JP2006117726A - Method for producing long fiber-reinforced polypropylene resin molding material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a long fiber-reinforced polypropylene resin molding material, wherein generation of fluff is reduced, and a polypropylene resin molded article having good mechanical strength and glass fiber dispersibility can be obtained. <P>SOLUTION: The long fiber-reinforced polypropylene resin molding material having an average diameter of 0.4-3.0 mm and a glass content of 30-75 mass% is produced by impregnating 2-18 glass fiber bundles, prepared by bundling 300-2,000 glass single fibers with a binder, with a molten polypropylene resin containing an acid-modified polypropylene resin and pultruding the bundles through a nozzle. The binder comprises a composition comprising an acid-modified polypropylene resin having a weight average molecular weight of 10,000-50,000 and an acid value of 10-50 mg [KOH/g], a silane coupling agent, and a polyurethane resin. The binder in an amount of 0.1-1.0 pt. mass in terms of solid content is adhered to 100 pts.mass of the glass fiber bundle. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a long fiber reinforced polypropylene resin molding material used for obtaining a polypropylene resin molded article having good dispersibility of glass fibers and excellent impact strength.

  A thermoplastic resin such as polypropylene resin is an inexpensive and lightweight material, and is a resin molding material that is widely used because of its ease of molding. In order to improve the mechanical properties, particularly impact resistance, a long fiber reinforced polypropylene resin molding material in which a polypropylene resin is reinforced with a fiber bundle such as glass fiber is known.

  And in order to improve the mechanical property of this long fiber reinforced polypropylene resin molding material, it is necessary to improve the impregnation property of the polypropylene resin with respect to the glass fiber and prevent the generation of voids between the single glass fibers.

  For example, in Patent Document 1 below, a glass fiber bundle introduced into an impregnation die is brought into contact with a protrusion or a roller provided inside the impregnation die, the glass fiber is opened by applying tension, and a polypropylene resin for the glass fiber bundle Have disclosed a method for producing a long-fiber thermoplastic resin molding material with improved impregnation of a thermoplastic resin.

Moreover, in the following patent document 2, a glass fiber bundle formed by applying a sizing agent containing an acid-modified olefin resin, polyethyleneimine, and, if necessary, a urethane resin to a glass fiber to form a bundle is formed into a long fiber reinforced polypropylene resin. It is used as a glass fiber bundle for materials, and improves the generation of fluff and impregnation with a polypropylene resin, which is a matrix resin, when producing a long fiber reinforced polypropylene resin molding material.
JP-A-6-254856 JP 2003-191236 A

  In Patent Document 1, the glass fiber bundle is opened by applying tension by bringing the glass fiber bundle into contact with a protrusion or a roller in a low-viscosity matrix resin. The front and rear protrusions and rollers cannot sufficiently open the fiber, and even if the matrix resin has a low viscosity, it is difficult to impregnate the glass fiber with the matrix resin. On the other hand, when a glass fiber bundle with weak convergence is used, when the fiber is opened by the protrusions or rollers, a part of the single fiber constituting the glass fiber bundle is cut by friction to become a fluff, and this fluff is a nozzle. There is a problem that the tensile resistance of the glass fiber bundle increases, the glass fiber bundle breaks, and the production stops.

  In particular, when a glass fiber bundle having a small number of glass fibers is used, fluff is likely to occur during the production of a long fiber reinforced thermoplastic resin molding material having a glass fiber content of 30 to 75% by mass. When fluff accumulates in the bending process part in the impregnation die and further clogs the inside of the nozzle downstream of the impregnation die, the glass fiber bundle may break, and stable production in a long time may be difficult. there were.

  Moreover, according to the said patent document 2, although the generation amount of the fluff at the time of manufacture can be reduced and also the resin molded product excellent in mechanical strength is obtained, the dispersibility of the glass fiber in a molded product is inferior. There is a problem, and particularly when the glass content is 40% by mass or less, the glass fibers are difficult to disperse in the polypropylene resin and are not suitable for use in injection molding.

  Therefore, an object of the present invention is to provide a method for producing a long-fiber polypropylene resin molding material used for reducing the amount of fluff generation and obtaining a polypropylene resin molded product having good mechanical strength and glass fiber dispersibility. is there.

  In order to achieve the above object, the method for producing a long fiber reinforced polypropylene resin molding material according to the present invention comprises 2 to 18 glass fiber bundles obtained by bundling 300 to 2000 glass single fibers with a sizing agent, and an acid-modified polypropylene resin. In a method for producing a long fiber reinforced polypropylene resin molding material having an average diameter of 0.4 to 3.0 mm and a glass content of 30 to 75% by mass As the sizing agent, an acid-modified polypropylene resin having a weight average molecular weight of 10,000 to 50,000 and an acid value of 10 to 50 mg [KOH / g], a silane coupling agent, and a polyurethane resin The sizing agent is attached in an amount of 0.1 to 1.0 part by mass with respect to 100 parts by mass of the glass fiber bundle. To.

  Since the glass fiber bundles bundled with the sizing agent comprising the above components are bundled with a relatively elastic film, the frictional resistance at the time of fiber opening can be reduced, and the amount of fluff generated can be reduced. Moreover, when the obtained long fiber reinforced polypropylene resin material is used as a molded product, the dispersibility of the glass fibers can be improved.

  Moreover, it is preferable that the adhesion amount of the sizing agent is 0.2 to 0.6 parts by mass with respect to 100 parts by mass of the glass fiber bundle.

  Furthermore, the polyurethane resin contained in the sizing agent is preferably 5 to 60 parts by mass with respect to 100 parts by mass of the acid-modified polypropylene resin.

  Moreover, it is preferable that the softening temperature of the said polyurethane resin in the said sizing agent is 100-180 degreeC.

  And it is preferable that this invention is a manufacturing method of the long fiber reinforcement polypropylene resin molding material for injection molding.

  According to the present invention, the conventional problems occurring when producing a long fiber reinforced polypropylene resin molding material, such as generation of fuzz, breakage of glass fiber bundles, and impregnation of polypropylene resin are not sufficiently improved. In addition, it is possible to produce a long fiber reinforced polypropylene resin molding material having good glass fiber dispersibility and particularly suitable for injection molding.

  The glass fiber used in the present invention is preferably drawn from a wound body wound into a predetermined shape, for example, a drum shape or a cylindrical shape.

  Moreover, as for the glass single fiber which comprises a glass fiber bundle, that whose fiber diameter is 4-30 micrometers is used preferably, More preferably, it is 10-25 micrometers. And it is preferable that the number of glass monofilaments is 300-2000, preferably 500-1500. According to this, it is easy to apply or impregnate the polypropylene resin as the matrix resin to the glass fiber bundle, and it is easy to adjust the glass content of the long fiber polypropylene resin molded product.

  In the present invention, in order to improve the handleability by suppressing the generation of fuzz and static electricity during use, or to improve the adhesion of the glass fiber to the polypropylene resin, which is a matrix resin, a specific sizing agent described later is added to the glass fiber. Give. The amount of the sizing agent to be added is essentially 0.1 to 1.0 part by mass, preferably 0.2 to 0.6 part by mass with respect to 100 parts by mass of the glass fiber bundle. When the application amount of the sizing agent is less than 0.1 parts by mass, it is difficult to sufficiently improve the handling property and the adhesiveness, and further, when the polypropylene resin is impregnated, yarn breakage is likely to occur. On the other hand, when the amount is more than 1.0 part by mass, it becomes difficult for the polypropylene resin to impregnate between the bundled single fibers of the glass, and there is a possibility that sufficient mechanical strength cannot be provided.

  In the present invention, a composition containing an acid-modified polypropylene resin, a polyurethane resin, and a silane coupling agent is used as a glass fiber sizing agent.

  The acid-modified polypropylene resin used in the sizing agent of the present invention preferably has a weight average molecular weight of 10,000 to 50,000, more preferably 20,000 to 35,000, and an acid value of 10 to 50 mg [KOH / g] is preferable, and more preferably 20 to 45 mg [KOH / g].

  When the weight average molecular weight is 10,000 or less, the glass fiber is poorly converged, and becomes fuzzy easily. When the weight average molecular weight is 50,000 or more, the dispersibility of the glass fiber is poor, and when a resin molded product is obtained, Undispersed fibers tend to occur.

  In addition, when the acid value is 10 mg [KOH / g] or less, the adhesion between the glass fiber and the matrix resin is poor, and when it is 50 mg [KOH / g] or more, the weight average molecular weight of the acid-modified polypropylene resin is inevitably. In addition, the glass fiber has poor bundling properties and there is an excess of acid (mainly carboxylic acid) that does not contribute to the reaction, so the solution stability at the time of bundling agent preparation decreases and solid content precipitates. It becomes easy and the handling as a sizing agent solution becomes difficult.

  The acid-modified polypropylene resin used in the present invention can be converted into a sulfone group after chlorsulfonating the polypropylene resin, or directly sulfonated. It can be obtained by copolymerizing the derivative, or by graft polymerizing an addition-polymerizable unsaturated carboxylic acid compound or derivative thereof to a polypropylene resin.

  Examples of the sulfonated polypropylene resin include those obtained by reacting the above-mentioned polypropylene resin with chlorine and sulfur dioxide or chlorosulfonic acid to form a chlorosulfonate, which is converted into a sulfone group, and a directly sulfonated polypropylene resin. Can be mentioned.

  Examples of the acid-modified polypropylene resin modified with an unsaturated carboxylic acid compound or a derivative thereof include those obtained by graft polymerization of an unsaturated carboxylic acid compound or a derivative thereof on a polypropylene resin.

  Here, examples of the unsaturated carboxylic acid used for carboxylic acid modification include maleic acid, fumaric acid, itaconic acid, acrylic acid, and methacrylic acid. Examples of unsaturated carboxylic acid derivatives include these acid anhydrides, esters, amides, imides, metal salts, and the like. Specific examples thereof include maleic anhydride, itaconic anhydride, methyl acrylate, ethyl acrylate, Butyl acrylate, glycidyl acrylate, methyl methacrylate, ethyl methacrylate, glycidyl methacrylate, maleic acid monoethyl ester, maleic acid diethyl ester, fumaric acid monomethyl ester, fumaric acid dimethyl ester, acrylamide, methacrylamide, maleic acid monoamide, Mention may be made of maleic acid diamide, fumaric acid monoamide, maleimide, N-butylmaleimide, sodium methacrylate and the like. Among these compounds, those having no free carboxylic acid group generate a carboxylic acid group by hydrolysis or the like after polymerization.

  Of the unsaturated carboxylic acid compounds and derivatives thereof, preferred are glycidyl esters of acrylic acid and methacrylic acid and maleic anhydride, and preferred acid-modified polypropylene resins modified by these are maleic anhydride and polypropylene resin. And those modified with an acid by graft polymerization, and those modified with a copolymer of polypropylene and glycidyl (meth) acrylate or maleic anhydride.

  The polyurethane resin used in the present invention may be a conventionally known one derived from a polymer polyol, an organic diisocyanate and, if necessary, a chain extender and / or a crosslinking agent, but a polyurethane having a softening temperature of 100 to 180 ° C. Resins are preferred.

  When the softening temperature of the polyurethane resin is 100 ° C. or lower, the film formed by the sizing agent becomes brittle and the sizing property is inferior. It becomes difficult and the impregnation property of the matrix resin is inferior.

  Specific examples of the polymer polyol include, for example, 1) polyester polyol [for example, polyethylene adipate diol, polybutylene adipate diol, polyethylene butylene adipate diol, polyneopentyl adipate diol, polyneopentyl terephthalate diol, polycaprolactone diol, polyvalero Lactone diol, polyhexamethylene carbonate diol, etc.] 2) polyether polyol [polyethylene glycol, polypropylene glycol, polyoxyethyleneoxypropylene glycol, polyoxytetramethylene glycol, ethylene oxide and / or propylene oxide adduct of bisphenols, etc.] Etc. The number average molecular weight of the polymer polyol is usually 500 to 6,000, preferably 800 to 3,000.

Specific examples of the organic diisocyanate include 1) aromatic diisocyanate; for example, 2,4′- or 4,4′-diphenylmethane diisocyanate (MDI), 2,4- or 2,6-tolylene diisocyanate (TDI), hydrogen Added urethane (H ₁₂ -MDI), 4,4′-dibenzyl diisocyanate, 1,3- or 1,4-phenylene diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, etc. 2) aliphatic diisocyanate; For example, ethylene diisocyanate, hexamethylene diisocyanate (HDI), lysine diisocyanate, etc. 3) Alicyclic diisocyanate; for example, isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate, etc. It is, may be used two or more thereof as a mixture. Among _these, preferred are _{MDI, TDI, H 12 -MDI,} HDI and IPDI.

  Examples of the chain extender and / or cross-linking agent used as necessary include active hydrogen-containing compounds having a number average molecular weight of less than 60 to 500, such as polyhydric alcohols [ethylene glycol, propylene glycol, 1,3-butylene glycol, 1, 4-butanediol, 1,6-hexanediol, 3-methylpentanediol, diethylene glycol, 1,5-pentanediol, neopentyl glycol, 1,4-bis (hydroxymethyl) cyclohexane, 1,4-bis (hydroxyethyl) ) Divalent alcohols such as benzene and 2,2-bis (4,4′-hydroxycyclohexyl) propane; Trivalent alcohols such as glycerin and trimethylolpropane; Pentaerythritol, diglycerin, α-methylglucoside, sorbitol, xylit, Ma Knitted, dipentaerythritol, glucose, fructose, sucrose, etc., 4-8 valent alcohols, etc.], polyhydric phenols [polyphenols such as pyrogallol, catechol, hydroquinone; bisphenols such as bisphenol A, bisphenol F, bisphenol S, etc.] Etc.], water, polyamine [aliphatic polyamine (ethylenediamine, hexamethylenediamine, diethylenetriamine, etc.), alicyclic polyamine (isophoronediamine, 4,4′-dicyclohexylmethanediamine, etc.), aromatic polyamine (4,4′- Diaminodiphenylmethane etc.), aromatic alicyclic polyamines (xylylenediamine etc.), hydrazine or its derivatives etc.]. If necessary, a compound containing a hydrophilic group and an active hydrogen group in the molecule (for example, lactic acid, dimethylolpropionic acid, aminoethylsulfonic acid, etc.) may be used in combination.

  The polyurethane resin can be used as an emulsion, an aqueous solution or a dispersion of a water-insoluble polyurethane resin, a water-soluble polyurethane resin, a self-emulsifying polyurethane resin or the like.

  The content of the polyurethane resin in the sizing agent of the present invention is preferably 5 to 60 parts by mass and more preferably 10 to 40 parts by mass with respect to 100 parts by mass of the acid-modified polypropylene resin in the sizing agent. .

  When the content of the polyurethane resin is 5 parts by mass or less, the bundling property is inferior, so that it becomes easy to fluff, and when it is 60 parts by mass or more, the fiber is difficult to open, so that the impregnation with the matrix resin is inferior.

  The silane coupling agent used in the present invention is γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -N′-β-. (Aminoethyl) -γ-aminopropyltrimethoxysilane, γ-anilinopropyltrimethoxysilane and other aminosilanes, γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltri Epoxy silanes such as methoxysilane, chlorosilanes such as γ-chloropropyltrimethoxysilane, mercaptosilanes such as γ-mercaptotrimethoxysilane, vinylmethoxysilane, N-β- (N-vinylbenzylaminoethyl) -Vinyl sila such as γ-aminopropyltrimethoxysilane Class, those selected γ- methacryloxypropyltrimethoxysilane one or the like propyl acrylate silanes such as trimethoxysilane is preferably used.

  The content of the silane coupling agent in the sizing agent of the present invention is preferably 5 to 90 parts by mass and preferably 15 to 65 parts by mass with respect to 100 parts by mass of the acid-modified polypropylene resin in the sizing agent. More preferred.

  If the content of the silane coupling agent is 5 parts by mass or less, the adhesive strength with the matrix resin is inferior, resulting in a decrease in mechanical strength. Moreover, since the color tone of a molded product will turn yellow, it is not preferable.

  The sizing agent used in the present invention further includes a polymer such as vinyl acetate resin, acrylic resin, polyester resin, polyether resin, phenoxy resin, polyamide resin, epoxy resin, polyolefin resin, or a modified product thereof. Alternatively, oligomers such as waxes represented by polyolefin wax can be added and used. However, the above polymers and oligomers are usually water dispersions obtained by water dispersion with surfactants, or water-solubilization by neutralization or hydration of carboxyl groups or amide groups present in the skeleton of the polymer or oligomer. It is generally used in the form of an aqueous solution, emulsion, or dispersion obtained by emulsification or dispersion.

  Further, a lubricant can be contained in order to impart lubrication performance to the sizing agent. Examples of the lubricant include those used in conventional sizing agents, such as plant waxes such as cadellin wax, carnauba wax, and wax, animal waxes such as beeswax, lanolin, and whale wax, montan wax, Mineral waxes such as petroleum waxes, fatty acid amides, and fatty acid ester, aromatic ester, fatty acid ether, and aromatic ether surfactants are preferably used.

  If this lubricant is too much, it will hinder the adhesion between the glass fiber and the matrix resin, and if it is insufficient, sufficient lubrication performance will not be obtained. It is appropriate to add about 0.05 to 0.5% by weight.

  In addition to the above components, the sizing agent may be an antistatic agent typified by an inorganic salt such as lithium chloride or potassium iodide, a quaternary ammonium salt such as an ammonium chloride type or an ammonium ethosulphate type, or an aliphatic group. A lubricant typified by an ester-based, aliphatic ether-based, aromatic ester-based, or aromatic ether-based surfactant may be included.

  The sizing agent used in the present invention is used in the form of an aqueous solution, an emulsion, or an aqueous dispersion as a whole, and is added in an amount of 0.1 to 1.0 parts by mass as a solid content to 100 parts by mass of the glass fiber bundle. It is important that it is 0.2 to 0.6 parts by mass. When the amount is less than 0.1 parts by mass, thread breakage tends to occur when glass fibers are impregnated with polypropylene resin as a matrix resin, and workability is inferior. On the other hand, if it exceeds 1.0 part by mass, the binding force of the glass fibers is strong, and the impregnation property when impregnating the polypropylene resin as the matrix resin is inferior.

  The polypropylene resin used as the matrix resin in the present invention is not particularly limited, but is compatible with the sizing agent that is acid-modified with maleic acid, acrylic acid, or the like in order to improve adhesion to glass fibers. It is preferable, and known additives such as colorants, modifiers, and fillers other than glass fibers can be appropriately blended in the polypropylene resin according to the application and molding conditions. According to the method, it can be used by kneading with polypropylene resin.

  Next, the manufacturing method of the long fiber reinforced polypropylene resin molding material of this invention is demonstrated.

  In the present invention, the long fiber reinforced polypropylene resin molding material can be produced, for example, by a process as shown in FIG.

  First, a continuous glass fiber bundle 1 drawn from a winding body (not shown) is introduced into the impregnation die 4. A molten matrix resin (polypropylene resin) 2 is supplied from the extruder 3 to the impregnation die 4, and the glass fiber bundle 1 is impregnated with the polypropylene resin. Then, the glass fiber bundle 1 impregnated with polypropylene resin is pulled out through the nozzle 5, thereby removing excess polypropylene resin, and a desired long fiber reinforced polypropylene shaped into a predetermined shape with a predetermined glass content. A resin rod 6 is obtained.

  The long fiber reinforced polypropylene resin rod 6 is cooled in a cooling bath 7 and taken up by a take-up machine 8. The taken long fiber reinforced polypropylene resin rod 6 is cut into a predetermined length by a pelletizer 9 with a rotary cutting blade, and a long fiber reinforced polypropylene resin molding material 10 is obtained.

  In the above example, the melt impregnation method in which the glass fiber bundle 1 is impregnated with the molten polypropylene resin is employed as a method of applying or impregnating the continuous glass fiber bundle 1 with the polypropylene resin, but other methods are employed. You can also. For example, after applying or impregnating a glass fiber bundle with an emulsion of polypropylene resin, a suspension in which polypropylene resin powder is dispersed in water or other liquid, or a resin solution in which polypropylene resin is dissolved in a solvent, A method of removing the dispersion medium or the solvent can also be adopted.

  In addition to the method using an impregnation die, a method such as a roll coater or a curtain coater can also be employed as the method for applying or impregnating. Furthermore, after making a polypropylene resin powder adhere to a glass fiber bundle, the method of heat-melting as needed and then cooling can also be employ | adopted. However, it is preferable to employ a melt impregnation method from the viewpoint that costs for drying and solvent removal are not necessary and cost.

  The long fiber reinforced polypropylene resin molding material thus obtained contains glass fibers in a matrix resin with substantially the same length and arranged in parallel in the same direction, preferably in the form of wire rods or pellets It is a shape. The glass fibers are substantially the same length and contained in parallel in the same direction. The majority of glass fibers are arranged in parallel substantially in parallel in the same direction. Means a state that may be partially curved or entangled with each other.

  The long fiber reinforced polypropylene resin molding material of the present invention comprises 2 to 18 glass fiber bundles, preferably 3 to 15. If the number is less than 2, the amount of single glass fibers in the glass fiber bundle increases, and if twisting occurs, the impregnation property is extremely inferior.

  Further, the glass content in the long fiber reinforced polypropylene resin molding material is not particularly limited, but in order to bring out the effects of the present invention remarkably, it is preferably 30 to 75 mass%, more preferably 40 to 70 mass% in the molding material. %. When the glass fiber content is less than 30% by mass, the reinforcing effect by the glass fiber is not obtained. When the glass fiber content exceeds 75% by mass, the impregnation with the matrix resin is inferior, and fluff is generated in the nozzle drawing process. However, disconnection tends to occur, which is not preferable.

  Although the length of the glass fiber in the long fiber reinforced polypropylene resin molding material of this invention is not specifically limited, Preferably it is 3-20 mm, More preferably, it is 6-16 mm. When the length is less than 3 mm, cracks and fluff are likely to occur during the production of the wire-like or pellet-like material of the long-fiber reinforced polypropylene resin molding material, and the effect of fiber reinforcement is hardly exhibited. On the other hand, when the length exceeds 20 mm, when molding by injection molding, it may be difficult to supply to the molding machine, or glass fibers may be dispersed or fluidity may be lowered.

  The average diameter of the long fiber reinforced polypropylene resin molding material of the present invention is preferably 0.4 to 3.0 mm, more preferably 0.7 to 2.6 mm. In the present invention, since a specific glass fiber film forming agent is used, the problem of workability when producing a polyolefin resin-forming material containing relatively thin average diameter glass fibers is improved. When the thickness is less than 0.4 mm, the bulk density of the molding material is reduced, and transportability is inferior. On the other hand, when the average diameter exceeds 3.0 mm, a high glass content (40% by mass or more) is not preferable because the dispersibility of the glass fibers is poor when molding by injection molding.

  Hereinafter, the present invention will be specifically described with reference to examples. However, these examples are illustrative of embodiments of the present invention and are not intended to limit the scope of the present invention.

[Manufacture of glass fiber bundles]
The glass fiber bundles of Production Examples 1 to 8 are bundled by using the raw materials shown in Table 1 and the bundling agent prepared at the blending ratio shown in Table 2 on 600 glass single fibers having a fiber diameter of 16 μm. Manufactured. The amount of sizing agent attached is shown in Table 2.

[Manufacture of long fiber reinforced polypropylene resin molding materials]
<Example 1>
An impregnation die in which a polypropylene resin containing an acid-modified polypropylene homopolymer resin at MI = 120 (g / 10 min) [temperature: 230 ° C., load: 2.16 kgf] is melted at 280 ° C. Seven glass fiber bundles were aligned, the glass fiber bundle was impregnated with the polypropylene resin while being opened in the impregnation die, and the resulting polypropylene resin rod was taken out from the impregnation die at a speed of 20 m / min. The polypropylene resin rod was cooled and cut into 8 mm with a pelletizer to obtain a long fiber polypropylene resin molding material of Example 1 having a glass content of 50% by mass.

<Example 2>
A long fiber polypropylene resin molding material of Example 2 having a glass content of 50% by mass was obtained in the same manner as in Example 1 except that the glass fiber bundle of Production Example 2 was used.

<Example 3>
A long fiber polypropylene resin molding material of Example 3 having a glass content of 50% by mass was obtained in the same manner as in Example 1 except that the glass fiber bundle of Production Example 3 was used.

<Example 4>
A long fiber polypropylene resin molding material of Example 4 having a glass content of 50% by mass was obtained in the same manner as in Example 1 except that the glass fiber bundle of Production Example 4 was used.

<Comparative Example 1>
A long-fiber polypropylene resin molding material of Comparative Example 1 having a glass content of 50% by mass was obtained in the same manner as in Example 1 except that the glass fiber bundle of Production Example 5 was used.

<Comparative example 2>
A long fiber polypropylene resin molding material of Comparative Example 2 having a glass content of 50% by mass was obtained in the same manner as in Example 1 except that the glass fiber bundle of Production Example 6 was used.

<Comparative Example 3>
A long fiber polypropylene resin molding material of Comparative Example 3 having a glass content of 50% by mass was obtained in the same manner as in Example 1 except that the glass fiber bundle of Production Example 7 was used.

<Comparative example 4>
A long fiber polypropylene resin molding material of Comparative Example 4 having a glass content of 50% by mass was obtained in the same manner as in Example 1 except that the glass fiber bundle of Production Example 8 was used.

[Evaluation item]
<Fuzzy workability>
In the production of the long fiber polypropylene resin molding materials of Examples 1 to 4 and Comparative Examples 1 to 4, it was allowed to move continuously for 24 hours to check for fluff generation by the nozzle part and nozzle clogging (fiber breakage) accompanying the fluff. The case where there was almost no occurrence and nozzle clogging occurred was marked with ◯, and the case where the number of nozzle disconnections due to fluff occurrence was 1 or more was marked with ×.

<Izod impact strength measurement with notches>
Polypropylene block polymer resin pellets having MI = 30 (g / 10 min) [temperature: 230 ° C., load: 2.16 kgf] of the long fiber polypropylene resin molding materials of Examples 1 to 4 and Comparative Examples 1 to 4 And dry blending to adjust the glass content to 40% by mass, a long fiber injection molding machine (manufactured by Nippon Steel Works [clamping force: 110 t, screw: screw for glass fiber, screw diameter: 40 mm]), and multipurpose A multi-purpose test piece (JIS-K-7139) is produced by injection molding under a molding condition in accordance with JIS-K6921-2 using a test piece mold, and an Izod impact with a notch in accordance with JIS-K-7110. The strength was evaluated.

<Fiber dispersibility evaluation>
Polypropylene block polymer resin pellets having MI = 30 (g / 10 min) [temperature: 230 ° C., load: 2.16 kgf] of the long fiber polypropylene resin molding materials of Examples 1 to 4 and Comparative Examples 1 to 4 And a glass content rate adjusted to 40% by mass, using a long fiber injection molding machine (manufactured by Nippon Steel), cylinder temperature 250 ° C., mold temperature 40 ° C., back pressure 0.3 MPa, length 60 mm. Ten flat color molded products each having a width of 60 mm and a thickness of 2 mm were molded, and the fiber dispersion state on the surface, in particular the presence or absence of undefibrated bundles, and the frequency were visually observed. Xx when the unopened bundle of long fibers is scattered on all 10 flat plates, xx when the unopened bundle of long fibers is scattered on several flat plates, and unopened bundles of long fibers on several flat plates The case where it was slightly seen was marked with ◯, and the case where the unopened bundle of long fibers was not seen on all 10 flat plates was marked with ◎.

The above evaluations are performed on the long fiber reinforced polypropylene resin molding materials of Examples 1 to 4 and Comparative Examples 1 to 4, and the results are summarized in Table 3.

  From the above results, in Comparative Example 2 using a sizing agent containing an acid-modified polypropylene resin having a weight average molecular weight of less than 10,000, during the production of a long fiber reinforced polypropylene resin molding material, a large amount of fluff is generated and disconnection occurs. The resin molded product using the same was inferior in mechanical strength. Further, in Comparative Example 3 using a sizing agent containing an acid-modified polypropylene resin having a weight average molecular weight exceeding 50,000, undispersed fibers are likely to occur in a molded product, and the fiber dispersibility is extremely poor. In Comparative Example 4 using a sizing agent that does not contain a polyurethane resin, a large amount of fluff is generated during the production of a long fiber reinforced polypropylene resin molding material, and disconnection is likely to occur, and a resin molded product using the same Was inferior in mechanical strength. A glass fiber bundle containing an acid-modified polypropylene resin having a weight average molecular weight of 10,000 to 50,000 and having a solid content of 1.0 mass part or more even when a sizing agent containing a polyurethane resin is used. In Comparative Example 1 used, when a molded product was used, undispersed fibers were likely to occur, and the appearance was poor.

  On the other hand, a sizing agent containing an acid-modified polypropylene resin having a weight average molecular weight of 10,000 to 50,000 and containing a polyurethane resin was attached in an amount of 0.1 to 1.0 part by mass with respect to 100 parts by mass of glass fiber. In Examples 1 to 4, at the time of producing the long fiber reinforced polypropylene resin molding material, fuzz hardly occurs, disconnection is very unlikely, and a resin molded product using the same is excellent in mechanical strength. It had good dispersibility.

  Among them, a sizing agent containing 5 to 60 parts by mass of a polyurethane resin having a softening temperature of 100 to 180 ° C. with respect to 100 parts by mass of the acid-modified polypropylene resin is used, and the solid content is 0.2 to 0 with respect to 100 parts by mass of the glass fiber. In Example 1 adhered in the range of .6 parts by mass, no undispersed fibers were observed in the resin molded product, and the fiber dispersibility was extremely good.

  According to the method for producing a long fiber reinforced polypropylene resin molding material of the present invention, a long fiber reinforced polypropylene resin molding material with less fuzzing and good resin impregnation property is obtained, and a resin molded product using the same is obtained by dispersing glass fibers. It can be made into a polypropylene resin molded product having good properties and excellent mechanical strength.

It is a basic block diagram which shows the manufacturing process of a long fiber reinforced polypropylene resin molding material.

Explanation of symbols

1: Glass fiber bundle 2: Matrix resin (polypropylene resin)
3: Extruder 4: Impregnation die 5: Nozzle 6: Long fiber reinforced polypropylene resin rod 7: Cooling tank 8: Take-up machine 9: Pelletizer 10: Long fiber reinforced polypropylene resin molding material

Claims (5)

2 to 18 glass fiber bundles obtained by bundling 300 to 2000 glass single fibers with a sizing agent are dipped in a molten polypropylene resin containing an acid-modified polypropylene resin and pulled out from a nozzle, and the average diameter is 0.4. A method for producing a long fiber reinforced polypropylene resin molding material having a glass content of 30 to 75% by mass at ˜3.0 mm,
A composition comprising an acid-modified polypropylene resin having a weight average molecular weight of 10,000 to 50,000 and an acid value of 10 to 50 mg [KOH / g], a silane coupling agent, and a polyurethane resin as the sizing agent. Using things,
A method for producing a long fiber reinforced polypropylene resin molding material, wherein 0.1 to 1.0 parts by mass of the sizing agent is attached to 100 parts by mass of the glass fiber bundle as a solid content.   The method for producing a long fiber reinforced polypropylene resin molding material according to claim 1, wherein the amount of the sizing agent attached is 0.2 to 0.6 parts by mass in solid content with respect to 100 parts by mass of the glass fiber bundle.   The method for producing a long-fiber-reinforced polypropylene resin molding material according to claim 1 or 2, wherein the content of the polyurethane resin contained in the sizing agent is 5 to 60 parts by mass with respect to 100 parts by mass of the acid-modified polypropylene resin. .   The method for producing a long-fiber reinforced polypropylene resin molding material according to any one of claims 1 to 3, wherein the softening temperature of the polyurethane resin in the sizing agent is 100 to 180 ° C. It is a manufacturing method of the long fiber reinforced polypropylene resin molding material for injection molding, The manufacturing method of the long fiber reinforced polypropylene resin molding material as described in any one of Claims 1-4.

Images