 
Characteristics of 
the laminated resin 
Tensile strength 
250 220 160 185 210 180 
Elongation on break 
900 740 500 350 900 740 
Characteristics of 
the lining material 
Temperature used for 
130 120 130 115 130 130 
heat-resistance 
Amount of consumption of 
1.1 1.2 1.1 0.7 1.2 1.1 
potassium permanganate 
Amount of consumption of 
0.2 0.3 0.3 0.3 0.2 0.2 
residual chlorine 
Peeling strength 
3.3 3.7 3.2 3.6 3.4 3.7 
Scratch-resisting property 
Good- Good Good Good- Good- Good 
Excellent Excellent 
Excellent 
Pressure for self-running 
1.0 0.6 0.6 0.6 0.7 0.4 
evagination 
__________________________________________________________________________ 
Item Comparative Example 1 
Comparative Example 2 
Comparative Example 
__________________________________________________________________________ 
3 
Construction of lining material 
Material for outer layer 
High density polyethylene 
Linear low density polyethylene 
Linear low density 
polyethylene 
styrene-ethylene-styrene 
resin 
Material for the intermediate layer 
-- -- -- 
Material the inner layer 
-- -- -- 
Ratio in thickness of the resin 
Thickness of the filmy layer 
0.7 0.7 0.7 
Characteristics of the laminated resin 
Tensile strength 370 330 270 
Elongation of break 
900 740 750 
Characteristics of the lining material 
Temperaure used for heat-resistance 
130 120 130 
Amount of consumption of potassium 
1.2 1.1 0.7 
permanganate 
Amount of consumption of residual 
0.3 0.2 0.2 
chlorine 
Peeling strength 2.0 2.0 1.7 
Scratch-resisting property 
Good-Excellent 
Good Good 
Pressure for self-running evagination 
&gt;2.0 1.5 1.0 
__________________________________________________________________________ 
*A resin manufactured by grafting an ethylenically unsaturated carboxylic 
acid to a styrenevinyl acetate copolymer 
TABLE 2 
__________________________________________________________________________ 
Item Example 7 
Example 8 
Example 9 
Example 10 
Example 11 
Example 
__________________________________________________________________________ 
12 
Construction of lining material 
Material for the outer layer 
High density 
Linear Crosslinked 
Polybutene 
High density 
Linear 
polyethylene 
low density 
low density polyethylene 
low density 
polyethylene 
polyethylene polyethylene 
Material for the intermediate layer 
-- -- -- -- Styrene-ethylene 
Same as 
butylene-styrene 
the left 
resin composition 
Material for the inner layer 
A mixture of 
Same as 
Same as 
Same as 
Same as Same as 
polyolefin and 
the left 
the left 
the left 
the left the left 
styrene-ethylene 
butylene-styrene 
resin composition 
Ratio in thichness of the resin 
1/1 1/1 1/1 1/1 1/1/1 1/1/1 
Thickness of the filmy layer 
0.7 0.7 0.7 0.7 0.7 0.7 
Characteristics of 
the laminated resin 
Tensil strength 220 200 140 150 200 170 
strength 
Elongation on break 
900 740 500 350 900 740 
Characteristics of 
the lining material 
Temperature used for heat-resistance 
130 120 130 115 130 130 
Amount of consumption of 
1.1 1.2 1.1 0.7 1.2 1.1 
potassium permanganate 
Amount of consumption of 
0.2 0.3 0.3 0.3 0.2 0.2 
residual chlorine 
Peeling strength 4.2 4.5 4.0 4.2 4.3 4.5 
Scratch-resisting property 
Good- Good Good Good- Good- Good 
Excellent Excellent 
Excellent 
Pressure for self-running 
1.0 0.6 0.6 0.6 0.7 0.4 
evagination 
__________________________________________________________________________ 
Test on the quality of water 
Using test pieces of the filmy layer of the lining material and the pipe 
lined with the lining material, tests were made in accordance with 
JWWA-K-115 to examine turbidity, color scale, amount of consumption of 
potassium permanganate, amount of consumption of residual chlorine, 
amounts of phenols, amines and cyan, odor and taste. 
A result of test is shown in Table 3. 
TABLE 3 
______________________________________ 
Test piece of 
the filmy layer 
Lined pipe 
______________________________________ 
Turbidity less than 0.5 
less than 0.5 
Color scale less than 1 less than 1 
Amount of consumption of 
1.0 mg/l 1.3 mg/l 
potassium permanganate 
Amount of consumption of 
0.3 ppm 0.2 ppm 
residual chlorine 
Phenols less than less than 
0.005 ppm 0.005 ppm 
Amine Not detected Not detected 
Cyan Not detected Not detected 
Odor and taste No problem No problem 
______________________________________ 
The lining material of the present invention is flexible and excellent in 
adhesive power acting between the tubular textile jacket 1 and the filmy 
layer 4. In case the lining material is used in the above described lining 
method, therefore, the lining material is easily evaginated without 
causing any damage of the filmy layer 4 or peeling it off from the tubular 
textile jacket 1. When the binder used in the above described lining 
material is heated to accelerate curing, the inner layer 3 is molten and 
intrudes into the texture of the tubular textile jacket 1 whereby any 
stress caused in the resin of the outer layer can be prevented. As is 
shown in FIG. 1, therefore, the adhesive power acting between the tubular 
textile jacket 1 and the filmy layer 4 is not significantly reduced even 
by elevation of temperature. 
Further, delamination does not occur between the individual layers in the 
filmy layer 4 so that a pipe line excellent in durability can be provided 
for a prolonged period of time. 
INDUSTRIAL APPLICABILITY 
The lining material of the present invention for pipe lines is flexible and 
has a moderate stretchability and excellent mechanical strength and 
adhesivity together with heat-resistance, abrasion-resistance and 
scratch-resistance (stress-crack resistance). Furthermore, the lining 
material entirely satisfies the safety regulations for the quality of 
water when used for city water pipe lines. Thus, the lining material is 
very useful since it is suitable for repair or reinforcement of city water 
pipe lines and also gas conduits as well as pipe lines for constructing 
power transmission wires and telecommunication cables.