TWI802160B - Rtm method using thermosensitive core-shell microspheres - Google Patents

Abstract

Present invention is related to an RTM method using thermosensitive core-shell microspheres having steps of: mixing a thermoplastic resin monomer, a catalyst and a thermosensitive core-shell microsphere under 150 ^oC to form a solution, injecting the solution into a closed mold arranged with fiber reinforced material, and raising the temperature above 150 ^oC letting the thermosensitive core-shell microsphere breaking and releasing an active material inside, reacting the thermoplastic resin monomer with the active material and the catalyst with the fiber reinforced material to form high-quality composite molding materials. The present invention introduces the special thermosensitive core-shell microsphere to RTM method which allows the polymerization time to be adjustable and flexible, and provids high-quality products.

Description

Method for applying temperature-sensitive core-shell microspheres to RTM molding

A method for RTM molding, especially an RTM molding method using temperature-sensitive core-shell microspheres.

Resin Transfer Molding (RTM) is a molding process widely used in the manufacture of high mechanical strength and light weight polymer composite materials. It mainly lays fiber reinforcements in the mold first, then seals the mold, injects resin and After it solidifies and hardens, the mold is opened to take out the finished product.

Resin transfer molding generally uses thermosetting resin for infusion. Before infusion, mix the thermosetting resin hardener and inject it into the mold, so that the thermosetting resin can soak the pre-laid fiber reinforcement, and then wait for curing and hardening. However, one of the difficulties of this molding technology is the fluidity of the resin. Since the hardener reacts and solidifies quickly after being mixed with the thermosetting resin, the fluidity injected into the mold will be quickly lost over time, resulting in partial failure of the finished product. Wet out to resin well, causing quality problems.

Furthermore, the environmental protection and environmental crisis arising from the inability to recycle and reuse thermosetting resins is also an urgent problem to be solved.

In order to improve the quality of finished products and reduce the process difficulties and shortcomings that may arise due to fluidity or rapid hardening during resin filling and pouring, the present invention provides a method for applying temperature-sensitive core-shell microspheres to RTM molding. The steps Comprising: mixing a thermoplastic resin monomer, a catalyst, and a temperature-sensitive core-shell microsphere at a temperature lower than 150 ^o C to form a perfusion solution, wherein the temperature-sensitive core-shell microsphere contains an active ingredient, a temperature-sensitive The sensitive composite shell is coated on the outside of the active ingredient, and the temperature-sensitive composite shell includes an organic shell and an inorganic shell from the inside to the outside; injecting the perfusion solution into a closed mold pre-laid with a fiber reinforcement , and raising the temperature to above 150 ^o C to rupture the temperature-sensitive composite shell; and the initiator in the temperature-sensitive core-shell microspheres is released and reacts with the thermoplastic resin monomer and the catalyst And harden into a thermoplastic resin, the thermoplastic resin and the fiber reinforced material are molded into a fiber composite material.

Wherein, the thermoplastic resin monomer includes caprolactam; and the thermoplastic resin includes nylon.

Wherein, the active ingredient includes an initiator, and the initiator includes methacrylic acid isocyanate-caprolactam.

Wherein, the initiator is grafted on the surface of a transition group and extends outward.

Wherein, the transition group includes polystyrene.

Wherein, the fiber reinforcement includes carbon fiber or glass fiber cloth.

Wherein, the organic shell layer includes polyvinylpyrrolidone; and the inorganic shell layer includes silicon dioxide.

As can be seen from the above description, the present invention has the following advantages and beneficial effects:

1. In the present invention, the special temperature-sensitive core-shell microspheres have the characteristic of breaking when the temperature is above 150 degrees, and the coated active ingredients can be released, so that the polymerization reaction of RTM monomer can be delayed until the perfusion solution infiltrates evenly Occurring after the fiber reinforcement in the mould, this method avoids premature polymerization and curing that would hinder the infusion process.

2. The present invention can produce highly impregnated thermoplastic carbon fiber composites with fiber reinforcement materials, and the controllable polymerization reaction time point can also improve the stability of the RTM process, thereby improving the polymerization conversion rate and product appearance quality.

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings that need to be used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some examples or embodiments of the present invention, and those skilled in the art can also apply the present invention to other similar scenarios. Unless otherwise apparent from context or otherwise indicated, like reference numerals in the figures represent like structures or operations.

It should be understood that "system", "device", "unit" and/or "module" as used herein is a method for distinguishing different components, elements, components, parts or assemblies of different levels. However, the words may be replaced by other expressions if other words can achieve the same purpose. As shown in the present application and claims, words such as "a", "an", "an" and/or "the" are not specific to the singular and may also include the plural, unless the context clearly indicates an exception. Generally speaking, the terms "comprising" and "comprising" only suggest the inclusion of clearly identified steps and elements, and these steps and elements do not constitute an exclusive list, and the method or device may also contain other steps or elements.

The flow chart is used in the present invention to illustrate the operations performed by the system according to the embodiment of the present invention. It should be understood that the preceding or following operations are not necessarily performed in the exact order. Instead, various steps may be processed in reverse order or simultaneously. At the same time, other operations can be added to these procedures, or a certain step or steps can be removed from these procedures.

＜Temperature-sensitive core-shell microspheres＞

Please refer to FIG. 1 , which is a schematic diagram of a preferred embodiment of the temperature-sensitive core-shell microsphere 10 of the present invention, which is in the form of a core-shell and includes an active ingredient 11 and a temperature-sensitive composite shell 12 from the inside out. coated on the outside of the active ingredient 11.

The active ingredient 11 includes an initiator such as methacrylic acid isocyanate-caprolactam (2-(Methacryloyloxy)ethyl isocyanate ε-caprolactam, MOCC).

The temperature-sensitive composite shell 12 includes an organic shell 121 and an inorganic shell 122 from the inside out. A preferred embodiment of the organic shell 121 is Polyvinylpyrrolidone (PVP), and the inorganic shell 122 is relatively A preferred example is silicon dioxide (SiO ₂ ). Wherein the temperature-sensitive composite shell layer 12 is temperature-sensitive, and will rupture at a temperature above 150 ^° C and release the active ingredient 11 coated therein.

Preferably, the active ingredient 11 is grafted on the surface of a transition group 13 inside the temperature-sensitive composite shell 12 and extends outward, as shown in FIG. 1 , the transition group 13 is relatively The most preferred is polystyrene (Polystyrene, PS).

In the manufacture of the temperature-sensitive core-shell microspheres 10 of the present invention, please refer to FIG. 2. Taking the manufacture of the aforementioned coated MOCC active ingredient 11 as an example, first take MOCC and styrene monomers for dispersion polymerization, and obtain The MOCC-PS structure is shown, and the MOCC is grafted on the surface of PS (that is, the transition group 13) and extends outward.

Then, the MOCC-PS structure is reacted with ethanol (EtOH)/deionized (DI) solution, ammonia water (NH ₄ OH) and tetraethyloxysilane (Tetraethyl Silicate, TEOS) to combine the organic shell layer 121 with the inorganic The shell 122 covers the outside of the MOCC-PS structure, forming the temperature-sensitive core-shell microsphere 10 of the present invention.

＜The method of applying temperature-sensitive core-shell microspheres to RTM molding＞

Please refer to Fig. 3, the present invention applies the aforementioned temperature-sensitive core-shell microspheres 10 to the RTM molding method, and the steps include:

Step S1: mixing a thermoplastic resin monomer, a catalyst, and the temperature-sensitive core-shell microspheres 10 at a temperature lower than 150 ^o C to form a perfusion solution;

Step S2: injecting the perfusion solution into a closed mold pre-laid with a fiber reinforcement, and raising the temperature to above 150 ^o C; and

Step S3: the temperature-sensitive core-shell microsphere 10 ruptures and releases the initiator coated inside and reacts with the thermoplastic resin monomer and the catalyst to harden into a thermoplastic resin, which is reinforced with the fiber The material is formed into a fiber composite material.

This embodiment takes molding thermoplastic resin nylon (Polyamide, PA, Nylon) as an example, which may be nylon 6 or nylon 66, and caprolactam is used as the thermoplastic resin monomer, the catalyst and the active component 11 coated The temperature-sensitive core-shell microspheres 10 are mixed into the perfusion solution at a temperature lower than 150 ^° C, and then the perfusion solution is poured into the closed mold on which the fiber reinforcement is pre-laid and the temperature is raised to above 150 ^° C, As the temperature rises, the temperature-sensitive core-shell microspheres 10 rupture and release the active ingredient 11 therein to undergo a polymerization reaction with the caprolactam monomer and the catalyst, finally forming a thermoplastic nylon resin and hardening, and The fiber reinforcement is shaped into a finished product.

The fiber reinforcement is preferably carbon fiber, glass fiber or other reinforced inorganic fiber cloth.

The above-mentioned manufacturing process provided by the present invention combined with fiber reinforcement can produce highly impregnated thermoplastic carbon fiber composites, and the introduction of the temperature-sensitive core-shell microspheres 10 can control the time point of the polymerization reaction to further improve the RTM manufacturing process. Stability, and after testing, it can increase the polymerization conversion rate (93%→97%) and improve the appearance quality of the product.

In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of the embodiments use the modifiers "about", "approximately" or "substantially" in some examples. grooming. Unless otherwise stated, "about", "approximately" or "substantially" indicates that the stated figure allows for a variation of ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximations that may vary depending upon the desired characteristics of individual embodiments. In some embodiments, numerical parameters should take into account the specified significant digits and adopt the general digit reservation method. Although the numerical ranges and parameters used to demonstrate the breadth of scope in some embodiments of the invention are approximations, in specific embodiments such numerical values are set as precisely as practicable.

Finally, it should be understood that the embodiments described in the present invention are only used to illustrate the principles of the embodiments of the present invention. Other variations are also possible within the scope of the present invention. Accordingly, by way of illustration and not limitation, alternative configurations of the embodiments of the present invention may be considered consistent with the teachings of the present invention. Accordingly, the embodiments of the present invention are not limited to the embodiments of the present invention explicitly shown and described.

10: Thermosensitive core-shell microspheres 11: Active ingredient 12: Temperature-sensitive composite shell 121: organic shell 122: Inorganic shell S1-S3: steps

The invention will be further illustrated by way of exemplary embodiments which will be described in detail by means of the accompanying drawings. These examples are non-limiting, and in these examples, the same number indicates the same structure, wherein: Fig. 1 is a schematic diagram of a preferred embodiment of the temperature-sensitive core-shell microspheres of the present invention. Fig. 2 is a flow chart of a preferred embodiment of the present invention for manufacturing the temperature-sensitive core-shell microspheres. Fig. 3 is a flow chart of the steps of applying the temperature-sensitive core-shell microspheres to the RTM molding method of the present invention.

S1-S3: steps

Claims (7)

A method for applying temperature-sensitive core-shell microspheres to RTM molding, the steps comprising: mixing a thermoplastic resin monomer, a catalyst, and a temperature-sensitive core-shell microspheres at a temperature lower than 150°C into a perfusion solution, wherein , the temperature-sensitive core-shell microspheres include an active ingredient and a temperature-sensitive composite shell, wherein the active ingredient includes an initiator, the temperature-sensitive composite shell is coated on the outside of the active ingredient, and the temperature-sensitive The type composite shell consists of an organic shell and an inorganic shell from the inside out; inject the infusion solution into a closed mold pre-laid with a fiber reinforcement, and raise the temperature to above 150°C to make the temperature sensitive type composite shell rupture; and the initiator in the temperature-sensitive core-shell microspheres is released and reacts with the thermoplastic resin monomer and the catalyst to harden into a thermoplastic resin, and the thermoplastic resin and the fiber reinforcement are molded into A fiber composite material. The method for applying temperature-sensitive core-shell microspheres to RTM molding according to claim 1, wherein the thermoplastic resin monomer includes caprolactam; and the thermoplastic resin includes nylon. The method for applying temperature-sensitive core-shell microspheres to RTM molding as described in Claim 1, wherein the initiator comprises methacrylate isocyanate-caprolactam. The method for applying temperature-sensitive core-shell microspheres to RTM molding as described in Claim 3, wherein the initiator is grafted on the surface of a transition group and extended outward. The method for applying temperature-sensitive core-shell microspheres to RTM molding as described in Claim 4, wherein the transition group includes polystyrene. The method for applying temperature-sensitive core-shell microspheres to RTM molding according to claim 1, 2, 3 or 4, wherein the fiber reinforcement comprises carbon fiber or glass fiber cloth. The method for applying temperature-sensitive core-shell microspheres to RTM molding according to claim 1, 2, 3 or 4, wherein the organic shell layer includes polyvinylpyrrolidone; and the inorganic shell layer includes silicon dioxide.

Images