JP2001163280A - Saddle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a saddle flexible, excellent in cushioning property and durable and never generating a toxic gas even by incineration disposal. SOLUTION: This saddle is formed of a thermoplastic elastomer painted with a urethane-based surface modifier.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a saddle which does not generate toxic gas even when incinerated, is flexible, has excellent cushioning properties, and has excellent durability.

[0002]

2. Description of the Related Art As a material for a bicycle saddle, a vinyl chloride resin is almost used. Vinyl chloride is easy to mold and process, and is inexpensive.However, when incinerating waste, it can generate toxic gases due to the chlorine content. There is a problem that it is expensive. Further, rubber requires a vulcanization step at the time of molding, and has a smell peculiar to rubber. On the other hand, a general thermoplastic resin does not require a vulcanization step,
Lack of flexibility and poor feel when sitting. That is, for example, polypropylene and polyethylene have high rigidity,
You lose the cushioning of the bicycle saddle.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above prior art, and does not generate toxic gas even when incinerated, is flexible, has excellent cushioning properties, and is durable. The purpose is to provide a good saddle.

[0004]

According to the present invention, the above objects are achieved by providing a saddle made of a thermoplastic elastomer coated with a urethane-based surface modifier. Further, the above object is to provide a block copolymer having at least one polymer block A composed of a vinyl aromatic compound in a molecule as a thermoplastic elastomer and having at least one polymer block B composed of a conjugated diene compound. Is more preferably achieved by using a hydrogenated block copolymer obtained by hydrogenating

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, olefin-based, urethane-based, and styrene-based elastomers are used as thermoplastic elastomers. Hardness is JIS K
It is preferably 90 or less with a 6253 type A durometer. If the hardness exceeds 90, the cushioning properties of the saddle will be lost.

In the present invention, as the thermoplastic elastomer, a hydrogenated block copolymer is preferably used because it has flexibility and elasticity and further has good cushioning properties as a saddle. Here, the hydrogenated block copolymer has at least one polymer block A composed of a vinyl aromatic compound in the molecule and at least one polymer block B composed of a conjugated diene compound. Can be obtained by hydrogenating the union, for example, (AB)
_n , (AB) _n -A (n represents an integer of 1 to 10),
(AB) _m -X (X represents a coupling agent residue;
Represents an integer of 2 to 15). A hydrogenated block copolymer obtained by hydrogenating a vinyl aromatic compound-conjugated diene compound block copolymer having a structure such as In the hydrogenated block copolymer, the content of the vinyl aromatic compound is preferably from 5 to 75% by weight, more preferably from 10 to 65% by weight.

As the vinyl aromatic compound constituting the block copolymer before hydrogenation, for example, styrene, α-
Examples include methylstyrene, o-, m- or p-methylstyrene, 1,3-dimethylstyrene, vinylnaphthalene, vinylanthracene and the like. Of these, styrene and α-methylstyrene are preferred. The vinyl aromatic compounds may be used alone or in combination of two or more. Further, as the conjugated diene compound constituting the block copolymer before hydrogenation, for example, 1,3-
Butadiene, isoprene, 2,3-dimethyl-1,3-
Butadiene, 1,3-pentadiene, 1,3-hexadiene and the like. Among these, isoprene,
Preference is given to 1,3-butadiene or mixtures thereof.
The conjugated diene compounds may be used alone or in combination of two or more.

[0008] The microstructure of the polymer block B in the block copolymer before hydrogenation is not particularly limited. For example, when the polymer block B is a block composed of polyisoprene, the amount of 1,4 bonds is preferably 30% or more. When the polymer block B is a block made of polybutadiene, the 1,4 bond amount is desirably 40% to 80%. The bonding mode between the polymer block A and the polymer block B in the hydrogenated block copolymer may be linear or branched, or any combination thereof.

When producing a hydrogenated block copolymer,
From the viewpoint of heat resistance and weather resistance, it is preferable to hydrogenate at least 70% of the unsaturated double bond derived from the conjugated diene compound in the block copolymer before hydrogenation. The amount of unsaturated double bonds in the polymer block B in the hydrogenated block copolymer can be determined by iodination measurement, an infrared spectrophotometer, a nuclear magnetic resonance apparatus, or the like.

Further, the hydrogenated block copolymer comprises:
A functional group such as a carboxyl group, a hydroxyl group, an acid anhydride, an amino group, or an epoxy group may be contained in the molecular chain or at the molecular terminal as long as the gist of the present invention is not impaired.

The thermoplastic elastomer used in the present invention includes, in addition to the hydrogenated block copolymer, olefin polymers and plasticizers (paraffins, naphthenes, aromatics, hydrocarbons such as liquid paraffin, etc.). Oils and the like, and known compounding agents such as stabilizers (antioxidants, ultraviolet absorbers, etc.), lubricants, fillers (calcium carbonate, talc, etc.), and coloring agents (pigments, dyes, etc.). Further, a styrene-based resin such as polystyrene, high-impact polystyrene, α-methylstyrene resin, and ABS may be added to the thermoplastic elastomer within a range that does not impair the purpose of the present invention.

By coating a saddle made of the above-mentioned thermoplastic elastomer with a urethane-based surface modifier, there is an effect that slipperiness with clothing is improved and durability is further improved. The amount of the urethane-based surface modifier applied is preferably such that the thickness of the urethane-based surface modifier is 50 μm or less. When the thickness of the surface modifying agent exceeds 50 μm, it is difficult to apply uniformly, and the cost of the coating is also high.
The lower limit of the thickness is preferably 1 μm or more. Here, as the urethane-based surface modifier, an isocyanate prepolymer having a plurality of isocyanate (-NCO) groups at the molecular terminals is used as a curing agent, and polyester polyol, polyether polyol, acrylic polyol, and alkyd polyol are used as main agents. A urethane-based coating to be crosslinked is preferably used. Examples of the isocyanate monomer to be prepolymerized include toluene diisocyanate (TDI), 4,4′-phenylmethane diisocyanate (MDI), xylene diisocyanate (XDI), hexamethylene diisocyanate (HDI), and isophorone diisocyanate (IPDI).
Is mentioned. Generally, a non-yellowing type HDI or IPDI system having good weather resistance is used, but it is better to use a yellowing type TDI or MDI or a cross-linking type isocyanate (crude MDI) in combination to improve abrasion resistance. . As the urethane-based paint, for example, a main agent GL-711 (trade name) manufactured by Sakai Chemical Co., Ltd. (solid content: 22.5 to 25.5)
%, Viscosity: 100 to 700 csp, main solvent: toluene)
And SGL-750A (trade name) (solid content: 26.5-3
0.5%, viscosity: 150 to 350 cps, main solvent: methyl ethyl ketone) and curing agent F-1 (trade name) (solid content: 48 to 52%, viscosity: 50 cps or less, main solvent:
A mixture of xylene, propylene glycol monomethyl ether acetate, NCO content: 11.7%) and a thinner can be used. Here, toluene, xylene, methyl ethyl ketone,
Propylene glycol monomethyl ether acetate can be used. Further, by adding a matting agent, for example, matting agent B (solid content: 5%, main solvent: xylene, toluene) manufactured by Sakai Chemical Co., to the urethane-based paint, the degree of gloss can be adjusted and the gloss can be eliminated. You can also.

When applying a urethane-based coating, it is preferable to apply a urethane-based coating after applying a urethane-based primer having excellent adhesion to a thermoplastic elastomer.
Here, as the urethane-based primer, for example, a primer SL-8866 (solid content: 5.2 to 7.2%, main solvent: toluene) or FP-5501 (solid) manufactured by Sakai Chemical Co., Ltd. Min: 5.2%,
Viscosity: 50 cps or less, main solvent: toluene) (all are trade names) can be used. In addition, SL-886
When 5 parts by weight of a hardener F-1 (trade name) manufactured by Sakai Chemical Co., Ltd. is added to 6, the normal and heat-resistant adhesive strength is further improved, and the durability of the saddle is increased.

The saddle of the present invention is, for example, injection molded thermoplastic elastomer pellets at 150 to 250 ° C.
Obtain a saddle base material, then wipe off the dust on the surface of the saddle with alcohol, and apply a urethane-based primer to 0.03 to 2MP.
It is obtained by applying a urethane-based paint after spray application at the air pressure of a.

The saddle of the present invention is excellent in molding workability, and has a feature of giving a molded article having good flexibility, rubber elasticity and mechanical properties, and is particularly useful as a bicycle saddle. In addition, the present invention is also useful as a saddle for a unicycle, a motorcycle with a motor, a health appliance, and the like.

[0016]

EXAMPLES The present invention will be further described with reference to the following examples, but the present invention is not limited to these examples. In these examples and comparative examples, the hardness, cushioning property, durability, and gloss of the bicycle saddle were evaluated by the following methods.

A) Hardness In accordance with JIS K6253, using an A-type durometer, three injection-molded 2 mm-thick sheets were piled up, and the hardness was measured to obtain an index of flexibility. b) Cushioning property The injection-molded saddle was mounted on a bicycle, and the feel when riding the bicycle was evaluated. …: Flexible and excellent in cushioning properties. X: Insufficient in flexibility and inferior in cushioning properties. c) Durability In accordance with JIS L1096 A-1 method, a 2 mm-thick injection-molded sheet was rubbed with a woven fabric, and the number of times the sheet was broken was measured and used as an index of durability. d) Gloss The injection molding saddle was visually evaluated by applying light from a fluorescent lamp from a distance of 30 cm. The evaluation criteria are as follows. …: There is no gloss and there is a high-class feeling. Δ: Some gloss was observed, and there was not much luxury. ×: Glossy, no luxury

Example 1 Septon 4055 polystyrene (A) -ethylene propylene (B) -polystyrene (A) hydrogenated block copolymer manufactured by Kuraray Co., Ltd. as a thermoplastic elastomer, styrene content: 30% , With a hydrogenation rate of 98% or more｝, manufactured by Nippon Polychem Co., Ltd.
Novatec PP MA2 (MFR: 16 g / 10 min) and Idemitsu Kosan Diana Process Oil PW-90 (paraffin type, kinematic viscosity: 95.54 cst (40 ° C.)) are 10
The mixture was mixed at a weight ratio of 0/30/120, and pellets (Septon Compound A) were obtained at 200 ° C. with a twin-screw extruder. This Septon Compound A is injection molded at 200 ° C. to produce a bicycle saddle. The dust on the surface of the saddle is wiped off with isopropanol, and a urethane primer FP-5501 (solid content: 5.2%, viscosity: 50 cps or less, main solvent: toluene) manufactured by Sakai Chemical Co., Ltd. is sprayed with a spray gun at an air pressure of 0.08 MPa. Was applied. After drying at room temperature for 5 minutes, Sakai Chemical's urethane-based paint GL-711 was diluted twice with a thinner, and a curing agent F-1 (trade name) (solid content: 48 to 52%, viscosity: 50 cps or less, mainly Solvent: xylene, propylene glycol monomethyl ether acetate) was added in a similar manner to a paint containing 10%, and dried at 80 ° C. for 10 minutes to evaluate. The spray gun used was Wonder Spray Gun W-71 (model W-71-3G) manufactured by Iwata Coating Machine Industry Co., Ltd. Similarly, a sheet having a diameter of 120 mm and a thickness of 2 mm was prepared and evaluated. Table 1 shows the results.

Example 2 In the same manner as in Example 1, the urethane primer FP-550 was used.
1 and dried at room temperature for 5 minutes, and then a urethane-based paint GL-711 manufactured by Sakai Chemical (solid content: 22.5 to 25.5%,
Viscosity: 100 to 700 csp, main solvent: toluene) is diluted twice with a thinner, and a matting agent B (solid content: 5%, main solvent: xylene, toluene) manufactured by Sakai Chemical Co. is added 10%, and spray gun is used. It was applied in the same manner, dried at 80 ° C. for 10 minutes, and evaluated. Table 1 shows the results.

Comparative Example 1 Septon Compound A was used as a thermoplastic elastomer in the same manner as in Example 1 to produce a bicycle saddle. Similarly, a sheet having a diameter of 120 mm and a thickness of 2 mm was prepared and evaluated. Table 1 shows the results.

Comparative Example 2 Instead of a thermoplastic elastomer, Mitsui Petrochemical Co., Ltd.
High-density polyethylene "Hi-zex (Hi-ze
x) Using 7000F ”(trade name), a bicycle saddle was produced by injection molding at 160 ° C. Similarly, the diameter 1
A sheet having a thickness of 20 mm and a thickness of 2 mm was prepared and evaluated. Table 1 shows the results.

Comparative Example 3 The bicycle saddle of Comparative Example 2 was coated with a urethane-based primer in the same manner as in Example 2, and a urethane-based paint GL-711 containing a matting agent was similarly coated with a spray gun at 80 ° C.
And dried for 10 minutes. Table 1 shows the results. Similarly, a sheet having a diameter of 120 mm and a thickness of 2 mm was prepared and evaluated. Table 1 shows the results.

According to the results shown in Table 1, Examples 1 and 2 coated with a urethane-based surface modifier are superior in durability to Comparative Example 1. Comparative Examples 2 and 3 have durability, but Examples 1 and 2
Harder, less flexible, and less cushioning. That is, according to Example 12, it is clear that the durability is improved by applying a urethane-based surface modifier, and a saddle that is flexible and has excellent cushioning properties can be obtained by using a thermoplastic elastomer as a material. Was.

[0024]

[Table 1]

[0025]

According to the present invention, it is possible to obtain a saddle that is flexible, has excellent cushioning properties, and has excellent durability without generating toxic gas even when incinerated.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F006 AA11 AA15 AB37 BA00 BA03 BA15 CA00 DA00 4J002 BP011 FD010 FD020

Claims (2)

[Claims] 1. A saddle comprising a thermoplastic elastomer coated with a urethane surface modifier. 2. A thermoplastic elastomer having at least one polymer block A comprising a vinyl aromatic compound in a molecule, and a polymer block B comprising a conjugated diene compound.
The saddle according to claim 1, wherein the saddle is a hydrogenated block copolymer obtained by hydrogenating a block copolymer having at least one of the following.