KR-20260065542-A - HEAT RESISTANCE COVER FOR AUTOMOBILE PARTS AND METHOD FOR MANUFACTURING THE SAME

Abstract

A method for manufacturing a heat-resistant cover for an automobile part according to one embodiment of the present invention comprises the steps of: providing a powder-type auxiliary material having flame retardancy or heat resistance and a restraining material having phase change properties; providing the auxiliary material to form a granular intermediate material of a predetermined size using the restraining material; providing a main foaming material comprising a polyol component and an isocyanate component; and mixing and foaming the intermediate material and the main foaming material, and diffusing the auxiliary material that decomposes from the intermediate material according to the phase change of the restraining material to form a heat-resistant cover of a polyurethane foam. By doing so, by controlling the release and diffusion of the auxiliary material (powder) in conjunction with the melting point of the phase change restraining material and the rise in the mixing temperature, the cell structure stability of the foam and the uniform dispersion of the auxiliary material can be simultaneously secured.

Inventors

• 이동화
• 오승민

Assignees

• (주)유피티

Dates

Publication Date

20260508

Application Date

20251029

Priority Date

20241030

Claims (5)

1. In a method for manufacturing a heat-resistant cover for automobile parts, A step of providing a powdered auxiliary material having flame retardancy or heat resistance and a restraining material having phase changeability; A step of arranging the auxiliary material to be formed into a granular intermediate material of a predetermined size using the above restraining material; A step of preparing a main foaming material comprising a polyol component and an isocyanate component; and A method for manufacturing a heat-resistant cover comprising the step of mixing and foaming the above intermediate material and the above main foaming material, and diffusing the above auxiliary material that decomposes from the above intermediate material according to the phase change of the above restraining material to form a heat-resistant cover of a polyurethane foam.
2. In paragraph 1, The above auxiliary material comprises at least one of graphite, expanded graphite, mica, vermiculite, silica, alumina, boron nitride, and mixtures thereof, and A method for manufacturing a heat-resistant cover comprising at least one of a wax or a thermoplastic resin that melts and undergoes a phase change within the foaming temperature range of the main foaming material.
3. In paragraph 1, The above restraining material undergoes a phase change at a predetermined phase change temperature, and A method for manufacturing a heat-resistant cover, comprising the step of forming the heat-resistant cover, wherein the intermediate material and the main foaming material are mixed at a mixing temperature having an initial value lower than the phase change temperature, and the mixing temperature is raised and controlled for a mixing time set so that the diffusion of the auxiliary material is completed before the gelation of the main foaming material begins.
4. In paragraph 3, The step of forming the heat-resistant cover further includes the step of measuring the viscosity of the mixture of the intermediate material and the main foaming material. A method for manufacturing a heat-resistant cover, comprising the step of controlling the mixing temperature to increase, wherein the measured viscosity becomes less than the gelation start viscosity of the main foaming agent by the time the diffusion of the auxiliary material is completed.
5. In paragraph 1, The step of preparing the intermediate material includes the step of preparing the intermediate material by performing a diffusion-triggered pretreatment in which a polyol-affinity surfactant is incorporated into a polyol-affinity fused wax layer. A method for manufacturing a heat-resistant cover in which, in the step of forming the heat-resistant cover, the diffusion of the auxiliary material is initiated by the melting of the wax layer or the surface migration of the surfactant in response to the phase change of the restraining material.

Description

Heat-resistant cover for automobile parts and method for manufacturing the same The present invention relates to a method for manufacturing a heat-resistant cover for automotive parts and belongs to the technical field of process-managing the dispersion, diffusion, foaming, and gelation behavior of flame-retardant or heat-resistant functional powders in the production process of a polyurethane foam-based cover. Interior materials, such as injector covers placed in the engine compartment and adjacent areas of automobiles, require thermal shielding and flame-retardant performance in addition to mechanical cushioning in high-temperature and thermal shock environments. To meet these requirements, an approach involving the introduction of inorganic and carbon-based powders, such as graphite, expanded graphite, mica, vermiculite, silica, alumina, and boron nitride, into polyurethane foams is widely known. However, powder auxiliary materials rapidly increase mixing viscosity due to their solid and high surface area characteristics, and fibrous or flat particles are prone to aggregation, which can easily impair dispersion uniformity. Generally, dispersibility is improved by high-shear mixing or surface treatment (e.g., surfactant or silane treatment), but excessive shear has an adverse effect on bubble nucleation and growth, and chemical treatment agents can interfere with foaming and gelation reactions, making the cell structure unstable. In addition, if powder is introduced into the main foaming system from the beginning, local concentration occurs simultaneously with the initiation of gelation, raising concerns about spatial variations in thermal performance. Therefore, a manufacturing technology is required that can process-control the timing and behavior of the introduction of functional powder to ensure uniform dispersion without damaging the cell structure of the foam and stably achieve the target flame retardant and heat-resistant performance. FIG. 1 is an exemplary diagram of a heat-resistant cover according to one embodiment of the present invention. FIG. 2 is a process flow diagram of a method for manufacturing a heat-resistant cover according to one embodiment of the present invention. FIG. 3 illustrates the time-temperature profile of a mixing and heating process according to one embodiment of the present invention. FIG. 4 illustrates a viscosity-time control curve of a mixture according to one embodiment of the present invention. FIG. 5 illustrates a schematic diagram of the auxiliary material glass and diffusion before and after the phase change of an intermediate material according to one embodiment of the present invention. Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The description of this embodiment is intended to provide exemplary examples so that those skilled in the art can easily reproduce the present invention, and is not intended to limit it to specific embodiments. The scope of protection of the invention is determined by the claims and their equivalents, rather than by the description in the specification. The drawings are schematic illustrations to aid understanding, and actual dimensions, proportions, layer thicknesses, etc., may be exaggerated, omitted, or simplified. Regarding the interpretation of terms, "includes/includes" is a non-exclusive concept and does not exclude additional components or steps. Numbers such as "First/Second" are for identification purposes only and do not imply relative importance or order, and "connection/connection" includes both direct and indirect connections unless otherwise noted. The order of execution of process steps may be changed or repeated unless specified in the context; range notations include both end values, and "approximately" signifies the standard tolerance in the art. "A or B" includes A, B, and combinations of A and B, unless otherwise specified in the context. FIG. 1 is an exemplary diagram of a heat-resistant cover according to one embodiment of the present invention. The heat-resistant cover (1) according to one embodiment of the present invention is not limited to a cover-type member that simply covers a predetermined heating element, but is implemented as various members requiring flame resistance and heat resistance in relation to heat (for example, a member that covers, surrounds, or is placed adjacent to a heating element, or a member that requires heat characteristics even if it is not placed near a specific heating element). Furthermore, the function of the heat-resistant cover (1) is not limited to its name alone, and in addition to flame resistance and heat resistance, it may additionally be equipped with various functions such as sound absorption and dust absorption. In one embodiment of the present invention, the case where the heat-resistant cover (1) is an injector cover that covers an injector of an automobile is given as an example, but this is merely o