FIBROUS BASIC MAGNESIUM SULFATE, PRODUCTION PROCESS THEREFOR AND RESIN COMPOSITION THEREOF

Abstract

Fibrous basic magnesium sulfate having excellent acid resistance. A fibrous powder comprising the fibrous basic magnesium sulfate, and an anionic surfactant (A) and a cationic surfactant (B), both coating the surface of the fibrous basic magnesium sulfate.

Claims

1. A fibrous powder comprising fibrous basic magnesium sulfate, and an anionic surfactant (A) and a cationic surfactant (B) , both coating the surface of the fibrous basic magnesium sulfate.

2. The fibrous powder according to claim 1, wherein the coating amount of the anionic surfactant (A) is 0.1 to 10 wt % based on the fibrous basic magnesium sulfate.

3. The fibrous powder according to claim 1, wherein the coating amount of the cationic surfactant (B) is 0.1 to 10 wt % based on the fibrous basic magnesium sulfate.

4. The fibrous powder according to claim 1 which has an average fiber length of 10 to 100 m, an average fiber diameter of 0.1 to 2 m and an average aspect ratio of 10 to 1,000.

5. The fibrous powder according to claim 1, wherein the chemical composition of the fibrous basic magnesium sulfate is Mg.sub.6(OH).sub.10.SO.sub.4.3H.sub.2O.

6. The fibrous powder according to claim 1, wherein the anionic surfactant (A) is at least one selected from the group consisting of carboxylic acid, sulfonic acid, sulfuric acid ester, phosphoric acid ester and salts thereof and has a hydrocarbon group having 10 to 40 carbon atoms as a hydrophobic group.

7. The fibrous powder according to claim 1, wherein the anionic surfactant (A) is at least one selected from compounds represented by the following formulas (1) and (2). ##STR00005## (In the above formulas, R.sup.a, R.sup.b and R.sup.c are the same or different and each a hydrocarbon group having 10 to 40 carbon atoms, and X.sup.1, X.sup.2 and X.sup.3 are the same or different and each a hydrogen atom or an alkali metal atom.)

8. The fibrous powder according to claim 1, wherein the cationic surfactant (B) is at least one selected from the group consisting of amine salts and quaternary ammonium salts and has a hydrocarbon group having 10 to 40 carbon atoms as a hydrophobic group.

9. The fibrous powder according to claim 1, wherein the cationic surfactant (B) is a quaternary ammonium salt represented by the following formula (3). ##STR00006## (In the above formula, R.sup.1 and R.sup.2 are the same or different and each a hydrocarbon group having 1 to 6 carbon atoms, and R.sup.3 and R.sup.4 are the same or different and each a hydrocarbon group having 10 to 40 carbon atoms. Y.sup.is a chlorine ion or a bromine ion.)

10. The fibrous powder according to claim 1, wherein the time from the start of adding 5.15 mL of 0.1N sulfuric acid to the end of addition is 10 minutes or longer in the following acid resistance testing method. (Acid Resistance Testing Method) 2 mL of 32 C. ethanol and a rotor are put into a beaker heated at 32 C., and the beaker is immersed in a thermostat (32 C.) to start stirring. After 1 minute, 0.1 g of a sample is injected into the beaker. One minute after the injection of the sample, 40 mL of 32 C. water is injected and a set of a pH meter electrode and a burette is immersed in the beaker. One minute after the injection of water, an automatic titrator (manufactured by DKK-TOA Corporation) is used to add 0. 1N sulfuric acid so that the pH of the test slurry always becomes 4.0 and the temperature thereof becomes 32 C. Titration is terminated when 5.15 mL of 0.1N sulfuric acid is added. Acid resistance is evaluated by a time from the start of adding 5.15 mL of 0.1N sulfuric acid to the end of addition.

11. A resin composition comprising 100 parts by weight of a resin and 0.1 to 200 parts by weight of the fibrous powder of claim 1.

12. A molded product of the resin composition of claim 11.

13. A process for producing the fibrous powder of claim 1, comprising the steps of: (i) dispersing fibrous basic magnesium sulfate in water, an organic solvent or a mixture thereof to prepare slurry; (ii) adding any one of an anionic surfactant (A) treatment solution or a cationic surfactant (B) treatment solution to the slurry under agitation; and (iii) adding the other treatment solution to the slurry under agitation.

14. The production process according to claim 13, wherein 0.1 to 10 wt % of the anionic surfactant (A) and 0.1 to 10 wt % of the cationic surfactant (B) are added based on the fibrous basic magnesium sulfate.

15. The production process according to claim 13, wherein a solution containing the anionic surfactant (A) is added to the slurry after a solution containing the cationic surfactant (B) is added.

Description

EXAMPLES

[0070] The following examples are provided for the purpose of further illustrating the present invention but are in no way to be taken as limiting. Physical properties were measured by the following methods in examples.

(a) Coating Amount of Anionic Surfactant (A) Phosphoric Acid Ester:

[0071] The phosphorus content of a sample was measured from absorbance by using a spectrophotometer. The amount of a phosphoric acid ester coated on the fibrous basic magnesium sulfate was calculated from the phosphorus content.

Stearic Acid:

[0072] The amount of stearic acid coated on the fibrous basic magnesium sulfate was calculated by an ether extraction method.

(b) Coating Amount of Cationic Surfactant (B) Tetradecylamine Acetate and Dioleyl Dimethylammonium Chloride:

[0073] After the nitrogen content of a sample was extracted by a Kjeldahl method, the nitrogen content was measured from absorbance by using a spectrophotometer. The amount of the cationic surfactant coated on the fibrous basic magnesium sulfate was calculated from the nitrogen content of the sample.

(c) Acid Resistance Testing Method

[0074] 2 ml of 32 C. ethanol and a rotor are put into a beaker heated at 32 C., and beaker is immersed in a thermostat (32 C.) to start stirring. After 1 minute, 0.1 g of a sample is injected into the beaker. One minute after the injection of the sample, 40 mL of 32 C. water is injected and a set of a pH meter electrode and a burette is immersed in the beaker. One minute after the injection of water, an automatic titrator (manufactured by DKK-TOA Corporation) is used to add 0.1N sulfuric acid so that the pH of the test slurry always becomes 4.0 and the temperature thereof becomes 32 C. Titration is terminated when 5.15 mL of 0.1N sulfuric acid is added. Acid resistance is evaluated by a time from the start of adding 5.15 mL of 0.1N sulfuric acid to the end of addition. As the time becomes longer, acid resistance becomes more excellent.

(d) Method of Measuring the Flexural Modulus of Resin Composition

[0075] 100 parts by weight of polypropylene, 6 parts by weight of a powder test sample and 12 parts by weight of talc were mixed and melt kneaded together by means of a double-screw extruder at about 180 C. to prepare a pellet. The obtained pellet was formed into a test piece having a length of 15 cm, a width of 5 cm and a thickness of 3 mm at about 200 C. by using an injection molding machine. This test piece was used to measure the flexural modulus of the resin composition in accordance with JIS. K. 7171.

(e) Method of Testing the Coating of a Resin Molded Article Containing the Test Powder

[0076] The coating stability and appearance of a resin composition containing the powder test sample were evaluated by an ion exchange water immersion test. A polypropylene primer (P.P. Primer of Rock Paint Co., Ltd.) was applied to one side of the test piece produced in the above testing method (d) and dried at 105 C. for 30 minutes. After drying, a top coating material (Planit #800 of Dai Nippon Toryo Co., Ltd.) was applied and dried at 105 C. for 30 minutes. The dried test piece was immersed in ion exchange water heated at 40 C. in a thermostat for 240 hours to check its coating stability and appearance after immersion. The coating stability and appearance were evaluated by the following methods.

Coating Stability:

[0077] After the resin test piece was immersed in ion exchange water, it was dried and cut with a cutter until the cutter reached the base of the resin to form 100 squares measuring 2 mm2 mm, and adhesive Cellophane tape was affixed to the surface of the resin and ripped off at 20 C. to count the number of remaining squares. 0 means that 100 squares remain, A means that 99 to 90 squares remain and X means that 89 or less squares remain.

Appearance:

[0078] After immersion in ion exchange water, the test piece was dried to check the existence of blisters on the coated surface visually. means that there are no blisters, means that there are 1 to 3 blisters and means that there are 4 or more blisters.

Reference Test

(Methylene Blue and Naphthol Yellow S Adsorption Test)

[0079] Commercially available fibrous basic magnesium sulfate (MOS.Math.HIGE of Ube Material Industries, Ltd.) was used to analyze the adsorption sites of the crystal surface. A methylene blue reagent and a naphthol yellow S reagent were each dissolved in ion exchange water to prepare 4 mg/L solutions.

[0080] 1.0 g of the fibrous basic magnesium sulfate powder was added to 200 mL of each of the prepared 4 mg/L solutions and kept stirred at 700 rpm with a chemical stirrer for 1 hour. After stirring, solid-liquid separation was carried out by centrifuging each of the obtained slurries, and the concentrations of methylene blue and naphthol yellow S were measured with a spectrophotometer. As a result, 0.20 mg of methylene blue and 0.12 mg of naphthol yellow S were adsorbed based on 1.0 g of the fibrous basic magnesium sulfate. Since both methylene blue which is existent as a cation and naphthol yellow S which is existent as an anion in an aqueous solution were adsorbed, it was found that a site having positive charge and a site having negative charge were existent on the crystal surface of the fibrous basic magnesium sulfate.

Comparative Example 1

(Preparation of Fibrous Basic Magnesium Sulfate Powder)

[0081] Fibrous basic magnesium sulfate was first synthesized by a conventionally known method. A magnesium hydroxide reagent was suspended in ion exchange water to prepare 635 mL of magnesium hydroxide slurry having a concentration of 138 g/L. 1,253 mL of a sulfuric acid reagent which was adjusted to have a concentration of 0.6 mol/L by using ion exchange water and 3.7 g of fibrous basic magnesium sulfate (MOS.Math.HIGE of Ube Material Industries, Ltd.) as a seed crystal were added to this slurry. This slurry was subjected to a hydrothermal treatment in an autoclave at 170 C. for 6 hours, and this treated slurry was filtered, washed with water, dried and pulverized to obtain a fibrous basic magnesium sulfate powder sample 1. The average fiber length, average fiber diameter, average aspect ratio and acid resistance of the powder sample 1 are shown in Table 1.

Example 1

(Surface Treatment of Fibrous Basic Magnesium Sulfate)

[0082] An anion surfactant (A) treatment solution and a cationic surfactant (B) treatment solution were first prepared.

[0083] 2.7 wt % of phosphoric acid ester (KMN-1018K of Sanyo Chemical Industries, Ltd.) was used as the anionic surfactant (A) based the fibrous basic magnesium sulfate. 2.2 mL of 0.2 mol/L NaOH and 50 mL of ion exchange water were added to 0.147 g of the phosphoric acid ester, and the resulting solution was emulsified to prepare the anionic surfactant (A) treatment solution.

[0084] 1 wt % of tetradecylamine acetate (Cation MA of NOF Corporation) was used as the cationic surfactant (B) based on the fibrous basic magnesium sulfate. 0.054 g of the tetradecylamine acetate was diluted with 50 mL of ion exchange water in a measuring cylinder to prepare the cationic surfactant (B) treatment solution.

[0085] The powder sample 1 prepared in Comparative Example 1 was suspended in ion exchange water to prepare 700 mL of slurry having a concentration of 7.76 g/L. This slurry was heated at 80 C. under agitation, and the anionic surfactant (A) treatment solution heated at 80 C. likewise was added to this slurry and kept stirred for 20 minutes. Thereafter, the cationic surfactant (B) treatment solution heated at 80 C. was added and kept stirred for 20 minutes.

[0086] The surface treated slurry was filtered, washed with water, dried and pulverized to obtain a fibrous basic magnesium sulfate powder sample 2. The average fiber length, average fiber diameter, average aspect ratio, acid resistance and coating amounts of the powder sample 2 are shown in Table 1.

Example 2

[0087] 2.7 wt % of phosphoric acid ester (KMN-1018K of Sanyo Chemical Industries, Ltd.) was used as the anionic surfactant (A) based on the fibrous basic magnesium sulfate. 3.3 mL of 0.2 mol/L NaOH and 50 mL of ion exchange water were added to 0.22 g of the phosphoric acid ester, and the resulting solution was emulsified to prepare the anionic surfactant (A) treatment solution.

[0088] 1 wt % of dioleyl dimethylammonium chloride (Cation 2-OLR of NOF Corporation) was used as the cationic surfactant (B) based on the fibrous basic magnesium sulfate. 0.1087 g of a dioleyl dimethylammonium chloride solution (75 wt % of an effective component) was diluted with 50 mL of ion exchange water in a measuring cylinder to prepare the cationic surfactant (B) treatment solution.

[0089] The powder sample 1 prepared in Comparative Example 1 was suspended in ion exchange water to prepare 800 mL of slurry having a concentration of 10.19 g/L. This slurry was heated at 80 C. under agitation, and the above anionic surfactant (A) treatment solution heated at 80 C. likewise was added to this slurry and kept stirred for 20 minutes. Thereafter, the cationic surfactant (B) treatment solution heated at 80 C. was added and kept stirred for 20 minutes.

[0090] The surface treated slurry was filtered, washed with water, dried and pulverized to obtain a fibrous basic magnesium sulfate powder sample 3. The average fiber length, average fiber diameter, average aspect ratio, acid resistance and coating amounts of the powder sample 3 are shown in Table 1.

Example 3

[0091] 1 wt % of dioleyl dimethylammonium chloride (Cation 2-OLR NOF Corporation) was used as the cationic surfactant (B) based on the fibrous basic magnesium sulfate. 0.1279 g of a dioleyl dimethylammonium chloride solution (75 wt % of an effective component) was diluted with 50 mL of ion exchange water in a measuring cylinder to prepare the cationic surfactant (B) treatment solution.

[0092] 2.7 wt % of phosphoric acid ester (KMN-1018K of Sanyo Chemical Industries, Ltd.) was used as the anionic surfactant (A) based on the fibrous basic magnesium sulfate. 3.9 mL of 0.2 mol/L NaOH and 50 mL of ion exchange water were added to 0.259 g of the phosphoric acid ester, and the resulting solution was emulsified to prepare the anionic surfactant (A) treatment solution.

[0093] The powder sample 1 prepared in Comparative Example 1 was suspended in ion exchange water to prepare 800 mL of slurry having a concentration of 11.99 g/L. This slurry was heated at 80 C. under agitation, and the above cationic surfactant (B) treatment solution heated at 80 C. likewise was added to this slurry and kept stirred for 20minutes. Thereafter, the anionic surfactant (A) treatment solution heated at 80 C. was added and kept stirred for 20 minutes.

[0094] The surface treated slurry was dehydrated, washed, dried and pulverized to obtain a fibrous basic magnesium sulfate powder sample 4. The average fiber length, average fiber diameter, average aspect ratio, acid resistance and coating amounts of the powder sample 4 arc shown in Table 1.

Example 4

[0095] 2 wt % of a stearic acid reagent was used as the anionic surfactant (A) based the fibrous basic magnesium sulfate. 2.9 mL of 0.2 mol/L NaOH and 50 mL of ion exchange water were added to 0.163 g of stearic acid to thermally dissolve it so as to prepare the anionic surfactant (A) treatment solution.

[0096] 1 wt % of dioleyl dimethylammonium chloride (Cation 2-OLR of NOF Corporation) was used as the cationic surfactant (B) based on the fibrous basic magnesium sulfate. 0.1087 g of a dioleyl dimethylammonium chloride solution (75 wt % of an effective component) was diluted with 50 mL of ion exchange water in a measuring cylinder to prepare the cationic surfactant (B) treatment solution.

[0097] The fibrous basic magnesium sulfate as the powder sample 1 prepared in Comparative Example 1 was suspended in ion exchange water to prepare 800 mL of slurry having a concentration of 10.19 g/L. This slurry was heated at 80 C. under agitation, and the anionic surfactant (A) treatment solution heated at 80 C. likewise was added to this slurry and kept stirred for 20 minutes. Thereafter, the cationic surfactant (B) treatment solution heated at 80 C. was added and kept stirred for 20 minutes.

[0098] The surface treated slurry was dehydrated, washed, dried and pulverized to obtain a fibrous basic magnesium sulfate powder sample 5. The average fiber length, average fiber diameter, average aspect ratio, acid resistance and coating amounts of the powder sample 5 are shown in Table 1.

Comparative Example 2

[0099] 2.7 wt % of phosphoric acid ester (KMN-1018K of Sanyo Chemical Industries, Ltd.) was used as the anionic surfactant (A) based the fibrous basic magnesium sulfate. 2.0 mL of 0.2 mol/L NaOH and 50 mL of ion exchange water were added to 0.14 g of the phosphoric acid ester, and the resulting solution was emulsified to prepare the anionic surfactant (A) treatment solution.

[0100] The powder sample 1 prepared in Comparative Example 1 was suspended in ion exchange water to prepare 700 mL of slurry having a concentration of 7.15 g/L. This slurry was heated at 80 C. under agitation, and the anionic surfactant (A) treatment solution heated at 80 C. likewise was added to this slurry and kept stirred for 20 minutes.

[0101] The surface treated slurry was dehydrated, washed, dried and pulverized to obtain a powder sample 6 treated with the anionic surfactant (A) alone. The average fiber length, average fiber diameter, average aspect ratio, acid resistance and coating amount of the powder sample 6 are shown in Table 1.

Comparative Example 3

[0102] 2 wt % of a stearic acid reagent was used as the anionic surfactant (A) based on the fibrous basic magnesium sulfate. 2.9 mL of 0.2 mol/L NaOH and 50 mL of ion exchange water were added to 0.163 g of stearic acid to thermally dissolve it so as to prepare the anionic surfactant (A) treatment solution.

[0103] The powder sample 1 prepared in Comparative Example 1 was suspended in ion exchange water to prepare 800 mL of slurry having a concentration of 10.19 g/L. This slurry was heated at 80 C. under agitation, and the anionic surfactant (A) treatment solution heated at 80 C. likewise was added to this slurry and kept stirred for 20 minutes.

[0104] The surface treated slurry was dehydrated, washed, dried and pulverized to obtain a powder sample 7 treated with the anionic surfactant (A) alone. The average fiber length, average fiber diameter, average aspect ratio, acid resistance and coating amount of the powder sample 7 are shown in Table 1.

Comparative Example 4

[0105] 1 wt % of tetradecylamine acetate (Cation MA of NOF Corporation) was used as the cationic surfactant (B) based on the fibrous basic magnesium sulfate. 0.082 g of the tetradecylamine acetate was diluted with 50 mL of ion exchange water in a measuring cylinder to prepare the cationic surfactant (B) treatment solution.

[0106] The powder sample 1 prepared in Example 1 was suspended in ion exchange water to prepare 800 mL of slurry having a concentration of 10.19 g/L. This slurry was heated at 80 C. under agitation, and the cationic surfactant (B) treatment solution heated at 80 C. likewise was added to this slurry and kept stirred for 20 minutes.

[0107] The surface treated slurry was dehydrated, washed, dried and pulverized to obtain a powder sample 8 treated with the cationic surfactant (B) alone. The average fiber length, average fiber diameter, average aspect ratio, acid resistance and coating amount of the powder sample 8 are shown in Table 1.

Comparative Example 5

[0108] 1 wt % of dioleyl dimethylammonium chloride (Cation 2-OLR of NOB Corporation) was used as the cationic surfactant (B) based on the fibrous basic magnesium sulfate. 0.1087 g of a dioleyl dimethyl ammonium chloride solution (75 wt % of an effective component) was diluted with 50 mL of ion exchange water in a measuring cylinder so prepare the cationic surfactant (B) treatment solution.

[0109] The powder sample 1 prepared in Comparative Example 1 was suspended in ion exchange water to prepare 800 mL of slurry having a concentration of 10.19 g/L. This slurry was heated at 80 C. under agitation, and the cationic surfactant (B) treatment solution heated at 80 C. likewise was added to this slurry and kept stirred for 20 minutes.

[0110] The surface treated slurry was dehydrated, washed, dried and pulverized to obtain a powder sample 9 treated with the cationic surfactant (B) alone. The average fiber length, average fiber diameter, average aspect ratio, acid resistance and coating amount of the powder sample 9 are shown in Table 1.

TABLE-US-00001 TABLE 1 (1) Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Anionic Type none phosphoric phosphoric phosphoric stearic acid surfactant acid ester acid ester acid ester (A) Coating 0 2.6 2.5 2.5 1.9 amount (wt % based on fibrous basic magnesium sulfate) Cationic Type None tetradecyl dioleyl dioleyl dioleyl surfactant amine dimethyl- dimethyl- dimethyl- (B) acetate ammonium ammonium ammonium chloride chloride chloride Coating 0 0.7 0.7 0.8 0.7 amount (wt % based on fibrous basic magnesium sulfate) Average fiber length (m) 50.2 51.8 52.6 48.6 49.5 Average fiber diameter (m) 0.6 0.6 0.5 0.5 0.6 Average aspect ratio () 65 67 72 61 65 Acid resistance (min) 3 18 31 37 15 Sample No. powder powder powder powder powder sample 1 sample 2 sample 3 sample 4 sample 5 (2) Comparative Comparative Comparative Comparative Example 2 Example 3 Example 4 Example 5 Anionic Type phosphoric stearic acid none none surfactant acid ester (A) Coating 2.6 1.9 0 0 amount (wt % based on fibrous basic magnesium sulfate) Cationic Type none none tetradecyl- dioleyl surfactant amine dimethyl- (B) acetate ammonium chloride Coating 0 0 0.7 0.8 amount (wt % based on fibrous basic magnesium sulfate) Average fiber length (m) 52.3 47.2 46.6 50.0 Average fiber diameter (m) 0.6 0.5 0.5 0.5 Average aspect ratio () 66 65 62 65 Acid resistance (min) 9 5 5 7 Sample No. powder powder powder powder sample 6 sample 7 sample 8 sample 9

[0111] It is understood from Table 1 that the fibrous powder of the present invention has improved acid resistance while it retains a high aspect ratio. It is also understood that the fibrous powder of the present invention has higher acid resistance than the fibrous basic magnesium sulfate treated with the anionic surfactant (A) alone and the fibrous basic magnesium sulfate treated with the cationic surfactant (B) alone.

Example 5

(Preparation of Resin Composition)

[0112] 6 parts by weight of the powder sample 2 prepared in Example 1, 100 parts by weight of polypropylene and 12 parts by weight of talc were mixed and melt kneaded together by means of a double-screw extruder at about 180 C. to prepare a pellet. The obtained pellet was formed into a test piece having a length of 15 cm, a width of 5 cm and a thickness of 3 mm at about 200 C. by means of an inj ection molding machine to obtain a resin sample 1. The flexural modulus of the resin sample 1 is shown in Table 2.

(Coating on Resin Composition)

[0113] A commercially available polypropylene primer (P.P. Primer of Rock Paint Co., Ltd.) was applied to half of the surface of the resin sample 1 with a bar coater to a film thickness of 25 m and dried at 105 C. for 30 minutes. After drying, a commercially available top coating material (Planit #800 of Dai Nippon Toryo Co., Ltd.) was applied to a film thickness of 25 um with a bar coater and dried at 105 C. for 30 minutes. The dried test piece was immersed in ion exchange water heated at 40 C. in a thermostat for 240 hours. After immersion, the coating stability and appearance of the dried test piece were evaluated. The results are shown in Table 2.

Example 6

[0114] A resin composition was prepared by using the powder sample 3 prepared in Example 2 in the same manner as in Example 5 to obtain a resin sample 2. The flexural modulus of the resin sample 2 is shown in Table 2. After a primer and a top coating material were applied to half of the surface of the resin sample 2 in the same manner as in Example 5 and immersed in ion exchange water, the coating stability and appearance of the resin sample 2 were evaluated. The results are shown in Table 2.

Example 7

[0115] A resin composition was prepared by using the powder sample 4 prepared in Example 3 in the same manner as in Example 5 to obtain a resin sample 3. The flexural modulus of the resin sample 3 is shown in Table 2. After a primer and a top coating material were applied to half of the surface of the resin sample 3 in the same manner as in Example 5 and immersed in ion exchange water, the coating stability and appearance of the resin sample 3 were evaluated. The results are shown in Table 2.

Example 8

[0116] A resin composition was prepared by using the powder sample 5 prepared in Example 4 in the same manner as in Example 5 to obtain a resin sample 4. The flexural modulus of the resin sample 4 is shown in Table 2. After a primer and a top coating material were applied to half of the surface of the resin sample 4 in the same manner as in Example 5 and immersed in ion exchange water, the coating stability and appearance of the resin sample 9 were evaluated. The results are shown in Table 2.

Comparative Example 6

[0117] A resin composition was prepared by using the powder sample 1 prepared in Comparative Example 1 in the same manner as in Example 5 to obtain a resin sample 5. The flexural modulus of the resin sample 5 is shown in Table 2. After a primer and a top coating material were applied to half of the surface of the resin sample 5 in the same manner as in Example 5 and immersed in ion exchange water, the coating stability and appearance of the resin sample 5 were evaluated. The results are shown in Table 2.

Comparative Example 7

[0118] A resin composition was prepared by using the powder sample 6 prepared in Comparative Example 2 in the same manner as in Example 5 to obtain a resin sample 6. The flexural modulus of the resin sample 6 is shown in Table 2. After a primer and a top coating material were applied to half of the surface of the resin sample 6 in the same manner as in Example 5 and immersed in ion exchange water, the coating stability and appearance of the resin sample 6 were evaluated. The results are shown in Table 2.

Comparative Example 8

[0119] A resin composition was prepared by using the powder sample 7 prepared in Comparative Example 3 in the same manner as in Example 5 to obtain a resin sample 7. The flexural modulus of the resin sample 7 is shown in Table 2. After a primer and a top coating material were applied to half of the surface of the resin sample 7 in the same manner as in Example 5 and immersed in ion exchange water, the coating stability and appearance of the resin sample 7 were evaluated. The results are shown in Table 2.

Comparative Example 9

[0120] A resin composition was prepared by using the powder sample 8 prepared in Comparative Example 4 in the same manner as in Example 5 to obtain a resin sample 8. The flexural modulus of the resin sample 8 is shown in Table 2. After a primer and a top coating material were applied to half of the surface of the resin sample 8 in the same manner as in Example 5 and immersed in ion exchange water, the coating stability and appearance of the resin sample 8 were evaluated. The results are shown in Table 2.

Comparative Example 10

[0121] A resin composition was prepared by using the powder sample 9 prepared in Comparative Example 5 in the same manner as in Example 5 to obtain a resin sample 9. The flexural modulus of the resin sample 9 is shown in Table 2. After a primer and a top coating material were applied to half of the surface of the resin sample 9 in the same manner as in Example 5 and immersed in ion exchange water, the coating stability and appearance of the resin sample 9 were evaluated. The results are shown in Table 2.

TABLE-US-00002 TABLE 2 (1) Example Example Example Example 5 6 7 8 Powder sample 2 6 (parts by weight) Powder sample 3 6 (parts by weight) Powder sample 4 6 (parts by weight) Powder sample 5 6 (parts by weight) Polypropylene 100 100 100 100 (parts by weight) Talc 12 12 12 12 (parts by weight) Flexural modulus 2002 1994 2020 1964 (MPa) Coating stability (//X) Appearance (//X) Resin sample No. Resin Resin Resin Resin sample sample sample sample No. 1 No. 2 No. 3 No. 4 (2) C. Ex. 6 C. Ex. 7 C. Ex. 8 C. Ex. 9 C. Ex. 10 Powder sample 1 6 (parts by weight) Powder sample 6 6 (parts by weight) Powder sample 7 6 (parts by weight) Powder sample 8 6 (parts by weight) Powder sample 9 6 (parts by weight) Polypropylene 100 100 100 100 100 (parts by weight) Talc 12 12 12 12 12 (parts by weight) Flexural modulus 2020 1960 1980 1976 2015 (MPa) Coating stability X X X (//X) Appearance X X X X X (//X) Resin sample No. Resin Resin Resin Resin Resin sample sample sample sample sample No. 5 No. 6 No. 7 No. 8 No. 9 C. Ex.: Comparative Example

[0122] It is understood from the evaluation results of coating stability and appearance shown in Table 2 that the resin composition of the present invention has improved coating stability as the peeling of the coating material and blisters are suppressed after immersion in ion exchange water. A big difference i.n flexural modulus among samples is not seen. It is understood from above that the resin composition of the present invention has excellent coating stability while it retains a high flexural modulus.

EFFECT OF THE INVENTION

[0123] The fibrous powder of the present invention has excellent acid resistance. The resin composition of the present invention has a good appearance and excellent coating stability.