Fixing resin composition for use in rotor

Patent metadata

Field	Value
Publication number	US-9960646-B2
Application number	US-201113820367-A
Country	US
Kind code	B2
Filing date	Aug 29, 2011
Priority date	Sep 2, 2010
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

The fixing resin composition for use in a rotor includes a thermosetting resin (A) containing an epoxy resin, a curing agent (B), and an inorganic filler (C), wherein the content of the inorganic filler (C) is equal to or more than 50% by mass, based on 100% by mass of the total content of the fixing resin composition.

First claim

The invention claimed is:

1. A rotor provided with
a rotor core fixed and installed on a rotating shaft, in which a plurality of hole portions arranged along the peripheral portion of the rotating shaft are formed,
a magnet inserted in the hole portion, and
a fixing member, composed of a cured product of a fixing thermosetting resin composition, that fixes the magnet, the fixing member filled in a separation portion between the hole portion and the magnet and on at least a side wall on an inner peripheral side of the rotor core out of side walls of the magnet,
wherein the fixing thermosetting resin composition includes:
a thermosetting resin (A) containing an epoxy resin;
a curing agent (B); and
an inorganic filler (C),
wherein a total concentration of sodium ions and chlorine ions in the fixing thermosetting resin composition is equal to or less than 500 ppm, and
wherein the fixing thermosetting resin composition further includes a low-stress agent, and
the low-stress agent contains a polybutadiene compound, an acrylonitrile-butadiene copolymerization compound, or a silicone compound, and
wherein, when a cure torque of the fixing thermosetting resin composition is measured over time at a measurement temperature of 175° C. using a curelastometer, the cure torque value at 60 seconds after measurement initiation is defined as T 60 and the maximum cure torque value up to 300 seconds after measurement initiation is defined as T max , the ratio of the cure torque value at 60 seconds after measurement initiation to the maximum cure torque value up to 300 seconds after measurement initiation, T 60 /T max (%), is equal to or more than 50%.

2. The rotor according to claim 1 , wherein the inorganic filler (C) contains silica.

3. The rotor according to claim 2 , wherein the content of silica is equal to or more than 40% by mass, based on 100% by mass of the total content of the fixing resin composition.

4. The rotor according to claim 1 , wherein the fixing resin composition contains alumina and silica, as said inorganic filler (C), and a content of the alumina is equal to or less than 10% by mass, based on 100% by mass of the total content of the fixing resin composition.

5. The rotor according to claim 1 , wherein the inorganic filler (C) contains two or more kinds of spherical silica having different average particle diameters, D 50 .

6. The rotor according to claim 5 , wherein the average particle diameter D 50 is equal to or less than 75 μm.

7. The rotor according to claim 1 , wherein the curing agent (B) contains a phenolic resin.

8. The rotor according to claim 1 , wherein the fixing resin composition further includes a curing accelerator (D).

9. The rotor according to claim 8 , wherein the curing accelerator (D) contains at least one selected from the group consisting of a tetra-substituted phosphonium compound, a phosphobetaine compound, an adduct of a phosphine compound and a quinone compound, and an adduct of a phosphonium compound and a silane compound.

10. The rotor according to claim 1 , wherein the fixing resin composition further includes an inorganic flame retardant (G).

11. The rotor according to claim 10 , wherein the inorganic flame retardant (G) contains a metal hydroxide or a composite metal hydroxide.

12. The rotor according to claim 1 , wherein a concentration of sodium ions in the fixing resin composition is equal to or less than 100 ppm.

13. The rotor according to claim 1 , wherein a concentration of chlorine ions in the fixing resin composition is equal to or less than 100 ppm.

14. The rotor according to claim 1 , wherein
the fixing resin composition further includes an ion scavenger, and
the ion scavenger includes hydrotalcites, or hydrous oxides of elements selected from the group consisting of magnesium, aluminum, bismuth, titanium, and zirconium.

15. The rotor according to claim 1 , wherein the magnet is constituted with a neodymium magnet.

16. The rotor according to claim 1 , wherein the fixing member is formed by insert molding using the fixing resin composition in a tablet shape.

17. The rotor according to claim 1 , wherein when the fixing member is filled in the separation portion between the hole portion and the magnet by injecting the fixing resin composition into the separation portion, a slit flow length of the fixing resin composition is equal to or more than 30 mm, the slit flow length obtained by injection-molding the fixing resin composition in a mold radially provided with slits each having a width of 3 mm, a thickness of 80 and an open tip, under the conditions of a mold temperature of 175° C., a molding pressure of 6.9 MPa, an injection time of 20 seconds, and a curing time of 90 seconds, and measuring the length of the resin composition flowing out to the slit.

18. The rotor according to claim 1 , wherein a glass transition temperature (Tg) of the fixing member is equal to or higher than 150° C.

19. The rotor according to claim 1 , wherein a flexural strength of the fixing member at 150° C. is equal to or more than 70 MPa.

20. The rotor according to claim 1 , wherein a flexural elastic modulus of the fixing member at 150° C. is equal to or less than 1.6×10 4 MPa.

21. The rotor according to claim 1 , wherein in the region which is equal to or higher than 25° C. and equal to lower than the glass transition temperature (Tg), the linear expansion coefficient (α1) is equal to or more than 10 ppm/° C. and equal to or less than 25 ppm/° C.

22. The rotor according to claim 1 , wherein a high-formula viscosity of the fixing resin composition, as measured at a measurement temperature of 175° C. and a load of 10 kg, using a high-formula viscosity measurement device, is equal to or more than 6 Pa·s and equal to or less than 50 Pa·s.

23. The rotor according to claim 1 , wherein a gel time of the fixing resin composition at 175° C. is equal to or more than 10 seconds and equal to or less than 40 seconds.

24. The rotor according to claim 1 , wherein a spiral flow of the fixing resin composition is equal to or more than 50 cm.

25. An automobile provided with the rotor according to claim 1 .

26. The rotor according to claim 1 , wherein the total concentration of sodium ions and chlorine ions in the fixing resin composition is equal to or less than 500 ppm and more than 10 ppb.

27. The rotor according to claim 1 , wherein the thermosetting resin (A) is selected from the group consisting of an epoxy resin, a phenolic resin, an oxetane resin, a (meth)acrylate resin, an unsaturated polyester resin, a diallyl phthalate resin, a maleimide resin.

28. The rotor according to claim 1 , wherein a content of the thermosetting resin (A) is equal to or more than 5% by mass and equal to or less than 40% by mass based on 100% by mass of the total content of the fixing thermosetting resin composition.

29. The rotor according to claim 1 , wherein a content of the epoxy resin is equal to or more than 70% by mass and equal to or less than 100% by mass based on 100% by mass of the thermosetting resin (A).

30. A fixing thermosetting resin composition used for forming a fixing member in a rotor provided with
a rotor core fixed and installed over a rotating shaft, in which a plurality of hole portions arranged along the peripheral portion of the rotating shaft are formed,
a magnet inserted in the hole portion,

Assignees

• Sasajima Hideaki
• Sumitomo Bakelite Co

Inventors

• Sasajima Hideaki

Classifications

• C08L63/00

  Compositions of epoxy resins; Compositions of derivatives of epoxy resins · CPC title

• H02K1/2766 Primary

  having a flux concentration effect · CPC title

• C08L63/04

  Epoxynovolacs · CPC title

• C08G59/621

  Phenols · CPC title

• C08G59/688

  containing phosphorus · CPC title