JPS6022240B2 - coated pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to metal pipes, tubes or conduits coated with a roaring composition.

It is known to coat pipes used for the transportation of oil, gas, etc., e.g. metal pipes such as steel pipes, cast iron pipes, etc., with a layer of pumice or asphalt compositions.

These layers are typically 3 to IQ ribs thick. In view of the conditions encountered by such coated pipes during their transport, storage, installation and use, in particular when it is an underground or offshore pipe, a number of standard specifications have been compiled for testing such sheathings. There is. Two such specifications are as follows: 1. In the flow test, the thickness of the coating layer of 5 ribs at a temperature of 70 degrees and an angle of 45 degrees should be less than 6 skins after 2 feeding hours.

0 In the stamping test, the mark made by a round stamping tool with a surface area of 1 mm may not exceed the 17 side after 2 anchor hours at a load of 2.5 kg and a temperature of 25 q0.

Furthermore, the following are also required: 01 In the bending test, the coating should not crack under the conditions of a deflection of 2 degrees, a thickness of 2 degrees, a temperature of 4°C, and a deflection rate of 1 degree/S.

'2} The coating composition itself has good corrosion protection properties.

One problem in selecting pipe asphalts is that asphalts with satisfactory mechanical properties sometimes have insufficient corrosion protection properties (or vice versa), so the selection of pipe asphalts has to balance these conflicting demands. This may end up being a compromise.

The present inventor has now discovered a pipe asphalt composition that satisfies these contradictory requirements. [ where each A is a thermoplastic polymer block of a monovinyl aromatic hydrocarbon or 1-alkene, B is an elastomeric polymer block of a conjugated diene or one or more 1-alkenes, and n is an integer, preferably 1 to 5] or a high-pitched derivative comprising 1 to 2% by weight, preferably 3 to 15% by weight of the hydrogenated derivative of the block copolymer.

Therefore, the present invention is characterized by being coated with such a cost-effective composition.

Relating to metal pipes, tubes or conduits. The light blue component of the light blue composition may be natural picumen or may be derived from natural oil.

An example of a suitable oak growing fraction is precipitated bitumen (precipitated bitumen).
cipiond skin men), e.g. propane bits;
en), such as blown propane bitumen; and mixtures thereof, such as 90:10 to 50:50 (by weight) mixtures of propane bitumen and blown propane bitumen. Examples of other suitable mineral components include mixtures of the above-mentioned bitumens with extenders such as petroleum extracts (e.g. aromatic extracts), petroleum distillates, petroleum retentates and the like.
It is preferable that the tortoise component has a softening point of 55 to 100°C and a penetration of 2 to 15 (on the 0.1 side) at 25°C. As described above, the pipe coating composition of the present invention contains a block copolymer, and the block copolymer is preferably a thermoplastic rubber having the following structure. A-8
1(-B-A)n Polymer block A is preferably 2,000 to 100,
00, particularly preferably a number average molecular weight in the range of 5,000 to 50,000.

The polymer floc 8 preferably has a molecular weight of 25,000 to 1,0
00,000, particularly preferably 35,000 to 150,
It has a number average molecular weight in the range of 0.000. When two or more blocks B are directly adjacent to each other due to a branched structure, they are treated as a single block with respect to molecular weight counting methods. The amount of polymer blocks A in the block copolymer is preferably from 10 to 7% by weight, particularly preferably from 20 to 5% by weight. As examples of monovinyl aromatics suitable for preparing the polymer block A of the block copolymers of the invention, mention may be made of styrene and alpha methylstyrene. Preferably, carbon atoms having 4 to 8 carbon atoms, particularly preferably butadiene and isoprene, are selected as the active compound used in the preparation of the polymer block B of the block copolymer of the present invention. Polymer block B may be prepared by copolymerization of one or more conjugated compounds with one or more monovinyl aromatic compounds. Examples of 1-alkenes useful in the preparation of either thermoplastic block A or elastomer block B include those having a carbon number per molecule such as ethylene, propylene, butene-1, hexene-1, octene-1, etc. 2 to 12 1-alkenes are included. Examples of suitable block copolymers include polystyrene-polyisoprene-polystyrene, polystyrene-polybutadiene-polystyrene, polyethylene-(ethylene-propylene copolymer)-polyethylene, polypropylene-(ethylene-propylene copolymer)-polypropylene, and these. hydrogenated products (particularly hydrogenated products of floc copolymers containing Jen homopolymer block).

The block copolymers can be formed in a number of different ways, including those described below.

For example: a pinylarene such as styrene is combined with a monovalent alkali metal hydrocarbyl (h) such as an alkyl lithium.
Polyvinyl arene block copolymers terminated with lithium ions may be polymerized in an essentially inert hydrocarbon medium in the presence of hydrocarbyl inhibitors to form lithium ion terminated polyvinyl arene block copolymers. Immediately thereafter, without post-treatment, a conjugated diene such as butadiene is introduced to perform block copolymerization, resulting in a block copolymer intermediate A bonded to lithium ions.
-Produce B. Finally, a pinylarene such as styrene is introduced to continue the polymerization to form the desired linear polymer A-B-
Form A. Whole polymers may also be made by the following coupling method.

That is, in the first step, a lithium-terminated polymer block A is made as described above, and then a conjugated gene is introduced so that the molecular weight of the conjugated gene polymer block in the final product is only half of the final molecular weight. Form a conjugated gene polymer block. At this point, a divalent coupling agent such as dibromomethane is added to form the desired three-block polymer A-B-(B-A)n (where n=1
), in other words, form A-B-A. This bu. Block polymers may contain meaningless coupling residues such as Block B' in them. The post-coupling group is ignored in the general description of the block copolymer herein. Non-bran copolymers, ie, branched copolymers, can be easily formed by using polygonal coupling agents such as trichlorobenzene, tetrachlorobenzene, and the like.

Hydrogenation of the block copolymer itself is not an essential component of the present invention.

Hydrogenation of the core block copolymer includes nickel, silica gel, Raney nickel, chromate steel, molybdenum sulfide, platinum powder, platinum oxide, palladium powder, and zinc oxide. It can be carried out using a variety of hydrogenation catalysts such as copper acid and the like under conventional conditions known to those skilled in the art. Preferred hydrogenation pressures range from atmospheric pressure to about 211 kg/kg, typically about 7 to 70.3 kg/kg/g.
It is. The hydrogenation temperature can vary from about 10 qo to about 316°C, but the maximum temperature is limited to prevent deterioration of the polymer. Hydrogenation may be complete (i.e., reducing all unsaturated groups) or irregular (i.e., reducing all unsaturated groups).
i.e. reduce a portion of the unsaturated groups, e.g. 20%)
Good too. By selectively hydrogenating only the central block, for example, polyisoprene can be converted into ethylene-propylene rubber (FPR).
) is also possible. Preparation of the composition of the invention comprises:
This can be easily carried out by mixing the polymer component in the form of a finely dispersed solid or in the form of a solution of, for example, benzene or toluene, into the molten turquoise component.

The solvent used may then be distilled off. The pipe coating compositions of the present invention may contain wax and/or mineral fillers. As the wax or wax composition, one having a freezing point of 60° C. or higher is suitable. The suitable amount of wax is based on the weight of the roaring quality component and the thermoplastic rubber.
1 to 6% by weight, preferably 5 to 4% by weight. The wax derived from pot oil is preferred, but animal waxes, insect waxes, vegetable waxes, mineral waxes and others can also be used. An example of pot oil wax is Bright Stock Slack Wax (BSSB).
, Medium Machine Oil Slack Wax (
High Melting Point Wax (HMPW) with MMOSW, Micro Crystalline Wax (MK
W) etc.

Additives may be present to raise the freezing point of the wax. A very wide variety of inorganic materials can be used as fillers. The filling material is ASTM (Amcrica
nSMieVforTesting Ma riais)
Particle sizes such that at least 5% by weight are retained on a 200 sieve are preferred. Fillers that give the best results are talc and threrite powder. Other preferred fillers include asbestos, siliceous fillers (e.g. silicates) and calcareous fillers. Mixtures of different fillers can also be used. 1 to 10 based on the weight of the thermoplastic rubber
0% by weight, preferably 20-8% by weight. Preferred new pipe coating compositions contain the following ingredients (all percentages are based on the total amount of {a and 'b}):
.

{a- 80-9% by weight of the blue-green component; 'bl Weight% of the previously described block copolymer 1-2; 'c
'wt% of wax 1-6; and d inorganic filler 1
~10% by weight The above composition is particularly suitable for coatings for marine pipelines.

It is preferred to treat pipes, tubes or conduits with a primer before applying the transpigment composition according to the invention to the pipes, tubes or conduits.

Preferably such primers are used which have a similar composition to the above compositions, except that they do not contain fillers and are generally dissolved in aromatic type solvents, such as kerosene. The cyanide composition of the present invention is suitably applied in liquid form to form a coating layer at least 3 ft thick, preferably 3 to 1 ft thick.

Therefore, it is necessary to heat the composition in order to obtain a sufficiently low viscosity. Generally, the transpigmentary composition contains 18
It is preferably applied in liquid form with a viscosity of 150 ratio S or less at 0°C. Next, the present invention will be explained by examples.

In the examples, the softening point measured by the ring and ball method is ASTM36~
26. Penetration was measured according to ASTM D5-61, respectively. Examples 1-9 Various phosphorescent compositions were prepared (these compositions are shown in the table below) and used to coat objects such as metal plates, pipes, etc.

The objects used were pretreated with a primer consisting of bitumen, rubber and wax dissolved in an aromatic solvent. The characteristics of the Wakachi material used are shown below.

Bitumen A: Propane bitumen; Softening point (ring and ball method) 58°C: 25
Penetration at qo: 12 (0.1 side).

Bitumen B: Propane bitumen; Softening point (ring and ball method) 66°C: Penetration at 25°C 12 (senryu).

Bitumen C: Blown propane bitumen; Softening point (ring and ball method) 87
．． 5qo; penetration degree 7 (0.1 rib) at 280.

Bitumen D: Blown bropan bitumen: Softening point (ring and ball method) 104qo; Penetration at 2yo 1.5 (0
．． 1 rib).

Rubber A: molecular weight 14,000-65 000-14,0
00 styrene-ptadiene-styrene block copolymer.

Rubber B: molecular weight 9,000-140,000-9,00
0 styrene-isoprene-styrene block copolymer.

Rubber C: molecular weight 10,000-50,000-10.0
00 styrene-hydrogenated butadiene-styrene floc copolymer.

HMPW: A high-temperature wax with a solidification point of 84.

MXW: Micro wax with a freezing point of 6.0.

BSSW: Bright Strax Slack wax with a freezing point of 73°C.

MMOSW: Medium machine oil slack wax with a freezing point of 63°C.

Slate dust: Slate dust in which 96% by weight of the particles have a size of 20 to 149 peaks.

These coatings were then flow tested, stamped and bent tested as previously described.

The coating compositions of Examples 1 and 2 were tested for corrosion in the following manner.

A mild steel plate (8 x 8 Sakaki), which had been previously shot blasted and primed, was coated with the bituminous composition to a thickness of 0.5 side.

Next, each of the above-mentioned metal plates was sealed to the other end of a cylinder made of PEDAIPEX, to which a titanium anode was fixed with a circle ring. The metal plate was connected to the negative terminal of the battery, and the titanium anode was connected to the negative terminal. Aerated seawater was then pumped into the cylinder. The electrical resistance of the coating was measured at regular intervals. The initial resistance value is typically between 1 and 100 ohms, but when this value falls below 100 ohms, the coating fails this test. Corrosion of the coating was evaluated based on the number of days that elapsed before it failed. The results are shown in the table below.

table

Claims (1)

[Scope of Claims] 1. A block copolymer having 80 to 99% by weight of a bituminous component and a structure of the following formula: A-B-(-B-A)_n [wherein each A is a monovinyl aromatic hydrocarbon] or 1-
B represents a thermoplastic polymer block of an alkene; B represents an elastomeric polymer block of a conjugated diene or one or more 1-alkenes; n represents the production number) or a hydrogenated derivative of the block copolymer 1-20 Metal pipes, tubes or conduits coated with bituminous compositions containing % by weight. 2. The metal pipe, tube, or tube according to claim 1, wherein the bituminous component is propane bitumen, blown propane bitumen, or a mixture of propane bitumen and blown propane bitumen. conduit. 3 The bituminous component has a softening point of 55 to 100°C by the ring and ball method,
The metal pipe, tube or conduit according to claim 1 or 2, characterized in that it has a penetration degree of 2 to 15 (0.1 mm) at 25°C. 4 Polymer block A is 2,000 to 100,000
Polymer block B has a molecular weight of 25,000~
A metal pipe, tube or conduit according to any one of claims 1 to 3, characterized in that it has a molecular weight of 1,000,000. 5. The metal pipe, tube or conduit according to any one of claims 1 to 4, characterized in that the bituminous composition further contains wax. 6. The metal pipe, tube or conduit according to claim 5, wherein the wax has a freezing point of 60° C. or higher. 7. The metal pipe according to claim 5 or 6, characterized in that the amount of wax is 1 to 60% by weight, based on the weight of the bituminous component and the thermoplastic rubber.
tube or conduit. 8. A metal pipe, tube or conduit according to any one of claims 1 to 7, characterized in that the bituminous composition further contains an inorganic filler. 9. The metal pipe, tube or conduit according to claim 8, wherein the inorganic filler is straight dust. 10. Metal pipe, tube or conduit according to claim 8 or 9, characterized in that the amount of inorganic filler is from 1 to 100% by weight, based on the weight of bituminous component and thermoplastic rubber. . 11. Claims 1 to 10, characterized in that the bituminous composition is coated with pumimer before being applied.
Metal pipes, tubes or conduits as described in any of paragraphs.