JP2000314066A - Felt and its production, and binder for felt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain, under a favorable work environment, a felt suitable as an internal trim material for automobile or household electric appliances or as a thermal insulation material by admixing a phenolic resin-contg. liquid binder with base material fibers followed by converting the mixture to fleeces which are then subjected to thermoforming process. SOLUTION: This mat felt is obtained by the following process: 100 pts.wt. of base material fibers such as synthetic fibers like of nylon, polyvinyl alcohol or polyester, natural fibers such as cotton or cloths as sewing waste are admixed with 5-30 (pref. 7-15) pts.wt., on a solid basis, of a liquid binder consisting of a resol-type phenolic resin dispersion, and the resulting mixture is desegregated using a fleece machine into fleeces, which are then subjected to a forming machine and converted to a mat, which, in turn, is heat-treated at 200-250 deg.C for 2-3 min.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing felt used for automobiles, home appliances, furniture interior materials, heat insulating materials, sound absorbing materials, cushioning materials, and the like. The present invention relates to a method for producing a felt capable of improving the felt quality.

[0002]

2. Description of the Related Art Conventionally, there are the following methods for manufacturing felt. A base fiber such as a synthetic fiber is shredded, and then oil or the like is added to facilitate the handling and the liquid content is adjusted. Next, a binder is added to the fleece and mixed, and then the mixture is heated and pressed to obtain a felt. As felt, mat felt used for vehicle interiors (ceilings, floors, etc.) and thermal insulation for air conditioners (density approx.
0.1 g / cm ³ ) and a board felt (density of about 0.3
０．７0.7 g / cm ³ ) is widely used. As the binder, a mixture of a powdery novolak type phenol resin and a curing agent such as hexamethylenetetramine is usually used.

[0003]

However, in the above-mentioned prior art, odor and dust due to the binder are likely to be generated at the time of manufacturing, and there has been a demand for improvement of the working environment. Moreover, the odor derived from the binder sometimes remained in the product. The present invention has been made in view of the above circumstances, and has the following objects. (1) To provide a felt manufacturing method capable of improving the working environment during manufacturing. (2) To provide a felt manufacturing method capable of suppressing the odor of a product.

[0004]

The above object can be attained by a method of manufacturing a felt by adding a liquid binder to a base fiber to form a fleece and heat-forming the fleece. As the liquid binder, a phenol resin is inexpensive and generates little odor, so that it is preferable in terms of cost and working environment. It is preferable to use a resol type phenol resin as the phenol resin.
Further, the felt of the present invention is obtained by the above-described method for producing felt.
The felt binder of the present invention is a binder used in the above method, and is characterized by being a liquid material.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an example of a method for producing felt of the present invention will be described in detail. First, a base fiber is prepared. As the base fiber, synthetic fibers such as nylon fiber, vinylon fiber, polyester fiber, polypropylene fiber and rayon fiber, and natural fibers such as wood fiber, cotton fiber, hemp fiber and kenaf fiber can be used. In addition, inorganic fibers such as glass fiber and carbon fiber can also be used. These fibers may be used alone,
Two or more of these may be used. As the base fiber, a sewn-off cloth (chip) made of the above fiber can be used.

After shredding the base fiber as required,
A liquid binder is added to and mixed with the base fiber. The liquid binder is a liquid binder, a solid (powder, etc.) added with an emulsifier or the like, if necessary, and suspended in a dispersion medium (water, etc.) to form a liquid, or the above solid in a solvent. Including those dissolved and liquid.

As the liquid binder, phenol resin,
Melamine resin, urea resin, urethane resin, polyimide resin, polyamide resin, epoxy resin, polyester resin, acrylic resin, vinyl acetate resin, vinyl chloride resin,
A resin containing at least one of vinylidene chloride resin, natural resin (such as cellulose and rosin), and petroleum resin can be used. Hardening agents used for these resins include hexamethylenetetramine and organic polyamines (triethylenetetramine, triethanolamine, etc.)
The use of such a method reduces the generation of odorous gas and smoke during heating. Among the above resins, a phenol resin, a melamine resin, a urea resin, a polyimide resin, a vinyl chloride resin, and a resin containing at least one of vinylidene chloride resins can impart flame retardancy to a felt product. Therefore, it is preferable. In particular, phenol resins are preferable in terms of cost and working environment because they are inexpensive and generate little odor.

As the phenol resin-containing binder, phenol and formaldehyde are used in the presence of an alkali catalyst such as sodium hydroxide or potassium hydroxide, and the phenol / formaldehyde molar ratio is 1 / 1.1.
A liquid (resole-type phenol resin binder) obtained by reacting under the conditions of 0 to 4.0 or a dispersion of a solid (resole-type phenol resin binder) obtained by the above reaction can be used. . When the dispersion is used, 3 to 10% by weight of an additive such as an emulsifier may be added to the liquid binder in order to obtain a uniform dispersion. As the emulsifier, an anionic, cationic, nonionic or the like can be used.

As the liquid binder obtained by the above-mentioned method, it is preferable to use a liquid binder having a free phenol content of less than 5% by weight and a free formaldehyde content of less than 0.5% by weight. When the free phenol content is 5% by weight or more or the free formaldehyde content is 1% or more, it is necessary to treat the liquid binder as a poisonous substance, which makes handling difficult. When the free formaldehyde content is 0.5% by weight or more, the odor increases.

As the liquid binder, a liquid novolak type phenol resin binder can be used. As this liquid novolak type phenolic resin binder,
A solid obtained by reacting phenol and formaldehyde in the presence of an acidic catalyst such as sulfuric acid or hydrochloric acid at a phenol / formaldehyde molar ratio of 1 / 0.5 to 0.9; A dispersion or solution of a mixture with a compound containing a functional group of a hydroxyl group (such as -NCO) such as an isocyanate compound can be used. The curing agent generates less odorous gas and smoke when heated than a curing agent such as hexamethylenetetramine.

The amount of the liquid binder to be added to the base fiber is appropriately set according to the type of the desired felt product, the required strength and the surface condition, and the like. When producing a mat felt, the amount of the liquid binder to be added is preferably 5 to 30 parts by weight, preferably 7 to 15 parts by weight as a solid content with respect to 100 parts by weight of the base fiber. . If the amount is less than 5 parts by weight, the base fibers in the felt product are not sufficiently bonded to each other and the strength of the product is reduced. If the amount exceeds 30 parts by weight, the product tends to be inferior in terms of tactile sensation and sound absorption. When manufacturing board felt, the amount of the liquid binder to be added is 20 parts by weight based on 100 parts by weight of the base fiber.
The amount is preferably from 40 to 40 parts by weight, preferably from 25 to 35 parts by weight. When the addition amount is less than 20 parts by weight, the base fibers are not sufficiently bonded to each other in the felt product, and the strength of the product is reduced. When the amount exceeds 40 parts by weight,
The product is inferior in terms of sound absorption and the like, which is economically disadvantageous.

Next, the mixture of the base fiber and the liquid binder is defibrated using a fleece machine to obtain a fleece. The mixture and the fleece are stored at room temperature for a long time (1
~ 5 months) is possible.

Next, forming is performed by depositing the obtained fleece by a forming apparatus to obtain a mat. When producing a mat felt, the above mat is preferably heated at 200 to 250 ° C. for 2 to 3 minutes to obtain a mat felt having a predetermined thickness. In the case of board felt, the mat is preferably used for 150 to 20 pieces.
After heating for 2 to 3 minutes at 0 ° C. to obtain a bulky mat,
The bulky mat is heated and formed into a predetermined shape by a press device provided with a heating means to obtain a felt product. It is preferable that the temperature condition at the time of the heat molding be 180 to 250 ° C. The pressure condition during molding is 10 to 50 kg / cm.
Preferably it is ² . When a resol-type phenol resin-containing binder having a property of being cured by heating is used as the liquid binder, molding can be performed without adding a curing agent.

According to the above felt manufacturing method, the following effects can be obtained. (1) Since the binder is in a liquid state, the binder is not scattered as dust when added as in the case of using a conventionally used solid (powder) binder, and the working environment is kept good. Can be. In addition, we prevent part of binder from being lost by scattering and improve the use efficiency of binder,
Material costs can be reduced. Also, the addition of the binder increases the liquid content of the fleece and makes the fleece easy to handle, eliminating the need for a step of adjusting the liquid content in the fiber by adding oil for adjusting the liquid content, etc. The process can be simplified. Therefore, it is possible to increase the production efficiency and reduce the production cost. (2) Since hexamethylenetetramine, which easily generates gases such as formaldehyde and ammonia when heated, is not used as a curing agent, a bad odor caused by the curing agent during manufacturing or the curing agent is heated during the molding process. Thus, generation of smoke can be prevented, and deterioration of the working environment can be prevented. Further, the odor caused by the curing agent is prevented from remaining in the product, and the odor of the product can be suppressed. For this reason, even when the product is used as an interior material of an automobile, for example, where the odor stays in the closed space and is likely to cause a problem, for example, the product can be prevented from causing discomfort to the user. (3) By using a resol-type phenol resin binder having a property of being cured by heating as a liquid binder, a curing agent is not required, material costs can be reduced, and an odor caused by the curing agent can be prevented.
Also, the free formaldehyde content is low (for example, 0.5
By using a resol-type phenolic resin binder, the amount of formaldehyde emission from the product can be kept low, and the user can be prevented from feeling uncomfortable or deteriorating their health.

The felt obtained by the above method can be used as interior materials for automobiles, interior materials for furniture and home appliances, heat insulating materials, sound absorbing materials, cushioning materials and the like.

In the above method, a liquid material obtained by reacting phenol with formaldehyde and a dispersion liquid of a solid material obtained by the above reaction are exemplified as the liquid binder. Alternatively, phenolic compounds such as cresol, resorcinol, 3,5-xylenol, bisphenol A, bisphenol F, and other substituted phenols, or those containing a phenolic resin obtained using a mixture thereof can be used. . Also, instead of formaldehyde, aldehyde compounds such as acetaldehyde, paraformaldehyde, formalin, benzaldehyde, salicylaldehyde, furfural, p-hydroxybenzaldehyde, terephthalaldehyde, or a mixture thereof can be used. Also in this case, the content of the free phenol compound in the liquid binder is less than 5% by weight, and the content of the free aldehyde compound is 0.5% by weight.
It is preferred to be less than. Further, the liquid binder may contain additives such as a release agent, a lubricant, a coloring agent, and a flame retardant, if necessary. These additives also
Instead of being mixed with the binder, it may be added to the base fiber separately from the binder.

Examples of the flame retardant include phosphoric ester flame retardants such as triphenyl phosphate, tricresyl phosphate, cresyl phenyl phosphate, tris (halopropyl) phosphate and tris (haloethyl) phosphate, chlorinated paraffin, and chlorine. Polyethylene, perchloropentacyclodecane, hexabromobenzene, decabromocyphenyl ether, tetrabromobisphenol A and its derivatives, halogen-containing organic compounds such as hexabromocyclododecane, antimony trioxide, antimonate, barium metaborate, Uses inorganic flame retardants such as zinc borate, aluminum hydroxide, ammonium bromide, calcium sulfate hydrate, and reactive flame retardants such as tetrabromophthalic anhydride, bromostyrene, and vinyl bromide It is, phosphorus-based flame retardant, a halogen-based flame retardant which preferable. Further, a polyphosphate carbamate may be used. FMVSS-302 (Federal Motor Vehicle Safetyty St.
andard No. 302), it is preferable to add, for example, 2 to 15 parts by weight of nonene W-2-50 (Marubishi Yuka KK) to 100 parts by weight of the base fiber in order to obtain a nonflammability determination. . UL94 (US Standard for Tests for F
lammability of Plastic Materials for Parts in Devi
ces and Appliances -Forth Edition 1991) 94V-
In order to pass 0, for example, the above-mentioned flame retardant (nonnene W
-2-50) is 15 to 30 with respect to 100 parts by weight of the base fiber.
It is preferable to add parts by weight.

[0018]

EXAMPLES The effects of the present invention will be clarified by showing specific examples. (Example 1) Cut pieces containing 70 to 80% by weight of cotton or rayon and 20 to 30% by weight of synthetic fibers were used as base fibers, and after chopping the base fibers, a liquid binder was sprayed (spout diameter 1. 5 mm) to the base fiber. As a liquid binder, a resol-type phenol resin liquid binder (Showa Polymer Shonor B)
RL-192). The liquid binder had a free phenol content of 3.8% by weight and a free formaldehyde content of 0.3% by weight. The added amount of the liquid binder was 15 parts by weight based on 100 parts by weight of the base fiber. The mixture of the base fiber and the liquid binder was defibrated using a fleece machine to obtain a fleece. The aerial concentrations of phenol and formaldehyde in the vinyl bag of these mixtures and fleece were determined by the method of Komei Rika K.K. K. Detector tube No. 183U, and no. As a result of measurement using 171SB, the air concentration of phenol was less than 0.3 ppm,
It was found that the aerial concentration of formaldehyde was less than 0.5 ppm, and all were sufficiently low values. Next, the obtained fleece is formed and subjected to heat molding for 3 minutes at 230 ° C. and 663 g / m ² by a press device to obtain a length of 20 cm, a width of 20 cm, and a thickness of 1.0 c.
m was obtained in the form of a sheet-like mat felt product.

The obtained mat felt product was subjected to the following tests. (1) Odor test A test piece obtained by cutting the felt product into a rectangular shape having a length of 5 cm and a width of 5 cm was left in an environment of a temperature of 22 ° C. and a humidity of 60% for 3 days, and then smelled by 10 panelists. The odor intensity was determined in one of four levels (0: odorless, 1: weak, 2: strong, 3: very strong), and the average value was calculated. In addition, the odor pleasure and discomfort levels were graded in four stages (0: very
1: unpleasant, 2: pleasant, 3: very pleasant), and the average value was calculated. (2) Presence or absence of smoke It was visually confirmed whether or not the fleece smoked during the heat molding. (3) Formaldehyde emission amount The formaldehyde emission amount of the test specimen was measured. The test method was based on JIS A5908 5.11. (4) Tensile Strength A tensile force was applied at a speed of 200 mm / min to a test piece obtained by cutting the felt product into a rectangular shape having a length of 20 cm and a width of 2.5 cm, and a maximum breaking load per test piece cross-sectional area was calculated. (5) Flame retardancy Based on FMVSS-302. Table 1 shows the test results. The mat and board in the table refer to a mat felt product and a board felt product, respectively.

Example 2 A mat was obtained in the same manner as in Example 1 except that the fleece obtained in the same manner as in Example 1 was left for 14 days, left at 90 ° C. overnight, and then heat-molded. A felt product was obtained. This mat felt product was subjected to the tests (1) to (5). The results are shown in Table 1.

(Example 3) Non-flammable agent Nonen W-2-50 (Marubishi Yuka KK) was used as the base fiber 10 in a liquid binder.
Example 1 except that 5 parts by weight was added to 0 parts by weight.
In the same manner as above, a mat felt product was obtained. The results of subjecting this mat felt product to the above tests (1) to (5) are also shown in Table 1.

Example 4 The amount of the liquid binder added was 30 parts by weight with respect to 100 parts by weight of the base fiber. The formed mat was heated at 150 ° C. for 3 minutes to solidify the surface layer, and then at 230 ° C. At a pressure of 25 kg / cm ² ,
Heat molding was performed for 1 minute under the conditions of 1015 g / m ² to obtain a rectangular board felt product having a length of 20 cm, a width of 20 cm and a thickness of 0.20 cm. The other test conditions were the same as in Example 1. The obtained board felt product,
The above tests (1) to (3) and the following test (6)
Was served. (6) Flexural strength The test method was based on JIS A 5908 5.6.
The results are shown in Table 1.

(Example 5) 100 parts by weight of a novolak type phenol resin (Showanol BRP594P manufactured by Showa Polymer), 3 parts by weight of an anionic emulsifier, and a heat-reactive water-soluble polyurethane resin (Daiichi Kogyo Seiyaku Co., Ltd.) as a curing agent A board felt product was obtained in the same manner as in Example 4 except that 10 parts by weight of Elastron H-3) and 20 parts by weight of water were uniformly mixed and used as a binder. This product was subjected to the tests (1) to (3) and (6). Table 1 shows the results
Are shown together.

(Comparative Example 1) A base fiber similar to that used in Example 1 was cut and defibrated, and the obtained fleece was mixed with a powdery novolak type phenol resin and hexamethylenetetramine. (Showa Polymer's Shaunol BRP5417, a mixing ratio of novolak-type phenol resin and hexamethylenetetramine of 100: 10 (weight ratio)) was added and mixed. The amount of the binder was 15 parts by weight with respect to 100 parts by weight of the fleece. Next, the mixture of the fleece and the binder was subjected to heat molding under the same conditions as in Example 1 to obtain a rectangular sheet mat felt product having a length of 20 cm, a width of 20 cm, and a thickness of 1.0 cm. This mat felt product is subjected to the above tests (1) to (5)
Was served. The results are shown in Table 1.

Comparative Example 2 A mat felt product was obtained in the same manner as in Comparative Example 1 except that the amount of the binder was 10 parts by weight with respect to 100 parts by weight of the fleece. This mat felt product was subjected to the tests (1) to (5). The results are shown in Table 1.

Comparative Example 3 The same base fiber as that used in Example 1 was shredded and defibrated, and the obtained fleece was used as a binder in the same Showa high polymer as that used in Comparative example 1. Shownol BRP5417 manufactured by the company was added and mixed. The amount of the binder was 35 parts by weight based on 100 parts by weight of the fleece. Next, the mixture of the fleece and the binder was subjected to heat molding under the same conditions as in Example 4 to have a length of 20 cm.
A rectangular sheet-shaped board felt product having a width of 20 cm and a thickness of 0.2 cm was obtained. This board felt product was subjected to the tests (1) to (3) and (6). The results are shown in Table 1.

Comparative Example 4 A board felt product was obtained in the same manner as in Comparative Example 3 except that the amount of the binder was 30 parts by weight with respect to 100 parts by weight of the fleece. This board felt product was subjected to the tests (1) to (3) and (6). The results are shown in Table 1.

[0028]

[Table 1]

From Table 1, it can be seen that in the comparative example using a mixture of novolak type phenol resin and hexamethylenetetramine as the binder, the obtained product has a relatively strong and unpleasant odor, a large amount of formaldehyde emission, and a large amount of formaldehyde emission. While smoke was observed, in the example using the liquid binder as the binder, it was found that the odor of the product was relatively weak and unpleasant, the amount of formaldehyde emission was small, and smoke was not observed.

[0030]

According to the felt manufacturing method of the present invention, the following effects can be obtained. (1) Since the binder is in a liquid state, the binder is not scattered as dust, so that a favorable working environment can be maintained. (2) Since it is not necessary to use hexamethylenetetramine as a curing agent at the time of production, it is possible to prevent the generation of offensive odor and smoke caused by the curing agent and to prevent the working environment from deteriorating. . Further, it is possible to prevent the odor caused by the curing agent from remaining in the product, and to prevent the user from feeling uncomfortable.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Tatsuo Iwata Inventor 10-1 Nakazawa-cho, Hamamatsu-shi, Shizuoka F-term in Yamaha Corporation (reference) 4J002 AB01W AB01X AF02X AH00W BA01X BB12W BD04X BD10X BE06W BF02X BG00X CC04X CC16X CC18X CD00X CF00X CF03W CK02X CL00W CL00X CM04X DA016 DL006 FA04W FA046 GL00 GN00 GQ00 4L047 AA08 AA12 AA28 BA15 BC14 CB03 CB06 CC09 CC16

Claims (5)

[Claims] 1. A method for manufacturing a felt, comprising adding a liquid binder to a base fiber to form a fleece, and heat-forming the fleece. 2. The felt manufacturing method according to claim 1, wherein a liquid binder containing a phenol resin is used. 3. The felt manufacturing method according to claim 2, wherein a resol type phenol resin is used as the phenol resin. 4. A felt obtained by the method for producing a felt according to claim 1. 5. A felt binder used in the felt manufacturing method according to claim 1, wherein the felt binder is a liquid material.