JPH051229B2 - - 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 in fields where airtightness and flame retardancy are required. The present invention relates to glass fiber reinforced composites used in applications such as [Prior Art] Conventionally, crystalline resins have been used as resins for glass fiber reinforced composites that are suitable for stamping with mechanical stamping presses because of their excellent mechanical properties, moldability, and low cost. Polypropylene is used. [Problems to be Solved by the Invention] However, 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 (for example, rib parts) , corner portions) and are flammable. [Means for Solving the Problems] In view of the above-mentioned points, the present inventors have developed a glass fiber-reinforced composite material that has good airtightness, especially in complex-shaped parts, by stamping, and further developed an airtightness material. 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 made by impregnating pine-like glass fiber with a polypropylene resin containing a flame retardant made of modified polypropylene and magnesium hydroxide whose surface is treated with an amine compound. It is. 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, when needle-punching the pine with a barbed needle, the barbed needle simply penetrates the pine and entangles the fibers in the pine, and only connects the pine loosely and never strongly. There isn't. Therefore, during stamping in a mechanical stamping press, the pine strands move freely with the flow of resin. In the present invention, a polypropylene resin containing a flame retardant made of modified polypropylene and magnesium hydroxide whose surface has been treated with an amine compound is used. The polypropylene resin (crystalline polypropylene) includes polypropylene homopolymer, crystalline ethylene-propylene random copolymer, crystalline ethylene-propylene block copolymer, crystalline ethylene-propylene random polymerized post-ethylene-propylene block copolymer, and crystalline propylene- It is a general term for butene copolymers, and the crystalline polypropylene of the present invention includes crystalline ethylene-propylene random copolymers with an ethylene content of 0.1 to 10% by weight, and crystalline ethylene with a total ethylene content of 1 to 20% by weight. -Propylene random polymerization post ethylene-
Propylene block copolymers are preferred from the viewpoint of physical properties and moldability. The crystalline polypropylene preferably has a melt flow rate index (MFR) of 0.5 to 100 g/10 minutes. The modified polyprolene 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. Examples of the modifier include vinyltriethoxysilane, methacryloyloxytrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, methacryloyloxycyclohexyltrimethoxysilane, γ-methacryloyloxypropyltriacetyloxysilane, and methacryloyl Oxytriethoxysilane, γ-
Organic silane compounds such as methacryloyloxypropyltriethoxysilane; Saturated carboxylic acids and acid anhydrides, acrylic glycidyl ether, 2-methyl-
Allyl glycidyl ether, sodium acrylate, sodium methacrylate, calcium acrylate, calcium methacrylate, magnesium acrylate, magnesium methacrylate, zinc acrylate, zinc methacrylate, aluminum acrylate, aluminum methacrylate, acrylic Metal salt compounds of (meth)acrylic acid such as iron acid (), 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-(acryloyloxymethyl)phenol, 4-acryloyloxybenzyl alcohol, 4-methacryloyloxyphenol, 4
-methacryloyloxybenzyl alcohol,
Examples include 4-(methacryloyloxymethyl)benzyl alcohol. Among these,
Organic silane compounds are preferred. The above-mentioned modifier is
One type may be used or two or more types may be used in combination. 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 polypropylene resin, modifier, and organic peroxide described above varies depending on the desired MFR of the modified polypropylene, 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 polypropylene 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. The modified polypropylene is mixed with the polypropylene resin, and the proportion of the modified polypropylene in the polypropylene resin is preferably 5% by weight or more, particularly 10 to 70% by weight. In addition to the modified polypropylene, the polypropylene resin used in the present invention needs to be further blended with a flame retardant, and the flame retardant is made of magnesium hydroxide whose surface has been treated with an amine compound. It is necessary. That is, although magnesium hydroxide is known as a heat retardant, its effects vary greatly depending on the type of surface treatment. Conventionally, commonly used products treated with higher fatty acids do not have sufficient effects, so magnesium hydroxide surface-treated with an amine compound, such as an aminosilane compound or an amino acid derivative, is preferably used. Here, the surface treatment is carried out by mixing magnesium hydroxide with a predetermined amount of surface treatment agent and dry blending using a tumbler type, V-type blender, Henschel mixer, etc., or by diluting it with a solvent such as alcohol or water. This is usually done using the method of dipping magnesium hydroxide. In addition, the above surface treatment is usually
The proportion is 0.3-10%, preferably 0.5-5%. Examples of aminosilane compounds used for surface treatment include γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, and N-β-(aminoethyl)-γ-amino Examples include propyltrimethoxysilane, and specific examples of amino acid derivatives include condensates of amino acids and fatty acids (lauroyl, sarcosine). As the magnesium hydroxide whose surface is treated with the above-mentioned amine compound, conventionally known magnesium hydroxide is used, with an average particle size of 0.3 to 10 μ and a specific surface area (BET) of 2 to 20 m ² /g. is usually used. The blending amount of the flame retardant is preferably 25 to 400 parts, particularly 50 to 200 parts, of magnesium hydroxide surface-treated with an amine compound per 100 parts of polypropylene. In the present invention, the ratio of the matte glass fibers and polypropylene resin is 10% of the glass fibers.
~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 made of polypropylene containing a heat retardant made of the above-mentioned modified polypropylene and magnesium hydroxide surface-treated with an amine compound, in a mat structure made of the above-mentioned long glass fibers (strands). Infiltrate the structure with resin and then, if necessary, compact the structure.
It is cooled and solidified to obtain a sheet-like resin-impregnated product. 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 in appropriate combinations, or the above operations may be performed continuously using a molten resin layer. The sheet-like resin-impregnated glass fiber-reinforced composite thus obtained is cut as necessary to produce a sheet-like glass fiber-reinforced composite of a desired size. By stamping the glass fiber reinforced composite of the present invention with a mechanical stamping press, it not only has high rigidity and high heat distortion temperature, but also has good airtightness and flame retardancy even in parts with complex shapes. It is possible to obtain a molded product with high properties. To stamp with a mechanical stamping press, for example, a sheet cut to a predetermined size is preheated to a temperature that melts the resin (at this time, the sheet is heated to allow the fibers, or strands, within it to recover elastically. There is swelling several times the thickness before preheating),
This swollen impregnated material is introduced as it is, or preferably two or more sheets are stacked one on top of the other, and introduced into a cooled mold for stamping and pressing. 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. [Example] Hereinafter, the present invention will be further explained with reference to Examples. First, the polymers used in each example are shown below. A: Predetermined amount of known antioxidant [BET (2,6-
MFR2.0g/10min with addition of di-tert-butyl hydroxytoluene), ethylene content 4
% (weight %, same hereinafter) of crystalline ethylene-propylene random copolymer B: MFR9.0 g/10 min with addition of a predetermined amount of a known antioxidant [Irganox 1010, manufactured by Ciba Geigy], total ethylene Crystalline ethylene-propylene random polymerization post-ethylene-propylene block copolymer C with a content of 5.5%: γ-methacrylacryloxypropyltrimethoxysilane and t-butylperoxybenzoate are added to B, and 100 parts (parts by weight, same below) of B.
Modified polypropylene D: 0.5 parts/0.25 parts respectively added and heat treated at 220°C for MFR 50 g/10 minutes: Hydroxylated polypropylene D: 40 parts A was surface treated with 2% higher fatty acid (oleic acid) as a flame retardant. magnesium
60 parts of flame-retardant polypropylene E: obtained by melt-mixing 40 parts of A, 60 parts of magnesium hydroxide surface-treated with 2% lauroyl sarcosine for flame retardancy.
40 parts of flame-retardant polypropylene F: obtained by melt-mixing 60 parts of magnesium hydroxide surface-treated with 2% γ-aminopropyltriethoxysilane for flame retardancy, and melt-mixing. Flame-retardant polypropylene G obtained by: 40 parts of C, magnesium hydroxide surface-treated with 2% higher fatty acid (oleic acid) for flame retardancy.
60 parts of flame-retardant polypropylene H:C obtained by melt-mixing 60 parts of magnesium hydroxide 60 parts surface-treated with 2% lauroyl sarcosine as a flame retardant.
60 parts of magnesium hydroxide surface-treated with 2% γ-aminopropyltriethoxysilane as a flame retardant were added to 40 parts of flame-retardant polypropylene I:C obtained by melt-mixing. The obtained flame-retardant polypropylene, and the magnesium hydroxide used above, had an average particle size of 0.71 μm and a specific surface area of 9.0 m ² /g. Examples 1 to 6, Comparative Examples 1 to 3 Surface-treated glass fiber continuous strands (average diameter 230μ) were piled up in a spiral pattern and needle-punched at a rate of about 22 needles in total per about 1 ^cm2 . 2 pieces of glass mats obtained by
Molten polymer (hereinafter referred to as melt polymer) supplied from an extruder between two glass mats,
Polymers previously formed into sheet shapes (hereinafter referred to as overlay polymers) are laminated alternately, heated (250°C) and cooled (20°C) under pressure (2 kg/cm ² ).
Then, it was cut with a cutter to obtain a flat plate of glass fiber reinforced composite. This flat plate was cut to an appropriate size, heated to 210°C in an infrared heating furnace, then charged onto a mold set in a hydraulic press, and press-molded into a semi-cylindrical molded product under the following conditions. did. Molding conditions: Mold clamping force 200 tons Mold cooling time 90 seconds Mold temperature 60°C Next, the molded product was tested for airtightness under the following conditions. That is, two semi-cylindrical molded bodies are assembled via packing to form an airtight container, and this is immersed in a water tank while applying an air pressure of 1.5 kg/cm ² to the inside, and the internal pressurized air is released. The presence or absence of leakage was determined by visually inspecting the presence or absence of air bubbles adhering to the surface of the airtight container. The airtightness results were evaluated as ◎: very good, ○: good, ×: slightly poor, and XX: poor. Flame retardancy was evaluated by holding the semi-cylindrical molded product horizontally and observing the combustion in the center using a Bunsen burner for 3 minutes until the flame went out (horizontal combustion test). The product was placed vertically and the combustion was observed at the edge for 3 minutes until the flame disappeared (vertical combustion test). Regarding flame retardant results, ◎: Extinguishes instantly when the flame is removed. ○: Disappears within 1 minute. ×: Disappears within 1 to 5 minutes. XX: Does not disappear even after 5 minutes. And so. These results are shown in Table-1. In the table, PP represents polypropylene resin and GF represents glass fiber.

[Table] [Effects of the Invention] As described above, the glass fiber reinforced composite of the present invention has good airtightness in complex-shaped parts by stamping, and is flame retardant. Reinforced composites can be obtained that give certain glass fiber reinforced molded articles.

Claims (1)

[Scope of Claims] 1. A glass fiber-reinforced composite obtained by impregnating pine-like glass fibers with a polypropylene resin containing a flame retardant made of modified polypropylene and magnesium hydroxide whose surface is treated with an amine compound. 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.