JP3136100B2 - Impact buffer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gondola installed on a ski resort and a shock absorbing material mounted on an upper part of a retractable lift, and more particularly, it is excellent in weather resistance, rebound resilience and impact resistance at low temperatures. The present invention relates to a crash cushioning material (also referred to as an end piece) made of a polyurethane elastomer.

[0002]

2. Description of the Related Art When a gondola and a lift installed at a ski resort are stored or when the gondola collides with each other during use, the gondola is prevented from being damaged, or the impact is given to a degree that does not cause discomfort to passengers. , A gondola and a lift are equipped with a crash cushioning material. This collision buffer is made of a molded article made of nylon 6, or tolylene diisocyanate (TDI) and polytetramethylene glycol (P).
A cast product of polyurethane using TMG) or the like is used.

[0003] However, these crash cushioning materials have poor cold resistance, and the tip of the gondola and the retractable lift are broken due to a collision between the lifts and the retractable lift, and have been replaced with new ones in about one year.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and it is an object of the present invention to provide excellent weather resistance, rebound resilience, and impact resistance, and in particular, to provide a low-temperature impact resistance. Another object of the present invention is to provide a shock absorbing material that can prolong the service life by preventing the tip of the gondola and the retractable lift from being cracked by using a material that is resistant to shocks.

[0005]

In general, when considering the low-temperature characteristics of the impact cushioning material, it is preferable to prepare the impact cushioning material from TDI-based polyurethane, but the physical properties are limited and the low-temperature characteristics are further improved. In order to do so, it is necessary to use an isocyanate component, a polyol component, and a curing agent component such that the hard segment and the soft segment contained in the polyurethane undergo phase separation at a low temperature. The present inventors have found that a urethane elastomer comprising a combination of paraphenylene diisocyanate (PPDI), a specific polyol component and a curing agent component has excellent low-temperature properties, and have completed the present invention. .

That is, the collision buffer of the present invention is a collision buffer composed of a polyurethane elastomer containing a urethane prepolymer and a curing agent, wherein the urethane prepolymer is composed of paraphenylene diisocyanate and polyol as isocyanate components. as component, polyester polyol, consists of at least one selected from the group consisting of polyether polyols and polycarbonate polyols, said polyol component, the number
Polycaprolactone having an average molecular weight of 900 to 1,100
It contains a polyol, and the curing agent comprises 1,4-butanediol, and has a low-temperature impact embrittlement temperature according to JIS K6261 of -60 ° C to -75 ° C,
The above object is achieved by using a curing agent which easily forms a hard segment.

Preferably, the above-mentioned polyol component contains a polycaprolactone polyol having a number average molecular weight of 900 to 1,100, and the curing agent contains 1,4-butanediol.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, one or more selected from the group consisting of polyester polyols, polyether polyols and polycarbonate polyols are used as a polyol component forming a urethane prepolymer.

The polyester-based polyols include:
For example, a condensate of a polycarboxylic acid and a low-molecular polyol having a molecular weight of 500 to 10,000 can be used.

Specifically, poly (ethylene adipate)
(Hereinafter referred to as “PEA”), poly (diethylene adipate) (hereinafter referred to as “PDA”), poly (propylene adipate) (hereinafter referred to as “PPA”), poly (tetramethylene adipate) (hereinafter referred to as “PBA”) ), Poly (hexamethylene adipate) (hereinafter referred to as “PHA”),
Poly (neopentylene adipate) (hereinafter referred to as "PNA"), a polyol composed of 3-methyl-1,5-pentanediol and adipic acid, a random copolymer of PEA and PDA, a random copolymer of PEA and PPA , PEA
And a random copolymer of PBA, a random copolymer of PHA and PNA, or a caprolactone polyol obtained by ring-opening polymerization of ε-caprolactone, and β-methyl-δ-valerolactone obtained by ring opening with ethylene glycol. Polyols (all of which have a molecular weight of 5
00 to 10,000).
Each of them may be used alone or in combination.

Further, examples of the polyester polyol include, for example, a copolymer of at least one of the following acids and at least one of glycols.

Acids: terephthalic acid, isophthalic acid, phthalic anhydride, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecane diacid, dimer acid (mixture), paraoxybenzoic acid, trimellitic anhydride, ε-caprolactone, β-methyl-δ-valerolactone.

Glycol: ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, polyethylene glycol, polytetramethylene glycol, 1,4-cyclohexanedi Methanol, pentaerythritol, 3-methyl-1,5-pentanediol.

The above polycaprolactone polyol will be further described. The polycaprolactone polyol that can be used in the present invention is not particularly limited as long as it has a hydroxyl group at a terminal.
And those obtained by a ring opening reaction with caprolactone.

As the polycaprolactone polyol, one kind may be used alone, or two or more kinds may be used in combination. The average molecular weight of the polycaprolactone polyol is not particularly limited, but is preferably about 600 to 4000. Particularly preferably, it is about 900 to 1100. When the average molecular weight is less than 600, the reaction rate with the polyisocyanate becomes too fast, and the average molecular weight is 400
If it exceeds 0, the viscosity of the obtained urethane prepolymer becomes too high, resulting in poor workability. The average number of functional groups of the polycaprolactone polyol is not particularly limited, but is preferably about 1.7 to 3.0.

The above polyether polyols include:
For example, an alkylene oxide (eg, ethylene oxide, propylene oxide) is given by ring-opening addition polymerization using a polyhydric alcohol (eg, diethylene glycol) which is an active hydrogen compound as an initiator, specifically, polypropylene glycol (PPG), Examples thereof include polyethylene glycol (PEG) and a copolymer of propylene oxide and ethylene oxide.

Also, there are those having a molecular weight of 500 to 5,000, which are provided by cationic polymerization of tetrahydrofuran. Specifically, there is polytetramethylene ether glycol (PTMG), and there is a copolymer of tetrahydrofuran and another alkylene oxide. Specifically, a copolymer of tetrahydrofuran and propylene oxide, a copolymer of tetrahydrofuran and ethylene Copolymers with oxides (all of which have a molecular weight of 500 to 100)
00 is preferable, and each of them is used alone or in combination.

The above-mentioned polycarbonate-based polyol is obtained by condensation of a conventionally known polyol (polyhydric alcohol) with phosgene, chloroformate, dialkyl carbonate or diallyl carbonate, and has various molecular weights. Particularly preferable as such a polycarbonate-based polyol, 1,6-hexanediol, 1,4-butanediol, 1,3-butanediol, neopentyl glycol, or 1,5-pentanediol was used as the polyol. Having a molecular weight of about 500 to 10,000. The polyol component of the urethane prepolymer that can be used in the present invention includes the above-mentioned polycarbonate-based polyol, a random copolymer of a polycarbonate-based polyol and a polycaprolactone-based polyol, and a random copolymer of a polycarbonate-based polyol and a polyester-based polyol Or a mixture of a polycarbonate-based polyol, a polycaprolactone-based polyol, and a polyester-based polyol.
Further, two or more of these may be used in combination.

(Method for Producing Urethane Prepolymer) The method for producing a urethane prepolymer by reacting one or more of the above polyol components with paraphenylene diisocyanate is not particularly limited. The reaction can be performed by a known method, including the temperature, reaction time, presence or absence of a solvent, and the like.

The urethane prepolymer thus obtained has an isocyanate group content% of 1% to 10%, especially 4%.
It is necessary to react the isocyanate component containing paraphenylene diisocyanate with the polyol component so that the content is 〜8%. If the isocyanate group content of the resulting urethane prepolymer exceeds 10% by weight, the amount of free paraphenylene diisocyanate increases and the storage stability of the urethane prepolymer becomes poor. On the other hand, if it is less than 1% by weight, the viscosity of the urethane prepolymer increases, and the handleability deteriorates.

In order to obtain the urethane elastomer used in the present invention, the urethane prepolymer obtained as described above and a curing agent may be mixed to cure the urethane prepolymer.

The curing agent that can be used is not particularly limited, and may be a commonly used curing agent that is conventionally used when a urethane prepolymer is cured to form a urethane elastomer. For example, a polyol compound, a polyamine compound and the like can be mentioned.

The polyol compound is not particularly limited, and any of a primary polyol, a secondary polyol, and a tertiary polyol may be used.

Specifically, ethylene glycol, 1,3
-Propanediol, 1,4-butanediol, 1,5
-Pentanediol, 1,6-hexanediol, propylene glycol, dipropylene glycol, 1,2-
Butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-pentanediol, 2,3-pentanediol, 2,5-hexanediol, 2,4-
Hexanediol, 2-ethyl-1,3-hexanediol, cyclohexanediol, 2-ethyl-2- (hydroxymethyl) -1,3-propanediol and the like can be mentioned.

The polyamine compound is not particularly limited, such as diamine, triamine and tetraamine, and any of primary amine, secondary amine and tertiary amine can be used.

Specifically, aliphatic amines such as hexamethylenediamine, alicyclic amines such as 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, and 4,4 '
-Methylenebis-2-chloroaniline, 2,2 ', 3
Aromatic amines such as 3'-tetrachloro-4,4'-diaminophenylmethane and 4,4'-diaminophenyl;
2,4,6-tris (dimethylaminomethyl) phenol and the like.

One of these curing agents may be used alone, or a plurality thereof may be used in combination.

The method for mixing the above-mentioned curing agent with the urethane prepolymer obtained as described above to cure the urethane prepolymer is not particularly limited. It can be carried out by a usual method, including the mixing ratio of the curing agent, the curing temperature, the curing time and the like.

The polyurethane elastomer used in the present invention may contain additives and the like. As the additive,
There are plasticizers, flame retardants, fillers, stabilizers, coloring agents and the like.

As the plasticizer, for example, dioctyl phthalate (DOP), dibutyl phthalate (DBP), dioctyl adipate (DOA), tricresyl phosphate (TCP), chlorinated paraffin and the like can be used.

Examples of the flame retardant include phosphoric esters such as tris- (β-chloropropyl phosphate, tris-dichloropropyl phosphate and trischloroethyl phosphate, and bromo compounds such as dibromoneopentyl glycol and tribromoneopentyl alcohol. Can be used.

The above-mentioned fillers include, for example, glass fiber, carbon black, calcium carbonate, talc, kaolin, zeolite, diatomaceous earth, perlite, permiculite,
Titanium dioxide or the like can be used.

As the above-mentioned stabilizers, conventionally used antioxidants, ultraviolet absorbers, light stabilizers, hydrolysis inhibitors and the like can be used.

The antioxidant acts as a radical chain inhibitor, a peroxide decomposer and the like, and the former includes phenols and aromatic amines having steric hindrance.

As a radical chain inhibitor, butylated hydroxytoluene, tetrakis [methylene-3- (3 ',
5′-di-tbutyl-4hydroxyphenyl) propionate] methane, n-octadecyl-β- (4′-hydroxy-3 ′, 5′-di-tbutylphenyl) propionate, 1,3,5 tris (4- t-butyl-3hydroxy-2,6dimethylbenzyl) isocyanuric acid, triethylene glycol bis-3 (2-tbutyl-4hydroxy-5
-Methylphenyl) propionate and the like can be used.

As a peroxide decomposing agent, 4,4′thiobis
(6-t-butyl-m-cresol, dilauryl-thiodipropionate, distearylthio-dipropionate, thiophenylphosphite and the like can be used.

As an ultraviolet absorber, salicylic acid phenyl salicylate, Pt-butylphenyl salicylate, benzophenone 2,4-di-hydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n -Octoxybenzophenone, benzotriazole-based 2 (2'-hydroxy-
5'-methylphenyl) benzotriazole, 2 (2'-
Hydroxy-3′-t-butyl-5′-methylphenyl) -5-chlorobenzotriazole, 2 (2′-hydroxy-3 ′, 5′-di-t-aminophenyl) benzotriazole, sialeacrylate-based Ethyl-2-cyano-3,5-diphenyl acrylate, 2 (2'-hydroxy-5'-t-octylphenyl) benzotriazole and the like can be used.

As the UV screen, pigments such as carbon black and zinc white can be used.

As a light stabilizer, there is a hindered amine. As the hindered amine, 2- (3,5-di-t-
Bis (1,2,2,6,6-pentamethyl-4-butyl-4-hydroxybenzyl) -2-n-butylmalonate
Piperidyl, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine succinate polycondensate, poly [[6- (1,1,3,
3- (tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2
2,6,6-tetramethyl-4-piperidyl) imino]], bis (1,2,2-di (tert-butyl-4-hydroxybenzyl) -2-n-butylmalonate
2,6,6-pentamethyl-4-piperidyl) and the like can be used.

As hydrolysis inhibitors, carbodiimide-based stabacol-1, PCD (Bayer), hexamethylenetetraamine, azodicarbonamide, 4-t
-Butyl catechol and the like can be used.

FIGS. 1 to 4 show an example of the shock absorbing material of the present invention. The impact damping material 1 includes a base 2 fixed to the upper part of the gondola and a side extending from the base 2. And a tapered portion 3 whose thickness is gradually reduced. These may be integrally formed, or a core for fixing to a gondola may be insert-molded in the base 2. It is desirable to apply an adhesive to this cored bar. An example is Chemlock 218 (trade name, manufactured by Lord First East).

In particular, a collision buffer made of a urethane elastomer obtained by using a polycaprolactone polyol having a number average molecular weight of 900 to 1,100 as a polyol component and 1,4-butanediol as a curing agent is used. Has the following characteristics.

The hardness (Shore D) is 50-60, JI
The tear strength according to SK6301 is 140 to 19
0 kgf / cm, 100% modulus in tensile strength 140-200 kgf / cm ² , breaking strength 300-
550kgf / cm ^2, extended 450~700%, JIS
The low-temperature impact embrittlement temperature according to K6261 is -60 to
-75 ° C.

In this case, the mixing ratio of paraphenylene diisocyanate, polycaprolactone polyol and 1,4-butanediol is usually 31.4 to 34.5 parts by weight with respect to 100 parts by weight of polycaprolactone polyol. Parts of 1,4-butanediol from 7.94 to 8.71 parts by weight. The resulting urethane prepolymer preferably has an isocyanate group (NCO) content of 6.2 to 6.8%, and a viscosity at 80 ° C. of preferably 500 to 1,000 cps.

[0045]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments.

Example 1 A. Preparation of Urethane Prepolymer An isocyanate component was added to the following polyol components, and reacted at 85 ° C. for 1 hour under a nitrogen stream to obtain a urethane prepolymer having a terminal isocyanate group.

The isocyanate group (NCO) content% of the obtained urethane prepolymer and the viscosity at 80 ° C. were measured. The viscosity of the prepolymer was determined using a Haake tachometer, Rotobisco RV-12.

Polyol component: One polycaprolactone polyol having an average molecular weight (hereinafter referred to as a number average molecular weight) of 980 (Placcel 210N, manufactured by Daicel Co., Ltd.)
00 parts by weight were used.

Isocyanate component: 32.7 parts by weight of paraphenylene isocyanate (PPDI, manufactured by DuPont) was used.

Curing agent: 1,4-butanediol (1,4B
D, manufactured by Kanto Chemical Co., Ltd.).

The content of isocyanate groups in the obtained urethane prepolymer was 6.45% (theoretical 6.45%).
Met.

The viscosity at 80 ° C. was 720 cps.

100 parts by weight of the urethane prepolymer obtained as described above is kept at 80 ° C., the above-mentioned curing agent is added, and the mixture is heated and cured at 110 ° C. for 10 hours to obtain a sheet-like material. Physical properties were measured.

The hardness (Shore D) of the sheet is 55
Met. The tear strength according to JIS K6301 was 163 kgf / cm, and the tensile strength was as follows.

100% modulus 193 kgf / c
m ² , breaking strength 488 kgf / cm ² , elongation 640%.

B. Production of Impact Buffer Material The urethane prepolymer (base material) obtained above was placed in an oven and preheated at 70 ° C. for 6 hours. The base material was weighed out in an amount of 850 g, and the curing agent was measured and calculated based on the NCO% of the amount of the base material. NCO% = 6.44, OH / NCO = 0.92, curing agent is 5
4.06 g. 12 g of a coloring agent (Black 2939, trade name of Sanyo Dyeing Co., Ltd.) was added to the above base material, and the mixture was stirred.

After the temperature of the vacuum dryer was raised to 80 ° C., the main agent was added and the mixture was defoamed for 60 minutes. Next, put a hot plate on one
The temperature was raised to 00 to 110 ° C, the curing agent was placed on a hot plate, and the liquid temperature was raised to 100 to 110 ° C. During stirring, the temperature was lowered to 70 ° C.

The mold previously kept at 100 ° C. was removed from the press, the upper mold was removed, and a die-free release agent was sprayed.

Next, a stirring rod was put in the main ingredient and set, and a curing agent was put in while stirring at a low speed, followed by stirring. The stirred material was immediately poured into a mold. The upper mold was placed and pressed.

Thereafter, the upper mold was removed, and the product was removed. The oven was heated to 110 ° C., and the product was placed in the oven (conditions: 110 ° C., 10 hours) and subjected to secondary vulcanization to obtain a collision buffer.

C. Evaluation of Impact Buffer Material The impact buffer material obtained in the above section B was observed for its low-temperature impact embrittlement temperature (° C.) and the state of breakage when actually mounted on the upper part of the drum. The evaluation methods and the results are as follows.

(1) Low temperature impact embrittlement temperature: JIS K6
261 was carried out. As a result, the temperature was -68 ° C.

(2) The crash cushioning material was attached to the upper part of the gondola installed at the ski resort as it was actually used, and the destruction state of the crash cushioning material was observed. As a result, the impact cushioning material of this example did not change for more than three years.

Conventional Example 1 When the impact cushioning material made of nylon 6 was evaluated in the same manner as in Example 1, the hardness (Shore D) was 55, and in the test attached to the gondola, the tip cracked in one year.

Conventional Example 2 A urethane impact cushioning material comprising TDI and PTMG was evaluated in the same manner as in Example 1. The hardness (Shore D) was 50, the low temperature impact embrittlement temperature was -40 ° C., and it was attached to a gondola. In the test, the tip cracked in one year.

Comparative Example 1 A urethane impact buffer consisting of NDI and an ester polyol was evaluated in the same manner as in Example 1. The hardness (Shore D) was 55, and the low-temperature impact embrittlement temperature was-.
In a test attached to a gondola at 30 ° C., the tip cracked in one year.

Example 2 A urethane prepolymer was obtained in the same manner as in Example 1 except that the following materials were used.

Polyol component: polycaprolactone polyol having an average molecular weight of 992 (manufactured by Daicel Chemical Industries, Ltd.)
100 parts by weight of trade name (Placcel 210N) were used.

Isocyanate component: 33.9 PPDI
Parts by weight were used.

The content of isocyanate groups in the obtained urethane prepolymer was 6.25% (theoretical 6.25%).
Met.

The viscosity at 80 ° C. is 2,320 cps
Met.

To 100 parts by weight of the obtained urethane prepolymer, 1,4-butanediol curing agent and trimethylolpropane were added in an equivalent ratio of 7: 2, and the molar ratio of OH groups to NCO groups was OH / NCO = It was blended so as to be 0.9.

The hardness (Shore D) of the sheet is 50
Met.

Using the obtained urethane prepolymer,
A collision cushioning material was obtained in the same manner as in Example 1, and the same test was performed. The same result as in Example 1 was obtained.

Example 3 A urethane prepolymer was obtained in the same manner as in Example 1 except that the following materials were used.

Polyol component: average molecular weight of 1,968
Of Polycaprolactone polyol having an average molecular weight of 992 (Placcel 210N, manufactured by Daicel Chemical Industries, Ltd.) was mixed in a ratio of 50:50.

Isocyanate component: 24.0 parts by weight of paraphenylene isocyanate (PPDI, manufactured by DuPont) was used.

Curing agent: 1,4-butanediol (1,4B
D, manufactured by Kanto Chemical Co., Ltd.).

The content of isocyanate groups in the obtained urethane prepolymer was 5.03% (theoretical 5.03%).
Met.

The viscosity at 80 ° C. is 3,000 cps
Met.

The hardness (Shore D) of the sheet is 50
Met.

Using the obtained urethane prepolymer,
A collision cushioning material was obtained in the same manner as in Example 1, and the same test was performed. The same result as in Example 1 was obtained.

[0083]

According to the impact cushioning material of the present invention, since it is composed of a polyurethane elastomer containing a urethane prepolymer composed of paraphenylene diisocyanate, a specific polyol component, and a curing agent, it is resistant to impact at low temperatures. By using the material, it is excellent in weather resistance, rebound resilience and impact resistance, and when used as a molded part, it does not cause cracks at the tip due to collision between the gondola and retractable lift, extending the life Can be.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of a collision buffer according to the present invention.

FIG. 2 is a plan view of the collision buffer shown in FIG.

FIG. 3 is a right side view of the collision buffer shown in FIG. 1;

FIG. 4 is a left side view of the collision buffer shown in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Impact buffer 2 Base 3 Tapered part

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinichiro Kawahara 6-5-6 Sakyo, Nara City, Nara Prefecture Nita Corporation Narayama Research Institute (56) References JP-A-3-220224 (JP, A) JP-A-63-270723 (JP, A) JP-A-1-126318 (JP, A) JP-A-2-298508 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 18 / 42-18/50 C08G 18/65-18/66 C08G 18/76

Claims (1)

(57) [Claims] 1. A collision buffer comprising a polyurethane elastomer containing a urethane prepolymer and a curing agent, wherein the urethane prepolymer comprises paraphenylene diisocyanate as an isocyanate component, and a polyester polyol or a polyol as a polyol component. At least one selected from the group consisting of ether polyols and polycarbonate polyols, wherein the polyol component has a number average molecular weight of 900 to 1,10.
0 polycaprolactone polyol, wherein the curing agent comprises 1,4-butanediol,
Low temperature impact embrittlement temperature according to K6261 is -60 ° C or more
A crash cushioning material having a temperature of -75 ° C.