JP5740705B2 - Composite molded body - Google Patents

Description

  The present invention is lightweight and excellent in mechanical strength, can also prevent the generation of rubbing and squeaking noise, and has breathability, sound absorption, design, deodorization, aromaticity, insect repellent, difficulty The present invention relates to a composite molded body having flammability and the like.

  Conventionally, foamed polystyrene resins and foamed polyolefin resins are often used for storage of fresh foods called fish boxes, boxes for transportation, and the like. Such a fish box has a non-breathable structure because it is necessary to prevent moisture and odors from leaking to the outside. In addition, when air permeability is required, air permeability is secured by making a hole in the product.

  On the other hand, the present applicant pays attention to the fact that such a foamed resin molded body can be used as a sound absorbing material or wall material that is lighter in weight and excellent in mechanical strength. A foamed molded product has been developed, and a patent application has already been filed as a foamed molded sound absorber (see Patent Document 1).

Moreover, since the foaming molding which has air permeability is excellent in lightweight property and sound absorption property, utilization as the interior material and underfloor filler for motor vehicles which aim at weight reduction is examined. However, in the case of automobiles, the usage environment such as vibration and heat is severe, and when the foamed molded article of Patent Document 1 is used as, for example, an underfloor filler, in addition to breakage of the molded product, it comes into contact with a common material or a different material. As a result, there is a problem that the interior environment of the vehicle is lowered due to rubbing and squeaking noises. Also, in recent years, housing has become highly confidential, making it difficult for sound generated inside the house to leak out, and this makes it easier for people to hear the sound of daily life and to be heard throughout the house. It has become.
Therefore, it is lightweight and excellent in mechanical strength, can also prevent the generation of rubbing and squeaking noise, and can be used for automobile interior materials, architectural sound absorbing materials, residential sound absorbing materials, etc. Development of a complex composite was desired.

JP 2006-110982 A

  The present invention solves the above problems, is lightweight and excellent in mechanical strength, can also prevent the generation of rubbing and squeaking noise, and sound absorption, design, deodorant, An object of the present invention is to provide a composite molded body having aromaticity, insect repellent properties, flame retardancy and the like.

In order to solve the above problems, the present invention provides an infinite number of foamed cells obtained by heat-foaming foamable resin particles in a mold and fused to each other at the contact surface. Produced by using a foamed molded article that is formed and having air permeability as a ridge, and spreading a fiber layer on the surface of the foamed molded article by spreading a solution in which fibers are dispersed from the upper surface to the lower surface of the ridge. The foamed molded product has a volume porosity of 10 to 40% and a bending stress of 0.25 MPa or more, and the foamed molded product is formed on the surface or front and back surfaces of the foamed molded product. The composite molded body is characterized in that a fiber layer that is glued in a state of slightly entering the surface layer portion and the surface space portion is provided, and this is the invention according to claim 1.

  The fiber layer preferably contains one or more of an adhesive, a colorant, a deodorant, a fragrance, an insect repellent, and a flame retardant, and this is the invention according to claim 2. To do.

  In the invention which concerns on Claim 1, the fiber layer which has stuck in the state which entered the surface layer part and surface space part of this foaming molding on the surface or front and back of the foaming molding which has air permeability in the state of entering a little. Since the fiber layer is provided as a cushioning material, the foamed molded product does not directly contact the automobile body, and it is possible to prevent the generation of rubbing noise and squeaking noise. Moreover, the mechanical strength of a molded object can be improved by setting it as a laminated structure with a fiber layer.

  In the invention according to claim 2, since the fiber layer contains one or more of adhesive, colorant, deodorant, fragrance, insect repellent, flame retardant, the fiber layer Arbitrary performance such as improvement in adhesive strength, improvement in design, or improvement in deodorizing property, aromaticity, insect repellent, flame retardancy, etc. can be added.

It is a perspective view which shows the composite molded object of this invention. It is an expanded sectional view which shows the principal part of the composite molded object of this invention. It is a perspective view which shows the container used for shaping | molding of this invention. It is explanatory drawing which shows the shaping | molding process of this invention. It is a graph which shows the relationship between the frequency of the composite molded object of this invention, and a sound absorption coefficient. It is a graph which shows the relationship between the bending stress and the bending of the composite molded object of this invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing a composite molded body of the present invention, in which 1 is a foam molded body and 2 is a fiber layer provided on the surface of the foam molded body 1. The foamed molded body 1 is composed of an infinite number of foamed cells obtained by filling foamed resin particles such as foamed polystyrene resin and foamed polyolefin resin into a mold and heating and foaming.
The fiber layer 2 is mainly composed of fibers of plants, animals, chemical fibers, etc., and plant fibers having high mechanical strength are particularly preferably made of Manila hemp.

Next, the foamed molded body 1 will be described.
As shown in FIG. 2, the foamed molded article 1 of the present invention is composed of innumerable foamed cells 11 obtained by heating and foaming foamable resin particles in a mold, and the adjacent foamed cells 11 and 11 are: The contact surfaces 11a and 11a themselves are softened and melted and bonded. That is, the fusion bonded portion is literally fused with the foamed resin material, and therefore has the same physical properties as the foamed resin material. The foamed molded body 1 has three-dimensional fine pores composed of continuous air holes formed by connecting spaces 12 surrounded by at least three foam cells 11, and has air permeability and the following physical properties. Is.

  That is, the volume porosity indicating the volume ratio (%) of the three-dimensional fine pores (excluding the pores in the foamed cells) that form fine passages in the foamed molded product 1 in the volume of the entire foamed molded product is 10 -40% and the foamed molded product itself has a bending stress of 0.25 MPa or more. This three-dimensional pore has a complicated spatial path that branches into a large number and turns in a zigzag, and its inner diameter repeats irregular expansion and contraction. It exhibits damping effects such as interference and resonance, and exhibits an excellent sound absorbing function.

  When the volume porosity is less than 10%, the strength increases, but the sound absorbing effect is insufficient. On the other hand, when the volume porosity exceeds 40%, the sound absorption effect tends to decrease, and it is not preferable for the structural reason that mechanical strength is difficult to obtain. Further, the strength of the sound absorber of the present invention requires at least a shape retention strength that can withstand handling.

Moreover, the foaming molding 1 of this invention has air permeability. As an example, the foamed cell 1 of the foamed molded product 1 of the present invention has a cut cross-section with a substantially circular or oval cross section, and the size is 1.5 to 5 on the basis of the major axis. .5mm. Thereby, the fine pore volume required for the sound absorbing action can be obtained. Further, if each foam cell is a substantially oval cross-sectional particle having a major axis / minor axis range of 3.0 or less, a fine pore volume necessary for sound absorbing action can be easily obtained.
In addition, the shape of the foam cell is not limited to a circular granule, and may be a polygonal granule or a cylindrical or polygonal cylindrical rod-like body. I just need it.

Next, the fiber layer 2 provided on the surface of the foam molded body 1 will be described.
This fiber layer 2 is provided for the purpose of a cushioning material that prevents the foamed molded body 1 from coming into contact with a co-material or dissimilar material to generate a rubbing sound or a squeaking noise when used as an automobile interior material. The plant fibers are mainly composed of plants, animals, and chemical fibers, and the plant fibers having high mechanical strength are particularly preferably made of Manila hemp.
In addition, although the thing of illustration shows the case where the fiber layer 2 is provided only in one surface, it can also provide in both front and back. Of course, two or more fiber layers having different characteristics can be provided depending on the application.

The fiber layer 2 is not simply attached to the surface of the foam molded body 1 with an adhesive or the like, but is formed by applying a papermaking technique. As shown in FIG. It is glued in a state where it slightly enters the surface layer part and the surface space part of the foam molded article 1, and is firmly fixed without using an adhesive. That is, the leg portion 2a of the fiber layer 2 is designed to drive a wedge into the space portion on the surface, and secures a strong bond between the fiber layer 2 and the foamed molded body 1.
And since the fiber layer 2 has air permeability, the sound absorption effect of the foaming molding 1 is not inhibited. Moreover, it becomes possible by making it the composite of the foaming molding 1 and the fiber layer 2 to improve the mechanical strength as a molding. In addition, as a result of measuring the bending stress in accordance with the provisions of JIS-K7221, the maximum value (bending strength) is 0.45 MPa or more, which is compared with the maximum bending stress (0.23 MPa) of the foamed molded body alone. It was confirmed that the improvement was about twice.

Next, the manufacturing method of the composite molded body of the present invention will be described.
In FIG. 3, an example of the container used for the shaping | molding of this invention is shown. The container 3 has a rectangular frame shape, and the foam molded body 1 having the air permeability described above is set at the bottom, and the foam molded body 1 is configured to play the role of a ridge in the papermaking technique. .
Next, as shown in the upper diagram of FIG. 4, a solution 10 in which a predetermined amount of fibers is dispersed is poured into the container 3. The solution 10 in which the fibers are dispersed can be obtained, for example, by leaving the fibers in water and stirring them with a mixer. Reference numeral 4 denotes a collection container.

  At this time, if an adhesive is added to the solution 10 in which the fibers are dispersed, the fiber layer 2 is firmly bonded to the surface of the foam molded body 1. Similarly, one or more of coloring agents, deodorants, fragrances, insect repellents, flame retardants and the like can be contained, improving design, or deodorizing, aromatic and flame retardant. Performance such as improvement can be added depending on the application.

Next, as shown in the lower diagram of FIG. 4, a fiber layer 2 is formed on the surface of the foam molded body 1 by spreading a solution in which fibers are dispersed from the upper surface to the lower surface of the foam molded body 1. Stale. In addition, 10a is a collection | recovery solution.
The solution in which the fibers are dispersed may be naturally dropped, but in order to shorten the molding time, a suction port 5 connected to a suction device (not shown) is provided on the collection container 4 side. It is preferable that a solution in which fibers are dispersed is applied by applying a suction force from the lower surface side of the glass. Then, if it takes out from a container and makes it dry, the composite molded object which provided the fiber layer 2 on the surface of the foaming molded object 1 will be obtained.

The composite molded body of the present invention has air permeability and can exhibit an excellent sound absorbing effect, and since a fiber layer is provided on the surface, the fiber layer serves as a cushioning material and generates rub and squeak noise. Occurrence can be prevented. Moreover, the mechanical strength of a molded object can be improved by setting it as a laminated structure with a fiber layer.
Furthermore, it can have coloring, deodorizing, aroma, insect repellent, flame retardant, etc. depending on the application, not only automobile interior materials, but also sound absorbing materials for buildings and houses. Can also be used.

Expandable resin particles of expanded polystyrene resin were heated and foamed in a mold to form an expanded molded article having an expansion ratio of 40 times, a volume porosity of 10%, and a bending stress of 0.25 MPa or more.
A 150 × 150 × 25 mm plate-like body was cut out from the foamed molded body and set on the bottom surface of the fuser 3 shown in FIG.
The solution in which the fibers were dispersed was obtained by placing 1.125 g of Manila hemp cut into small pieces in 0.5 liter of water and then stirring with a mixer for 30 seconds.
As shown in FIG. 4, a fiber layer was adhered to the surface of the foamed molded product by spreading the solution in which fibers were dispersed from the upper surface to the lower surface of the foamed product using the foamed molded product. After taking it out of the container, it was dried to obtain a composite molded body in which the fiber layer (about 0.11 mm) was adhered to the surface of the foamed molded body as shown in FIG.

About the obtained composite molded object, the result of having performed various physical-property evaluation is shown below.
(1) Breathability Breathability was measured using a breathability tester. Air at a constant flow rate [m ³ / cm ² sec] was passed, the pressure difference [kPa] at this time was measured, and the ventilation resistance [kPa sec / m] was obtained. The air resistance of the composite molded body of the present invention is 1.74 [kPa sec / m], which is 20% or more higher than the air resistance of 1.40 [kPa sec / m] of the foam molded body alone. It was confirmed that This is sufficiently breathable as a vehicle interior material, a sound absorbing material for buildings, and the like.

(2) Sound absorption characteristics The sound absorption was measured using a normal incidence sound absorption rate measuring device, and the material was measured in a frequency range of 25 mm in thickness and 800 to 5000 Hz (JIS A1405-1).
FIG. 5 is a graph showing the relationship between the frequency and the sound absorption coefficient of the composite molded body of the present invention. It is confirmed that the inventive product 1 has a sound absorption coefficient substantially equal to the sound absorption of the foam molded body alone (conventional product). did it. In addition, it was confirmed that the peak frequency of the sound absorption rate can be changed by changing conditions such as the beating degree of fiber and the amount of fiber (Invention 2).

(3) Bending strength Bending strength (maximum value of bending stress) was measured by a method based on JIS-K7221-2, and the result is shown in FIG. The maximum value of the measured bending stress was 0.45 MPa, and it was confirmed that the bending stress was improved about twice as much as the maximum value (0.23 MPa) of the bending stress of the foam molded body alone.

(4) About prevention of generation of rubbing sound and squeaking sound The evaluation of rubbing sound and squeaking sound is to evaluate whether sound is generated when a foamed molded product is manually reciprocally rotated by applying a load on a glass plate. did. The foamed molded body alone generated rubbing sound and itching sound, but the invention product did not generate sound.

DESCRIPTION OF SYMBOLS 1 Foam molded object 2 Fiber layer 2a Leg part 3 Container 4 Collection | recovery container 5 Suction port 10 Solution which disperse | distributed fiber
10a Recovery solution 11 Foam cell
11a Adhesive surface 12 Space

Claims (2)

An infinite number of foamed cells obtained by heating and foaming foamable resin particles in a mold are fused to each other on the contact surface, and a continuous vent hole is formed between the foamed cells so as to have air permeability. , And a composite molded body produced by gluing a fiber layer on the surface of the foam molded body by spreading a solution in which fibers are dispersed from the upper surface to the lower surface of the cocoon . The volume porosity is 10 to 40%, the bending stress is 0.25 MPa or more, and the surface of the foam molded body or the front and back surfaces are slightly penetrated into the surface layer portion and the surface space portion of the foam molded body. A composite molded body characterized in that a fiber layer glued with is provided.   The composite molded body according to claim 1, wherein the fiber layer contains one or more of an adhesive, a colorant, a deodorant, a fragrance, an insect repellent, and a flame retardant.