JPH0735450B2 - Oil-impregnated polyurethane elastomer-method for producing molded articles - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing an oil-containing polyurethane elastomer molded article. More specifically, it relates to a method for producing an oil-containing polyurethane elastomer molded article in which a lubricant is supported on a carrier and blended.

[Conventional technology]

The oil-impregnated polyurethane elastomer molded product has been conventionally used as a sliding material or the like. Then, the production thereof is carried out by adding a chain extender after uniformly dispersing the lubricating oil on the polyol side or the prepolymer side, which is a raw material of the polyurethane elastomer, and then curing and molding, or further crushing the cured product and heating. It is performed by, for example, a method of melting and then putting in a molding die and molding.

However, in such a method, since the lubricating oil is directly added, the reactivity of the polyurethane-forming reaction is influenced by the added oil, and a problem is caused in moldability. Specifically, there are phenomena such that the flow of the molding material and the bite into the extruder are bad, and the molded product peels off.

[Problems to be solved by the invention]

The present inventors have studied that the oil-impregnated polyurethane elastomer molded article is compounded in a form in which the polyurethane elastomer is supported by the carrier, not by directly adding the lubricating oil to the polyurethane elastomer, and as a result, the microporous beads are used as the carrier. Therefore, without causing the above-mentioned drawbacks,
Moreover, we succeeded in obtaining a polyurethane elastomer molded product whose sliding characteristics were improved to the level of lubrication with oil or grease.

[Means for solving problems]

Therefore, the present invention relates to a method for producing an oil-impregnated polyurethane elastomer molded article, wherein the production of an oil-impregnated polyurethane elastomer molded article is carried out by immersing a microporous bead-filled polyurethane elastomer molded article in a lubricating oil to form microporous beads in the molded article. It is performed by impregnating with lubricating oil.

The microporous beads to be filled in the polyurethane elastomer are substantially spherical or amorphous porous bodies having a particle size of about 1 to 3000 μm and having a pore size of about 5 to 10 μm.
000Å and a pore volume of about 0.1 to 2.0 ml / g are generally used, and if there is a commercially available product, it can be used as it is.

Specifically, styrene-divinylbenzene copolymer microporous beads, SiO ₂ microporous beads, etc. are used, and the former commercial products are those of Mitsubishi Kasei Kogyo's Diaion HP series, and the latter commercial products. Examples include Fuji Davidson Chemical Products Microbeads Silica Gel 3A, 4B, 5D or Syloid 63-978.

As the polyurethane elastomer, not only a thermoplastic polyurethane elastomer but also a thermosetting or kneading type polyurethane elastomer is used.

The polyol component used for producing the polyurethane elastomer has a molecular weight of about 500 to 3000, preferably about 1500 to 2500 polyester polyol, polyether polyol, acrylic polyol, silicone polyol, 1,4-polybutadiene polyol, 1, 2-Polybutadiene polyol, phenolic polyol, flame retardant polyol, castor oil polyol and the like are used.

Of these, polyester polyols preferably used include dicarboxylic acids such as adipic acid, isophthalic acid and terephthalic acid, and ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, 1,6-hexanediol, trimethylolpropane, neopentyl. Condensation reaction products with polyols such as glycols, polycaprolactone polyols, polycarbonate polyols, etc., and as polyether polyols, polypropylene glycol-based polyols or their ethylene oxide modified products, amine modified products, or polyoxytetramethylene glycol, etc., respectively. Used.

As the other reaction component, diisocyanate, 1,
Aliphatic diisocyanates such as 4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, lysine diisocyanate, etc., isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate or xylylene Aromatic diisocyanates such as diisocyanate, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, tolidine diisocyanate, p-phenylene diisocyanate and 1,5-naphthylene diisocyanate are used.

During the reaction of both of these, a chain growth agent can coexist in the reaction system. Examples of the chain growth agent include 1,4-butanediol, 1,6-hexanediol, 2,3-butanediol and p -Phenylene di (β-hydroxyethyl) ether, p-xylylene glycol, glycerin monoallyl ether, glycols such as dimethylol dihydropyran, ethylenediamine, 3,3'-dichloro-4,4'-
Diamine such as diaminodiphenylmethane, diethyltoluylenediamine, N, N'-diaminopiperidine, or water is used.

The filling of the microporous beads into the polyurethane elastomer and the molding of the filling are generally carried out by compounding by a polyurethane-forming reaction in the presence of the microporous beads by the following method, and foaming if necessary. You can also

(1) After mixing microporous beads with the polyol component, excess diisocyanate is added and reacted.
A chain growth agent is added to the obtained liquid prepolymer containing free diisocyanate, poured into a mold and allowed to cure for a predetermined time, then taken out of the mold and in its original shape or after being crushed and then an injection molding machine. After being melted by heating using, it is heated at a temperature of 80 to 120 ° C. for about 15 to 48 hours in a remolded state in a molding die.

(2) A high molecular weight dihydroxy compound, microporous beads, a chain growth agent and a diisocyanate (used in an amount less than the functional groups present in both the dihydroxy compound and the chain growth agent) are mixed and reacted. The reaction product can be stored and rolled and can be crosslinked in a later stage by mixing with other diisocyanates. If 4,4'-diphenylmethane diisocyanate is used as the diisocyanate, it can be crosslinked by peroxide. When an unsaturated chain growth agent is used,
It can be crosslinked with sulfur, formaldehyde and the like.

Further, in the case of a thermoplastic polyurethane elastomer, it is mixed with microporous beads using an extruder or a Banbury mixer, and the mixture is heated and melted, and then molded by an injection molding method, a press molding method, or the like. The composite and molding are carried out.

The microporous bead-filled molded product produced in this manner has about 5 parts by weight of the polyurethane elastomer component.
~ 60 wt% microporous beads are loaded. If the filling rate of microporous beads is less than this,
The amount of lubricating oil impregnated therein will be small, and the intended purpose of improving the lubricating characteristics will not be achieved. On the other hand, if the proportion is higher than this, mixing and molding will be difficult.

Molded products filled with microporous beads are mineral oil (# 30-400), fluorine oil (# 400), ester oil (400cst), polyglycol oil (# 400), silicone oil (# 400, # 200), etc. By immersing it in various lubricating oils represented by, and impregnating the lubricating oil into the microporous beads filled in the molded article.

When the lubricating oil is impregnated, it is immersed in an organic solvent capable of swelling the polyurethane elastomer, for example, methyl ethyl ketone, toluene, ethanol, trichloroethane, etc., and allowed to swell. Impregnation is performed more smoothly.

[Operation] and [Effect of the invention] The oil-containing polyurethane elastomer molded article according to the present invention,
Lubricating oil is retained in the microporous beads dispersed and filled therein, and the lubricating oil exuded at the temperature under the use conditions forms a film of the lubricating oil on the surface of the molded product.

As a result of the lubricating oil film being formed on the surface of the molded product in this way, the addition of solid lubricants such as ethylene tetrafluoride resin and molybdenum disulfide will limit the sliding properties to the lubrication level of oil and grease. Can be improved to

Further, by interposing the microporous beads, the lubricating oil can be smoothly dispersed and filled in the polyurethane elastomer, and no problem is observed in terms of moldability.

Therefore, this oil-containing polyurethane elastomer molded article,
It can be effectively used for sliding parts used under high pressure and high speed.

〔Example〕

 Next, the present invention will be described with reference to examples.

Example 1 After drying styrene-divinylbenzene copolymer microporous beads (Mitsubishi Kasei Kogyo product Diaion HP-20; pore volume about 1.0 ml / g) at a temperature of 100 to 120 ° C. for 8 hours or more, 125 parts of a mixture of 10 parts (weight, same below) and 100 parts of polycaprolactone diol (OH number 56.1).
While heating to ℃, add 60 parts of trizine diisocyanate (molecular weight 264) to this, stir under reduced pressure for about 30-40 minutes, then add 13.7 parts of 1,4-butanediol and immediately pour onto a hot plate to cure. Let

The cured product is crushed, and the crushed product is molded into a sheet of dimensions 150 x 150 x 2 mm under the molding conditions of nozzle 180-200 ° C and cylinder 170-190 ° C using an injection molding machine. The molded article was secondly vulcanized at a temperature of about 100 to 120 ° C for 48 hours.

This sheet-shaped vulcanized molded product was immersed in methyl ethyl ketone at room temperature for 1 hour to allow it to swell, and then immersed in lubricating oil (Idemitsu Kosan Product Dexron II) at 80 ° C for 15 hours to apply to the microporous portion of the molded product. Impregnated with lubricating oil.

Example 2 In Example 1, instead of the styrene-divinylbenzene copolymer microporous beads, the same amount of SiO ₂ -based microporous beads (Fuji Devison Chemical Product Cyroid 244; pore volume of about 1.16 ml / g) was used. Was given.

Comparative Example 1 In Examples 1 and 2, microporous beads were not used.

Comparative Example 2 In Examples 1-2, 6 parts of powdery molybdenum disulfide was used instead of the microporous beads.

The following items were measured for the lubricating oil polyurethane elastomer sheets obtained in each of the above Examples and Comparative Examples.

[Physical properties] Hardness, 100% modulus, tensile strength, elongation,
Tearing strength.

[Compression set] 80 ℃, 70 hours [Suzuki type friction and wear test] Mating material SUS304 Test condition: Linear velocity 500mm / s Load 5kg / cm ² Temperature 25 ℃ (Condition A), 120 ℃ (Condition B) Time 15 minutes The results obtained are shown in the following table.

Claims (6)

[Claims] 1. A method for producing an oil-containing polyurethane elastomer molded article, which comprises immersing a microporous bead-filled polyurethane elastomer molded article in a lubricating oil and impregnating the microporous beads in the molded article with the lubricating oil. 2. The method for producing an oil-containing polyurethane elastomer molded article according to claim 1, wherein the microporous beads are styrene-divinylbenzene copolymer microporous beads. 3. The method for producing an oil-containing polyurethane elastomer molded article according to claim 1, wherein the microporous beads are SiO ₂ microporous beads. 4. The oil-impregnated polyurethane elastomer molded article according to claim 1, wherein the molded article filled with microporous beads is a molded article filled with about 5 to 60% by weight of microporous beads with respect to the polyurethane elastomer. Manufacturing method. 5. The method for producing an oil-containing polyurethane elastomer molded article according to claim 1, wherein the molded article filled with microporous beads is dipped in an organic solvent to be swollen and then dipped in lubricating oil. 6. The method for producing an oil-containing polyurethane elastomer molded article according to claim 5, wherein the organic solvent is methyl ethyl ketone.