JPH0347291B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a glass fiber reinforced composite material suitable for stamping with a mechanical stamping press (a type of stamping molding), and particularly requires airtightness, airtightness, and flame retardancy. It is used for applications in various fields. [Prior Art] Conventionally, crystalline resins have been used as resins for glass fiber reinforced composites that are suitable for stamping with a mechanical stamping press because of their excellent mechanical properties, moldability, and low cost. Polypropyline is used. [Problems to be Solved by the Invention] When a glass fiber reinforced composite made of crystalline polypropylene as a base polymer is stamped using a mechanical stamping press, parts with particularly complex shapes (e.g. ribs, corners, etc.) It has the major drawbacks of poor airtightness and flammability. [Means for Solving the Problems] In view of the above-mentioned points, the present inventors have developed a glass fiber-reinforced composite that has good airtightness, especially in complex-shaped parts, by stamping, and has also developed an airtightness. The present invention was completed as a result of extensive research aimed at providing a glass fiber reinforced composite with good properties and flame retardancy. That is, the present invention provides a glass fiber-reinforced composite for mechanical press molding, which is made by impregnating mat-like glass fibers with a polypropylene resin containing modified polypropylene. The mat-shaped glass fiber used in the present invention is a mat consisting of strands in which long glass fibers (strands) are uniformly dispersed, and the mat has sufficient integrity or preservation to maintain a uniform strand distribution. It is desirable to have a shape. For this purpose, in needle punching the mat with a barbed needle, the barbed needle simply passes through the mat and entangles the fibers in the mat, binding the mat loosely and never strongly. This allows the pine strands to move freely with the flow of resin during stamping in a mechanical stamping press. In the present invention, polypropylene resin including modified polypropylene is used. The polypropylene resin (crystalline polypropylene) includes polypropylene homopolymer, crystalline ethylene-propylene random copolymer, crystalline ethylene-propylene block copolymer, crystalline ethylene-propylene random polymerization post ethylene-propylene block copolymer, and crystalline propylene It is a general term for butene copolymers.
The crystalline polypropylene of the present invention includes a crystalline ethylene-propylene random copolymer having an ethylene content of 0.1 to 10% by weight and a crystalline ethylene-propylene random polymerized post ethylene-propylene block having a total ethylene content of 1 to 20% by weight. Copolymers are preferred from the viewpoint of physical properties and moldability. The crystalline polypropylene mentioned above has a melt flow rate index (MFR) of 0.5 to
Preferably, the rate is 100g/10 minutes. The modified polypropylene in the present invention is a general term for those obtained by heat treating the above-mentioned crystalline polypropylene with a modifier such as an organic silane compound or unsaturated carboxylic acid in the presence of a catalyst such as an organic peroxide. Particularly preferred are those modified with an organic silane compound. The above-mentioned modified polypropylene has a grafting rate of the modifier of 0.01 to 10% by weight, especially
It is preferable that the amount is 0.1 to 5% by weight and the MFR is 1 to 150 g/10 minutes. The modifiers include vinyltriethoxysilane, methacryloyloxytrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, methacryloyloxycyclohexyltrimethoxysilane, γ-methacryloyloxypropyltriacetyloxysilane, methacryloyl Organic silane compounds such as oxytriethoxysilane and γ-methacryloyloxypropyltriethoxysilane, acrylic acid, maleic anhydride, itaconic anhydride, endo-bicyclo-[2,2,1]-5-heptene-2,3 - unsaturated carboxylic acids and acid anhydrides such as dicarboxylic anhydride, acrylic glycidyl ether, 2-methyl-allyl glycidyl ether, sodium acrylate, sodium methacrylate, calcium acrylate, calcium methacrylate, magnesium acrylate, Metal salt compounds of (meth)acrylic acid such as magnesium methacrylate, zinc acrylate, zinc methacrylate, aluminum acrylate, aluminum methacrylate, iron acrylate (), iron methacrylate (), triallyl cyanurate , tri(2-methylallyl) cyanurate, 1,3,5
-Triacryloylhexahydro-S-triazine, 1,3,5-triacryloylhexahydro-S-triazine, 1,3,5-trimethacryloylhexahydro-S-triazine, 4-acryloyloxyphenol, 4- Examples include (acryloyloxymethyl)phenol, 4-acryloyloxybenzyl alcohol, 4-methacryloyloxyphenol, 4-methacryloyloxybenzyl alcohol, and 4-(methacryloyloxymethyl)benzyl allure. Among these, organic silane compounds are preferred. The above-mentioned modifiers may be used alone or in combination of two or more. Furthermore, the organic peroxide mentioned above is preferably one having a 1-minute half-life temperature of about 160 to 260°C, such as tert-butylperoxyisopropyl carbonate, di-tert-butylperoxyisopropyl carbonate, etc. Butyl diperoxyphthalate, tert-butyl peroxyacetate, 2,5-dimethyl-2,
5-di(tert-butylperoxy)hexane, 2,
5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, tert-butyl peroxylaurate, tert-butyl peroxymale acid, tert-butyl peroxybenzoate, methyl ethyl ketone peroxide, dicumyl peroxide, cyclohexanone peroxide,
Examples include tert-butylcumyl peroxide, 2,5-dimethylhexane 2,5-dihydroperoxide, and the like. These organic peroxides are 1
Only the seeds may be used, or two or more types may be used in combination. The blending ratio of the polyolefin resin, modifier, and organic peroxide described above varies depending on the desired MFR of the modified polyolefin, but in general,
Preferably, the modifier is in the range of 0.01 to 10 parts by weight, particularly 0.1 to 5 parts by weight, and the organic peroxide is in the range of 0.01 to 5 parts by weight, particularly 0.1 to 2 parts by weight, based on 100 parts by weight of the polyolefin resin. In addition, the blending ratio of the modifier and organic peroxide is
5 to 80 parts of organic peroxide per 100 parts by weight of modifier
Parts by weight ranges are preferred. The modified polypropylene used in the present invention can be prepared, for example, by mixing a polypropylene resin, a modifier, and an organic peroxide by a method known per se, preferably by a suitable known mixing method under conditions in which the organic peroxide does not decompose. The polypropylene resin, the modifier, and the organic peroxide are mixed by applying a temperature at which the polypropylene resin melts but does not decompose.
Preferably, it is obtained by heating the reaction at a temperature of about 180 to 260°C, particularly 220 to 250°C. The simplest heat treatment operation is to melt and heat the mixture in an extruder at the above temperature for about 2 to 5 minutes. The modified polypropylene obtained as described above has an MFR of 1 to 150 g/10 minutes, particularly 10 to 150 g/10 minutes.
Preferably 10 minutes. It is preferable to use the modified polypropylene in combination with the crystalline polypropylene. The proportion of modified polypropylene in the polypropylene resin is preferably 5% by weight or more, particularly 10 to 70% by weight. It is preferable to blend a flame retardant into the polypropylene resin used in the present invention. Examples of the flame retardant include brominated aromatic flame retardants such as decabrom diphenyl ether, bis(3,
5-dibromo-4-dibromopropoxyphenyl) sulfone, bis(pentabromophenoxy)
A mixed system of ethane or the like and antimony trioxide, a salt of polyphosphoric acid, for example a salt of polyphosphoric acid and a base such as a basic nitrogen compound, for example a melamine salt of ammonium carbamyl polyphosphate are preferably used. The blending amount of the flame retardant is preferably 1 to 100 parts by weight of the brominated aromatic flame retardant and 0.5 to 50 parts by weight of antimony trioxide, and the salt of polyphosphoric acid and a base is preferably 1 to 100 parts by weight, based on 100 parts by weight of the polypropylene resin. is preferably 10 to 200 parts by weight. Alternatively, some or all of the above flame retardants may be replaced with other flame retardants, such as substituted S-triazine compounds such as 1,3,5-triazine and trisphenoxy-S-triazine compounds, benzylguanamine, and reaction of guanamine and aldehyde. products, melamine, 1,3,6-tris(4,6-diamino-1,3,5-triazine-2)hexane, and the like. Furthermore, an inorganic filler can be added to the polypropylene resin of the present invention.
As the inorganic filler, calcium carbonate,
(heavy calcium carbonate, light calcium carbonate), talc, magnesium hydroxide, calcined clay, kaolin clay, silica powder, diatomaceous earth, aluminum hydroxide, barium sulfate, calcium sulfate, etc. Inorganic filler is polypropylene resin
It is preferable that the amount is 50 parts by weight or less per 100 parts by weight. In the present invention, the ratio of the pine-like glass fiber in the first half to the polypropylene resin is 10 to 10.
60% by weight, especially 20-50% by weight and polypropylene resin 90-40% by weight, especially 80-50% by weight are preferred. The glass fiber reinforced composite of the present invention is produced by impregnating a polypropylene resin containing the modified polypropylene into a mat structure made of the long glass fibers (strands) described above, and then compressing this structure if necessary. It is obtained as a sheet-like resin-impregnated product by cooling and solidifying. To do this, layers of pine and resin are stacked one on top of the other, heat and pressure are applied, and then cooled. A plurality of mat and resin layers may be used and combined as appropriate, or the above operations may be performed continuously using a molten resin layer. The sheet-shaped resin-impregnated glass fiber-reinforced composite thus obtained is cut as necessary to produce a sheet-shaped glass fiber-reinforced composite of a desired size. By stamping the glass fiber reinforced composite of the present invention using a mechanical stamping press, not only does it have high rigidity and heat distortion temperature, but it can also be molded with good airtightness even in parts with complex shapes. Obtainable. To stamp with a mechanical stamping press, for example, a sheet cut to size is preheated to a temperature that melts the resin (at this time the sheet is preheated to restore the elasticity of the fibers or strands within it). This swollen impregnated material (swells up to several times its previous thickness) is introduced into a cooled mold either as it is, or preferably in two or more layers, and subjected to a stamping press. By stamping the glass fiber reinforced composite of the present invention using a mechanical stamping press, various glass fiber reinforced resin molded products can be manufactured. Hereinafter, the present invention will be explained by giving examples. [Example] Polymers used in each example are shown below. A: A predetermined amount of known antioxidant was added.
Crystalline ethylene-propylene random copolymer B with MFR 2.0 g/10 minutes and ethylene content 4% (wt%, same hereinafter): A predetermined amount of known antioxidant was added.
MFR9.0g/10min, crystalline ethylene-propylene random polymerized post-ethylene-propylene block copolymer with total ethylene content of 5.5% C: γ-methacryloxypropyltrimethoxysilane and t-butyl peroxybenzoate are added to B. , 0.5 parts/0.25 parts, respectively, were added to 100 parts (by weight, same hereinafter) of B, and MFR 50 g/10 minutes was obtained by heat treatment at 220°C. Modified polypropylene D: Maleic anhydride and t-butyl peroxy were added to A. Benzoate, 0.5 parts each per 100 parts of A
Obtained by adding 0.25 parts and heat-treating at 220℃
MFR60g/10min Modified polypropylene E: Bis(3,5-dibromo-
4-dibromopropoxyphenyl) sulfone and antimony trioxide as a flame retardant aid,
Halogen-based flame-retardant polypropylene F obtained by blending 12 parts and 6 parts of each with 100 parts of B and melt-kneading: B and melamine salt of ammonium carbamyl polyphosphate as a flame retardant [Marubishi Yuka Kogyo Co., Ltd., Nonnen
Blending 100 parts of R604-10] to 100 parts of B,
Non-halogenated flame-retardant polypropylene obtained by melt-kneading Experiments 1 to 12 Surface-treated continuous glass fiber strands (average diameter 23 μm) were layered in a spiral pattern, with a total of 22 needles per approximately 1 ^cm2 . Glass pine obtained by needle punching (area weight 900
g/cm ² ), a molten polymer (hereinafter referred to as melt polymer) supplied from an extruder between these two glass mats, and a polymer previously formed into a sheet with a thickness of 0.5 mm (hereinafter referred to as overlay polymer). (for use) were stacked alternately and under pressure (2Kg/cm ² ).
Heated (250℃), cooled (20℃), then cut with a cutter to make a glass fiber reinforced composite (300×300×
A flat plate of 0.37 cm) was obtained. This flat plate was cut into an appropriate size, heated to 210°C in an infrared heating furnace, and then charged onto a mold set in a hydraulic press to pressure-form a semi-cylindrical molded product. Molding conditions: Mold clamping force 6000 tons Mold cooling time 90 seconds Mold temperature 60°C Next, the molded product was tested for airtightness under the following conditions. In other words, two semi-cylindrical molded bodies are assembled via a gasket to form an airtight container, and inside the
This was immersed in a water tank while applying an air pressure of 1.5 Kg/cm ² , and the presence or absence of leakage of internal pressurized air was determined by visually inspecting the presence or absence of air bubbles adhering to the surface of the airtight container. The proportions (by weight) of the polypropylene component (PP) and glass fibers (GF) and optionally incorporated inorganic filler (talc) in the reinforced composite, as well as the type of overlay polymer and melt polymer, and the hermeticity results can be complicated. Table 1 summarizes the results of the evaluation of the curved portion and the gently curved portion. Regarding the airtightness results, ○: Good, ×: Slightly poor.
XX: Poor, XXX: Evaluated as extremely poor.

[Table] Examples 1 to 5 and Comparative Examples 1 to 2 were flammable when irradiated with a gas burner, but Examples 6 and 7 were self-extinguishing and had a flame retardant effect after irradiation with a gas burner. [Effects of the Invention] As described above, according to the present invention, by stamping, it is possible to obtain a reinforced composite that provides a glass fiber-reinforced molded product with good airtightness in complex-shaped parts.

Claims (1)

[Scope of Claims] 1. A glass fiber-reinforced composite for mechanical press molding, which is made by impregnating pine-like glass fibers with a polypropylene resin containing modified polypropylene. 2. The glass fiber reinforced composite according to claim 1, wherein the modified polypropylene is a polymer obtained by modifying crystalline polypropylene with an organic silane compound or an unsaturated carboxylic acid compound. 3. The glass fiber reinforced composite according to claim 1, wherein a flame retardant is blended with the polypropylene resin. 4. The glass fiber reinforced composite according to claim 3, wherein the flame retardant comprises a brominated aromatic flame retardant and antimony trioxide. 5. Claim 3, characterized in that the flame retardant consists of a salt of polyphosphoric acid and a basic nitrogen compound.
Glass fiber-reinforced composite as described in .