KR960011756B1 - Method for manufacturing frtp - Google Patents

Abstract

The material has excellent mechanical strength, heat resistance, and surface brilliancy and thus results in the good flow of the reinforced fiber into rib portion or thin part of the molding, and is prepared by employing polyester resin, having excellent adhesive property to both reinforced fiber and thermoplastic resin, along with good fluidity and heat resistance. The improvement accounts for the application of the molding in component parts for automobiles.

Description

Manufacturing Method of Fiber Reinforced Thermoplastics

1 is a glass fiber mat lamination.

The present invention relates to a method for producing a plate-shaped fiber-reinforced thermoplastic molded article that is lightweight and reusable, and has excellent mechanical strength, surface gloss and heat resistance by using a thermoplastic resin and a mat-shaped reinforcing agent.

In general, plate-shaped fiber-reinforced thermoplastics are used for automobile parts, mechanical parts, building materials, and electrical and electronic parts by stamping molding without lightening, excellent mechanical strength, and hardening process. It means a method of heating a prepreg above the melting temperature of the resin to make the plate-like material have fluidity, putting it in a heated mold, compression molding, and cooling the mold to produce an arbitrary molded article.

However, polypropylene (Polypropylene) is mainly used as a thermoplastic resin used in the existing stamping molding method, but it has poor surface gloss and paintability and heat resistance that cannot withstand the coating temperature of the automobile. In addition, polyethylene terephthalate resin reinforced with short fibers can be obtained simply by injection molding, but the impact strength is very low, there is also a disadvantage that can not be used for exterior parts of automobiles.

Therefore, in order to obtain a molded article that can be used in automobile parts, it is necessary to manufacture a molded article using fiber-reinforced thermoplastics having excellent surface gloss and excellent adhesion between reinforcing fibers and thermoplastic resins, and having excellent mechanical properties and heat resistance.

US Pat. Nos. 4,455,343 and 4,457,970, which use polypropylene resins, are known in the art to treat the surface of reinforcing fibers with silane and to needle punching the reinforcing fiber mats so that the reinforcing fibers flow well during stamping molding. The reinforcing fibers are not sufficiently filled in the rib-shaped portion or the thin portion, and the physical properties are insufficient, so that the surface gloss is very bad and cannot be used for the exterior parts.

US Pat. No. 4,379,802, which uses a polyethylene terephthalate resin, uses a polyethylene terephthalate resin as its outer resin, its copolymer as its inner resin, and a glass fiber cloth (cotton fabric) on both sides to improve surface gloss. Glass Fiber Veil) is used, but the thermoplastic resin is not sufficiently impregnated into the glass fiber cloth, and thus has poor physical properties and a low crystallization rate.

The present invention is excellent in mechanical strength and heat resistance and excellent surface gloss, using a polyester resin excellent in adhesion between the reinforcing fibers and thermoplastic resin, excellent fluidity and heat resistance, reinforcing fibers to ribs or thin parts during stamping molding It is an object of the present invention to provide a fiber-reinforced thermoplastic molded article in which flows.

The thermoplastic resin used in the present invention uses a low melting point polyester resin or a resin composition in which a metal salt of an organic acid having 5 to 25 carbon atoms is added to the resin to improve the crystallization rate. In addition, the fibrous reinforcing agents used in the present invention include glass fibers, carbon fibers, aramid fibers, etc., and used in the form of a needled mat having fluidity so as to be evenly filled in the mold together with the resin during stamping molding. The fibrous reinforcing agent is manufactured by needle punching after dispersing the filament condensed into 30 to 300 monofilaments having a thickness of 3 to 25 microns into 1 to 200 pieces on a conveyor belt.

Specifically, the polyethylene terephthalate resin composition is used as the thermoplastic resin laminated to the outside of the glass fiber mat, the composition is 0.4 to 1.0 intrinsic viscosity when measured in 35 ℃ ortho-chlorophenol solution Sodium, potassium, calcium, zinc, or magnesium salts of 10 to 25 carbon atoms of organic acids having 10 to 25 carbon atoms in order to improve productivity and improve surface gloss by lowering the temperature crystallization temperature and increasing the crystallization rate to 80 to 99.5 wt% of phosphorus polyethylene terephthalate resin Or 0.2-10 wt% of sodium, calcium, potassium, zinc or magnesium salts of a copolymer of α-olefin-based hydrocarbons with α, β-unsaturated carboxylic acids and 0.3-10 wt% of a compound selected from the following components A, B, and C. do.

(In Formulas B and C, R may be the same as or different from each other in the hydrocarbon group having 5 to 25 carbohydrates, and R 'is hydrogen or a hydrocarbon group having 5 to 25 carbohydrates.)

On the other hand, the polyethylene terephthalate resin composition used in the range of 30 to 70wt% of the total weight of the molded article may contain a small amount of polymerization by-products, such as diethylene glycol or glutaric acid, stearic acid, Such as behenic acid, montanic acid, and the like. Also, the α-olefin hydrocarbons are suitable for those having 10 or less carbohydrates such as ethylene, propylene, 1-butyl, styrene, and α, β-unsaturated carboxylic acids. Acrylic acid, methacrylic acid, maleic anhydride, etc. are mainly used.

The metal salts of the copolymers of α-olefin hydrocarbons with α, β-unsaturated carboxylic acids include sodium, potassium, calcium, zinc or magnesium salts of ethylene / acrylic acid, ethylene / methacrylic acid, propylene / maleic anhydride, styrene / maleic anhydride copolymers. In this copolymer, the α-olefin hydrocarbon portion occupies 40 to 90 wt% of the total, and the metal salt of the copolymer of α -olefin hydrocarbon and α, β-unsaturated carboxylic acid is 20 to 95 wt%. Use neutralized ones.

Polyalkylene glycols or derivatives thereof having a molecular weight of 100 or more include polyethylene glycol, polyneopentyl glycol, polytetramethylene glycol, mono or diglycidyl ether of polyethylene glycol, mono or diglycidyl ether of polyneopentyl glycol, and the like. The same thing exists, It is preferable to use the thing of 150-2000 molecular weight.

Among the components B and C, organic ketones and organic amides include benzophenone, irucaramide, N-ethyl-p-toluenesulfonamide and the like.

In addition, the internal resin laminated and impregnated between the glass fiber mats is ethylene glycol or 1,4-butanediol in 1 mole of terephthalic acid (TPA) or dimethyl terephthalate (DMT). It is used in the range of 10 to 50wt% of the total weight of the molded product by polymerizing a single or mixed polyhydric alcohol 0.5 to 4.0 mol and 0.01 to 1.0 mol of polytetramethylene etherglycol (PTMG, PTMEG) having a molecular weight of 300 to 3000. In order to control the melting temperature (Tm), dimethylisophthalate (DMI) 0.001 to 0.1 mol (Mole) may be added during the polymerization, and the molding time is shortened by increasing the crystallization rate during molding. To this end, 0.01 to 10 parts by weight of a metal salt of 10 to 25 organic acids of carbohydrate may be added to 99.99 to 90 parts by weight of the polymerized resin.

In addition, a small amount of a polymerization catalyst is used to improve the reactivity and shorten the reaction time during polymerization, and the melt index (MI) of the polyester resin thus polymerized is 10 to 40 g / when measured at 2.16 Kg load at 230 ° C. 10 min, and a weight average molecular weight was 80,000-100,000.

In the present invention, when the reinforcing fiber is a glass fiber, in order to increase the adhesion to the polyester resin, the amine silane or vinyl silane is treated on the surface of the reinforcing fiber as a coupling agent, the treatment of the coupling agent (Coupling Agent) The coupling agent is dissolved in an aqueous solution, completely impregnated by dipping, coating or spraying, and then the coupling agent is reacted with the fiber surface while drying at 60 to 120 ° C. for 10 to 30 minutes.

Amine silanes used as coupling agents include γ-aminopropyltriethoxysilane and γ-aminopropyltrimethoxysilane. Vinyl silanes include vinyltrimethoxysilane, binitriethoxysilane, and vinyl-tris ( 2-methoxyethoxy) silane, and other γ-methacryloxypropyltrimethoxy silane, and the like, and when the reinforcing fiber is other than glass fiber, bisphenol A type epoxy resin, noblock type epoxy resin, and glycy An epoxy resin, such as a diester type epoxy resin, is treated with a coupling agent.

Prepreg impregnated with a sheet-like fiber-lowering thermoplastic, i.e., a mat-shaped reinforcement controlling thermoplastic resin, can contain 20 to 60% of the total weight of the reinforcing fiber and a thickness of 1 to 10 mm, but 2 to 7 mm is suitable. If the thickness of the prepreg is less than 2mm, the flowability of the glass fiber during stamping molding is very small, and the glass fiber tends to be gathered in one part.If the thickness is more than 7mm, heat transfer is not good to the inside and the temperature difference between the surface and the inside is large. Non-uniform product is obtained.

The fiber-reinforced thermoplastic composite according to the present invention has excellent adhesion between the reinforcing fibers and the thermoplastic resin, and thus has excellent mechanical properties and heat resistance, excellent surface gloss, and good flowability of the reinforcing fibers during stamping molding. Therefore, the reinforcing fiber is distributed, so its performance is excellent when used in automobile parts or mechanical parts.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

Example 1

(1) External resin sheet manufacturing process

After drying 973 g of polyethylene terephthalate resin having an intrinsic viscosity of about 0.65 as an external resin in a dehumidifying dryer at 130 ° C. for 4 hours, 90% of neutralized ethylene / methacrylate acrylate 10 g and N-ethyl-p-toluene sulfonamide 15 g and 2 g of IGANOX B-215, a stabilizer of CIBA-GEIGY, was introduced into a twin screw extruder heated at 290 ° C, reacted, extruded to a chip state, and a dehumidifying dryer of 130 ° C. It was dried for 4 hours and then made into a 0.4 mm thick sheet using a casting machine.

(2) Internal resin sheet manufacturing process

The internal resin was added 970 g of dimethyl terephthalate, 675 g of 1,4-butanediol, 1000 g of polytetramethylene ether glycol having a molecular weight of 1000, and 19.4 g of dimethylisophthalate as a polymerization catalyst. Reacted for a while. The melt temperature of the polymerized resin was 202 ° C., the melt in dextrose was 18 g / 10 min, and the weight average molecular weight was 95,000.

Using a twin-screw extruder heated at 220 ° C. with 2 g of sodium stearate in 998 g of polymerized resin, a resin with improved crystallization rate was prepared, and then chipped into 0.4 mm thick sheet in the same manner as the external resin. made.

(3) glass fiber mat manufacturing process

A filament was made by concentrating 200 monofilaments with a particle diameter of 18 u treated with γ-aminopropyltriethoxy silane as a coupling agent, and using a glass fiber in which the filaments were combined to prepare a glass fiber mat and needle punching (needle punching). ). The number of needle punches per square centimeter (Cm ² ) was 18 and the weight of the final mat was 900 g / m ² .

(4) Prepreg manufacturing process

Using two glass fiber mats, the glass fiber content was 40wt% and the weight of the outer resin was 40wt%, and the weight of the inner resin was 20wt%. Prepreg was prepared by impregnating a hot press heated to 270 ° C. for 15 minutes and cooling to 50 ° C. The thickness of the prepreg in which the glass fiber mat was impregnated with the polyester resin was 3.8 mm.

Example 2

Example 2 is the same as in the manufacture of the internal resin sheet of Example 1, except that it is made of a sheet using only polymerized resin without kneading sodium stearate to the polymerized resin, and the production of other external resin sheets, glass fiber mats Preparation and impregnation of the prepreg was also carried out in the same manner as in Example 1 and the thickness of the prepared prepreg was 3.85mm.

Example 3

Example 3 is the same as in Example 1 except that the weight of the final mat in the manufacturing of the glass fiber mat of Example 1 to 675g / m ² , the glass fiber content of the prepared prepreg is 30wt%, The thickness was 3.9 mm.

Comparative Example 1 and Comparative Example 2

Comparative Example 1 was prepared in the same manner as in Example 1 using 90wt% of continuous long fibers and 10wt% of 5Cm short fibers in the preparation of the glass fiber mat of Example 1. Comparative Example 2 was prepared in the same manner as in Example 1 using short fibers of 5 cm in length in the preparation of the glass fiber mat of Example 1. In addition, the preparation of the external resin and the internal resin of Comparative Example 1 and Comparative Example 2 and the preparation and impregnation of the sheet were performed in the same manner as in Example 1, and the thickness of the prepared prepreg was 3.78 in Comparative Example 1. mm and Comparative Example 2 were 3.82 mm.

Comparative Example 3

Comparative Example 3 comprises 963 g of dried polyethylene terephthalate resin having an intrinsic viscosity of about 0.65, 10 g of 95% neutralized ethylene / sodium acrylate, 25 g of polyethylene glycol having a molecular weight of 2000, and Iganox B in preparing the external resin composition of Example 1 2 g of -215 was prepared using a twin screw extruder heated to 290 ° C. In addition, the manufactory of the inner resin, the manufacture of the glass fiber mat, the manufacture of the inner resin and the outer resin sheet, and the preparation of the prepreg were prepared in the same manner as in Example 1, and the thickness of the prepared prepreg was 3.8 mm.

The properties of Examples and Comparative Examples carried out above were measured and shown in Table 1 below, and the test methods thereof are shown in Table 2 below.

Claims (6)

20 to 60 wt% of the reinforcing fiber mat manufactured by combining 1 to 200 filaments of 30 to 3,000 reinforcing fibers selected from glass fibers, carbon fibers, and aramid fibers having a thickness of 3 to 25 μm. Sodium, potassium, calcium, zinc or magnesium salts or α-olefins of organic acids having 10 to 25 carbon atoms in 80 to 99.5 wt% of polyethylene terephthalate resin having an intrinsic viscosity of 0.4 to 1.0 as measured in a resin at 35 ° C. ortho-chlorophenol Polyethylene terephthalate resin in which 0.2-10 wt% of sodium, potassium, calcium, zinc or magnesium salts of a copolymer of a hydrocarbon and an α, β-unsaturated carboxylic acid and 0.3-10 wt% of a compound selected from the following components A, B, and C are mixed. 30 to 70 wt% of the outer resin sheet of the composition, Wherein in formulas B and C, R may be the same as or different from each other in the hydrocarbon group having 5 to 25 carbohydrates, and R 'may be hydrogen or a hydrocarbon group having 1 to 10 carbohydrates. 0.5 to 4.0 moles of polyhydric alcohols alone or mixed with ethylene glycol or 1,4-butanediol to polyhydric acid selected from dimethyl terephthalate and 0.01 to 1.0 mole of polytetramethylene ether glycol having a molecular weight of 300 to 3000 were polymerized in the presence of a catalyst. A method for producing a fiber-reinforced thermoplastics molded article characterized by laminating and impregnating 10-50 wt% of an internal resin sheet made of a resin composition in the same order as in FIG. The method of claim 1, wherein the reinforcing fiber mat is manufactured using only continuous long fibers. The method according to claim 1, wherein the reinforcing fiber mat is manufactured using 99-50 wt% of continuous long fibers and 1-50 wt% of short fibers having a length of 1-20 cm. The method according to claim 1, wherein the internal resin of the molded product is polymerized by adding 0.001 to 0.01 moles of dimethylisophthalate during the polymerization to control the melting temperature. The method according to claim 1 and 4, in order to improve the crystallization rate of the internal resin to shorten the molding time by kneading 0.01 to 10 parts by weight of 10 to 25 organic acid metal salts of carbohydrates to 99.99 to 90 parts by weight of the polymerized internal resin A method for producing a fiber-reinforced thermoplastic molded article characterized by producing an internal resin. The method of manufacturing a fiber-reinforced thermoplastics molded article according to claim 1, wherein when the plate-shaped thermoplastic composite molded article is manufactured, the internal resin is continuously added in a molten state by using an extruder.