JP2002101492A - Foamed sheet for speaker edge and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a material for a speaker edge that is excellent in well- balanced performance such as acoustic performance, recycle performance, flexibility, anti-hydrolysis, resistance to deterioration due to oxidation after forming, weight reduction, heat resistance, ease of molding, design and outward appearance of mold. SOLUTION: This invention provides the manufacturing method for the speaker edge sheet consisting of a foaming body made of a styrenic thermoplastic polymer composition with a Shore hardness A of 0-60 or an olefinic group thermoplastic polymer composition with a Shore hardness A of 0-60.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foamed sheet material for a speaker edge and a manufacturing method thereof, and more particularly to a foamed sheet material for a speaker edge for automobiles requiring heat resistance.

[0002]

2. Description of the Related Art Generally, urethane foam sheets and vulcanized foam rubber sheets are used as materials for foam sheets for speaker edges. In any case, harmful gases are generated during waste combustion treatment. There are also environmental problems such as difficulty in recycling. Furthermore, in terms of durability, the urethane foam sheet has disadvantages such as poor resistance to hydrolysis, and the vulcanized foam rubber is heavy in weight, deteriorated by oxidation after molding, and poor in design. Therefore, there is a demand for a sheet for a foamed speaker edge which does not deteriorate in durability due to hydrolysis, is light in weight, has resistance to oxidation deterioration after molding, and is recyclable.

[0003]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found that a foam made of a specific thermoplastic polymer composition has acoustic properties, recyclability, flexibility, and resistance to hydrolysis. The inventors have found that the present invention has an excellent balance among decomposability, resistance to oxidation deterioration after molding, light weight, heat resistance, moldability, designability, and appearance of a molded product, and completed the present invention.

That is, the present invention relates to (I) Shore (Sh)
ore) a styrene-based thermoplastic polymer composition having an A hardness of 0 to 60 (a block composed of a vinyl aromatic monomer and at least one polymer block mainly composed of a conjugated diene compound, and having a number average molecular weight of 50,000
Hydrogenated product of a block copolymer having a molecular weight of up to 150,000, for example, manufactured by Kuraray Co., Ltd., trade names: Septon 4033, 4
055), when a foam sheet of an olefin-based thermoplastic polymer composition having a Shore A hardness of 0 to 60 is used for a speaker edge, its acoustic properties (for example, reverb effect), recyclability, flexibility, Hydrolysis resistance, oxidation deterioration resistance after molding, light weight, heat resistance, moldability, designability,
In addition, they found that the balance of the appearance of the molded product and the like became excellent, and reached an improvement in the characteristics of the speaker edge.

Incidentally, the thermoplastic polymer composition constituting (I) may be further added with other thermoplastic polymers, antioxidants, ultraviolet absorbers, lubricants, pigments, foaming agents, fillers and the like. Good.

[0006] Each component is described below: (I) of the present invention comprises a styrene thermoplastic polymer composition having a Shore A hardness of 0 to 60 and a foam of an olefin thermoplastic polymer composition. When a sheet made of a thermoplastic polymer composition having a Shore A hardness of more than 60 is used, the intended flexibility cannot be satisfied.

As the styrene-based thermoplastic polymer composition used in (I) of the present invention, known ones can be used, and a block comprising a vinyl aromatic monomer,
50 to 150 parts by weight of a rubber softener, 100 parts by weight of a hydrogenated product of a block copolymer having a number average molecular weight of 50,000 to 150,000, comprising a conjugated diene compound as a main component, and a polyolefin resin 0 to
In the case of using 50 parts by weight and having a melt flow rate at 230 ° C. and a load of 2.16 kg of 5 g / 10 min or more, particularly, acoustic properties (for example, reverb effect),
Excellent balance of recyclability, flexibility, hydrolysis resistance, oxidation deterioration resistance after molding, light weight, heat resistance, molding workability, designability, and appearance of other molded products, calendar workability,
It is preferable because a sheet having excellent foaming properties can be obtained.

The olefin-based thermoplastic polymer composition used in the above foam includes polyethylene (high-density polyethylene, low-density polyethylene, linear polyethylene), polypropylene, and ethylene-propylene (random) copolymer. Copolymer, ethylene-butene (random) copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene ionomer resin And thermoplastic olefin-based elastomers (hard component: polypropylene, soft component: ethylene / propylene rubber, etc.). Further, the constituent components may be diversified by adding a third component or the like.

If the expansion ratio is smaller than 1.2 times, there will be problems in acoustic characteristics and lightness, and if it exceeds 2.5 times, there will be problems in strength.

DESCRIPTION OF THE PROCESS FOR PRODUCING SHEET
After kneading with a two-roll warm-up roll, reverse L
In a calender such as a four-roll calender, it is laminated on one side of the support sheet. Subsequently, application of a surface treatment agent, heat foaming, embossing, and surface treatment are sequentially performed. Thereafter, the foamed layer is obtained by slicing the support sheet in parallel with the support sheet or by peeling the support sheet. As the above-mentioned support sheet, paper, cloth, non-woven fabric and the like can be used.

[0011]

According to the present invention, a recyclable foam speaker edge which is light in weight without deterioration in durability due to hydrolysis can be obtained. The speaker edge using this elastomer foam sheet is lightweight, effective in acoustics, and excellent in external vibration absorption. Furthermore, recyclability, flexibility, hydrolysis resistance, oxidation deterioration resistance after molding, heat resistance, moldability,
It can solve all the problems of other prior arts which are well-balanced in design and appearance of molded products.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Example 1 A resin composition (1) having the composition shown in Table 1 below
Was kneaded with a Banbury mixer for 5 minutes, then kneaded with a two-roll warm-up roll for 6 minutes, and then the above composition was subjected to ester taffeta undercoating using an inverted L-shaped four-roll calender. The sheet was stuck on the lower surface of the sheet to a thickness of 0.4 mm.

Table 1 (Blend (1)) Hydrogenated product of styrene-conjugated diene block copolymer (Kuraray Co., Ltd., trade name: Septon 4033) 30 parts by weight (Kuraray Co., Ltd., trade name: Septon 4055) Part Paraffin oil (Idemitsu Petrochemical Co., Ltd. product name PW380) 40 parts by weight Polypropylene (Japan Polyolefin Co., Ltd. product name PH943B) 20 parts by weight Blowing agent (Otsuka Chemical Co., Ltd. product name AZ-H) 5 parts by weight Phenol Antioxidant (AO-60 manufactured by Asahi Denka Kogyo Co., Ltd.) 0.1 part by weight Phosphite antioxidant (PEP-36 manufactured by Asahi Denka Kogyo Co., Ltd.) 0.1 part by weight Acrylic lubricant (Asahi Denka Kogyo Co., Ltd. product name LS-5) 0.3 parts by weight Pigment (Toyo Ink Mfg. Co., Ltd. product name TE color) 3 parts by weight

[0014] The laminated sheet obtained above is heated to a temperature of 210 ° C.
Through a foaming furnace for 2 minutes to foam, a total thickness of 0.8 mm
Was obtained. Next, the surface of the resin layer of the foam laminated sheet was embossed at a temperature of 150 ° C. to flatten the surface. Subsequently, peeled off the support, 0.8
mm in Example 1 was obtained. This sheet-shaped material had an excellent balance of acoustic properties, recyclability, flexibility, hydrolysis resistance, oxidation-deterioration resistance after molding, light weight, heat resistance, moldability, designability, and appearance of other molded products. .

[0015]

Example 2 A resin composition (1) having the composition shown in Table 1 above was kneaded for 5 minutes by a Banbury mixer, and then kneaded for 6 minutes by a two-roll warm-up roll. Using a roll calender, the above composition was stuck to a thickness of 0.4 mm on the lower surface of the support sheet that had been subjected to the ester taffeta lower process.

The surface of the laminated sheet obtained above is coated with a primer (Unistol “P” manufactured by Mitsui Petrochemical Industries, Ltd.).
-801 ") with a gravure coater (120 lines / square inch) (dry weight 2.5 g / m ² ), dried, and then a urethane-based surface treatment agent (trade name" CRISVON3354 "100, manufactured by Dainippon Ink and Chemicals, Inc.) A mixture of 5 parts by weight of a pigment and 5 parts by weight of a pigment is applied (dry weight 2.5 g /
m ² ) and dried. Thereafter, the laminated sheet was passed through a foaming furnace at a temperature of 210 ° C. for 2 minutes to foam the compound (1), and a foamed laminated sheet having a total thickness of 0.85 mm was obtained.

Next, the resin layer surface of the foamed laminated sheet is flattened by embossing at a temperature of 150 ° C., and further, a urethane-based surface treating agent (trade name “CRISVON3354” manufactured by Dainippon Ink and Chemicals, 100 parts by weight and mat) (Dai Nippon Ink & Chemicals, product name "HAUL
AC MAT A-1008 "5 parts by weight of a mixture (dry weight 2.5 g / m ² ), drying and subsequent peeling from the support to obtain a 0.8 mm foamed sheet of Example 2 Was. As in Example 1, this sheet-like material had acoustic properties, recyclability, flexibility, hydrolysis resistance, oxidation-deterioration resistance after molding,
Excellent balance of light weight, heat resistance, moldability, design, and appearance of other molded products.

Table 2 below compares the foam of the present invention obtained in Examples 1 and 2 with a conventional urethane foam (denoted as urethane) and a vulcanized rubber foam (denoted as vulcanized rubber). The results are shown. Example 1 Example 2 Urethane vulcanized rubber Acoustic ◎ ◎ × ○ Recyclability ◎ ◎ × × Flexibility ◎ ◎ ◎ △ Hydrolysis resistance ◎ ◎ × ◎ Oxidation degradation resistance after molding ◎ ◎ ○ × Light weight ◎ ◎ △ × Heat resistance ◎ ◎ ○ ◎ Moldability ◎ ◎ △ × Designability ◎ ◎ × × Molded product appearance ◎ ◎ ○ ○

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 91/00 H04R 31/00 H04R 31/00 B29K 23:00 // B29K 23:00 25:00 25: 00 B29L 7:00 B29L 7:00 31:38 31:38 B29C 67/22 (72) Inventor Toshihiko Kono 6-29-1 Tarui, Sennan-shi, Osaka Toyo Cross Co., Ltd. (72) Inventor Hideto Tsujii 6-29-1, Tarui, Sennan-shi, Osaka F-term (reference) in Toyo Cross Corporation 4F074 AA17 AA24 AA25 AA28 AA32 AA40B AB00 AB01 AB05 AD01 AG02 BA00 4F212 AA03 AA13 AD16 AG01 AH39 UA09 UB02 UB13 UC05 UG05 UP03 BB03X BB05X BB06X BB07X BB12X BB15X BB22X BB23X BP01W FD02Y GQ00 5D016 AA12 CA03 DA06 HA01 HA07 JA03

Claims (4)

[Claims] 1. A styrene-based thermoplastic polymer composition having a Shore A hardness of 0 to 60, or a Shore A hardness of 0 to 60.
A sheet for a speaker edge, comprising a foam of the olefin-based thermoplastic polymer composition. 2. A block according to claim 1, wherein the styrenic thermoplastic polymer composition comprises a block composed of a vinyl aromatic monomer and a block mainly composed of a conjugated diene compound, and has a number average molecular weight of 50,000 to 150,000. 100 parts by weight of hydrogenated copolymer, softener for rubber 5
A speaker edge sheet comprising 0 to 150 parts by weight and 0 to 50 parts by weight of a polyolefin resin and having a melt flow rate of 5 g / 10 minutes or more at 230 ° C. and a load of 2.16 kg. 3. The speaker edge sheet according to claim 1, wherein the expansion ratio of the foam of the present invention is 1.2 to 2.5 times (cell porosity: 10 to 90%). 4. The method according to claim 1, 2 or 3,
The resin composition is adhered to a support sheet by a calendering method, then a surface treatment agent is applied, heated and foamed, embossed, and then the foamed layer is sliced parallel to the support sheet or the support sheet is peeled off. A method for manufacturing a sheet for a speaker edge.