JPH0616096A - Hood insulator - Google Patents

Abstract

PURPOSE:To enhance heat resistance and sound absorption by bonding a thermoplastic resin fiber base material, using the hardening substance of a setting resin and a hardening agent and/or a thermosetting resin and a film forming resin. CONSTITUTION:A thermoplastic resin fiber base material A is bonded. using the hardening substance of a setting resin and hardening agent and/or a thermosetting resin B and a film forming resin C. In this case, in the hardened substance, the ratio of the setting resin and the hardening agent and/or the thermosetting resin B to the film forming resin C is 99.5:0.5-50:50. The total wt. of the component B and the component C is 20-400 pts.wt. per 100 pts.wt. of the base material A. This provides a hood insulator having light wt., heat resistance and being excellent in sound absorption.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a bonnet insulator.

[0002]

2. Description of the Related Art The hood of a passenger car is equipped with a bonnet insulator made of a material that is lightweight and has excellent sound absorbing properties in order to reduce noise generated from the engine.

Conventionally, such a bonnet insulator has been prepared by impregnating a glass fiber base material with a water-soluble resol-type phenol resin and drying it, or by impregnating an organic fiber base material with a thermoplastic resin such as an acrylic resin emulsion and drying it. Put the prepreg into the mold of the desired shape,
It is manufactured by a method of heat and pressure molding.

[0004]

However, although the former is a bonnet insulator excellent in heat resistance and sound absorption, it is heavy and deteriorates in the working environment due to the short glass fiber generated in the processing step or is discarded at the time of disposal. Environmental pollution was a problem. The latter is lightweight and has a good sound absorbing property, but has a drawback of insufficient heat resistance.

That is, there is a demand for a bonnet insulator which is light in weight, has heat resistance, and is excellent in sound absorption, and has three beats.

[0006]

Means for Solving the Problems The inventors of the present invention have made extensive studies in view of the above-mentioned circumstances. As a result, a bonnet insulator obtained by using a curable resin and a film-forming resin in a thermoplastic resin fiber base material is also lightweight. Therefore, they have found that both heat resistance and sound absorption are excellent, and completed the present invention.

That is, in the present invention, the thermoplastic resin fiber base material (A) is bonded by a cured product of a curable resin, a curing agent and / or a thermosetting resin (B), and a film-forming resin (C). It is intended to provide a bonnet insulator.

Curable resin and curing agent used in the present invention and /
Alternatively, the form of the thermosetting resin (B) is not particularly limited, but the form is preferably an organic solvent solution or an aqueous solution in terms of excellent workability for impregnation into the thermoplastic resin fiber base material (A), From the viewpoint of preventing environmental pollution, the aqueous solution is more preferable.

In the present invention, as the curable resin and the curing agent, and / or the thermosetting resin (B) [hereinafter, these are simply referred to as the resin (B)], any of known and commonly used resins can be used. Examples thereof include phenol resin, resorcinol resin, urea resin, melamine resin and the like. These resins may be used alone or in combination of two or more.

The method for producing the phenolic resin is not particularly limited, but for example, phenols and aldehydes are condensed as needed by adjusting the molar ratio of aldehydes / phenols to 0.8 to 2.0. 80 in the presence of a catalyst for
The reaction may be performed at -100 ° C for 30 minutes to 5 hours. At that time, if necessary, a method of dehydrating under reduced pressure and substituting the solvent with alcohol may be used.

When obtaining a phenol resin, examples of phenols include phenol, cresol, catechol, xylenol, naphthol, and examples of aldehydes include formaldehyde, poraform, dioxane and the like.

Examples of the catalyst include sodium hydroxide,
Examples thereof include potassium hydroxide and zinc acetate. Of course, in the above reaction, urea, melamine, guanamine and the like may be used in combination with the phenols, or they may be post-added to the phenol resin for use.

As the resin (B), a thermosetting resol-type phenol resin is preferably used when a cured product excellent in heat resistance is obtained, and melamine is preferable in that the prepreg can be cured at a low temperature in a short time. It is preferable to use a resin.

When a melamine resin is used as the resin (B), it is preferable to use a curing agent such as ammonium sulfate in combination. When a novolac type phenol resin is used as the resin (B), a curing agent such as hexamethylenetetramine or divinylbenzene is also used.

As the film-forming resin (C), any known and commonly used synthetic resin having a film-forming property other than the resin (B) can be used. For example, it has good workability and does not deteriorate the environment. When added, acrylic resin, polyvinyl alcohol, vinyl acetate resin, polyvinyl butyral, ethylene vinyl acetate copolymer, etc. may be mentioned. As the resin (B), polyvinyl alcohol is preferable in that a higher sound absorbing effect can be obtained by using a smaller amount. Polyvinyl alcohol has a degree of polymerization of 1000 or less, especially 200 to
It is preferably 500.

The form of the film-forming resin (C) is preferably an emulsion or an aqueous solution. The weight ratio of the resin (B) and the film-forming resin (C) is not particularly limited, but is usually (B) / (C) = 9 in terms of solid content weight ratio.
The ratio is 9.5: 0.5 to 50:50, and (B) / (C) = 99.5: 0.5 to the obtained cured product in terms of heat resistance.
It is preferably 80:20.

The present invention is characterized in that a thermoplastic resin fiber base material is used as the base material (A). Examples of the thermoplastic resin fiber base material (A) include woven or non-woven fabrics made of polyester resin, acrylic resin, polyamide resin, etc. as fibers by wet or dry spinning [hereinafter, referred to simply as base material (A). . ]. By using the thermoplastic resin fiber base material, the weight of the bonnet insulator itself can be reduced and the releasability can be improved.

The weight ratio of the resins (B) and (C) to the substrate (A) is usually 20 to 20 in total of the components (B) and (C) per 100 parts by weight of the substrate (A). 40
0 parts by weight. The weight per unit area is usually 50 to 600 g /
m ² .

The bonnet insulator of the present invention is
The base material (A) is impregnated with the resins (B) and (C) and dried,
A bonnet insulator can be easily obtained by obtaining a resin-impregnated base material (hereinafter, referred to as a prepreg) in advance and subjecting the prepreg to thermocompression-curing molding with a mold having a desired shape.

Of course, in the above operation, a method of spraying the resins (B) and (C) on the base material (A) in a mold having a desired shape, and then directly drying and simultaneously thermosetting molding is also adopted. sell. The former is more advantageous in terms of workability, and the resins (B) and (C) may include, for example, plasticizers, fillers, flame retardants, deodorants, foaming agents, coupling agents, if necessary. Etc. may be added before use.

The method for producing the prepreg itself according to the present invention is not particularly limited, but it can be produced, for example, by the following steps. Resin (B) is prepared and resin (C) is added thereto. Further, a colorant or a release agent is added to this if necessary.

Substrate (A) is impregnated with the above formulation. The amount of the resin component impregnated into the base material (A) is usually the base material (A).
20 to 400 parts by weight per 100 parts by weight, and the weight per unit area is 50 to 600 g / m ² .

The method of impregnating the base material (A) with the resin component is not particularly limited, but for example, a roll coater, a bar coater,
A mangle roll or a spray may be used. As the form of the base material (A), a sheet-like form is preferable because it is excellent in continuous productivity.

The prepreg obtained above is dried. When a water-soluble resol resin is used as the resin (B), the drying temperature of the prepreg at this time is usually 90
˜120 ° C. for 10 to 15 minutes, 180 to 200 ° C. for 30 seconds to 1 minute. Drying at this time is usually performed in a circulating hot air dryer, but far infrared rays or microwaves may be applied.

The prepreg thus obtained can be molded into a molded product by pressure-molding and curing while degassing if necessary. In pressure molding, for example, a prepreg may be placed in a mold, and pressure may be applied while applying heat as needed to perform shaping. It is preferable to carry out pressure molding when heat is applied when obtaining a molded product having a complicated shape or when obtaining a molded product having a rising portion.

The molding temperature in this case varies depending on the mass of the prepreg, but in the case of a prepreg having a mass of 400 g / m ² , for example, it is 200 to 230 ° C. and 20 to 60 seconds. The desired cured product obtained in this manner is not limited to bonnet insulators for automobiles, but may be, for example, a washing unit,
It can be used for bathtubs, speaker edges, air filters, oil filters, housing wall materials, housings for microwave ovens, electric kettles, air conditioners, personal computers, etc.

[0027]

EXAMPLES Unless otherwise specified, "part" means "part by weight" and "%" means "% by weight". Example 1 811 g of 37% aqueous formaldehyde solution, 517 g of phenol, and 30 g of 25% aqueous ammonia solution were placed in this order in a flask equipped with a reflux condenser, and the temperature was raised to 80 ° C. over 1 hour. The reaction was carried out at this temperature for 3 hours and cooled to room temperature. The obtained phenol resin initial condensate aqueous solution,
The solid content was 60.5% and the viscosity was 95 cps. 100 parts of the above-mentioned phenol resin and 20% polyvinyl alcohol aqueous solution (polymerization degree 500, saponification degree 88 mol%)
15 parts were mixed (hereinafter, simply referred to as impregnating liquid). Next, the above impregnating liquid is applied to a polyester nonwoven fabric (150 g / m
² ) was impregnated and dried in a hot air drying oven at 150 ° C. for 3 minutes. A prepreg of 400 g / m ² was obtained by this method (hereinafter, simply referred to as prepreg). The prepreg was heat-molded at 200 ° C. for 20 seconds with a bonnet insulator molding press.

The molded product had good release from the mold and the bonnet insulator had a sharp shape.
Also, the heat resistance test at 200 ° C. showed almost no deformation. When the sound absorption test was conducted, the result was good.

The above prepreg was subjected to January 25 ° C. × 70% RH
The same molding was carried out after storage under the conditions described above, but a bonnet insulator comparable to that obtained above was obtained. Comparative Example 1 A bonnet insulator was produced under the same conditions as in Example 1 except that the phenol resin used in Example 1 was used as the impregnating liquid and the film-forming resin was not used.
The obtained molded product had poor sound absorption. Comparative Example 2 The same polyester non-woven fabric as used in Example 1 (15
0 g / m ²⁾ the fiber hard finishing acrylic emulsion (manufactured by Dainippon Ink and Chemicals Incorporated Voncoat R3380
A) was similarly impregnated and dried in a hot air drying oven at 150 ° C. for 3 minutes.

The impregnated cloth was dried to obtain a prepreg of 405 g / m ² (hereinafter, simply referred to as prepreg). When the obtained prepreg was molded with a bonnet insulator molding press under the same conditions as in Example 1, the prepreg adhered to the mold and it was difficult to release it from the mold. Moreover, the deformation was remarkable in the heat resistance test at 200 ° C.

[0031]

[Table 1]

[0032]

According to the present invention, a prepreg composed of a resole resin and a thermoplastic resin fiber base material is molded to produce a molded product. A molded product with excellent mold releasability, good sound absorption, and excellent mold reproducibility is obtained without the need to use a mold release agent without causing poor heat resistance as in the case of using a plastic resin. It has a particularly remarkable effect of being obtained.

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Claims (10)

[Claims] 1. A bonnet in which a thermoplastic resin fiber base material (A) is bonded with a cured product of a curable resin and a curing agent and / or a thermosetting resin (B) and a film-forming resin (C). Insulator. 2. The ratio of a cured product of a curable resin, a curing agent and / or a thermosetting resin (B), and a film-forming resin (C) is
The ratio is 99.5: 0.5 to 50:50, and the total of the components (B) and (C) is 20 to 400 parts by weight per 100 parts by weight of the base material (A). Bonnet insulator as described. 3. The bonnet insulator according to claim 1, wherein the substrate (A) is a polyester resin non-woven fabric. 4. The bonnet insulator according to claim 1, wherein the base material (A) is an acrylic resin nonwoven fabric. 5. The bonnet insulator according to claim 1, wherein the base material (A) is a vinylon resin non-woven fabric. 6. The curable resin, the curing agent and / or the curable resin (B) is a resol type phenol resin.
Bonnet insulator as described. 7. The bonnet insulator according to claim 1, wherein the curable resin and the curing agent and / or the curable resin (B) are melamine resins. 8. The bonnet insulator according to claim 1, wherein the film-forming resin (C) is polyvinyl alcohol. 9. The bonnet insulator according to claim 8, wherein the film-forming resin (C) is polyvinyl alcohol having a degree of polymerization of 1000 or less. 10. The weight of the curable resin and the curing agent and / or the curable resin (B) is 2 per 100 parts by weight of the base material (A).
0 to 400 parts by weight and weight of 50 to 600 g
/ M ² The bonnet insulator according to claim 1.