Fiber reinforced thermoplastic resin molded product having a good surface appearance

A fiber reinforced thermoplastic resin molded product having a good surface appearance; fiber reinforced thermoplastic resin pellets useful for making fiber reinforced thermoplastic resin molded products; and processes for making fiber reinforced thermoplastic resin molded products and processes for producing fiber reinforced thermoplastic resin pellets.

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 The present invention relates to fiber reinforced thermoplastic resin
 molded products having excellent mechanical properties and a good surface
 appearance, fiber reinforced thermoplastic resin pellets and the methods
 of producing such pellets useful for producing such products. The present
 invention further relates to the methods of producing the molded product
 having a good surface appearance, using the pellet.
 The molded product of the present invention can be used in various fields
 as follows: motorcar interiors such as a console box, an instrument panel
 and a trim; motorcar exteriors such as a bumper, a fender, a front grill,
 a rear spoiler and a side protector; motorcar-related members such as
 members inside an engine room, for example, a fan, a fan shroud, a battery
 tray and a fuse box; housings for electrical equipment such as a
 notebook-sized personal computer and a portable telephone; structural
 members of electric appliances; office furniture; building materials; and
 containers.
 2. Description of Related Art
 A fiber reinforced thermoplastic resin in which its matrix is a
 thermoplastic polymer and its reinforcing fibers are glass fibers has
 widely been used, exclusively in a pellet form, as a material for
 injection molding making mass production possible. As pellets containing
 glass fibers, there are known a short fiber reinforced thermoplastics
 pellet (a compound pellet) obtained by melting and compounding chopped
 glass fibers having a length of 3-12 mm and a matrix thermoplastics
 polymer in an extruder, extruding the blend into a strand form, and
 cutting the resultant, and a long fiber reinforced thermoplastics pellet
 obtained by causing continuos glass fibers tow to pass through a melted
 matrix thermoplastics polymer bath to impregnate the tow with the melted
 resin, pulling out and cooling the tow into a strand form and then cutting
 the strand.
 Concerning the short fiber reinforced thermoplastics pellet, its glass
 fibers are damaged in the melt compounding step, so that the length of the
 fibers in the actually-obtained pellet becomes far shorter than that of
 the fibers before the compounding. The fibers are also damaged in
 injection molding. Thus, the weight average fiber length (Lw) of an
 injection-molded product using such a short fiber reinforced
 thermoplastics pellet is reduced to about 0.3-0.6 mm. The glass fibers,
 therefore, do not become entangled with each other so that reinforcing
 effect is not exhibited, resulting in poor mechanical properties.
 In the long fiber reinforced thermoplastics pellet, since its fibers are
 not damaged during the production thereof, which is different from the
 short fiber reinforced thermoplastics pellet, an injection-molded product
 having satisfactory mechanical properties can be obtained. However, the
 length of the fibers causes the dispersibility of the fibers to
 deteriorate, resulting in such appearance badness that the fibers bundle
 is in sight from the surface of the product.
 In particular, when a method is used where a master pellet having high
 concentration of its glass fibers is mixed with a pellet containing only a
 matrix thermoplastics polymer and does not contain any glass fiber at the
 time of molding so as to make up the contained amount of the glass fibers
 to a given value, causing a problem where appearance badness resulting
 from non-uniform dispersion of the glass fibers comes into prominence.
 Thus, investigations have been made for dispersing glass fibers uniformly
 by setting up an especial blending nozzle onto a molding machine, making a
 gate of a mold narrow, or setting the backpressure of a screw at the time
 of molding to a high value. However, such manners for enlarging shearing
 force in blending and injection steps are not very effective for an
 improvement in the dispersibility of the fibers. Conversely, the fibers
 are unfavorably damaged.
 From the viewpoint that it is preferable for an improvement in
 dispersibility of glass fibers to get the glass fibers in the state of a
 monofilament sufficiently wet with a matrix thermoplastics polymer, a
 method of getting the glass fibers wet with the matrix thermoplastics
 polymer in the process of producing a pellet is disclosed (Japanese Patent
 Application Laid-Open No. 3-13305). However, the improvements in the
 dispersibility of the fiber and a surface appearance are unsatisfactory.
 Japanese Patent Application Laid-Open No. 5-239286 discloses a method of
 specifying the MI (melt index) of a matrix thermoplastics polymer and the
 blend ratio of the resin to glass fibers to raise dispersibility of the
 fiber and reduce the damage of the fibers. Japanese Patent Application
 Laid-Open No. 5-124036 discloses a method of using a resin having a lower
 melting viscosity as a master pellet of a high glass fiber content, and
 using a resin having a higher melting viscosity as a pellet not containing
 any glass fiber, to raise dispersibility of the glass fibers and
 mechanical properties of a molded product.
 In these methods in the prior art, the surface appearance of a molded
 product can be improved to some degree, and there are not brought such bad
 results that the glass fibers are projected from the surface of the
 product. However, the dispersibility of the glass fibers is not completely
 improved, so that the glass fibers may be present in a bundle form near
 the surface of the product. If the product includes pigments and dyes and
 the glass fibers tow is present near its surface, the concentration of the
 colored resin is small at the area where the tow is present. Thus, the
 color becomes uneven so as to result in appearance badness. In other
 words, even when the glass fiber is not in sight from the surface,
 appearance badness such as color unevenness cannot be overcome if the
 glass fibers are non-uniformly dispersed. Furthermore, if the glass fibers
 are non-uniformly dispersed and the glass fibers tow is locally present,
 physical properties such as mechanical properties of the product are
 aversely influenced. Accordingly, there remain problems that physical
 properties vary between lots of injection-molded products or between
 locations of the same molded product.
 SUMMARY OF THE INVENTION
 An object of the present invention is to provide a fiber reinforced
 thermoplastic resin molded product wherein the dispersibility of glass
 fibers in a matrix thermoplastics polymer is improved and the glass fibers
 tow is prevented from being present after molding as much as possible, to
 exhibit a good surface appearance with improved, less-fluctuated
 mechanical properties.
 Another object of the present invention is to provide a pellet for
 obtaining a molded product having such a good surface appearance with
 improved, less-fluctuated mechanical properties.
 Still another object of the present invention is to provide preferable
 methods for producing the molded product and the pellet.
 The fiber reinforced thermoplastic resin molded product of the present
 invention comprises a thermoplastic resin as a matrix polymer and glass
 fibers as reinforcing fibers, and has a good surface appearance,
 wherein the glass fibers are contained in an amount of 2 to 20 vol % of the
 molded product, the weight average fiber length (Lw) of the glass fibers
 present in the molded product is from 0.8 to 1.8 mm, the glass fibers of 2
 mm or more in length are contained in an amount of 20 or less wt % of the
 total glass fibers, and the glass fibers of 3 mm or more in length are
 contained in an amount of 5 or less wt % of the total glass fibers.
 The molded product of the present invention satisfying the above-mentioned
 requirements has a very good surface appearance, and its glass fibers are
 uniformly dispersed to exhibit good mechanical properties. Moreover, the
 scattering in properties depending on locations and lots of the molded
 product can be reduced.
 One of preferred processes for producing the molded product of the
 invention is a process of blending a master pellet which contains a great
 deal of the glass fibers with a pellet which does not substantially
 contain any glass fiber to be used. The master pellet is preferably the
 following pellet of the present invention.
 The fiber reinforced thermoplastic resin pellet of the present invention
 comprises a thermoplastic resin as a matrix polymer and glass fibers as
 reinforcing fibers,
 wherein the length of the pellet is about 2 to 12 mm, the glass fibers
 having substantially the same length as the pellet is contained in an
 amount of 20 to 60 vol % of the total pellet, in the state of aligned or
 twisted fibers along the longitudinal direction of the pellet, and
 L/D.sup.2 is 0.45 or more and L/D is from 1.1 to 6 wherein L represents
 the length of the pellet and D represents the diameter thereof. This
 pellet is blended with a resin pellet which does not substantially contain
 any glass fiber, and then the blend can be injection-molded to produce the
 above-mentioned molded product.
 The above-mentioned fiber reinforced thermoplastic resin pellet (referred
 to as pellet A) may be blended with a thermoplastic resin pellet which
 does not substantially contain any glass fiber (referred to as pellet B),
 in the manner that the weight ratio of A to B is from 0.08 to 3.
 Preferably, the resultant blend, which is included in the scope of the
 present invention, is used.
 In order to produce the molded product of the present invention, there is
 preferably used a process wherein the fiber reinforced thermoplastic resin
 pellet A is mixed with a thermoplastic resin pellet B which does not
 substantially contain any glass fiber, in the manner that the weight ratio
 of A to B is from 0.08 to 3, and then the blend is injection-molded. In
 this case, the pellet A and the pellet B are preferably selected in such a
 manner that a thermoplastic resin constituting the fiber reinforced
 thermoplastic resin pellet A flows more easily than a thermoplastic resin
 constituting the thermoplastic resin pellet B which does not substantially
 contain any glass fiber, in order to make the dispersibility of the glass
 fibers better.
 A preferred process for producing the fiber reinforced thermoplastic resin
 pellet A continuously, comprises the steps of:
 immersing continuous long glass fibers tow into a melted matrix
 thermoplastics polymer bath and causing the tow to pass through the bath,
 thereby impregnating the glass fibers tow with the matrix thermoplastics
 polymer,
 rotating the continuous long glass fibers tow continuously around the
 center axis of the tow with a twister, thereby twisting the tow to prepare
 a fiber reinforced strand, and
 pulling out the fiber reinforced strand in which the twisted tow is
 impregnated with the matrix thermoplastics polymer, and cutting the strand
 into pieces having a predetermined length, thereby obtaining the pellet.
 DESCRIPTION OF THE PREFERRED EMBODIMENTS
 The fiber reinforced thermoplastic resin molded product of the present
 invention comprises a thermoplastic resin as a matrix polymer and
 comprises glass fibers as reinforcing fibers.
 Examples of the used thermoplastic include typical resins as follows:
 polyolefin resins such as polyethylene, polypropylene, propylene-ethylene
 copolymer, ethylene-propylen rubber (EPR), and ethylene-propylene-diene
 terpolymer (EPDM); styrene resins such as polystyrene,
 acrylonitrile-butadiene-styrene (ABS) resin,
 acrylonitrile-styrene-copolymer (AS) resin, (AXS) resin; polyamides such
 as nylon 6, nylon 6-6, nylon 6-10, nylon 6-12, nylon 12 and nylon MXD
 (aromatic polyamide); saturated polyesters such as polyethylene
 terephthalate and polybutylene terephthalate, acrylic resins,
 polycarbonate, polyoxymethylene (POM), polyphenylene oxide (PPO),
 polyphenylene sulfide (PPS), polysulfone, polyethersulfone,
 polyetherketone, and polyetheretherketone. Any one of these resins may be
 used as a copolymer or a derivative, or two or more kinds thereof may be
 used in a blend form.
 In the case in which such a polyolefin which is nonpolar and is difficult
 to bond as polyethylene, polypropylene, propylene-ethylene copolymer is
 used as the matrix thermoplastics polymer, it is preferable for an
 improvement in the bonding strength to the glass fibers to add an
 appropriate amount of acid-modified polypropylene, polyethylene,
 ethylene-propylene-diene terpolymer (EPDM), or the like to the matrix
 thermoplastics polymer.
 If as an acid for the modification there is used an unsaturated carbonic
 acid or an acid anhydride thereof such as (meth)acrylic acid, maleic acid
 (maleic anhydride), fumaric acid, itaconic acid (itaconic anhydride), or
 crotonic acid, the modification with the acid can be attained by
 copolymerization or the like. Derivatives such as esters, amides or metal
 salts of such acids may also be used. The modification with the acid may
 be attained by adding a peroxide and an acid anhydride to the polyolefin
 and then heating and reacting the blend in an extruder for producing a
 pellet. When polypropylene is used as the matrix thermoplastics polymer,
 it is recommendable to use maleic anhydride-modified polypropylene, which
 is obtained by graft-polymerizing polypropylene with maleic anhydride.
 The acid-modified polyolefin may be caused to be present in a pellet by
 adopting, e.g., a method of blending the acid-modified polyolefin with
 polyolefin (a main component in the matrix thermoplastics polymer) so as
 to make up the acid-modified polyolefin to a part of the matrix
 thermoplastics polymer, or a method of forming a coating film of the
 acid-modified polyolefin on the surface of the glass fibers. In order to
 form the coating film, polyolefin of an emulsion type (or a solution type)
 may be applied by dip coating, spray coating or the like.
 Depending on use of the molded product, known additives as follows may be
 added to the matrix thermoplastics polymer: modifiex such as a dispersant,
 a lubricant, a plasticizer, a flame retarder, an antioxidant, an
 anti-static agent, a light stabilizer, a UV absorber and a crystallization
 promoter (a nucleating agent); colorants such as a pigment or a dye;
 fillers in a particle form, such as carbon black, titanium oxide, talc,
 calcium carbonate, mica and clay; fillers in a fiber form, such as milled
 fiber and wollastonite; and whisker such as potassium titanate. These
 additives may be contained in a pellet by adding them to the pellet in the
 production thereof, or may be added to a hopper of an injection molding
 machine when a product is predicted from the pellet. It is preferable to
 add the above-mentioned particle-form filler in an amount of about 5 wt %
 of the total of the matrix thermoplastics polymer and the glass fibers.
 The wording "matrix thermoplastics polymer" herein means a blend of the
 thermoplastic resin and the above-mentioned additives.
 The glass fibers which can be used are not especially limited. For example,
 E-glass or S-glass may be used. The diameter of the fibers is usually from
 5 to 25 .mu.m. If the glass fibers have a diameter of 5 .mu.m or less, the
 fibers are easily damaged so that the productivity of the fibers tow is
 lowered. Moreover, many fibers must be bundled when pellets are
 continuously produced. Unfavorably, therefore, labor for connecting the
 glass fibers tow is troublesome and the productivity thereof is lowered.
 On the other hand, if the glass fibers have a diameter over 25 .mu.m, the
 aspect ratio of the fibers is lowered on the basis of the fact that a
 preferable length of the pellet is specified. Thus, reinforcing effect is
 not sufficiently exhibited. More preferably, the diameter of the fibers
 ranges from 8 to 20 .mu.m.
 It is preferable for the production of the pellet to use a glass fiber tow
 (roving) wherein the glass fibers are bundles with a suitable bundling
 agent. Preferably, the number of the fiber tow ranges from 300 to 5000.
 Within this range, the tow is sufficiently impregnated with the
 thermoplastic resin. If the number is over 5000, the center of the fiber
 tow may not be unfavorably impregnated with the resin. More preferably,
 the number of the fiber tow ranges from 500 to 3000.
 In order to improve wettability of the glass fibers to the matrix
 thermoplastics polymer, the glass fibers may be subjected to a known
 surface treatment. The surface treatment is conducted by applying various
 coupling agents such as silane, titanate, aluminum, chromium, zirconium or
 borane type coupling agents. The coupling agents excellent in the
 wettability to the thermoplastic resin are silane and titanate types.
 Especially preferable are silane coupling agents, the typical examples of
 which are aminosilanes such as .gamma.-aminopropyltriethoxysilane;
 epoxysilanes such as .gamma.-glycydoxypropyltrimethoxysilane; and
 vinylsilanes such as vinyltrichlorosilane.
 The molded product of the present invention is a product obtained by
 molding the above-mentioned matrix thermoplastics polymer and glass
 fibers. The greatest characteristic thereof is that the amount of the
 glass fibers in the molded product is specified and the amount of the
 fibers having a large length is restricted to a specified value or less,
 so as to improve a surface nature and mechanical properties of the molded
 product.
 In the fiber reinforced thermoplastic resin molded product of the present
 invention, the glass fibers must be contained in an amount of 2 to 20 vol
 % of the molded product. If the amount of the glass fibers is less than 2
 vol %, reinforcing effect based on the fibers is not sufficient. If the
 amount is over 20 vol %, the glass fibers are projected from the surface
 of the product. As a result, unfavorably the surface nature deteriorates.
 Preferably, the lower limit and the upper limit of the content of the
 glass fibers are 4 vol % and 15 vol %, respectively. The requirements
 about the content of the glass fibers, the average length, and the like in
 the product of the present invention are related to neither blended amount
 nor length of fibers blended at the time of molding, but related to the
 content of the glass fibers and the length of the product after the
 molding.
 Concerning the glass fibers contained in the product of the present
 invention, their weight average length (Lw) must be from 0.8 to 1.8 mm. If
 the glass fibers are shorter than 0.8 mm, reinforcing effect is not
 sufficiently exhibited and mechanical properties deteriorate. However, if
 the glass fibers are longer than 1.8 mm, in the case of a thin molded
 product the fiber may be projected from its surface. Moreover, its
 dispersibility deteriorates so that the fibers tow may be present. Thus,
 its surface appearance may become bad. Additionally, the deterioration of
 the dispersibility causes the following: the Izod impact value of the
 molded product varies considerably, depending on locations of the product.
 That is, when plural samples are sampled from molded products having an
 average-weight fiber length over 1.8 mm and then their mechanical
 properties such as their Izod impact values are measured, the scattering
 in the measured values is large among the plural samples. This
 demonstrates that since the dispersibility of the glass fibers in the
 molded product is non-uniform, the following arises: while the samples
 containing an appropriate amount of the glass fibers exhibit good impact
 values, the samples wherein the region containing less glass fibers is
 sampled exhibit lower impact values. Moreover, if there is a glass fiber
 bundle in the molded product, the Izod impact value at this place is
 larger than the value at the place where there is no fiber bundle, because
 fiber bundles affect the Izod impact value. From this standpoint, the
 upper limit of the weight average fiber length (Lw) is set up to 1.8 mm in
 the present invention. More preferably, the lower limit and the upper
 limit of the weight average fiber length (Lw) of the glass fibers are 0.9
 mm and 1.6 mm, respectively.
 The weight average fiber length (Lw) of glass fibers is a value obtained
 from the following equation when an image processor "LUZEX LF" (Nireco
 corporation) is used to measure respective lengths (Li) of about 2000-3000
 glass fibers:
EQU Lw=L1.times.(the weight percentage (i.e., the weight fraction)
EQU of fibers having a fiber length of L1)+L2.times.
EQU (the weight percentage of fibers having a fiber length of L2)+
EQU L3.times.(the weight percentage of fibers having a fiber length of L3)+ . .
 . +Ln.times.
EQU (the weight percentage of fibers having a fiber length of
 Ln)=.SIGMA.(Li.times.Wi/100)
 wherein the actually-measured fiber length is represented by Li (i=1, 2, 3
 . . . , n) , and the weight percentage of fibers having a fiber length of
 Li is represented by Wi (i=1, 2, 3 . . . , n).
 The number-average fiber length is calculated from the following equation:
EQU Ln=.SIGMA.Li/n
 The weight percentage of fibers having a fiber length of 2 mm or more and
 that of fibers having a fiber length of 3 mm or more are also obtained
 from the above-mentioned measurement.
 In the molded product of the present invention, the weight percentage of
 the glass fibers having a fiber length of 2 mm or more must be 20 or less
 wt % of all the glass fibers contained in the molded product. Even when
 the weight average fiber length (Lw) satisfies the defined range, the
 surface nature deteriorates and mechanical properties such as an impact
 value vary because of a drop in the dispersibility of the glass fibers if
 the percentage of the fibers having a length of 2 mm or more is over 20 wt
 % of all the glass fibers. Thus, such a case is unfavorable. From the same
 standpoint, the weight percentage of the glass fibers having a fiber
 length of 3 mm or more must be 5 or less wt %.
 In order to obtain a molded product satisfying the above-mentioned
 requirements defined in the present invention, it is preferable to adopt a
 producing process in which the glass fibers can be sufficiently dispersed.
 For example, if there is adopted a process in which a part of a melted
 resin is, in a batch manner, put into a mold and glass fibers adjusted to
 satisfy the above-mentioned requirements are scattered thereto, a molded
 product of the present invention can be produced. According to this
 process, however, mass-production is impossible so that a high cost cannot
 be avoided.
 Thus, the inventors have decided that the molded product of the present
 invention is obtained by injection molding, which makes mass-production
 possible, and then found a pellet making it possible that, when a molded
 product is obtained from the pellet through an injection molding step, the
 molded product satisfies the requirements defined in the present
 invention. In the present invention, there is adopted a process of
 blending a pellet which contains many glass fibers (a master pellet) and a
 matrix resin pellet which does not substantially contain any glass fiber
 but contains only a matrix thermoplastics polymer in a desired ratio and
 then molding the blend in order to change the amount of the glass fibers
 in the molded product easily in a molding step. The inventors have
 therefore succeeded in an improvement in the dispersibility of the glass
 fibers after the molding and the control of the length of the glass fibers
 in the molded product by defining an optimal formulation shape and
 structure of the master pellet and the blend ratio of the master pellet to
 the resin pellet.
 The pellet (master pellet) of the present invention is a fiber reinforced
 thermoplastic resin pellet containing a thermoplastic resin as a matrix
 polymer and containing glass fibers as reinforcing fibers, wherein the
 length of the pellet is about 2 to 12 mm, the glass fibers having
 substantially the same length as the pellet is contained in an amount of
 20 to 6 vol % of the total pellet, in the state of lined-up or twisted
 fibers along the longitudinal direction of the pellet, and L/D.sup.2 is
 0.45 or more and L/D is from 1.1 to 6 wherein L represents the length of
 the pellet and D represents the diameter thereof.
 The pellet of the present invention (referred to as a pellet A,
 hereinafter) becomes substantially columnar if the producing process as
 described later is adopted. The length of the pellet A is about 2 to 12
 mm. As the pellet A is shorter, the dispersibility of the glass fibers in
 a melting and compounding step in the injection molding machine becomes
 better. However, in order to improve mechanical properties of the molded
 product, it is necessary that the glass fibers have some degree of length.
 In order to balance the two with each other and set up the weight average
 fiber length (Lw) of the glass fibers in the molded product to 0.8-1.8 mm,
 as described above, it has been found that the length of the glass fibers
 in the pellet should be set up to 2-12 mm. The glass fibers are pulled and
 arranged in the state of lined-up or twisted fibers in the pellet A so
 that the length of the glass fibers is substantially the same as that of
 the pellet A. In the present invention, therefore, the length of the
 pellet A is set up to 2-12 mm. Even if all of the pellets A used in a
 molding step do not have a length of 2-12 mm, the molded product of the
 present invention may be obtained. Thus, the length of the pellet is
 defined as "about" 2-12 mm.
 The damage of the glass fibers cannot be avoided in an injection molding
 step. Thus, in the case that the length of the pellet A is less than 2 mm,
 the weight average fiber length of the glass fibers in the molded product
 unfavorably becomes smaller than 0.8 mm. However, if the length is over 12
 mm, bridges between the pellets are caused in a hopper of an injection
 molding machine so that handling of the pellet A becomes difficult.
 Moreover, a great deal of long fibers having a length of 2 mm or more, or
 3 mm or more remains in the molded product. Thus, such a case is
 unfavorable because of bad surface appearance. The lower limit of the
 length of the pellet A (glass fiber length) is more preferably 3 mm, and
 most preferably 4 mm. The upper limit thereof is more preferably 10 mm,
 and most preferably 9 mm. If a preferable producing process described
 later is used, the length of the glass fibers in the pellet becomes
 substantially equal to or somewhat longer than the length of the pellet.
 There may however be a case that glass fibers which are shorter than the
 pellet are incorporated into the pellet. Any pellet containing such fibers
 are also within the scope of the present invention.
 The pellet A of the present invention is made up to a so-called long fiber
 reinforced thermoplastics pellet structure, which contains the glass
 fibers in the state of aligned or twisted fibers along the longitudinal
 direction of the pellet A, that is, in the state that the glass fiber tow
 is pulled and arranged. In this case, the length of the glass fibers in
 the pellet can easily be controlled, and a satisfactory length of the
 glass fibers can be kept in the molded product. Besides, the pellet can
 easily be produced. Preferably, the glass fibers should be "twisted" since
 the impregnation with the resin and resistance against buckling and
 rupture are improved. The twisted fibers are also effective for keeping
 the satisfactory length of the fibers since the twisted glass fibers are
 somewhat longer than the pellet.
 The amount of the glass fibers in the pellet A is set up to 20-6 vol %.
 From the standpoint of the production-effectivity of the pellet per unit
 volume of the glass fibers, in each of the pellet the glass fibers are
 preferably contained in an amount of 20 or more vol %. Considering that
 the master pellet (pellet A) and the matrix resin pellet are mixed to
 produce a molded product having a predetermined amount of the glass
 fibers, the amount of the glass fibers can be more widely changed as a
 larger amount of the glass fibers is contained in the master pellet.
 However, if the amount of the blended glass fibers is over 60 vol %, the
 glass fibers tow is insufficiently impregnated with the matrix
 thermoplastics polymer and further the glass fibers may unfavorably fall
 apart from the pellet A, and thus the amount of the glass fibers should be
 set up to 25-50 vol %.
 In the pellet A in a substantially columnar form, the relationships between
 the length of the pellet (L) and the diameter thereof (D)should be as
 follows: L/D.sup.2 is 0.45 or more and L/D is from 1.1 to 6. Since the
 amount of the glass fibers in the pellet A is high, if the diameter of the
 pellet A is far larger than the length thereof, that is, L/D.sup.2 is
 smaller than 0.45, the pellet is easily broken and fuzz of the glass
 fibers is unfavorably raised on the surface of the pellet. Even when the
 pellet diameter D becomes large so that L/D.sup.2 exceeds 0.45, if L/D is
 less than 1.1, similarly the pellet is easily broken and fuzz of the glass
 fibers is raised on the surface of the pellet. On the other hand, if L/D
 is over 6, the pellet gets slender and the pellet may easily be broken in
 a molding step, suffering from difficult control of the fiber length.
 A preferable example of the process for producing the pellet A continuously
 is a process comprising the steps of:
 immersing continuous long glass fibers tow into a melted matrix
 thermoplastics polymer bath and causing the tow to pass through the bath,
 thereby impregnating the glass fibers tow with the matrix resin,
 rotating the long glass fibers tow continuously around the center axis of
 the tow with a twister, thereby twisting the tow to prepare a fiber
 reinforced strand, and
 pulling out the fiber reinforced strand in which the twisted tow is
 impregnated with the matrix thermoplastics polymer, and cutting the strand
 into pieces having a predetermined length, thereby obtaining the pellet.
 The step of twisting the tow is preferably performed at the same time of
 the step of impregnating the tow with the resin. Specifically, a melt
 resin is extruded from an extruder into a cross head to prepare a resin
 bath, and then a continuos and long glass fibers tow is pulled and
 arranged to pass through the resin bath. In the case, the impregnation and
 the twisting may be simultaneously performed by setting up a twister such
 as a twisting roller at the downstream of the cross head, and causing the
 tow to pass through the resin bath while twisting the tow. The glass
 fibers tow impregnated with the resin (fiber reinforced resin strand) is
 cooled and then is cut into pieces of 2-12 mm in length, so that the fiber
 reinforced thermoplastic resin pellet A can be obtained. Short fibers
 produced by breakdown of the glass fiber during the impregnation of the
 fibers with the resin are also twisted and involved in the tow by the
 twisting. Therefore, the occurrence frequency of any trouble based on cut
 fibers is reduced.
 The pellet A is usually blended with a pellet which does not substantially
 contain any glass fiber but contains only a matrix thermoplastics polymer
 (pellet B), in use. The pellet A and the pellet B may be beforehand
 dry-blended so that the amount of the glass fibers is set up to 30 wt % of
 the total pellets. Such a blend is also included in the fiber reinforced
 thermoplastic resin pellet of the present invention. The pellet A is
 blended with the pellet B in the manner that A/B (weight ratio) is set up
 to 0.08 to 3. When the blend ratio is less than 0.08, the ratio of the
 pellet B to the pellet A is large. In this case, if the pellets are
 insufficiently kneaded in injection molding, the glass fibers cannot be
 uniformly dispersed. Thus, this case is unfavorable. Conversely, if A/B is
 over 3, the dispersibility deteriorates.
 In the case that the pellet A is blended with the pellet B, it is
 preferable that the thermoplastic resin constituting the pellet A, that
 is, the matrix thermoplastics polymer of the pellet A, is made of a resin
 having a larger fluidity than the thermoplastic resin constituting the
 pellet B. The pellet A contains the glass fibers of a high concentration.
 Thus, the dispersibility of the glass fibers is better as the fluidity of
 the matrix thermoplastics polymer is lower. However, if the whole of the
 matrix thermoplastics polymer constituting a molded product is made of a
 resin having a high fluidity, resistances against impact and heat drop.
 This is because resins having a high fluidity generally have a low
 molecular weight. Accordingly, the dispersibility of the glass fibers and
 the strength of the product can be improved by selecting a resin having a
 high molecular weight, that is, exhibiting a low fluidity, as the matrix
 thermoplastics polymer of the pellet B.
 A fluidity can be compared with another fluidity by using MFR (melt flow
 rate), MI (melt index), a melting viscosity or the like. If the matrix
 thermoplastics polymer of the pellets A and B is, for example,
 polypropylene (PP), it is preferable to set up MFR (g/10 minutes,
 conditions: temperature=230.degree. C., load=2.16 kgf) of PP of the pellet
 A to two or more times (and preferably 3 or more times) as much as MFR of
 PP of the pellet B. MFR of PP of the pellet B may be appropriately
 selected under the consideration of the blend ratio thereof to the pellet
 A, the fluidity of the resin in the step of molding, and physical
 properties of the molded product, but is usually from 1 to 60, and
 preferably from 5 to 30.
 The matrix thermoplastics polymers of the pellet A and the pellet B are
 preferablymade of the same polymer. However, it is permissible to use the
 pellets A and B whose matrix thermoplastics polymers are made of different
 polymers, if they are compatible with each other or can act as a polymer
 alloy to exhibit good properties.
 The molded product of the present invention can be produced by
 injection-molding the pellets A and B in the manner that A/B (weight
 ratio) is made up to 0.08-3. A pellet blend wherein the pellet A and the
 pellet B are blended is introduced into a hopper of an injection molding
 machine, and then is melted in its injection unit while being subjected to
 screw-press, so as to be injected into a mold. Even when the requirements
 about the structure of the pellet A, the blend ratio of the pellet A to
 the pellet B, and the like, are defined within the scope described above,
 any molded product satisfying the requirements of the present invention
 may not be obtained if the conditions for injection molding are
 inappropriate. Thus, it is preferable to select the conditions
 experimentally. Other known producing processes may be used to obtain the
 molded product of the present invention.

EXAMPLES
 The present invention will be more specifically described by way of
 Examples, hereinafter. However, the present invention is not restricted to
 Examples, and any alternation or modification made within the scope of the
 subject matter of the present invention are included in the scope of the
 present invention.
 First, the following will describe materials used in Examples, Comparative
 Examples, and reference Examples.
 [1] Matrix Resin
 Each of glass fiber-containing pellets A was obtained by using each of the
 following a-1 to a-4 as a matrix thermoplastics polymer, and adding glass
 fibers described in Item [2] and an additive described in Item [3] to each
 of the resins, in a blend formulation shown into Tables 1-3. (Producing
 processes thereof will be described later.)
 a-1: Crystalline polypropylene pellet [density=0.909 g/cm.sup.3, MFR
 (measurement conditions: temperature=230.degree. C., and load=2.16
 kgf)=100 g/10 minutes]
 a-2: Crystalline polypropylene pellet [density=0.909 g/cm.sup.3, MFR
 (measurement conditions: temperature=230.degree. C., and load=2.16 kgf)=60
 g/10 minutes]
 a-3: Crystalline polypropylene pellet [density=0.909 g/cm.sup.3, MFR
 (measurement conditions: temperature=230.degree. C., and load=2.16
 kgf)=200 g/10 minutes]
 a-4: Pellet or crushed pieces of maleic anhydride-modified polypropylene
 ("YOUMEX 1001" manufactured by Sanyo Chemical Industries, Ltd.)
 [density=0.95 g/cm.sup.3, Molecular weight=40,000 (weight average
 molecular weight by GPC process), melting viscosity=16,000 cps
 (160.degree. C.), acid value=26 mgKOH]
 [2] Glass Fibers Tow (Roving)
 Continuous tow of E-glass fibers having an average diameterof 13 .mu.m and
 650 tex was surface-treated with a silane coupling
 (.gamma.-aminopropyltriethoxysilane), and then was surface-treated with a
 maleic anhydride-modified polypropylene emulsion. The resultant was used.
 In the glass fiber-containing pellet A-12, chopped glass fibers cut into
 pieces of 6 mm in length were used.
 [3] Additive
 b-1: titanium oxide having a Mhos' hardness of 6-7 and an average particle
 size of 0.25 .mu.m.
 b-2: zinc oxide having a Mhos' hardness of 4-4.5 and an average particle
 size of 0.5 .mu.m.
 b-3: zinc sulfide having a Mhos' hardness of 3.5 and an average particle
 size of 0.5 .mu.m.
 b-4: calcium carbonate having a Mhos' hardness of 3-3.5 and an average
 particle size of 0.15 .mu.m.
 [4] Pellet B
 As the pellet B not containing any glass fibers, pellets described below
 were used. The content of the Y unit described below was gained by
 calculation from the weight obtained by immersing 2 g of a block copolymer
 into 300 g of boiling xylene for 20 minutes to dissolve the copolymer in
 the xylene, cooling the solution to room temperature, filtering the
 precipitated solid phase with a glass filter, and drying the solid phase.
 B-1: propylene-ethylene block copolymer composed of 90 wt % of a
 crystalline polypropylene unit (X unit) having a density of 0.909
 g/cm.sup.3, and 10 wt % of propylene-ethylene random copolymer unit (Y
 unit) whose ethylene content was 39 wt %, and having, as a whole, MFR
 (measurement conditions: temperature=230.degree. C., and a load=2.16 kgf)
 of 6.5 g/10minutes.
 B-2: propylene-ethylene block copolymer composed of 90 wt % of a
 crystalline polypropylene unit (X unit) having a density of 0.909
 g/cm.sup.3, and 10 wt % of propylene-ethylene random copolymer unit (Y
 unit) whose ethylene content was 39 wt %, and having, as a whole, MFR
 (measurement conditions: temperature=230.degree. C., and a load=2.16 kgf)
 of 15 g/10 minutes.
 B-3: propylene-ethylene block copolymer composed of 90 wt % of a
 crystalline polypropylene unit (X unit) having a density of 0.909
 g/cm.sup.3, and 10 wt % of propylene-ethylene random copolymer unit (Y
 unit) whose ethylene content was 39 wt %, and having, as a whole, MFR
 (measurement conditions: temperature=230.degree. C., and a load=2.16 kgf)
 of 30 g/10 minutes.
 B-4: propylene-ethylene block copolymer composed of 90 wt % of a
 crystalline polypropylene unit (X unit) having a density of 0.909
 g/cm.sup.3, and 10 wt % of propylene-ethylene random copolymer unit (Y
 unit) whose ethylene content was 39 wt %, and having, as a whole, MFR
 (measurement conditions: temperature=230.degree. C., and a load=2.16 kgf)
 of 60 g/10 minutes.
 Examples 1-20 and Comparative Examples 1-14
 Each of the matrix thermoplastics polymers a and each of the additives b
 were blended into a formulation shown in Tables 1-3, to prepare a melted
 bath. Subsequently, a continuous glass fiber roving was twisted and
 simultaneously caused to pass through the melted resin bath to impregnate
 the roving with the resin (see Japanese Patent Application Laid-Open No.
 5-169445). Thus, a glass fiber reinforced resin prepreg having a diameter
 shown in the corresponding table was prepared. The resultant prepreg was
 cut with a strand cutter to prepare a pellet shown in the corresponding
 table (a glass fiber-containing pellet A). A-12 was a pellet obtained by
 cutting the glass fiber roving beforehand into pieces of 6 mm in length to
 prepare a chopped glass, using the chopped glass to dry-blend the matrix
 thermoplastics polymer pellet and the additive shown in Table 3, and
 melting and compounding the blend in a uniaxial extruder. In some kinds of
 resins, when their density changes, the percentage by volume of glass
 fibers changes. For convenience' sake, therefore, all of the blended
 amounts are represented by using the unit "wt %".
 The glass fiber-containing pellet A and the pellet B not containing any
 glass fiber were dry-blended at a ratio shown in Tables 3-8. The blend was
 molded with an injection machine "JSW J200SA" (manufactured by The Japan
 Steel Works, Ltd.) into a test piece for measuring mechanical properties
 (JIS standard) and a flat plate (130.times.100.times.3 mm (thickness)).
 Their physical properties were measured by the following measuring
 methods. The results are shown in Tables 4-8.
 1. Flexural Strength and Flexural Modulus
 They were measured according to JIS K 7203. The temperature for the
 measurement was set up to 23.degree. C.
 2. Izod Impact Value (with a Notch)
 It was measured according to JIS K 7110. The thickness of the test piece
 was set up to 4 mm. The temperature for the measurement was set up to
 23.degree. C. A coefficient of variation was a value of (standard
 deviation/absolute value of the average value) .times.100%.
 3. Surface Roughness
 It was measured according to JIS B 0601. In the present invention, the
 surface roughness was not obtained from the roughness curve of a unit
 length for measurement, but a parameter of the roughness curved-surface in
 a unit area for measurement (a central surface) and a height of the area
 surrounded by the central surface (a height along the Z direction), as an
 average roughness of the central surface).
 4. Glass Fiber Length (the Length of Glass Fibers in a Molded Product)
 Glass fibers remaining after the molded product was burnt to ashes were
 dispersed in water to which a surfactant was added, in an ultrasonic
 cleaner, and then the glass fibers were passed through a 1 mm sieve to
 separate into passed fibers and non-passed fibers. The weight of each of
 the two fibers was measured after it was dried. Each of the two glass
 fibers was again dispersed in water and then transferred to a petri dish.
 It was moved to the field of vision of an optical microscope, and observed
 at a suitable magnification. An image processor ("LUZEX LF" [Nireco
 corporation]) was used to measure the length (Li) of about 2000-3000 of
 the glass fibers. The weight average fiber length (Lw) and the
 number-average fiber length (Ln) were calculated as follows.
EQU Lw=L1.times.(the weight percentage of fibers having a fiber length of
 L1)+L2.times.
EQU (the weight percentage of fibers having a fiber length of L2)+L3.times.
EQU (the weight percentage of fibers having a fiber length of L3)+ . . .
 +Ln.times.
EQU (the weight percentage of fibers having a fiber length of
 Ln)=.SIGMA.(Li.times.Wi/100)
 wherein the actually-measured fiber length is represented by Li (i=1, 2, 3
 . . . , n), and the weight percentage of fibers having a fiber length of
 Li is represented by Wi (i=1, 2, 3 . . . , n).
 The number-average fiber length (Ln) is calculated from the following
 equation:
EQU Ln=.SIGMA.Li/n
 The weight percentage of fibers having a fiber length of 2 mm or more and
 that of fibers having a fiber length of 3 mm or more were also obtained.
 They are also shown in Tables 3-8.
 5. Dispersibility of the Glass Fibers
 The flat plate (130.times.100.times.30 mm (thickness)) was molded with a
 direct gate having a diameter of 3 mm, and then a soft X-ray photograph of
 the resultant molded product was taken to examine the state of the
 contained glass fibers, that is, whether or not there was a lump of the
 glass fibers which was not disentangled. The product having one or more
 lump was represented as x, and the product not having any lump was
 represented as .smallcircle..
 TABLE 1
 Glass
 fiber-contairnng peilet (A)
 A-1 A-2 A-3 A-4 A-5
 A-6 A-7 A-8
 Formula- Matrix
 tion thermoplastics
 polymer
 a-1 47.9 47.0 45.0 43.0 23.2 56.0
 50.5 48.0
 a-4 2.0 2.0 2.0 2.0 2.8 1.6 1.8
 2.0
 Glass fibers 50 50 50 50 70 40 45
 50
 Additive
 b-1 0.1 -- -- -- -- -- --
 --
 b-2 -- 1.0 -- -- -- -- --
 --
 b-3 -- -- 3.0 -- 4.0 2.4 2.7
 --
 b-4 -- -- -- 5.0 -- -- --
 --
 Pellet Pellet length 8.0 8.0 8.0 8.0 8.0 8.0 8.0
 8.0
 (mm)
 Pellet diameter 3.0 3.0 3.0 3.0 3.0 3.0 3.0
 3.0
 (mm)
 L/D 2.7 2.7 2.7 2.7 2.7 2.7 2.7
 2.7
 L/D.sup.2 0.90 0.90 0.90 0.90 0.90 0.90
 0.90 0.90
 Cracks, or fuzz None None None None None None
 None None
 TABLE 2
 Glass fiber-containing
 pellet (A)
 A-9-1 A-9-2 A-9-3 A-9-4 A-9-5 A-9-6 A-9-7
 A-9-8 A-9-9
 Formul- Matrix
 tion thermoplastics
 polymer
 a-1 45.0 45.0 45.0 45.0 45.0 45.0 45.0
 45.0 45.0
 a-4 2.0 2.0 2.0 2.0 2.0 2.0 2.0
 2.0 2.0
 Glass fibers 50 50 50 50 50 50 50
 50 50
 Additive 3.0 3.0 3.0 3.0 3.0 3.0 3.0
 3.0 3.0
 b-3
 Pellet Pellet length 3.0 3.0 4.0 8.0 12 6.0 8.0
 10 3.0
 (mm)
 Pellet diameter 1.5 2.0 2.0 2.0 2.0 3.0 1.0
 1.5 3.0
 (mm)
 L/D 2.0 1.5 2.0 4.0 6.0 2.0 8.0
 6.7 1.0
 L/D.sup.2 1.33 a.75 1.00 2.00 3.00 0.66 8.00
 4.46 0.33
 Cracks, or fuzz None None None None None None None
 None Exis-
 tense
 Glass
 fiber-containing pellet (A)
 A-9-10 A-9-11 A-9-12 A-9-13 A-9-14 A-9-15
 A-9-16 A-9-17
 Formul- Matrix
 ation thermoplastics
 polymer
 a-1 45.0 45.0 45.0 45.0 45.0 45.0
 45.0 45.0
 a-4 2.0 2.0 2.0 2.0 2.0 2.0 2.0
 2.0
 Glass fibers 50 50 50 50 50 50 50
 50
 Additive 3.0 3.0 3.0 3.0 3.0 3.0 3.0
 3.0
 b-3
 Pellet Pellet length 4.0 15 7.0 13 13 2.3 2.1
 3.0
 (mm)
 Pellet diameter 3.0 3.0 5.0 5.0 4.0 2.0
 2.0 2.5
 (mm)
 L/D 1.3 5.0 1.4 2.6 3.3 1.15
 1.05 1.2
 L/D.sup.2 0.43 1.66 0.28 0.52 0.83 0.57
 0.52 0.48
 Cracks, or fuzz Exis- None Exis- None None None
 Exis- None
 tense tense
 tense
 TABLE 3
 Glass fiber-contaning pellet
 (A)
 A-10 A-11 A-12
 Formul- Matrix
 ation thermoplastics
 polymer
 a-1 -- -- 45.0
 a-2 45.0 -- --
 a-3 -- 45.0 --
 a-4 2,O 2.0 2.0
 Glass fibers 50 50 50 (chopped)
 Additive 3.0 3.0 3.0
 b-3
 Pellet Pellet length 8.0 8.0 8.0
 (mm)
 Pellet diameter 3.0 3.0 3.0
 (mm)
 L/D 2.7 2.7 2.7
 L/D.sup.2 0.90 0.90 0.90
 Cracks, or fuzz None None None
 TABLE 4
 Example
 1 2 3 4 5 6
 Blend Pellet A A-1 40 -- -- -- -- --
 A-2 -- 40.0 -- -- -- --
 A-3 -- -- 40.0 -- -- --
 A-4 -- -- 40.0 -- --
 A-5 -- -- -- -- 42.8 14.3
 A-8 -- -- -- -- -- --
 Pellet B-1 60.0 60.0 60.0 60.0 57.2 85.7
 Blend ratio: A/B 0.67 0.67 0.67 0.67 0.75 0.17
 Results Flexural strength 11.8 12.3 12.6 12.3 14.7 9.8
 (kg/mm.sup.2)
 Flexural 472 471 473 470 590 295
 Modulus (kg/mm.sup.2)
 Notched Izod 12.5 12.3 15.5 16.2 19.5 10.9
 impact (kgcm/cm.sup.2)
 Coefficient of 3.5 4.1 4.6 5.0 4.0 3.8
 variation (%)
 (Izod impact)
 Surface roughness 290 300 300 300 330 280
 (nm)
 Weight average 1.10 1.25 1.31 1.55 1.22 1.15
 fiber length
 Lw (mm)
 Lw/Ln 1.3 1.4 1.5 1.5 1.5 1.3
 Content of fibers 7.5 12.3 12.1 17.3 11.6 9.8
 of 2 mm or more
 in length (wt %)
 Content of fibers 1.3 3.1 4.2 4.1 3.5 2.2
 of 3 mm or more
 in length (wt %)
 Dispersiblity of .largecircle. .largecircle. .largecircle.
 .largecircle. .largecircle. .largecircle.
 fibers (with
 eyes)

Example Comparative Example

19 20 21 22 13 14
 Blend Pellet A A-3 40.0 40.0 -- -- 40.0 --
 A-10 -- -- 40.0 -- -- --
 A-11 -- -- -- 40.0 -- --
 A-12 -- -- -- -- --
 40.0
 Pellet B B-1 -- -- -- -- --
 60.0
 B-2 60.0 -- -- -- --
 B-3 -- 60.0 60.0 -- -- --
 B-4 -- -- -- 60.0 60.0 --
 Blend ratio A/B 0.67 0.67 0.67 0.67 0.67 0.67
 Results Flexural strength 12.3 12.0 12.0 11.9 12.1 11.5
 (kg/mm.sup.2)
 Flexural 471 472 470 468 470 470
 Modulus (kg/mm.sup.2)
 Notched Izod impact (kgcm/cm.sup.2) 15.2 15.8 15.5 14.7 16.1
 6.1
 Coefficient of variation (%) 4.5 4.2 4.7 4.6 7.2 2.6
 (Izod impact)
 Surface roughness 300 300 310 310 340 350
 (nm)
 Weight average fiber length Lw 1.41 1.50 1.55 1.53 1.65
 0.67
 (mm)
 Lw/Ln 1.5 1.6 1.6 1.6 1.65 1.2
 Content of fibers of 2 mm or 16.3 18.5 19.2 19.1 22.6 0
 more in length (wt %)
 Content of fibers of 3 mm or 4.3 4.5 4.8 4.9 7.6 0
 more in length (wt %)
 Dispersibility of fibers .largecircle. .largecircle.
 .largecircle. .largecircle. x .largecircle.
 (with eyes)
 Examples 1-20 according to the present invention had satisfactory strength,
 elasticity modulus, Izod impact value and the like, and a small scattering
 in the Izod impact value. Moreover, their surface roughness was small, and
 their dispersibility of the fibers was good. Thus, it can be understood
 that the glass fibers having an appropriate length were uniformly
 contained.
 In Comparative Examples 1 and 2 in Table 4, the amounts (wt %) of the
 fibers having a length of 2 mm or more and of the fibers having a length
 of 3 mm or more were large. In Comparative Example 3, the amount of the
 fibers having a length of 3 mm or more was large. These did not satisfy
 the requirements of the molded product of the present invention. As a
 result, their surface roughness was substantially equal to that of
 Examples, but the dispersibility of the fibers was poorer that that of
 Examples. The scattering in the impact value was also large. It appears
 that this was based on the fact that molding conditions were
 inappropriate. In Comparative Example 4, the blended amount of the glass
 fibers was 22.8 vol % (45 wt %) , and was over the value defined as the
 requirement of the present invention (20 vol %). Thus, the glass fibers
 were projected from the surface, so that its surface roughness
 deteriorated extremely.
 Comparative Examples 5 and 6 in Table 6 were examples wherein their weight
 average fiber length was insufficient. It appears that this resulted from
 rapture of the glass fibers in the injection molding step since L/D of the
 pellets was larger than 6. In the pellets having L/D.sup.2 of less than
 0.45, or L/D of less than 1.1, that is, A-9-9. A-9-10, A-9-12, and A-9-16
 in Table 2, cracks of the pellets were generated and fuzz was raised. It
 can be understood, in particular from the result of A-9-16, that even if
 L/D.sup.2 is 0.45 or more, a good pellet cannot be obtained if L/D is less
 than 1.1.
 All of Comparative Examples 7-10 were examples wherein many long fibers
 were contained, so that the dispersibility of the fibers was poor and the
 scattering in the impact value was large. It can be considered that this
 resulted from poor dispersibility of the fibers because of the following
 reasons: in Comparative Examples 7, 9 and 10, too long pellets were used,
 and in Comparative Example 8, the diameter of the pellet was larger and
 thus L/D.sup.2 was less than 0.45.
 In Comparative Example 11 in Table 7, the amount of the glass fibers was
 small, and the weight average length was also small. Therefore, its impact
 value was low, and the molded product was not practicable. In Comparative
 Example 12, the blend ratio of the pellet A to the pellet B was over 3.
 For this reason, the glass fibers were contained in a large amount of 14.4
 vol % (32 wt %), but Comparative Example 12 was poorer than Example 18
 wherein the glass fibers were contained in an amount of 13.3 vol % (30 wt
 %), in the impact value and the like. It can be considered that rapture of
 the glass fibers arose.
 In Comparative Example 13 in Table 8, many long fibers were contained so
 that the dispersibility thereof was bad. It can be considered that this
 resulted from poor dispersibility of the glass fibers because of larger
 MFR of the pellet B-4 MFR of matrix resin of A-3 is smaller than twice of
 MFR of matrix resin of B-4. In Comparative Example 14, the short fiber
 reinforced thermoplastics pellet A-12 using chopped glass fibers was used.
 In the molded product, therefore, its weight average fiber length was
 short and its mechanical strength was low.