JP2000239483A - Lubricant for propulsion process having incorporated therewith granular highly water-absorbing resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lubricant which can block gaps in sand particles thereby inhibiting effluence of a lubricant liquid, does not need agitation for a long time and is easy to weigh automatically by composing it of a composition obtained by adding a specific amount of a lipophilic stabilizer to a mixture comprising a W/O water-soluble vinyl polymer emulsion and a granular highly water-absorbing resin in a specific wt. ratio. SOLUTION: The title composition comprises 100 pts.wt. of a mixture comprising a W/O water-soluble vinyl polymer emulsion and a granular highly water- absorbing resin in a wt. ratio of 90:1 to 50:50 and 10 pts.wt. or less of a lipophilic stabilizer added thereto. Preferably the oil phase of the W/O water-soluble vinyl polymer emulsion is at least one of liquid aliphatic, aromatic and alicyclic hydrocarbons. The water-soluble vinyl polymer is preferably an acrylamide homopolymer or copolymer. The granular highly water-absorbing resin is preferably an amorphous or spherical particle having a grain size of 10-2,000 μm. The lipophilic stabilizer is preferably a lipophilic inorganic filler.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricant for a propulsion method comprising a W / O type water-soluble vinyl polymer emulsion containing a particulate superabsorbent resin.

[0002]

2. Description of the Related Art The propulsion method frequently used for laying pipes for sewerage or the like is a method in which a cast iron pipe or a concrete fume pipe is pushed into the ground, so that the propulsion resistance increases as the propulsion distance increases. For this reason, construction is proceeding while injecting a lubricant liquid between the pipe and the ground to reduce propulsion resistance. Recently, a product which is supplied in advance as a powder obtained by mixing a thickening agent and a particulate superabsorbent resin with a mineral powder such as bentonite, and is prepared by adding water on site to a lubricant liquid has been developed and used. However, when the amount of the powder mixture added at a time is too large or when the stirring power is weak, mama powder (lumpy insoluble matter) is generated, and the function as a lubricant may not be sufficiently exhibited. Further, there is a problem that dust is generated when the lubricant liquid is prepared.

In order to prevent this phenomenon, a mineral powder, a superabsorbent resin and a thickener are mixed and dispersed in a liquid such as mineral vegetable oil or polyethylene glycol. However, if the viscosity is low, the thickener or superabsorbent resin will sediment and separate at the bottom during storage of the product, making it uneven, or forming a hard precipitate (hard cake), resulting in poor redispersibility. Since the operation of redispersing the lubricant is required before preparing the lubricant liquid, the operation efficiency is reduced. In addition, if the viscosity is increased, the separation can be suppressed, but there is a disadvantage that it is difficult to take out from the container and to add / dissolve.

As a countermeasure, a water-in-oil type water-soluble polymerization emulsion may be used as a single product. However, since a thickener component alone does not contain a superabsorbent resin, it is difficult to inject ground into a ground having high water permeability. In addition, the mixing effect is low and the mixing effect of the mixer used for preparing lubricants is low. There are many disadvantages that it takes time to dissolve.

Although a water-in-oil superabsorbent resin emulsion can be used alone, it is not possible to increase the particle size in consideration of the stability of the product during storage. In general, the particle size is relatively small. Even when the liquid is prepared, since it does not contain a thickening component, the viscosity is low, the liquid is easily lost, and the effect is limited.

A method of mixing a water-in-oil type water-soluble polymer emulsion and a water-in-oil type superabsorbent resin emulsion to form a single solution is also conceivable, but the type of emulsifier used for each and the HLB (hydrophilic) Base and lipophilic group), the emulsion is likely to become unstable when separated, causing a high probability of separation or agglomeration, as well as the product stability of water-in-oil superabsorbent resin emulsions. Since the particle size of the superabsorbent resin itself is small, there is a drawback that the effect of the superabsorbent resin as a lubricant is hardly expected.

[0007]

Therefore, there is a need for the development of a product containing a superabsorbent resin and a water-soluble polymer that can overcome or mitigate the disadvantages of conventional products used as lubricants for propulsion methods. .

According to the present invention, there is provided a mixture of a water-soluble W / O type vinyl polymer emulsion and a particulate superabsorbent resin in a weight ratio of 99: 1 to 50:50.
It is satisfied by using a composition obtained by adding up to 10 parts by weight of a lipophilic stabilizer per part by weight as a lubricant for a propulsion method.

Since the composition of the present invention is a liquid product, it can be easily measured automatically, does not require long-time stirring for preparation, and has a high effective utilization rate. Further, it has stability in which no phase separation or gelation phenomenon is observed at room temperature for at least 90 days in the form of a liquid product prepared in advance, and has high fluidity at low temperatures.

[0010]

Preferred Embodiment The W / O water-soluble vinyl polymer emulsion can be produced by a reversed-phase suspension polymerization method of a water-soluble vinyl monomer. In this method, a hydrocarbon-based solvent and an emulsifier are added to a reaction vessel, mixed, and a water-soluble monomer aqueous solution and a polymerization initiator are added thereto with stirring to carry out a polymerization reaction.

The hydrocarbon solvents used include aliphatic, alicyclic or aromatic hydrocarbons such as n-pentane, n-hexane, n-heptane, n-octane, cyclopentane, cyclohexane, benzene, toluene and xylene. Hydrogen and mineral oils such as kerosene, light oil, naphtha and liquid paraffin.

As the emulsifier, a nonionic surfactant is generally used. Examples thereof include sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene higher alkyl ether, polyoxyethylene alkylphenyl ether, and polyoxyethylene higher fatty acid ester. And polyoxyethylene polyoxypropylene alkyl ethers.

Examples of the water-soluble vinyl monomer include (meth) acrylamide, (meth) acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, vinylsulfonic acid, styrenesulfonic acid, allylsulfonic acid, methylvinylether, and vinyl acetate. , Itaconic acid, maleic acid,
Fumaric acid, and mixtures thereof. Acrylamide and mixtures thereof with other monomers such as acrylic acid are preferred.

The initiator used in this polymerization reaction is an azo-based or peroxide-based initiator, and is used for bulk polymerization, solution polymerization or ordinary suspension polymerization (O / W) of a vinyl monomer.
Initiator which is usually used for the mold may be used.

Usually, the stability of the W / O type water-soluble vinyl polymer emulsion itself is not so high. Therefore, if other substances are mixed into the emulsion, the emulsion is easily broken, and mixing of other substances is rarely used. There is no. However, in the case of a highly water-absorbent resin, it is presumed that at least a part of the water is transferred from the water-soluble vinyl polymer solution droplets to the water-absorbent resin, and the particle volume is reduced, so that the inherent stability of the emulsion is hardly impaired. You.

Various super water-absorbing resins are known, and any of them can be used. Among them, graft copolymers of polyvinyl alcohol and poly (meth) acrylic acid, and crosslinked epichlorohydrin of polyvinyl alcohol , Polyvinyl alcohol phosphoric acid condensate, acrylonitrile and vinylidene chloride or alkali hydrolyzate of copolymer of vinyl chloride and copolymerizable vinyl monomer, copolymer of acrylic acid and divinylbenzene, homo or copolymer of acrylamide Diaclamide, radiation-crosslinked polyethylene glycol, and acid-heat-treated starch can be used.

The shape of the superabsorbent resin may be irregular or spherical, but when mixed with the emulsion, the viscosity of the mixture is low, and the sediment is easily redispersed when left for a long period of time. preferable. In the case of the amorphous type, the tendency is opposite to the above, but the stability can be ensured by adjusting the compounding amount and using a little more stabilizer.

Naturally, the water absorption capacity of the superabsorbent resin is preferably high, usually 100 times or more. Such superabsorbent resins are available on the market, for example, Mitsubishi Chemical Corporation.
Are available in various grades under the trade name Aqua Pearl. This commercial product or commercial products from other comparable manufacturers can be used in the present invention.

The composition of the present invention can be prepared by adding a particulate superabsorbent resin and a stabilizer to a W / O type water-soluble vinyl polymer emulsion with stirring and mixing. In this case, the mixing ratio of the emulsion and the superabsorbent resin is 99: 1 to 1 by weight (emulsion: superabsorbent resin).
The ratio can be selected between 50:50, and within this range, it is possible to maintain a viscosity suitable for handling the composition.

The lipophilic stabilizer is added for the purpose of preventing phase separation or gelation of the composition and keeping the composition stable. Suitable stabilizers for this purpose are lipophilic inorganic fillers such as organic bentonite, lipophilic calcium carbonate, lipophilic synthetic smectite, hydrophobic microsilica, which dissolves in the oil phase of the emulsion and thickens. In addition, inorganic or organic fillers such as hydrophilic microsilica, polyethylene fiber and ground pulp can be added as auxiliary stabilizers.
The total amount of the lipophilic stabilizer and the auxiliary stabilizer, if used, is preferably up to 10 parts by weight per 100 parts by weight of the W / O-type water-soluble vinyl polymer emulsion to which the superabsorbent resin is added. It is.

The polyethylene fiber and the ground pulp not only help stabilize the composition, but also play a role in preventing the loss of the filler in a formation having a large gap when injected into the ground as a lubricant. The addition of the stabilizer and the co-stabilizer may be before, simultaneously with, or after the superabsorbent resin is added to the emulsion.

[0022]

The present invention will be described in more detail with reference to the following examples.

Reference Example W / O type water-soluble vinyl polymer
A reaction flask made of marjon glass was charged with 240 g of isoparaffin having a boiling point of 200 ° C. and 15 g of sorbitan monooleate,
A monomer mixture 33 composed of 400 g of deionized water, 30 mol% of acrylic acid and 70 mol% of acrylamide was added thereto.
0 g was gradually added dropwise with stirring to form an emulsion. After introducing nitrogen into the solution and performing nitrogen substitution, 0.08 g of dimethylazobisisobutylene was added as an initiator, the temperature was kept at 50 to 60 ° C., and stirring was continued for about 2 hours to terminate the polymerization reaction. . Thereafter, 15.0 g of polyoxyethylene oleate having an average addition mole number of ethylene oxide of 7.5 was added to obtain a W / O-type acrylic acid / acrylamide copolymer emulsion.

Examples 1 to 5 and Comparative Examples 1 and 2 The W / O emulsions prepared in the Reference Examples, the superabsorbent resin, and the lipophilic stabilizer were mixed at the weight ratio shown in Table 1, and the mixture was stirred at room temperature ( (20 ° C.) and the number of days until separation and solidification was measured.

Table 1 Example Comparative Example 1 2 3 4 5 1 2 Emulsion of Reference Example 90 80 70 75 80 80 80 Superabsorbent resin ¹⁾ 10 20 30 25 20 20 20 Organic bentonite ²⁾ 1 0.5 0.3--- − Hydrophobic microsilica ³⁾ − − − 0.5 − − − Hydrophobic tankar ⁴⁾ − − − − 10 − 30 ────────────────────────流動 Flowability immediately after mixing Good Good Good Good Good Good Good Solidification Separation amount after 90 days (%) 1 1 2 2 1 18 数 Days to solidification>90>90>90>90> 90 3 ── 1) Aqua Pearl A3 manufactured by Mitsubishi Chemical Corporation, average particle size 25
2) S-BEN manufactured by Toyoko Jun 3) Aerosil R972 manufactured by Nippon Aerosil Co., Ltd. 4) Gelton 50 manufactured by Shiraishi Calcium Industry Co., Ltd.

As shown in Table 1, the composition of the example was 90
Stable for more than a day, the composition of the comparative example separates in a short time,
Solidified.

Examples 6 to 9 and Comparative Examples 3 and 4 The components used in Examples 1 to 5 were used in the weight ratios shown in Table 2 except that spherical KI gel manufactured by Kuraray Co., Ltd. was used as the superabsorbent resin. They were mixed, allowed to stand at room temperature (20 ° C.), separated, and the number of days until solidification was measured.

Table 2 Example Comparative Example 6 7 8 9 3 4 Emulsion of Reference Example 80 75 40 80 80 80 Superabsorbent resin ⁵⁾ 20 25 40 20 20 20 Liquid paraffin--20---Organic bentonite ⁶⁾ 0.5 0.3 1 − − − Hydrophobic micro silica ³⁾ − − − − − 15 Hydrophobic tankar ⁴⁾ − − − 10 − − ──────────────────────流動 Fluidity immediately after mixing Good Good Good Good Good Solidification Separation amount after 90 days (%) 1 1 2 1 45 日 Days to solidification>90>90>90> 90 1) 5) Spherical KI gel manufactured by Kuraray Co., Ltd., 8-32 mesh 6) Orben manufactured by Shiraishi Calcium Co., Ltd. 3) and 4) Same as Table 1.

The products of the examples exhibited stability of 90 days or more, while the products of the comparative examples separated and solidified in a short period of time.

Examples 10 to 11 and Comparative Example 5 A composition having a weight composition shown in Table 3 was prepared in the same manner as in the above example, and a 1% aqueous solution thereof was subjected to a filtration test. API
Standard sand was spread to a thickness of 5 cm on a standard filtration tester, 450 ml of the test liquid was poured on the sand, and the amount of the liquid flowing out under a pressure of 0.3 kgf / cm ² was measured.

[0031] Table 3 Example Comparative Example 10 11 5 Example Emulsion 80 40 100 superabsorbent polymer ¹⁾ 20 40 - Organic bentonite ²⁾ 0.5 1 - Liquid paraffin - 20 - ──────────流出 Effluent volume: 1 minute (ml) 23 18 126 3 minutes (ml) 35 26 283 5 minutes (ml) 42 29 355 10 minutes After (ml) 48 31 Standard sand after 10 minutes Resin accumulation Resin accumulation No change Surface condition １１ ) Same as Table 1. 2) Same as Table 1.

In the lubricant liquid of the embodiment, the swollen water-absorbing resin particles can block the gap between the sand particles to prevent the lubricant liquid from flowing out. On the other hand, the lubricant liquid of the comparative example is short from the gap between the sand particles. It shows that it is difficult to maintain the required time between the propulsion pipe and the ground.

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Claims (5)

[Claims] 1. A weight ratio of W / O type water-soluble vinyl polymer emulsion to granular superabsorbent resin of 99: 1 to 50:50.
A lubricant for a propulsion method comprising a composition obtained by adding up to 10 parts by weight of a lipophilic stabilizer per 100 parts by weight of the mixture to the mixture. 2. An oil phase of a W / O type water-soluble vinyl polymer emulsion wherein the oil phase is a liquid aliphatic, aromatic or alicyclic hydrocarbon,
The lubricant for a propulsion method according to claim 1, which is a mixture thereof. 3. The lubricant for a propulsion method according to claim 1, wherein the water-soluble vinyl polymer is a homo- or copolymer of acrylamide. 4. The particulate superabsorbent resin has a particle size of 10 to 2000 μm.
The lubricant for propulsion method according to any one of claims 1 to 3, wherein the lubricant is an amorphous or spherical particle having a particle size of m. 5. The lubricant for a propulsion method according to claim 1, wherein the lipophilic stabilizer is a lipophilic inorganic filler.