JP3046418B2 - Filler for fiber reinforced thermoplastic resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filler for a fiber-reinforced thermoplastic resin to be mixed with a thermoplastic resin to produce the fiber-reinforced thermoplastic resin.

[0002]

2. Description of the Related Art Fiber reinforced thermoplastic resins in which inorganic short fibers such as glass fibers are mixed as a filler with thermoplastic resins such as polycarbonate and polyethylene have been known. In order to produce such a fiber-reinforced thermoplastic resin, inorganic short fibers are supplied into an extruder while the thermoplastic resin is being extruded by a single-screw or twin-screw extruder, and the thermoplastic resin and the inorganic short fibers are mixed. To produce a pellet-shaped fiber-reinforced thermoplastic resin, or after mixing the thermoplastic resin and inorganic short fibers in a V-blender or the like, and extruding with a single-screw or twin-screw extruder to form a pellet-shaped fiber-reinforced thermoplastic resin. Had been manufactured. Thereafter, the fiber-reinforced thermoplastic resin in the form of pellets was manufactured into a molded product as required by, for example, an injection molding machine.

However, chopped strands composed of filaments having an average fiber diameter of about 6 to 13 μm and an average fiber length of about 2 to 20 mm obtained by cutting long glass fibers are used as the inorganic fiber filler to be mixed with the thermoplastic resin. In this case, it can be uniformly mixed with the thermoplastic resin.However, due to the fiber shape of the filament having a relatively large diameter, the molded fiber-reinforced thermoplastic resin molded article has a large anisotropy in molding shrinkage, It is not suitable for applications requiring warpage or dimensional accuracy, and has a problem that the surface of the fiber-reinforced thermoplastic resin molded article is rough due to floating of fibers, thereby impairing the appearance of the product. Therefore, the applicant of the present application has disclosed in
No. 18454, a composition obtained by blending an inorganic short fiber having an average fiber diameter of 2 μm or less with a thermoplastic resin as a composition having an excellent appearance, a small anisotropy in molding shrinkage, and high physical strength. Patent Document 2 discloses a plastic resin composition, and in Japanese Patent Application No. Hei 2-13505, an inorganic short fiber having an average fiber diameter of 2 μm or less in order to stably supply the inorganic short fiber to a hopper of an extruder without causing a so-called bridging phenomenon. Was formed into a sheet-like sheet piece having a side of 1 to 30 mm square, and a filler for fiber-reinforced thermoplastic resin was proposed. In order to produce a thermoplastic resin composition using such a filler,
In the course of extruding the thermoplastic resin with a single-screw or twin-screw extruder, the production of pellets is from 1 to
Inject and mix the inorganic short fibers made into a 30 mm square,
A pellet composition is prepared by mixing in an extruder, or a blend of a predetermined amount of inorganic short fibers previously formed into a thermoplastic resin in a 1 to 30 mm square is supplied to a single or twin screw extruder to be blended. Then, a pellet composition was produced.

[0004]

SUMMARY OF THE INVENTION However, the sheet density of a short sheet made of inorganic short fibers having an average fiber diameter of 2 μm or less in a square of 1 to 30 mm has a bulk density of about 0.03 g / cm ³ and a thermoplastic resin powder. Bulk density of 0.1 to 0.5 g / c
there is a large open than that of the m ^3. For this reason, when the inorganic short fiber made into a 1-30 mm square is fed by a hopper equipped with a fixed amount feeding machine while the thermoplastic resin is extruded by a single-screw or twin-screw extruder, the thermoplastic resin in which the filler is melt-softened is used. It becomes a state of floating on the resin, biting into the resin is poor, and it is difficult to mix 10% by weight or more. In addition, when a mixture prepared by mixing a predetermined amount of inorganic short fibers previously formed into a 1-30 mm square with a thermoplastic resin is supplied to a single-screw or twin-screw extruder, when the mixture flows down the hopper due to a difference in bulk density between the two. In addition, there has been a problem that the two are separated from each other and the mixing ratio of the filler in the extruded pellets fluctuates. An object of the present invention is to provide a filler for a fiber-reinforced thermoplastic resin that solves such a problem.

[0005]

In order to solve the above-mentioned problems, the present invention has been studied diligently. As a result, it is possible to form a sheet by mixing a thermoplastic resin powder and an inorganic short fiber at a predetermined ratio. It has been found that when the bulk density of the sheet piece is increased, the bite into the resin is improved, and when mixed with the resin powder, separation is difficult.

The filler for fiber-reinforced thermoplastic resin of the present invention has been made based on such knowledge, and has an average fiber diameter of 2 μm.
A filler for a fiber-reinforced thermoplastic resin obtained by forming the following inorganic short fibers into a sheet-like sheet piece having a side of 1 to 30 mm square, wherein the sheet-like sheet piece contains a thermoplastic resin powder.

The thermoplastic resin powder is preferably a thermoplastic resin of the same type as the thermoplastic resin to be reinforced by blending a filler, and specific examples thereof include polyethylene (PE) and polypropylene ( PP), polybutene,
Olefin polymers exemplified by polyisobutylene, polymethylpentene-1, ethylene-propylene copolymer, etc .; ethylene-vinyl acetate copolymer (EVA), ethylene-vinyl acetate-vinyl chloride copolymer, polyvinyl acetal, Substituted olefin polymers such as polyvinyl acetate (PVA), vinyl alcohol-vinyl acetate copolymer and polyvinyl chloride (PVC); chlorinated polyolefin polymers such as chlorinated polyethylene, chlorinated polypropylene and chlorinated polyvinyl chloride Fluorine resins such as polytetrafluoroethylene (PTFE), polytetrafluoroethylene-propylene copolymer, vinylidene fluoride resin, polytetrafluoroethylene-hexafluoropropylene copolymer; polymethyl methacrylate (PMMA), methyl methacrylate To Ethyl acrylate and as a component, n
Copolymers with -butyl acrylate and the like, acrylate polymers such as polyethyl acrylate and polybutyl acrylate; polystyrene (PS), high impact polystyrene (HIPS), methyl methacrylate-styrene copolymer (MS), Acrylonitrile-styrene copolymer (AS), acrylonitrile-butadiene-styrene copolymer (ABS), methyl methacrylate-butadiene-styrene copolymer (MBS), methyl metalacrylate-
Acrylonitrile-butadiene-styrene copolymer (M
ABS), methyl methacrylate-alkyl acrylate rubber-styrene copolymer (MAS) and others
Acrylonitrile-acrylic rubber-styrene copolymer disclosed in U.S. Pat.
No. 52; styrene-based polymers represented by acrylonitrile-chlorinated polyolefin-styrene copolymer; nylon-6 (PAD6), nylon-
66 (PAD66), nylon-12 (PAD12),
Polyamide resin represented by nylon 6,12, nylon-11, MX polyamide (MXD6), etc .; polyethylene terephthalate (PET), polybutylene terephthalate (PBT), cyclohexanedimethanol or diol and ethylene glycol as diol component Polyester with phthalic acid (PCTA, PCT
G) and other saturated polyester resins (PE
S): Liquid crystal polymer such as a copolymer of polyhydroxybenzoic acid and polyethylene terephthalate; polyacetal (POM); polyvinyl acetal; polyesterimide, polyamideimide, polyarylate, polyetherketone, polyestercarbonate, Udel polysulfone, polyether Sulfone, polycarbonate (P
C), heat-resistant engineering plastics such as polyphenylene ether (PPE), polyphenylene sulfide, etc., and one or a mixture of two or more selected from the above, for example, PC / ABS, PC / MBS
PC / styrene copolymer composition such as PC / PE
PC / polyester resin composition such as T, PC / PBT, PC / PCTA, PC / PCTG, diene rubber, acrylic rubber, particulate rubber or olefin elastomer obtained by crosslinking these, thermoplastic styrene -Polycarbonate resin compositions represented by blending thermoplastic elastomers such as butadiene copolymers and polyester elastomers, PPE / PS,
Examples include PPE / HI-PS, other polyphenylene ether-based resin compositions, compositions such as POM / polyurethane elastomers, and other thermoplastic resins.

[0008] As the inorganic short fiber used as a raw material of the sheet sheet to be mixed with the thermoplastic resin, glass fiber is preferable, and the glass fiber is obtained by converting glass melted by a glass melting furnace from a perforated plate into a filament having a desired uniform diameter. A method of producing flocculent ultra-fine glass fiber by drawing out, guiding into a high-temperature, high-speed burner flame and fibrillating, a glass fiber having a large specific surface area with an average fiber diameter of 2 μm or less produced by the so-called short fiber flame method is suitable. Alkali-free glass such as E glass is preferable as a raw material of the glass fiber. This is when using C glass etc.
This is because the degradation of the thermoplastic resin is accelerated by the promotion of alkali hydrolysis by the glass fiber, and the deterioration of the physical properties is prevented. Specific examples of such E glass fibers having an average fiber diameter of 2 μm or less include EGW-E0800-NWS (manufactured by Nippon Inorganic Corporation) (average fiber diameter 0.8 μm).
m), EGW-E0600-NWS (average fiber diameter 0.6
μm).

Further, in order to improve the adhesion between the thermoplastic resin and the glass fiber, the glass fiber may be subjected to a surface treatment before the glass fiber is formed into a sheet piece. As a specific example of the surface treatment method, a gas fiber is immersed in a 0.01 to 1% by weight aqueous solution of a silane coupling agent such as aminosilane, epoxy silane, acrylic silane, or vinyl silane. Heat treatment for 2 to 2 hours.

[0010] A method of forming a sheet sheet is to add and mix a predetermined amount of thermoplastic resin powder when the glass fiber is defibrated by an ordinary beater or pulper, or to prepare a defibrated glass fiber dispersion solution. Mix and disperse resin powder,
The paper may be formed by a usual long net method or a round net method.

The resin powder has a particle diameter of 1 to 1000 μm.
m, preferably 5 to 250 μm, which is 1 μm
If the average particle size is less than 1,000 μm, the yield is poor, and if the average particle size exceeds 1000 μm, the dispersibility is poor, and the paper tends to fall off after the average particle size is formed. Also,
The mixing ratio of the resin powder is in the range of 10 to 95% by weight, preferably 50 to 80% by weight. This is because if the amount is less than 10% by weight, the effect of increasing the bulk density of the sheet-like sheet piece is small, and if it exceeds 95% by weight, it is difficult to form a sheet-like sheet piece.

If the mixing ratio of the resin powder is adjusted in advance to the mixing ratio of the thermoplastic resin and the reinforcing fibers of the fiber-reinforced thermoplastic resin to be produced, the single-screw or twin-screw extruder can be used to form the papermaking machine. By supplying only the sheet pieces, it is not necessary to separately supply the resin powder to the extruder, and the bite of the sheet sheet into the melt-softened thermoplastic resin, or separation of the thermoplastic resin powder and the sheet sheet, etc. Don't worry.

The reason why the formed sheet piece is formed to be 1 to 30 mm square on one side is that when the size of the formed sheet piece is less than 1 mm, the sheet piece is formed before the sheet piece is uniformly dispersed. This is because the inorganic short fibers are dispersed and cannot be uniformly dispersed, and if it exceeds 30 mm, they are not uniformly dispersed when blended in a thermoplastic resin. In order to form a sheet-like sheet piece in a side of 1 to 30 mm square, the sheet-like sheet may be cut using, for example, a square-cut pelletizer.

The blending amount of the sheet sheet into the thermoplastic resin is determined in consideration of the amount of the thermoplastic resin contained in the sheet sheet, and the dimensional accuracy (low shrinkage) and mechanical strength of the obtained molded article are taken into consideration. The proportion of the inorganic short fiber filler in the composition is about 2 to 50% by weight, preferably from 2 to 50% by weight, from the viewpoint of improvement effects such as fluidity when blended to produce a fiber-reinforced thermoplastic resin, economy and the like. It may be about 8 to 40% by weight.

[0015]

Next, embodiments of the present invention will be described. Example 1 E glass fiber having an average fiber diameter of 0.8 μm and an average fiber length of 5 to 50 mm (EGW-E0800- manufactured by Nippon Inorganic Corporation)
(NWS) in a normal paper-making process, a polycarbonate resin powder having an average particle diameter of 75 to 250 μm (Iupilon E-2000 manufactured by Mitsubishi Gas Chemical Co., Ltd.) was added at the ratio shown in Table 1 below, and the thickness of each was about The paper was made into a 2 mm sheet, and each of the obtained sheets was cut with a square-cut pelletizer, and a 4 mm × 4 mm square chip-like sheet piece A,
B, C, and D. Each of the obtained sheet pieces A, B,
C, D and the polycarbonate resin powder were mixed at a ratio shown in Table 2 below in a V blender, melted and kneaded in an extruder,
Pellets 1, 2, 3, and 4 were produced.

[0016]

[Table 1]

[0017]

[Table 2]

As is apparent from Tables 1 and 2, according to the present invention, the bulk density of the sheet-like sheet piece is increased, the flow in the extruder hopper becomes smooth, and the filling of the glass fiber into the thermoplastic resin is carried out. The amount could be increased. Further, the uniform dispersibility of the fibers in the resin of the pellet was also good. still,
The uniform dispersibility of the fibers in the resin of the pellet was evaluated by cutting the pellet at right angles to the axial direction and visually observing the cross section.

Example 2 Sheet-formed sheet pieces A, B, C, and D containing the thermoplastic resin powder obtained in Example 1 and the polycarbonate resin powder were put into a measuring hopper, and were melted and kneaded by an extruder. Then, pellets 5, 6, 7, and 8 were produced. As a result, as shown in Table 3 below, the fluidity in the measuring hopper and the uniform dispersibility of the fibers in the resin of the pellets were also good.

[0020]

[Table 3]

Example 3 In the same manner as in Example 1, when making E glass fiber in the usual paper making process, a polycarbonate resin powder and a silane coupling agent were added as shown in Table 4 below to obtain an E glass fiber. Each sheet is cut with a square-cut pelletizer.
4 mm square piece-like sheet-shaped sheet pieces E and F were obtained. The obtained sheet-shaped sheet pieces E and F were melted and kneaded with an extruder to melt and knead the polycarbonate resin and the E glass fiber contained in each sheet-shaped sheet piece to produce pellets 9 and 10.

[0022]

[Table 4]

As is apparent from Table 5 below, according to the present invention, not only the bulk density of the sheet sheet is increased, the flow in the extruder hopper becomes smooth, but also the filling amount of the glass fiber in the pellet is reduced. 10% and 20% were obtained, and it was confirmed that pellets containing a required amount of glass fiber could be produced without newly adding polycarbonate resin powder.

[0024]

[Table 5]

[0025]

As described above, the filler for the fiber-reinforced thermoplastic resin of the present invention has an increased bulk density by encapsulating a thermoplastic resin powder in a sheet-forming sheet piece.
The fluidity in the hopper of the extruder is improved, the penetration into the thermoplastic resin is good, and the blending of 10% by weight or more is possible, and the blending ratio of the filler in the pellets does not change. Further, if the mixing ratio of the resin powder is adjusted in advance to the mixing ratio of the thermoplastic resin and the reinforcing fiber of the fiber-reinforced thermoplastic resin to be produced, it is necessary to supply a new thermoplastic resin with an extruder. Instead, pellets can be formed and productivity is improved.

Claims (5)

(57) [Claims] 1. A fiber-reinforced thermoplastic resin filler formed by forming inorganic short fibers having an average fiber diameter of 2 μm or less into a sheet-like sheet piece having a side length of 1 to 30 mm, wherein a thermoplastic resin powder is added to the sheet-like sheet piece. A filler for fiber-reinforced thermoplastic resin, wherein the filler is included. 2. The fiber-reinforced thermoplastic resin according to claim 1, wherein the thermoplastic resin powder is a thermoplastic resin of the same kind as the thermoplastic resin to be reinforced by blending a filler. Filling material. 3. The fiber-reinforced thermoplastic resin according to claim 1, wherein the inorganic short fibers are formed of E glass, and the surface of the short fibers is treated with a coupling agent. Filling material. 4. The thermoplastic resin powder has a particle diameter of 1 to 1.
The filler for fiber reinforced thermoplastic resin according to claim 1 or 2, wherein the filler has a thickness of 000 µm, preferably 5 to 250 µm. 5. The thermoplastic resin powder is 10 to 95% by weight, preferably 50 to 80% by weight, based on the sheet material.
The filler for a fiber-reinforced thermoplastic resin according to any one of claims 1 to 4, wherein the filler is contained.