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and the indenter, it was calculated from Ei, which was an elasticity modulus of particles, using the following equa› tions 3 and 4. 

E$_{1}$ : elasticity modulus of particles (GPa) 

B$_{2}$ : elasticity modulus of the machine indenter (1140 GPa) 

B$_{3}$ : elasticity modulus of the machine stage (200 GPa) 

v$_{1}$ : Poisson’s ratio of particles (set at 0.4) 

v$_{2}$ : Poisson’s ratio of the machine indenter (0.07) 

v$_{3}$ : Poisson’s ratio of the machine stage (0.3) 

Ii: compressive displacement magnitude at the time of particle compression (µm) 

E*: complex elasticity modulus with an object to be determined (GPa) 

R$_{1 }$ radius of particle (µm) 

P: load (mN) 

The elasticity modulus was calculated using a deforma› tion range of 1-5% of a particle diameter that was an elastic deformation range. (7) Bulk Density: 

Particles were softly filled into a graduated cylinder of 10 ml, the weight of the particles in the graduated cylinder was measured, and the mass per unit volume was determined as the bulk density. (8) Touch Feeling: 

Using the obtained particles, a sensory test due to 8 panels was carried out. The estimation method was carried out by a sensory test with respect to three items of"foreign material feeling", "softness" and "smoothness" wherein a small amount of particles (about 0.02 g) were put on the back of a hand, and the particles were scrubbed by three fingers of another hand. With respect to the respective items, the average points of eight persons when the following rank points were allotted were ranked in accordance with the following standards. 

"Foreign Material Feeling" 

3 point: There is no foreign material feeling. 

2 point: There is slightly foreign material feeling. 

1 point: There is foreign material feeling. 

"Softness" 

3 point: soft feeling 

2 point: slightly soft feeling 

1 point: hard feeling 

"Smoothness" 

3 point: smooth 

2 point: slightly smooth 

1 point: There is a catching feeling. 

<Determination Standards> 

9.0-6.5 point: o 

6.4-4.5 point: ll 

4.4-3.0 point: x 

(9) Measurement of Lightness: 

Using a spectrophotometry "SE-2000" supplied by Nip› pon Denshoku Industries Co., Ltd., the lightness L was measured. As the standard, a standard white board attached to the equipment (y=95.99, x=94.04, z=113.10) was used. 

<img src='content_image/933220.jpg'>

(10) Quantitative Analysis of Sodium Acetate Contained in Polyvinyl Alcohol Group: 

It was determined by sodium acetate dissolution and titration method described in JIS "method for testing poly- vinyl alcohol" (10726 (1994)). 

## Reference Example 1 Washing 1 of Sodium Acetate in Polyvinyl Alcohol Group 

50 g of polyvinyl alcohol ( supplied by Nippon Synthetic Chemical Industry Co., Ltd., G-type "Gohsenol" (registered trademark) GM-14, weight average molecular weight: 29,000, SP value: 32.8 (J/cm 3 ) 112 , content of sodium acetate: 0.23 mass % ) and 500 ml of methanol were added in a 1 L round bottom flask, and stirred under a room temperature condition for one hour. Thereafter, the solution was filtrated by suction filtration (filter paper SA, 90 mmcp ). Following thereto, the same operation was repeated two times, totally three times, and then, by drying it at 80° C. for 10 hours, polyvinyl alcohol little with content of sodium acetate was obtained. The quantified sodium acetate in the obtained polyvinyl alcohol was 0.05 mass %. 

[ 3 ] 

## Example 1 Method for Producing Polyamide 1010 Polymer Particles 

24.5 g of polyamide 1010 (weight average molecular weight: 22,500, "Hiprolon" (registered trademark) -200, supplied by Hipro Polymers Co. Ltd.), 273.5 g ofN-methyl- 2-pyrrolidone as the organic solvent and 42 g of polyvinyl alcohol little with content of sodium acetate prepared in Reference Example 1 as the polymer B other than polyamide 1010 resin (weight average molecular weight: 29,000, SP value: 32.8 (J/cm 3 ) 112 ) were added into a 1,000 ml pressure resistant glass autoclave (supplied by Taiatsu Techno Cor› poration, Hyper Glaster, TEM-Vl 000N), after replaced with nitrogen of 99 volume % or more, heated up to 180° C., and stirred for 2 hours until the polymers were dissolved. At that time, the concentration of oxygen is 1 % or less theoretically. Thereafter, 350 g of ion exchange water was dropped as the poor solvent at a speed of 2.91 g/min. through a feeding pump. At the time added with the ion exchange water of about 110 g, the system changed to white color. After the whole amount of water was completely poured, the tem- perature was lowered while being stirred, the obtained suspension was filtered, re-slurry washing was performed by adding 700 g of ion exchange water, and the filtrated substances were vacuum dried at 80° C. for 10 hours to obtain 24.0 g of white solid material. When the obtained powder were observed by a scanning electron microscope, they were polyamide 1010 polymer particles having a true sphere-like particle shape (FIG. 7), an average particle diameter of 7.5 µm, and a particle diameter distribution index of 1.12. When wide angle X-ray diffraction spectrum was determined for the polyamide 1010 polymer particles, as diffraction angle 28, peaks were exhibited at positions of 20 degrees and 24 degrees (FIG. 1). Where, the melting point of the polyamide 1010 used in this Example was 207° C., the heat of fusion was 29.0 Jig, and the cooling crystal- lization temperature was 144° C. The SP value determined by the calculation method was 22.47 (J/cm 3 ) 112 . Further, the estimated value of the interfacial tension of this system was 2 mN/m or less. The solubility (room temperature) of polyamide relative to water, which was the poor solvent, was 0.1 mass % or less. 

The estimation results of the properties of the obtained polyamide 1010 polymer particles were shown in Table 1. 

