Claims
- 1. An additive for synthetic resins which comprises particles which are surface-coated with petaloid porous hydroxyapatite having a chemical formula Ca.sub.5 (PO.sub.4).sub.3 (OH), the petaloid porous hydroxyapatite being contained in the particles in a ratio of not less than 5% by weight, and the particles satisfying the following formulas (a)-(d):
- (a) 0.1.ltoreq.dx1.ltoreq.20(.mu.m)
- (b) 1.ltoreq..alpha..ltoreq.2, where .alpha.=d20/dx1
- (c) 0.ltoreq..beta..ltoreq.1.7, where .beta.=(d90-d10)/d50, and
- (d) 40/dx1.ltoreq.Sw1.ltoreq.400
- wherein,
- dx1: Average particle diameter (.mu.m) measured by a photograph of an electron microscope;
- .alpha.: Dispersion coefficient;
- d50: 50% average particle diameter (.mu.m) measured by a particle size distribution tester using a microtrack FRA laser;
- .beta.: Sharpness; a particle size distribution value; the smaller the value becomes, the sharper the distribution becomes;
- d90: 90% particle diameter of the total particles passed through a sieve measured by a particle size distribution tester using a microtrack FRA laser;
- d10: 10% particle diameter of the total particles passed through a sieve measured by a particle size distribution tester using a microtrack FRA laser;
- Sw1: BET specific surface m.sup.2 /g by a nitrogen adsorbing method.
- 2. The additive for synthetic resins of claim 1, wherein the particles have the average particle diameter dx1 satisfying the following formula (e):
- (e) 0.25.ltoreq.dx1.ltoreq.10(.mu.m).
- 3. The additive for synthetic resins of claim 1, wherein the particles have the average particle diameter dx1 satisfying the following formula (f):
- (f) 0.5.ltoreq.dx1.ltoreq.8(.mu.um).
- 4. The additive for synthetic resins of claim 1, wherein the particles have the dispersion coefficient a and the sharpness B both satisfying the following formulas (g) and (h), respectively:
- (g) 1.ltoreq..alpha..ltoreq.1.5; and
- (h) 0.ltoreq..beta..ltoreq.1.0.
- 5. The additive for synthetic resins of claim 1, wherein the particles have the BET specific surface Sw1 satisfying the following formula (i):
- (i) 100/dx1.ltoreq.Sw1.ltoreq.350.
- 6. The additive for synthetic resins of claim 1, wherein the particles satisfy the following formulas (j)-(l):
- (j) 0.01.ltoreq.dx2.ltoreq.1(.mu.m);
- (k) 90.ltoreq..omega.1.ltoreq.99, and
- (l) 60.ltoreq..omega.2.ltoreq.95
- wherein,
- dx2: Average micropore diameter (.mu.m) of particles measured from a distribution of the micropore measured by a mercury penetration method,;
- .omega.1. : Static percentage of voids (%) calculated from the following equation (m): ##EQU3## wherein the apparent specific volume (ml/g) is measured according to a static method of pigment test of JIS K5101-91 20.1,
- .omega.62: Pressurized percentage of voids (%) calculated from the following equation (n): ##EQU4## wherein the thicknes is measured by a slide calipers after packing 0.5 g of a sample in a cylinder having a section of 2 cm.sup.2, pressurizing the sample with a pressure of 30 kg/cm.sup.2 for 30 seconds.
- 7. The additive for synthetic resins of claim 1, wherein the particles satisfy the following formulas (o) and (p);
- (o) 95.ltoreq..omega.1.ltoreq.99, and
- (p) 70.ltoreq..omega.2.ltoreq.95.
- 8. The additive for synthetic resins of claim 1, wherein the weight of the petaloid porous hydroxyapatite with respect to the particle weight is not less than 25% by weight.
- 9. The additive for synthetic resins of claim 1, wherein the weight of the petaloid porous hydroxyapatite with respect to the particle weight is not less than 50% by weight.
- 10. The additive for synthetic resins of claim 1, wherein the weight of the petaloid porous hydroxyapatite with respect to the particle weight is not less than 90% by weight.
- 11. The additive for synthetic resins of claim 1, wherein the additive for synthetic resins is an anti-blocking agent for synthetic resins.
Priority Claims (1)
Number |
Date |
Country |
Kind |
7-200504 |
Jul 1995 |
JPX |
|
Parent Case Info
This application is a division of prior application Ser. No. 08/983,291, filed Jan. 12, 1998, now U.S. Pat. No. 5,844,022.
US Referenced Citations (4)
Foreign Referenced Citations (1)
Number |
Date |
Country |
7-118011 |
Sep 1995 |
JPX |
Divisions (1)
|
Number |
Date |
Country |
Parent |
983291 |
Jan 1998 |
|