JP2006193736A - Fiber reinforced polypropylene resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fiber reinforced polypropylene resin composition capable of obtaining molded articles which reduce the lowering of mechanical strength and reduce surface white spots when molded into the molded articles, pellets, and their molded articles. <P>SOLUTION: The fiber reinforced polypropylene resin composition comprises 20-95 wt.% polypropylene resin and 80-5 wt.% glass fibers which are composed of glass monofilaments and a bundling agent, have a weight average fiber length of 2-100 mm and an ignition loss of 0.5-1.5 wt.%, and the pellets are composed of the composition, and the molded articles are composed of the pellets. Further, the fiber reinforced polypropylene resin composition comprises a resin mixture of 99.9-60 wt.% polypropylene resin and 0.1-40 wt.% modified polyolefin resin and, based on 100 pts.wt. the above resin mixture, 5-400 pts.wt. glass fibers which are composed of glass monofilaments and the bundling agent, have a weight average fiber length of 2-100 mm and an ignition loss of 0.5-1.5 wt.%, and the pellets are composed of the composition, and the molded articles are composed of the pellets. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fiber reinforced polypropylene resin composition and pellets thereof, and a molded body made of the resin composition or pellets. More specifically, when formed into a molded body, a fiber-reinforced polypropylene resin composition and pellets thereof that can provide a molded body with less reduction in mechanical strength and reduced surface white spots, and the resin composition or The present invention relates to a molded article that is made of pellets, has little decrease in mechanical strength, and has reduced white spots on the surface.

Conventionally, it is known that fillers, glass fibers, and the like are blended as means for improving mechanical strength such as rigidity and impact strength of polypropylene resin.
For example, Chapter 6 of “Interface Control and Composite Material Design” (Fumio Ide, Sigma Publishing (1995)) describes a polypropylene resin composition with enhanced mechanical strength using glass fiber. ing.

  JP-A-3-121146 contains a resin component composed of a polyolefin and a modified olefin polymer as a molding polyolefin resin composition having improved mechanical strength and the like, and reinforcing fibers, A fiber reinforced molding polyolefin resin composition having a length of at least 2 mm in the resin is described.

Japanese Patent Laid-Open No. 3-121146 Interface Control and Composite Material Design (Fumio Ide, Sigma Publishing (1995)) Chapter 6

However, the fiber reinforced polypropylene resin composition described in the above-mentioned publication ("Interface control and composite material design") or patent publication (Japanese Patent Laid-Open No. 3-121146), or pellets obtained from the resin composition Further reduction of the white spots on the surface of the molded body made of was desired.
Under such circumstances, the object of the present invention is to provide a fiber-reinforced polypropylene resin composition and its pellets, which, when formed into a molded body, yields a molded body with little reduction in mechanical strength and reduced surface white spots. An object of the present invention is to provide a molded article comprising the resin composition or pellets, having a small decrease in mechanical strength and reduced white spots on the surface.

As a result of intensive studies in view of the actual situation, the present inventors have found that the present invention can solve the above problems, and have completed the present invention.
That is, the present invention
Polypropylene resin (component (A)) 20 to 95% by weight, glass monofilament (B-I) and sizing agent (B-II), weight average fiber length of 2 to 100 mm, ignition loss 0. Fiber reinforced polypropylene resin composition containing glass fiber (component (B)) 80 to 5% by weight which is 5 to 1.5% by weight (however, the total amount of fiber reinforced polypropylene resin composition is 100% by weight) It is related to.

The present invention also provides:
A resin mixture (D) containing 99.9 to 60% by weight of a polypropylene resin (component (A)) and 0.1 to 40% by weight of a modified polyolefin resin (component (C)) (however, the resin mixture (D )), And 100 parts by weight of the resin mixture (D) is composed of a glass monofilament (B-I) and a sizing agent (B-II), and has a weight average fiber length of 2 to 2. The fiber-reinforced polypropylene resin composition contains 5 to 400 parts by weight of glass fiber (component (B)) having a thickness of 100 mm and an ignition loss of 0.5 to 1.5% by weight.

  And this invention concerns on the pellet which consists of said fiber reinforced polypropylene resin composition, and also this invention is a molded object which consists of said fiber reinforced polypropylene resin composition, or a molded object which consists of the pellet It is related to.

  According to the present invention, when formed into a molded body, a fiber-reinforced polypropylene resin composition and its pellets that can provide a molded body with little reduction in mechanical strength and reduced surface white spots, and the resin composition Alternatively, it is possible to obtain a molded body that is made of pellets, has a small decrease in mechanical strength, and has reduced white spots on the surface.

  Examples of the polypropylene resin (component (A)) used in the present invention include propylene homopolymer, propylene-ethylene random copolymer, propylene-α-olefin random copolymer, propylene homopolymer, and ethylene and propylene. And a propylene block copolymer obtained by copolymerization.

  The polypropylene resin (component (A)) used in the present invention may be partially or entirely modified with an unsaturated carboxylic acid or a derivative thereof from the viewpoint of mechanical strength such as impact strength and rigidity. In addition, as unsaturated carboxylic acid or its derivative used for modification | denaturation of polypropylene resin (component (A)), it is the same as the unsaturated carboxylic acid or its derivative used for modified polyolefin resin (component (C)) mentioned later Is mentioned.

Examples of a method for producing the polypropylene resin (component (A)) used in the present invention include a solution polymerization method, a slurry polymerization method, a bulk polymerization method, and a gas phase polymerization method. Moreover, the method of using these polymerization methods independently may be used, and the method of combining at least 2 types may be used.
And as a manufacturing method of polypropylene (component (A)), for example, "New polymer manufacturing process" (edited by Koji Saeki, Industrial Research Committee (published in 1994)), JP-A-4-323207, JP-A-61 Examples include polymerization methods described in JP-A No. 287917.

  Examples of the catalyst used for the production of the polypropylene resin (component (A)) include a multisite catalyst and a single site catalyst. As the multi-site catalyst, a catalyst obtained by using a solid catalyst component containing a titanium atom, a magnesium atom and a halogen atom is preferable. As the single-site catalyst, a metallocene complex is preferable.

  The melt flow rate (MFR) of the polypropylene resin (component (A)) used in the present invention is such that the dispersibility of the glass fiber (component (B)) in the molded body is reduced, the appearance of the molded body is poor, and the impact strength is reduced From the viewpoint of preventing the above, it is preferably 1 to 500 g / 10 minutes, more preferably 5 to 300 g / 10 minutes, still more preferably 10 to 200 g / 10 minutes, and still more preferably 50 to 150 g / 10. Minutes. In addition, MFR is A. S. T.A. M.M. It is a value measured at 230 ° C. and 21.2 N load according to D1238.

When the polypropylene resin (component (A)) used in the present invention is a propylene homopolymer, the isotactic pentad fraction is preferably 0.95 to 1.0, more preferably 0.96 to 1. 0.0, more preferably 0.97 to 1.0. The isotactic pentad fraction is defined as A.I. The method published in Macromolecules, Vol. 6, 925 (1973) by Zambelli et al., Ie isotactic linkage in pentad units in a propylene molecular chain measured using ¹³ C-NMR, in other words In other words, it is the fraction of propylene monomer units at the center of a chain in which five consecutive propylene monomer units are meso-bonded. However, the assignment of the NMR absorption peak is based on Macromolecules, Vol. 8, page 687 (1975), which was subsequently published.

  In the case where the polypropylene resin (component (A)) used in the present invention is a propylene block copolymer obtained by homopolymerizing propylene and then copolymerizing ethylene and propylene, the propylene homopolymer portion is isotactic. The pentad fraction is preferably 0.95 to 1.0, more preferably 0.96 to 1.0, and still more preferably 0.97 to 1.0.

  The weight average fiber length of the glass fiber (component (B)) used in the present invention is 2 to 100 mm. The weight average fiber length of the glass fiber (component (B)) is preferably 3 to 50 mm, more preferably from the viewpoint of improvement in mechanical strength such as rigidity and impact strength, and ease of production and molding. 3 to 30 mm. In addition, the weight average fiber length of glass fiber (component (B)) is the length in the polypropylene resin composition of this invention, and can be measured by the method described in Unexamined-Japanese-Patent No. 2002-5924. it can.

  The ignition loss of the glass fiber (component (B)) used in the present invention is 0.5% from the viewpoint of improvement in mechanical strength such as rigidity and impact strength, appearance of the obtained molded body and ease of production. -1.5% by weight, preferably 0.5-1.4% by weight, more preferably 0.6-1.4% by weight, still more preferably 0.7-1.4% by weight. (However, the total amount of glass fiber (component (B)) is 100% by weight). In addition, the ignition loss of glass fiber (component (B)) can be measured by the ignition loss method based on JIS-R3420.

  The count (weight per 1,000 m) of the glass fiber (component (B)) used in the present invention is preferably 200 to 5000 g / km, more preferably 500 to 4000 g, from the viewpoint of ease of production. / Km, more preferably 1000 to 3000 g / km.

The glass fiber (component (B)) used by this invention is a component which consists of a glass monofilament (BI) and a sizing agent (B-II).
Examples of the glass monofilament (BI) used in the present invention include glasses such as E glass (Electrical glass), C glass (Chemical glass), A glass (Alkali glass), S glass (High strength glass), and alkali-resistant glass. Can be melt-spun into filaments. The glass monofilament (B-I) used in the present invention is preferably a filament formed by melt spinning E glass from the viewpoint of the reinforcing effect.

  Examples of the sizing agent (B-II) used in the present invention include polyolefin resin, polyurethane resin, polyester resin, acrylic resin, epoxy resin, starch, vegetable oil and the like. Furthermore, you may mix | blend lubricants, such as acid-modified polyolefin resin, a surface treating agent, and paraffin wax.

  In order to improve the wettability and adhesion between the glass fiber (component (B)) and the polypropylene resin used in the present invention, a surface treating agent may be added to the sizing agent (B-II). Examples of the surface treatment agent include silane coupling agents, titanate coupling agents, aluminum coupling agents, chromium coupling agents, zirconium coupling agents, and borane coupling agents. Is a silane coupling agent or titanate coupling agent, more preferably a silane coupling agent.

  Examples of the silane coupling agent include triethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3,4 -Epoxycyclohexyl) ethyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, etc., preferably γ-aminopropyltriethoxysilane, N-β- (aminoethyl) ) -Γ-aminopropyltrime It is an aminosilane such as Kishishiran.

  The heat loss starting temperature of the sizing agent (B-II) used in the present invention is preferably from the viewpoint of the appearance of the molded product obtained from the fiber reinforced polypropylene resin composition and the ease of production of the fiber reinforced polypropylene resin composition. Is 180 to 300 ° C, more preferably 190 to 270 ° C, particularly preferably 200 to 250 ° C, and most preferably 220 to 250 ° C. The heat loss start temperature of the sizing agent (B-II) is calculated by TG measurement measured from room temperature to 600 ° C. at a heating rate of 10 ° C./min in an air atmosphere. The calculation method of the heat loss start temperature from the TG curve is performed by the method described in the reading of the TG curve described in JIS K7120-1987.

  As a method of treating the glass monofilament (B-I) used in the present invention with the sizing agent (B-II), a conventionally used method such as an aqueous solution method, an organic solvent method, a spray method, etc. Is mentioned.

The modified polyolefin resin (component (C)) used in the present invention is
(1) A homopolymer of an olefin different from the component (A) (polypropylene resin) used in the present invention, a copolymer of at least two olefins, or at least two olefins after homopolymerizing the olefins Graft copolymerized unsaturated carboxylic acid and / or derivative thereof to block copolymer obtained by block polymerization of copolymerized part,
(2) Copolymerized with at least one olefin and unsaturated carboxylic acid and / or derivative thereof.

  Examples of the method for producing the modified polyolefin resin (component (C)) used in the present invention include, for example, “Practical Polymer Alloy Design” (Fumio Ide, Industrial Research Group (1996)), Prog. Polym. Sci. 24, 81-142 (1999), JP-A No. 2002-308947, and the like, and any of a solution method, a bulk method, and a melt-kneading method may be used. Moreover, you may manufacture combining these methods.

Examples of the unsaturated carboxylic acid used in the modified polyolefin resin (component (C)) include maleic acid, fumaric acid, itaconic acid, acrylic acid, and methacrylic acid. Moreover, examples of the unsaturated carboxylic acid derivative include acid anhydrides, ester compounds, amide compounds, imide compounds, metal salts, and the like of the above unsaturated carboxylic acids. Specific examples thereof include maleic anhydride and itaconic anhydride. Acid, methyl acrylate, ethyl acrylate, butyl acrylate, glycidyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, glycidyl methacrylate, monoethyl maleate, diethyl maleate, monomethyl fumarate, Examples include dimethyl fumarate, acrylamide, methacrylamide, maleic acid monoamide, maleic acid diamide, fumaric acid monoamide, maleimide, N-butylmaleimide, and sodium methacrylate. Moreover, you may use what dehydrates and produces | generates unsaturated carboxylic acid by the process grafted to a polypropylene like citric acid and malic acid.
The unsaturated carboxylic acid and / or derivative thereof is preferably glycidyl ester of acrylic acid, glycidyl ester of methacrylic acid, or maleic anhydride.

As the modified polyolefin resin (component (C)) used in the present invention, preferably,
(1) a modified polyolefin resin obtained by graft polymerization of maleic anhydride to a polyolefin resin having a unit derived from ethylene and / or propylene as a main constituent unit of the polymer;
(2) A modified polyolefin resin obtained by copolymerizing an olefin mainly composed of ethylene and / or propylene and glycidyl methacrylate or maleic anhydride.

  Further, as the modified polyolefin resin (component (C)) used in the present invention, preferably, from the viewpoint of mechanical strength such as impact strength, fatigue characteristics, rigidity, etc., as a polymer structural unit, an unsaturated carboxylic acid and / or A modified polyolefin resin containing 0.1 to 10% by weight of a unit derived from the derivative (however, the total amount of the modified polyolefin resin is 100% by weight). Further, in the case of a modified polyolefin resin obtained by random copolymerization or block copolymerization using an unsaturated carboxylic acid and / or derivative thereof, the content of units derived from the unsaturated carboxylic acid and / or derivative thereof is 3 to 10% by weight is preferable, and in the case of a modified polyolefin resin obtained by graft polymerization, the content of units derived from unsaturated carboxylic acid and / or a derivative thereof is preferably 0.1 to 10% by weight.

  When the fiber reinforced polypropylene resin composition of the present invention contains a polypropylene resin (component (A)) and glass fiber (component (B)), each content of the component (A) and the component (B) (A) is 20 to 95% by weight, and component (B) is 80 to 5% by weight. However, the total amount of the fiber-reinforced polypropylene resin composition is 100% by weight. From the viewpoint of improvement in mechanical strength such as rigidity and impact strength, and ease of production and molding, the component (A) is preferably 30 to 90% by weight and the component (B) is 70 to 10% by weight. More preferably, the component (A) is 40 to 90% by weight, the component (B) is 60 to 10% by weight, and more preferably, the component (A) is 50 to 90% by weight, Component (B) is 50 to 10% by weight.

  When the fiber-reinforced polypropylene resin composition of the present invention contains polypropylene resin (component (A)), glass fiber (component (B)), and modified polyolefin resin (component (C)), polypropylene resin (component (A)) ) And a modified polyolefin resin (component (C)), the component (A) and the component (C) are contained in the resin mixture (D). % By weight, and component (C) is 0.1 to 40% by weight. However, the total amount of the resin mixture (D) is 100% by weight. Preferably, the component (A) is 99.5 to 70% by weight and the component (C) is 0.5 to 30% by weight from the viewpoint of improvement in mechanical strength such as rigidity and impact strength and fatigue characteristics. Yes, more preferably, component (A) is 99 to 80% by weight and component (C) is 1 to 20% by weight.

  And content of the glass fiber (component (B)) contained in the fiber reinforced polypropylene resin composition of this invention is 5-400 weight part with respect to 100 weight part of said resin mixture (D), and rigidity. From the viewpoint of improvement of mechanical strength such as impact strength and ease of production and molding, it is preferably 10 to 300 parts by weight, more preferably 10 to 200 parts by weight, and still more preferably 10 ~ 100 parts by weight.

In addition, the fiber-reinforced polypropylene resin composition of the present invention includes, as necessary, stability of known substances generally added to the polypropylene resin, for example, antioxidants, heat stabilizers, neutralizers, ultraviolet absorbers and the like. Agents, anti-bubble agents, flame retardants, flame retardant aids, dispersants, antistatic agents, lubricants, anti-blocking agents such as silica, colorants such as dyes and pigments, plasticizers, nucleating agents, crystallization accelerators, etc. May be blended.
Further, glassy flakes, mica, glass powder, glass beads, talc, clay, alumina, carbon black, Wollastonite and other plate-like and powdery inorganic compounds, whiskers and the like may be blended.

As a method for producing the fiber-reinforced polypropylene resin composition of the present invention, a pultrusion molding method is used. The pultrusion molding method is basically a method of impregnating a resin while drawing a continuous fiber bundle, for example,
(1) A method of impregnating a resin by passing a fiber bundle through an impregnation liquid containing a resin emulsion, suspension or solution,
(2) After the resin powder is sprayed onto the fiber bundle, or after the fiber bundle is passed through the tank containing the powder and the resin is adhered to the fiber, the resin is melted and impregnated.
(3) A method of supplying and impregnating the resin to the crosshead from an extruder or the like while passing the fiber bundle through the crosshead is preferable, and the method using the crosshead of the above (3) is preferable. A method using a crosshead described in JP-A-3-272830 is preferred.

  In the pultrusion molding method, the resin impregnation operation may be performed in one stage, or may be performed in two or more stages. Moreover, you may blend the pellet manufactured by the pultrusion molding method, and the pellet manufactured by the melt kneading method.

  Examples of the shape of the fiber-reinforced polypropylene resin composition of the present invention include, for example, a strand shape, a sheet shape, a flat plate shape, and a pellet shape obtained by cutting the strand into an appropriate length. From the viewpoint of application to easy injection molding, it is in the form of a pellet having a length of 2 to 50 mm, more preferably 2 to 30 mm, and further preferably 3 to 15 mm.

  The pellet of the present invention is a pellet obtained from the composition of the present invention. When applied to injection molding, the pellet is obtained from the viewpoint of obtaining a molded product having excellent strength without impairing injection moldability. It is preferable that the length of the pellet is 2 to 50 mm, more preferably 2 to 30 mm, and still more preferably 3 to 15 mm.

  The molded product of the present invention is a molded product obtained from the composition of the present invention or a pellet thereof. Examples of the molding method include an injection molding method, an injection compression molding method, and a gas assist molding method.

  The molded body of the present invention includes a fender, an over fender, a grill guard, a cowl louver, a wheel cap, a side protector, a side molding, a side lower skirt, a front grill, a side, which require mechanical strength, durability and good appearance. Exterior parts such as steps, roof rails, rear spoilers and bumpers, interior parts such as instrument panel lowers and trims that require heat-resistant rigidity, bumper beams, cooling fans, fan shrouds, lamp housings, car heater cases, fuse boxes, air cleaners It can be used for plastic parts for automobiles such as parts in the engine such as cases.

  Also, parts of various electrical products such as electric tools, cameras, video cameras, microwave ovens, electric kettles, pots, vacuum cleaners, personal computers, copiers, printers, FDD, CRT machine housings, and various machines such as pump casings It can be used for parts such as parts, tanks, pipes, structures such as building forms.

Hereinafter, the present invention will be described with reference to examples and comparative examples. The manufacturing method of the sample for evaluation used in the examples or comparative examples is shown below.
(1) Manufacturing method of glass fiber reinforced pellet The glass fiber reinforced pellet was manufactured by the method described in Unexamined-Japanese-Patent No. 3-121146. The impregnation temperature was 270 ° C., and the take-up speed was 13 m / min.

(2) Method for producing sample for evaluation The sample for evaluation was produced by injection molding the glass fiber reinforced pellet obtained in the above (1) under the following conditions using the following molding machine manufactured by Japan Steel Works. .
In addition, as a sample for vitiligo index measurement, a 150 mm × 150 mm, 3 mm thick flat plate was molded and evaluated. In addition, 1 part by weight of a pigment master batch (carbon black concentration: 14% by weight) was added to 100 parts by weight of the glass fiber reinforced pellets at the time of blending the raw materials and colored black.
Nippon Steel Works molding machine Clamping force: 150t
Screw: Deep groove screw for long fibers Screw diameter: 46mm
Screw L / D: 20.3
Molding conditions Cylinder temperature: 250 ° C
Mold temperature: 50 ℃
Back pressure: 0 MPa

Evaluation methods in Examples and Comparative Examples are shown below.
(1) Flexural modulus (unit: MPa)
A. S. T. T. et al. According to MD 790, measurement was performed under the following conditions.
Measurement temperature: 23 ° C
Sample thickness: 3.2 mm
Span: 50mm
Tensile speed: 2 mm / min

(2) Bending strength (unit: MPa)
A. S. T. T. et al. According to MD 790, measurement was performed under the following conditions.
Measurement temperature: 23 ° C
Sample thickness: 3.2 mm
Span: 50mm
Tensile speed: 2 mm / min

(3) IZOD impact strength (unit: KJ / m ² )
A. S. T. T. et al. The measurement was performed under the following conditions according to MD256.
Measurement temperature: 23 ° C
Sample thickness: 3.2 mm [with V notch]

(4) Vitiligo Index Using the scanner GT-9600 manufactured by Epson, obtained in (2) above under the conditions of 256 gradations, resolution 50 dpi, exposure 20, gamma 50, highlight 61, shadow 60, and threshold 110. Images of the obtained 10 flat plates were taken into a computer (analysis area 2186 cm ² ). The area of white spots was calculated from the captured image using the particle analysis function of high-definition image analysis software (IP-1000PC) manufactured by Asahi Engineering. The vitiligo index was obtained by indexing the area ratio of each sample when the area of vitiligo spots in Comparative Example 2 was 100.

(5) Residual weight average fiber length The weight average fiber length was measured using the flat plate shape | molded for the vitiligo index measurement by the method described in Unexamined-Japanese-Patent No. 2002-5924.

Comparative Example 1
By the method described in JP-A-3-121146, glass fiber reinforced pellets having a composition shown in Table 1 and a glass fiber content of 40% by weight and a pellet length of 9 mm were prepared. The polypropylene resin used was a propylene homopolymer (MFR = 80 g / 10 min), and the glass fiber used had an average fiber diameter of 17 μm, a loss on ignition of 0.36 wt%, a heating loss start temperature of 219 ° C., and a count of 2310 g / The modified polyolefin resin used was a maleic anhydride-modified polypropylene resin (MFR = 60 g / 10 minutes, maleic anhydride graft amount = 0.6% by weight). Further, the obtained glass fiber reinforced pellets were injection molded. Table 1 shows the flexural modulus, flexural strength, IZOD impact strength, vitiligo index, and residual weight average fiber length of the obtained sample. The maleic anhydride-modified polypropylene resin used was prepared by the method described in JP-A No. 2002-308947.

Example 1
Evaluation was performed in the same manner as in Comparative Example 1 except that the glass fiber used in Comparative Example 1 was changed to an ignition loss of 1.2 wt% and a heating loss start temperature of 232 ° C. The glass fiber sizing agent used was not changed.

Comparative Example 2
By the method described in JP-A-3-121146, glass fiber reinforced pellets having a composition shown in Table 1 and a glass fiber content of 40% by weight and a pellet length of 9 mm were prepared. The polypropylene resin used was a propylene homopolymer (MFR = 80 g / 10 min), and the glass fiber used had an average fiber diameter of 17 μm, a loss on ignition of 0.35 wt%, a heating loss start temperature of 225 ° C., a count of 2310 g / The modified polyolefin resin used was a maleic anhydride-modified polypropylene resin (MFR = 60 g / 10 minutes, maleic anhydride graft amount = 0.6% by weight). Further, the obtained glass fiber reinforced pellets were injection molded. Table 1 shows the flexural modulus, flexural strength, IZOD impact strength, vitiligo index, and residual weight average fiber length of the obtained sample. The maleic anhydride-modified polypropylene resin used was prepared by the method described in JP-A No. 2002-308947.

Example 2
Evaluation was performed in the same manner as in Comparative Example 2 except that the glass fiber used in Comparative Example 2 was changed to an ignition loss of 0.70 wt% and a heating loss start temperature of 233 ° C. The glass fiber sizing agent used was not changed.

Ａ−１：プロピレン単独重合体（ＭＦＲ＝８０ｇ／１０分）
Ｂ−１：ガラス繊維(強熱減量１．２ｗｔ％、加熱減量開始温度２３２℃、平均繊維径１７μｍ、番手２３１０ｇ／ｋｍ) 収束剤は、Ｂ−３と同じ。
Ｂ−２：ガラス繊維(強熱減量０．７０ｗｔ％、加熱減量開始温度２３３℃、平均繊維径１７μｍ、番手２３１０ｇ／ｋｍ) 収束剤は、Ｂ−４と同じ。
Ｂ−３：ガラス繊維(強熱減量０．３６ｗｔ％、加熱減量開始温度２１９℃、平均繊維径１７μｍ、番手２３１０ｇ／ｋｍ)
Ｂ−４：ガラス繊維(強熱減量０．３５ｗｔ％、加熱減量開始温度２２５℃、平均繊維径１７μｍ、番手２３１０ｇ／ｋｍ)
Ｃ−１：無水マレイン酸変性ポリプロピレン樹脂（ＭＦＲ＝６０ｇ／１０分、マレイン酸グラフト量＝０．６重量％）

A-1: Propylene homopolymer (MFR = 80 g / 10 min)
B-1: Glass fiber (ignition loss 1.2 wt%, heating loss start temperature 232 ° C., average fiber diameter 17 μm, count 2310 g / km) The sizing agent is the same as B-3.
B-2: Glass fiber (ignition loss 0.70 wt%, heating loss start temperature 233 ° C., average fiber diameter 17 μm, count 2310 g / km) The sizing agent is the same as B-4.
B-3: Glass fiber (ignition loss 0.36 wt%, heating loss start temperature 219 ° C., average fiber diameter 17 μm, count 2310 g / km)
B-4: Glass fiber (ignition loss 0.35 wt%, heating loss start temperature 225 ° C., average fiber diameter 17 μm, count 2310 g / km)
C-1: Maleic anhydride modified polypropylene resin (MFR = 60 g / 10 min, maleic acid graft amount = 0.6 wt%)

It can be seen that Examples 1 and 2 that satisfy the requirements of the present invention have little decrease in mechanical strength and have reduced white spots on the surface of the molded article.
On the other hand, Comparative Examples 1 and 2 that do not satisfy the loss on ignition of the glass fiber (component (B)), which is a requirement of the present invention, are insufficient in reducing white spots on the surface of the molded product. I understand.

Claims (5)

  Polypropylene resin (component (A)) 20 to 95% by weight, glass monofilament (B-I) and sizing agent (B-II), weight average fiber length of 2 to 100 mm, ignition loss 0. Fiber reinforced polypropylene resin composition containing glass fiber (component (B)) 80 to 5% by weight which is 5 to 1.5% by weight (however, the total amount of fiber reinforced polypropylene resin composition is 100% by weight) .   A resin mixture (D) containing 99.9 to 60% by weight of a polypropylene resin (component (A)) and 0.1 to 40% by weight of a modified polyolefin resin (component (C)) (however, the resin mixture (D )), And 100 parts by weight of the resin mixture (D) is composed of a glass monofilament (B-I) and a sizing agent (B-II), and has a weight average fiber length of 2 to 2. A fiber-reinforced polypropylene resin composition containing 5 to 400 parts by weight of glass fiber (component (B)) having a thickness of 100 mm and an ignition loss of 0.5 to 1.5% by weight.   The fiber-reinforced polypropylene resin composition according to claim 1 or 2, wherein the polypropylene resin (component (A)) is a polypropylene resin modified with an unsaturated carboxylic acid or a derivative thereof.   A fiber reinforced polypropylene resin composition according to any one of claims 1 to 3, wherein glass fibers (component (B)) are arranged in parallel with each other in the pellet. Polypropylene resin resin composition pellets.   It is a molded object which consists of the fiber reinforced polypropylene resin composition in any one of Claims 1-3, or the fiber reinforced polypropylene resin composition pellet of Claim 4, Comprising: In the said molded object, glass fiber (component (( B)) a molded article having a weight average fiber length of 1 to 20 mm.