WATER-SOLUBLE LUBRICANT COMPOSITION FOR PLASTICALLY WORKING ALUMINUM MATERIAL

Abstract

A water-soluble lubricant composition for warm and hot plastically working of an aluminum material comprising (A) hydrophilic polyester resin, (B) alkali metal salt of a polymaleic acid resin, (C) alkali metal salt of carboxylic acid and (D) water, and optionally (E) a wax.

Claims

1. A water-soluble lubricant composition for warm and hot plastically working of an aluminum material comprising (A) hydrophilic polyester resin, (B) alkali metal salt of a polymaleic acid resin, (C) alkali metal salt of carboxylic acid and (D) water.

2. A composition as defined in claim 1 wherein further (E) a wax is contained.

3. A composition as defined in claim 1, wherein the hydrophilic polyester resin is a hydrophilic polyester resin having a naphthalene structure or a bisphenol structure.

4. A composition as defined in claim 3 wherein the hydrophilic polyester resin is a hydrophilic polyester resin having a bisphenol structure.

5. A composition as defined in claim 1, wherein the hydrophilic polyester resin is a polyester resin having at least one of an alkali metal salt, an ammonium salt or an amine salt of a carboxyl group, an alkali metal salt, an ammonium salt or an amine salt of a sulfonyl group as a hydrophilic functional group.

6. A composition as defined in claim 1, wherein the hydrophilic polyester resin has a glass transition temperature (Tg) of −20 to 200° C.

7. A composition as defined in claim 6, wherein the hydrophilic polyester resin has a glass transition temperature (Tg) of 40 to 110° C.

8. A composition as defined in claim 1, wherein the hydrophilic polyester resin is a hydrophilic polyester resin having a bisphenol structure having a glass transition temperature (Tg) of 40 to 110° C.

9. A composition as defined in claim 1, which comprises 0.01 to 10% by weight of (A), 0.01 to 10% by weight of (B), 0.01 to 20% by weight of (C), the balance being (D).

10. A composition as defined in claim 2, which comprises 0.01 to 10% by weight of (A), 0.01 to 10% by weight of (B), 0.01 to 20% by weight of (C), 0.01 to 10% by weight of (E), the balance being (D).

11. A lubricant composition for spinning of an aluminum wheel according to claim 1.

Description

EXAMPLES

[0044] The invention will be described in more detail with reference to the following examples and comparative examples to which, however, the invention is not limited.

Examples 1 to 11 and Comparative Examples 1 to 6

[0045] Sodium hydroxide was added to water to form a solution, and then polymaleic acid resin was added thereto while heating and stirring at 80° C. to obtain a solution by neutralization reaction. After dissolving the polymaleic acid resin, NaOH was further added to the solution to form a solution, and carboxylic acid was added while heating and stirring at 80° C. to obtain a solution by neutralization reaction. After cooling the aqueous solution to room temperature, a hydrophilic polyester resin was added and stirred to prepare a solution. Next, wax was optionally added and mixed. In this manner, lubricant compositions for water-soluble plastic working of aluminum materials of Examples and Comparative Examples having the blending amounts described in the Table were prepared.

[0046] In Tables 1 to 5, the numerical values of the amounts in each Table indicate the weight % of the solid content. As Comparative Example 1, a composition containing a graphite-based lubricant was prepared and used for comparison. As Comparative Example 2, a composition containing the polyester resin used in Patent Literature 2 was prepared and used for comparison.

[0047] As Comparative Example 3, a composition containing the polyester resin used in Patent Literature 2, an alkali metal salt of an inorganic acid and wax, which also containing the components in the same amounts as in Patent Literature 2 was prepared and used for comparison.

[0048] As Comparative Example 4, a composition not containing the alkali metal salt of polymaleic acid resin of Example 9 was prepared and used for comparison. As Comparative Example 5, a composition not containing the alkali metal salt of carboxylic acid of Example 9 was prepared and used for comparison. In Comparative Example 6, a composition in which the alkali metal salt of polymaleic acid resin of Example 9 was substituted with hydroxyethyl cellulose was prepared and used for comparison.

[0049] In the Table, the following hydrophilic polyester resin (A) was used.

(A-1) Polyethylene terephthalate (PET) type polyester aqueous dispersion
Molecular weight: 3000
Hydrophilic group: —COONH.sub.4

Tg: 52° C.

[0050] (A-2) PET type polyester aqueous dispersion
Molecular weight: 20000
Hydrophilic group: —SO.sub.3Na

Tg: 77° C.

[0051] (A-3) PET type polyester aqueous dispersion
Molecular weight: 15000
Hydrophilic group: —SO.sub.3Na

Tg: 20° C.

[0052] (A-4) PET type polyester aqueous dispersion
Molecular weight: 15000
Hydrophilic group: —SO.sub.3Na

Tg: −20° C.

[0053] (A-5) Polyethylene naphthalate (PEN) type polyester aqueous dispersion
Molecular weight: 26000
Hydrophilic group: —SO.sub.3Na

Tg: 40° C.

[0054] (A-6) PEN type polyester aqueous dispersion
Molecular weight: 26000
Hydrophilic group: —SO.sub.3Na

Tg: 110° C.

[0055] (A-7) PEN type polyester aqueous dispersion
Molecular weight: 28000
Hydrophilic group: —SO.sub.3Na (less than that of (A-6)

Tg: 110° C.

[0056] (A-8) Bisphenol A type polyester aqueous dispersion
(Carboxylic acid/bisphenol A series)
Molecular weight: 4000
Hydrophilic group: —COOH/amine

Tg: 60° C.

[0057] (A-9) Bisphenol A type polyester aqueous dispersion
Molecular weight: 5000
The carboxylic acid moiety is different from (A-8).
Hydrophilic group: —COOH/amine

Tg: 72° C.

[0058] (A-10) Bisphenol A type polyester aqueous dispersion
Molecular weight: 4500
The carboxylic acid moiety is different from (A-8) and (A-9).
Hydrophilic group: —COOH/amine

Tg: 65° C.

[0059] (A-11) Polyester polyol
Molecular weight: unknown
Hydrophilic group: None

Tg: −36° C.

[0060] In the Table, the following sodium salt of polymaleic acid resin (B) was used.

(B-1) Sodium salt of isobutylene maleic anhydride

[0061] In the Table, the following alkali metal salt of carboxylic acid (C) was used.

(C-1) disodium adipate
(C-2) disodium isophthalate
In the Table, the following wax (E) was used.

(E-1) Paraffin wax

[0062] In the Table, the following cellulose type polymer (F) was used.
(F-1) hydroxyethyl cellulose
In the Table, the following alkali metal salt of inorganic acid (G) was used.
(G-1) sodium pyrophosphate
In the Table, the following commercially available graphite-based lubricant (H) was used.
(H-1) graphite-based lubricant

Spray Coating Hardness

[0063] The lubricant composition for water-soluble plastic working of aluminum materials of Examples and Comparative Examples was spray-coated on an iron mold heated to 300° C. under the conditions of spray pressure of 0.3 MPa, spray distance of 300 mm, 4 cc/10 sec. After spray application, the mold temperature was returned to room temperature, and the film hardness was judged by the degree of peeling of the coating film when the film adhered to the mold was rubbed with cloth. When rubbed ten times, it is “x soft” for those in which the base of the mold can easily be watched, and “◯ hard” for the case where the coating does not easily peel off even if rubbed 10 times.

Lubricity Test

[0064] Friction coefficient was measured by ring compression test. The lubricant composition for water-soluble plastic working of aluminum materials of Examples and Comparative Examples was spray-coated on an iron mold under the above spraying conditions. The mold was set in a 100 t press. Next, an aluminum ring (material: A5052, shape: φ54×φ27×18 mm) was heated to 350° C. in an electric furnace and pressed between upper and lower molds. The friction coefficient was calculated by compression rate and inner diameter deformation.

Presence or Absence of Aluminum Weld to Mold

[0065] After the ring compression test, the degree of aluminum adhesion on the mold surface was evaluated by appearance. “X presence” indicates that aluminum welding is observed, and “O absence” indicates that aluminum welding is not observed.

TABLE-US-00001 TABLE 1 composition Ex. 1 Ex. 2 Ex. 3 Ex. 4 hydrophilic A-1 0.8 — — — polyester A-2 —  0.65 — — resin (A) A-3 — —  0.25 — A-4 — — —  0.25 A-5 — — — — A-6 — — — — A-7 — — — — A-8 — — — — A-9 — — — — A-10 — — — — A-11 — — — — alkali metal salt of B-1 1.6 1.6 1.6 1.6 polymaleic acid resin (B) alkali metal salt of C-1 7.2 7.2 7.2 7.2 carboxylic acid (C) C-2 — — — — wax (E) E-1 — 0.8 0.5 0.5 cellulose type F-1 — — — — polymer (F) alkali metal salt of G-1 — — — — inorganic acid (G) commercially H-1 — — — — available graphite- based lubricant (H) water (D) balance balance balance balance spray coating hardness ◯ hard ◯ hard ◯ hard ◯ hard ring friction  0.128  0.112  0.145  0.143 compression coefficient test presence or ◯ ◯ ◯ ◯ absence of absence absence absence absence aluminum weld to mold

TABLE-US-00002 TABLE 2 composition Ex. 5 Ex. 6 Ex. 7 Ex. 8 hydrophilic A-1 — — — — polyester A-2 — — — — resin (A) A-3 — — — — A-4 — — — — A-5  0.25 — — — A-6 — 0.4 0.8 — A-7 — — — 0.4 A-8 — — — — A-9 — — — — A-10 — — — — A-11 — — — — alkali metal salt of B-1 1.6 1.6 1.6 1.6 polymaleic acid resin (B) alkali metal salt of C-1 7.2 7.2 — 7.2 carboxylic acid (C) C-2 — — 7.2 — wax (E) E-1 — — — — cellulose type F-1 — — — — polymer (F) alkali metal salt of G-1 — — — — inorganic acid (G) commercially H-1 — — — — available graphite- based lubricant (H) water (D) balance balance balance balance spray coating hardness ◯ hard ◯ hard ◯ hard ◯ hard ring friction  0.119  0.133  0.110  0.132 compression coefficient test presence or ◯ ◯ ◯ ◯ absence of absence absence absence absence aluminum weld to mold

TABLE-US-00003 TABLE 3 Com. composition Ex. 9 Ex. 10 Ex. 11 Ex. 1 hydrophilic A-1 — — — — polyester A-2 — — — — resin (A) A-3 — — — — A-4 — — — — A-5 — — — — A-6 — — — — A-7 — — — — A-8  0.25 — — — A-9 —  0.25 — — A-10 — —  0.25 — A-11 — — — — alkali metal salt of B-1 1.6 1.6 1.6 1.6 polymaleic acid resin (B) alkali metal salt of C-1 7.2 7.2 7.2 7.2 carboxylic acid (C) C-2 — — — — wax (E) E-1 0.5 0.5 0.5 — cellulose type F-1 — — — — polymer (F) alkali metal salt of G-1 — — — — inorganic acid (G) commercially H-1 — — — 1.3 available graphite- based lubricant (H) water (D) balance balance balance balance spray coating hardness ◯ hard ◯ hard ◯ hard ◯ hard ring friction  0.131  0.135  0.131  0.145 compression coefficient test presence or ◯ ◯ ◯ ◯ absence of absence absence absence absence aluminum weld to mold

TABLE-US-00004 TABLE 4 Comparative Example composition 2 3 4 5 6 hydrophilic A-1 — — — — — polyester A-2 — — — — — resin (A) A-3 — — — — — A-4 — — — — — A-5 — — — — — A-6 — — — — — A-7 — — — — — A-8 — —  0.25  0.25  0.25 A-9 — — — — — A-10 — — — — — A-11 0.4 5.0 — — — alkali metal salt B-1 1.6 — — 1.6 — of polymaleic acid resin (B) alkali metal salt of C-1 7.2 — 7.2 — 7.2 carboxylic acid (C) C-2 — — — — — wax (E) E-1 — 1.0 0.5 0.5 0.5 cellulose type F-1 — — — — 1.6 polymer (F) alkali metal salt of G-1 — 5.0 — — — inorganic acid (G) commercially H-1 — — — — — available graphite-based lubricant (H) water (D) balance balance balance balance balance spray coating hardness x soft x soft x soft x soft x soft ring friction  0.191  0.3<  0.198  0.3<  0.139 compression coefficient test presence or X X X X X absence of presence presence presence presence presence aluminum weld to mold

[0066] Comparative Examples 2 and 3 in which a hydrophilic polyester resin used in Patent Literature 2 and having low glass transition temperature (Tg) of −36° C. was blended, were inferior in all of spray coating hardness, coefficient of friction, aluminum deposition to the metal mold to that of the graphite-based lubricant of Comparative Example 1.

[0067] The hydrophilic polyester resin blend system of Examples 1 to 11 exhibited lubricity equal to or higher than that of the graphite-based lubricant of Comparative Example 1. Above all, Examples 5 to 11 in which the hydrophilic polyester resin having the naphthalene structure or the bisphenol structure was blended show higher lubricity of friction coefficient of less than 0.14 at a lower concentration than that of Examples 1 to 4 in which the terephthalic acid type hydrophilic polyester resin was used. In particular, Examples 9 to 11 are particularly preferable in which the hydrophilic polyester resin having the bisphenol structure was blended because higher lubricity of friction coefficient of less than 0.14 was stably obtained at a lower concentration.

[0068] After the ring compression test of Examples 1 to 11, excellent releasability was observed without sticking of the aluminum ring to the mold and aluminum welding. This is considered that the spray coating film was hard and excellent in heat resistance, and the metal contact was suppressed because the film followed between the metal mold and the aluminum material.

[0069] Comparative Example 4 in which alkali metal salt of polymaleic acid resin was not contained, Comparative Example 5 in which alkali metal salt of the carboxylic acid was not contained, Comparative Example 6 in which alkali metal salt of polymaleic acid resin was substituted with cellulose type polymer, all of them were inferior to those of the graphite-based lubricant of Comparative Example 1 in all of spray coating hardness, friction coefficient and aluminum welding to metal mold. From this, it was found that (A) hydrophilic polyester resin, (B) alkali metal salt of polymaleic acid resin, (C) alkali metal salt of carboxylic acid, and (D) water are essential components.

[0070] The lubricants for water-soluble plastic working of aluminum materials of Example 2 and Example 9 were evaluated on an actual machine using a spinning machine. A pre-determined amount of lubricant was spray coated to a heated mandrel (mold). Subsequently, a heated aluminum wheel for automobiles was installed to the mandrel and the lubricant was spray coated also on the rim portion of the aluminum wheel. Thereafter, spinning was applied to the rim portion of the aluminum wheel. After machining 3,200 aluminum wheels of 14 to 20 inches, excellent results were obtained both in moldability (dimensional accuracy) and releasability.

INDUSTRIAL APPLICABILITY

[0071] The water-soluble lubricant composition for plastically working of an aluminum material of the present invention exhibits lubricity and releasability equal to or higher than that of a graphite-based lubricant even under severe environments of warm and hot plastic working. Accordingly, the present lubricant can be suitably used as a lubricant for water-soluble plastic working of aluminum material.