JPH0620751B2 - Manufacturing method of sliding parts by monomer casting method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sliding component including a shaft and its bearing, for example, a journal and a journal bearing, a spline shaft and its bearing, which are fitted with each other. More specifically, the present invention relates to a method for manufacturing a sliding component, in which a resin lining is formed on the surface of a shaft or a bearing by a monomer casting method.

[Conventional technology]

A so-called conventional processing method has been conventionally proposed in which a low-viscosity monomer or prepolymer is injected into the clearance between the bearing and the shaft to polymerize and harden the resin, and a resin is lined on the surface of the bearing (Japanese Patent Laid-Open Publication No. Sho. 60-178013 and JP-A-63-212518). In these conventional processing methods, a ω-lactam melt containing a polymerization catalyst and a ω-lactam melt containing a polymerization initiator are simultaneously injected or injected into a mold and reacted in the mold. , The resin lining is formed. Conventionally, as the above-mentioned polymerization initiator, Japanese Patent Laid-Open No.
60-178013 discloses a lactam anion and an acyllactam, and JP-A-63-212518 discloses a compound having the formula: and [Wherein A represents a halogen atom, or (Wherein Y represents C ₃ -C ₁₁ alkylene),
a is an integer of 1, 2 or 3, b is an integer of 2 or more, R ₁ represents an alkylene group, an aralkyl group, an alkyloxy group, an aryloxy group, a halogen group or an aralkyloxy group. , R ₂ represents a divalent or higher valent group selected from a hydrocarbon group and a hydrocarbon having an ether bond, and Z is (1) a polyether having a minimum molecular weight of about 2,000, and (2) a polyether having a minimum molecular weight of about 2,000. Represents a polyester segment having a segment, or (3) a hydrocarbon having a minimum molecular weight of 1,000. ] The polymerization initiator represented by the following is disclosed.

On the other hand, as the lactam polymerization initiator, various ones other than the above are known, for example, in JP-A-63-86723, the formula [In the following formula, Q is a lactam residue having a C _{3 to} C ₁₁ alkylene group, which is bonded to carbonyl through a nitrogen atom of the lactam; A is an aliphatic or aromatic hydrocarbyl group or hydrocarbyl Is an ether group; m
Is 0 or 1; when m is 0, n is 0 or 1
When p is 1 and m is 1, n is in the range of 1 to 3 and p = n. ]; And a lactam polymerization characterized by containing at least two lactam terminal groups represented by: and an elastic skeleton derived from a telechelic polyamine containing at least two primary or secondary amino groups. Initiators are disclosed.

[Problems to be Solved by the Invention]

The sliding parts obtained by applying the resin lining by the monomer casting method are used by injecting grease into the clearance between the shaft and the bearing having the resin lining.

The general-purpose grease is injected into the sliding parts obtained by the above conventional method, and when used at high temperature (100 ° C or higher),
There is a drawback that the lined polyamide resin is deteriorated. As the resin deteriorates, cracks occur in the polyamide resin, causing the polyamide resin and the resin to separate from the bearing surface, increasing the vibration noise or sliding depending on the part to which the sliding parts are applied. It also leads to an increase in sliding resistance.

The present invention is for solving the above-mentioned problems, and an object thereof is to select a polymerization catalyst and a polymerization initiator to be used in a lining of a polyamide-based resin in a high temperature atmosphere. Another object of the present invention is to provide a method of manufacturing a sliding component having excellent durability, which is capable of preventing the deterioration of the polyamide resin and the reduction of the adhesive strength with the metal interface even under the condition where grease is present.

[Means for Solving the Problems]

That is, the gist of the present invention is that a casting material containing the following compositions (A) and (B) in the clearance between the bearing and the shaft that is fitted in the bearing and is rotatably or reciprocally supported. Is injected and polymerized and cured to form a resin lining on the surface of the shaft or the bearing: (A) ω containing a polymerization catalyst of an alkali metal or alkaline earth metal compound -Lactam liquid material; (B) lactam polymerization initiator represented by the following formula Or (In the formula, Z is polypropylene oxide polyol, A
Is an aliphatic or aromatic hydrocarbyl group, Q is a lactam residue having a C _{3 to} C ₁₁ alkylene group, t is at least 1, m is 0 or 1, and
When m is 0, n is 0 or 1, p is 1. When m is 1, n is in the range of 1 to 3, p = n, and R ₁
Is an alkyl group, an aralkyl group, an alkyloxy group, an aryloxy group, a halogen group or an aralkyloxy group. ) -Omega-lactam liquid substance containing at least 1);

The sliding component to which the present invention is applied first includes a shaft such as a round shaft or a square shaft having an appropriate bearing (the bearing here includes a bearing unit which is independent or separate, and a bearing portion which is integrated with the main body of the device. ), Supported rotatably or reciprocally in the axial direction, and then containing a required amount of a polymerization catalyst of an alkali or alkaline earth metal compound, an ω-lactam solution, that is, a casting material (A), And a ω-lactam solution containing a polymerization initiator, that is, a mixed and stirred low-viscosity solution of the casting material (B) is injected into the clearance between the bearing and the shaft, or these solutions are first introduced into the inner space of the bearing. Is poured in an appropriate amount, and then the shaft is fitted into the bearing to uniformly spread the solution in the clearance, and is polymerized and cured by heating, and a resin lining is formed on the surface of the shaft or the bearing. That is, it is based on the existing processing in which the resin lining is directly formed in the clearance between the shaft and the bearing which are actually fitted. In this case, since it is difficult to remove the resin lining after the polymerization, it is preferable to preliminarily provide the bearing with an appropriate seal except for the portion (bearing surface) where the function of the bearing is desired. Further, in order to promote the polymerization reaction uniformly and smoothly, it is preferable to preheat the shaft and the bearing, if necessary, before the injection of the solution and keep the temperature suitable for the polymerization. Furthermore, the resin lining can be firmly fixed on the bearing surface by applying an appropriate primer on the bearing surface of the bearing and an appropriate release agent on the shaft before injecting the solution or the like. . When it is desired to apply a resin lining on the shaft, a primer may be applied to the shaft and a release agent may be applied to the bearing.

Hereinafter, the present invention will be described in detail.

(Ω-lactam) The ω-caprolactam used in the present invention includes γ-lactam.
Butyrolactam, δ-valerolactam, ε-caprolactam, ω-enanthlactam, ω-capryllactam,
ω-undecanolaccam, ω-laurinlactam and the like can be mentioned. These ω-lactams may be used alone or in combination of two or more kinds.

(Polymerization catalyst) The polymerization catalyst of the alkali metal or alkaline earth metal compound contained in the casting material (A) used in the present invention is selected from those used in the known anionic polymerization of ω-lactam. be able to. As a concrete example,
Alkali metals, alkaline earth metals, their hydrides,
Oxides, hydroxides, carbonates, alkyl compounds, aryl compounds, alkoxides, Grignard compounds, and reaction products of the above metals or metal compounds with ω-lactam, for example, sodium salt, potassium salt of ω-lactam,
Examples include magnesium halide salts. The amount of the alkali polymerization catalyst used is 0.01 to 0.01% based on the total ω-lactam.
It is in the range of 15 or 20 mol% or more.

(Polymerization Initiator) The lactam polymerization initiator according to the present invention is represented by the following formula: Or (In the formula, Z is polypropylene oxide polyol, A
Is an aliphatic or aromatic hydrocarbyl group, Q is a lactam residue having a C _{3 to} C ₁₁ alkylene group, t is at least 1, m is 0 or 1, and
When m is 0, n is 0 or 1, p is 1. When m is 1, n is in the range of 1 to 3, p = n, and R ₁
Is an alkyl group, an aralkyl group, an alkyloxy group, an aryloxy group, a halogen group or an aralkyloxy group. ) This initiator may be produced by the reaction of an acylramtam monomer having at least two acyllactam groups with a telechelic polypropylene oxide polyol. In order to form a block copolymer with excellent properties, at least 90 mol%, more preferably 95 mol% of the hydroxyl groups of the polypropylene oxide polyol are converted to lactam end groups prior to substantial lactam polymerization. Is good. To do this, the initiator may be pre-formed, or it may be generated in-situ before being placed under lactam polymerization conditions.

The number average molecular weight of the lactam polymerization initiator is about 500 to about 15,00.
0, preferably about 1,000 to about 10,000 is advantageous. Preferred lactam initiators are those having a molecular weight of at least about 1,000, preferably about 2,000 to about 6,000. Unless otherwise specified, all molecular weights referred to herein mean number average molecular weights measured by a method known in the art.

The initiator according to the present invention can be obtained by sequentially performing the following steps that proceed at ambient temperature.

a) complexing the acid halide groups of the polyfunctional acid halide with a tertiary amine, b) at least one but not all of the complexed acid halide groups is represented by the formula (In the formula, Y is a C _{3 to} C ₁₁ alkylene group), a step of reacting with a lactam monomer to substitute a halogen for a lactam residue to form an halogenated annium salt, c) the remaining At least 90 of the complexed acid halide groups
Reacting mol% with a polyfunctional secondary hydroxyl group to form a carboxyl group, and d) removing the ammonium halide salt. Advantageously, the acid halide group is slightly in excess of the stoichiometric amount with respect to the hydroxyl group. In this method, the acid halide groups react with the hydroxyl groups of the polypropylene oxide polyol to form ester bonds and substituted ammonium halide by-products. An example of this reaction is as follows. Ie Where X is chlorine or bromine, NR ₃ is a tertiary amine; Z, Q, A and m are as previously described; and K> dx. The acidic acid halide can be reacted with the lactam monomer in step b) to form the initiator by
It may contain more than one acid halide group. In that case, the polyfunctional acid halide can remove two molecules of substituted ammonium halide per coupling reaction to couple two or more telechelic polypropylene oxide polyols.

This initiator is a non-interfering solvent such as cyclohexane,
It is preferably produced in the presence of toluene, tetrahydrofuran or acetone.

The initiator can also be formed at elevated temperatures, for example 30-150 ° C, depending on the nature of the solvent used. When a solvent is used, the solvent used can be removed by distillation after the initiator is formed.

Advantageously, the telechelic polypropylene oxide polyol has a number average molecular weight of about 300 to 10,000, preferably at least about 500, more preferably at least 1,000. The polylactam segment formed by the addition polymerization of the lactam monomer to the initiator gives a hard and crystalline segment, while this telechelic polypropylene oxide polyol is a nylon block copolymer that is soft and elastic. Selected to provide the backbone of the segment.

The soft segment contributes to its glass transition temperature, Tg, of about 0 ° C or lower, preferably about -25 ° C or lower, when incorporated into the nylon block copolymer. The glass transition temperature can be easily measured by a differential scanning calorimetry at a scanning rate of 10 to 20 ° C./minute under a nitrogen atmosphere.

The polyfunctional acid halide that can be preferably used for producing the lactam polymerization initiator is represented by the following formula.

(In the formula, m is 0 or 1, m is 0, n is 0 or 1 and p = 1, and when m is 1, n is in the range of 1 to 3, p = n, and X is chlorine or bromine, A is an aliphatic or aromatic hydrocarbyl group or hydrocarbyl ether group, R ₁ is an alkyl group, an aralkyl group, an alkyloxy group, an aryloxy group, a halogen group or an aralkyloxy group. The preferred group as A is paraphenylene or metaphenylene and (Where x is in the range of 3-8), and more preferred are para-phenylene or meta-phenylene and mixtures thereof, which provide nylon block copolymers with outstanding physical properties. Other preferred diacid halides contain an oxalyl group, where m = 0 and n = 1.

Suitable lactam to react with complexed by acid halide, those having an alkylene group of C ₃ -C _11, preferably, based on the ready availability and their reactivity, alkylene of C ₃ or C ₅ Those having a group, that is, 2-pyrrolidinone or ε-caprolactam.

Third, which can be used to complex polyfunctional acid halides
Examples of secondary amines are trialkylamines, pyridines and alkyl-substituted pyridines, quinolines, and other substituted amines having substituents that do not substantially interfere with the amine's function as a complexing agent and the formation of the lactam initiator. Is. The ammonium salt and excess tertiary amine are preferably removed after the initiator is formed.

The lactam polymerization initiator is preferably prepared by reacting 1 equivalent of a telechelic polypropylene oxide polyol based on the number of amino groups with 1 equivalent of an acid halide based on the number of acid halide groups. However, if a polymeric lactam initiator having a backbone with alternating hard and hard segments is desired, the polyfunctional acid halide is combined with two or more telechelic polypropylene oxide polyols. To react. In this case, the equivalent ratio of the telechelic polypropylene oxide polyol to the acid halide is
Selected less than 1: 1. For example, if the telechelic polypropylene oxide polyol is trifunctional and a difunctional acid halide is added to couple two polypropylene oxide polyols, a polymeric tetrafunctional initiator will be obtained. , It is advantageous to use an equivalence ratio of 1: 3. The above description of the hard segment preferably follows the molecular weight specifications generally discussed for the telechelic polypropylene oxide polyol.

The resulting nylon block copolymer weight average molecular weight can be varied over a wide range, from about 18,000 to about
A range of 100,000 is advantageous. The molecular weight is generally
It depends on the molar ratio of lactam monomer to lactam polymerization initiator.

The concentration of the initiator or the concentration of activated N-lactam groups present during the polymerization of the lactam monomer, supplied by the lactam polymerization initiator, affects the overall reaction rate. The total amount of activated N-lactam groups, i.e. the number of equivalents of initiator groups, can vary depending on the functionality and / or concentration of initiator present in the mixture. Generally, the functionality of the initiator or number of activated N-lactam groups per molecule is at least 2, preferably from about 2 to about 10, and more preferably from about 3 to about 6. Generally, the amount of lactam polymerization initiator used is at least 0.1 mol% and more preferably 0.25 to 1.0 mol% of the total moles of caprolactam monomer used.

Ε-in the presence of a suitable catalyst using a lactam polymerization initiator
When a nylon-6 block copolymer is produced by reacting with a caprolactam monomer, the resulting block copolymer generally has a lactam polymerization initiator of the general formula Polyamide chain having a repeating unit of is added. Nylon-6 block copolymers, on the other hand, are produced essentially from ε-caprolactam, but other lactam monomers can be included as long as the reaction rate or degree of polymerization of caprolactam polymerization is not substantially impaired.

(Other compounding materials) Furthermore, in the present invention, other additives such as a plasticizer, a foaming agent, a face dye, an antioxidant, and an internal mold release agent are compounded unless the polymerization reaction is substantially inhibited. can do.

〔Example〕

Next, the present invention will be described in more detail based on examples.

In the following examples, appearance evaluation and resin deterioration evaluation were performed as follows.

Appearance of sliding parts: Grease (Automix A made by Idemitsu Petrochemical Co., Ltd.) was injected into the clearance between the shaft and the bearing of the sliding parts molded according to the examples described below, and the grease was placed in an oven at 120 ° C for 2 hours.
After being left for 40 hours, sliding between the shaft and the bearing was repeated 10,000 times, after which the shaft was removed from the bearing, and it was visually observed whether or not cracks were formed in the resin lined on the bearing. The indication of evaluation is as follows.

○: No cracks were generated at all ×: Degradation evaluation of cracked resin: 30 pieces of ASTM D-638-72 type IV dumbbells were cut out from a flat plate-shaped molded article formed according to the examples described below, and this test was conducted. The piece was immersed in specified grease (Autolex A manufactured by Idemitsu Petrochemical). 120 ℃ in this state
After standing for 240 hours in the oven, the tensile elongation was measured according to ASTM D-638-72.

Embodiment 1 In FIGS. 1 and 2, (1) shows an outer spline bearing, (2) shows a shaft of an inner spline fitted to the bearing (1) and reciprocally supported, and (3) ) Is the bearing
The resin lining which consists of polyamide system resin formed on the bearing surface (4) of (1) is shown. (5) and (6) are centering centers.

In the sliding component of this example, first, the bearing (1) was coated with a primer, the shaft was coated with a release agent, and then the bearing (1) and the shaft were coated.
(2) was preheated and kept at 130 to 160 ° C. Then, the following casting materials (A) and (B) are mixed in equal amounts, and the clearance (7) between the bearing (1) and the shaft (2) (about 0.2 m
m) and polymerized and cured at 130 to 160 ° C. to form a resin lining (3) on the bearing surface (4) of the bearing (1).
The appearance of the obtained sliding parts after deterioration was evaluated.

Similarly, 90 g of each of the following casting materials (A) and (B) were weighed and mixed, and immediately 1
Inject into a flat plate molding die having a cavity of 220 mm in length, 180 mm in width, and 3 mm in depth, the temperature of which is controlled at 40 ° C.,
Hold at 140 ° C for 5 minutes. The obtained molded product was evaluated for resin deterioration.

Casting material (A) ε-caprolactam 291 g Brommagnesium caprolactam 84 g Casting material (B) ε-caprolactam 167 g Polymerization initiator 167 g having the following chemical structure (However, Z in the formula represents polypropylene oxide having a molecular weight of about 5,000.) Appearance of sliding parts and evaluation results of deterioration of resin Table 1
Shown in.

Example 2 A bearing was resin-lined in the same manner as in Example 1 except that the following were used as the polymerization initiator contained in the casting material (A).

(However, Z in the formula represents polypropylene oxide having a molecular weight of about 5,000.) Table 1 shows the appearance of the sliding parts and the resin deterioration evaluation results.

Example 3 A bearing was resin-lined in the same manner as in Example 1 except that the following were used as the polymerization initiator contained in the casting material (A).

(However, Z in the formula represents polypropylene oxide having a molecular weight of about 5,000.) Table 1 shows the appearance of the sliding parts and the resin deterioration evaluation results.

Example 4 The bearing was resin-lined in the same manner as in Example 1 except that the following were used as the polymerization initiator contained in the casting material (A).

(However, Z in the formula represents polypropylene oxide having a molecular weight of about 5,000.) Table 1 shows the appearance of the sliding parts and the resin deterioration evaluation results.

Comparative Example 1 A bearing was resin-lined in the same manner as in Example 1 except that the following were used as the polymerization initiator contained in the casting material (A).

(In the formula, it represents a copolymer obtained by blocking the end of polypropylene oxide having a molecular weight of Z of about 5000 with polyethylene oxide.) Table 1 shows the appearance of the sliding part and the evaluation result of the deterioration of the resin.

As can be seen from Table 1, when the bearing is resin-lined using the casting material (B) in which the polymerization initiator is selected according to the present invention, the lining is not deteriorated or damaged even by a long-term sliding test at high temperature. It can be seen that this does not occur and there is no physical deterioration of the resin itself.

[Effects of the Invention] As described above, the sliding component produced by the monomer molding method of the present invention has excellent grease resistance and is a highly accurate sliding component having no rattling, which is a characteristic of the prior art. Yes, its industrial utility value is extremely high.

[Brief description of drawings]

FIG. 1 is a sectional view showing a sliding component manufactured according to an embodiment of the present invention. FIG. 2 is a plan view showing the sliding component of FIG. (1): Outer spline bearing (2): Inner spline shaft (3): Resin lining (4): Bearing inner surface (5) and (6): Centering center (7): Clearance

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location B29L 31:04 4F (72) Inventor Tadashi Murayama 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd. (72) Inventor Shoji Igawa 1 Toyota-cho, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Takahiro Iwase 1- Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Tsutomu Sugiura 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Automobile Co., Ltd. (72) Inventor Atsuyuki Tsuzuki 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Automobile Co., Ltd.

Claims (1)

[Claims] 1. A casting material containing the following compositions (A) and (B) is injected into a clearance between a bearing and a shaft which is fitted in the bearing and is rotatably or reciprocally supported. To form a resin lining on the surface of the shaft or the bearing, thereby producing a sliding component: (A) a liquid ω-lactam containing a polymerization catalyst of an alkali metal or alkaline earth metal compound; (B) Lactam polymerization initiator represented by the following formula Or (In the formula, Z is polypropylene oxide polyol, A
Is an aliphatic or aromatic hydrocarbyl group, Q is a lactam residue having a C _{3 to} C ₁₁ alkylene group, t is at least 1, m is 0 or 1, and
When m is 0, n is 0 or 1, p is 1. When m is 1, n is in the range of 1 to 3, p = n, and R ₁
Is an alkyl group, an aralkyl group, an alkyloxy group, an aryloxy group, a halogen group or an aralkyloxy group. ) A ω-lactam liquid containing at least one of