KR101793050B1 - Foamable composition for polyurethane foam, polyurethane foam, and jounce bumper comprising the same - Google Patents

Abstract

One aspect of the present invention relates to a polyisocyanate composition comprising 100 parts by weight of a polyisocyanate compound; And 350 parts by weight to 450 parts by weight of a polycaprolactone polyol having an OH value of 50 mgKOH / g to 70 mgKOH / g, or a polyalkylene adipate 300 having an OH value of 30 mgKOH / g to 50 mgKOH / g By weight to 400 parts by weight of the foamable composition for polyurethane foam.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a foam composition for polyurethane foam, a polyurethane foam, and a self-

The present invention relates to a foam composition for polyurethane foam, a polyurethane foam, and a porcelain bumper comprising the same.

The polyurethane foam has micropores having a size of 50 mu m to 400 mu m in the foam generated by the foaming agent when the foaming agent is cast, and the density ranges from 0.3 g / cc to 0.8 g / cc. These polyurethane foams are applied to various products or fields such as insole, outsole, and reinforced skin foam of shoes.

Recently, as trade barriers in the automotive industry have been lifted and climate variability has become even more widespread, studies are underway on automotive component materials that can exhibit equivalent physical properties under different climatic conditions.

Particularly, polyurethane foam has a unique nonlinear type elasticity as compared with general vulcanized rubber, and is excellent in vibration and shock absorbing property, and is used as a part for improving the ride feeling when the vehicle is running.

Polyurethane foam obtained by foaming a polyurethane prepolymer obtained by reacting a conventional polyisocyanate compound with a polyester polyol having a number average molecular weight of 500 to 5,000 and an OH value of 22.4 mgKOH / g to 224.0 mgKOH / g is used. In a cryogenic environment, There is a problem that the shock absorbability is lowered and the hygroscopicity is lowered in a high humidity environment and the service life is shortened.

In addition, the polyurethane foam has low heat resistance, cracking occurs when compression and relaxation are repeated, and elasticity is lowered, and it is difficult to impart mechanical and dynamic properties required for a vehicle jounce bumper.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a foam composition for polyurethane foam which is excellent in cold resistance and hygroscopic hygroscopicity even at a cryogenic temperature or a high humidity environment while maintaining mechanical and dynamic properties, To provide a urethane foam.

In order to achieve the above object, one aspect of the present invention is a polyisocyanate composition comprising 100 parts by weight of a polyisocyanate compound and 350 to 450 parts by weight of a polycaprolactone polyol having an OH value of 50 mgKOH / g to 70 mgKOH / g A foamable composition for a polyurethane foam.

In one embodiment, the polyisocyanate compound may be an aromatic diisocyanate.

In one embodiment, the aromatic diisocyanate may be 1,5-naphthalene diisocyanate.

In one embodiment, the polycaprolactone polyol may be a polycaprolactone diol or a polycaprolactone triol.

According to another aspect of the present invention, there is provided a polyisocyanate composition comprising 100 parts by weight of a polyisocyanate compound, 300 parts by weight of a polyalkylene adipate having an OH value of 30 mgKOH / g to 50 mgKOH / g, And 400 parts by weight of a polyurethane foam.

In one embodiment, the polyisocyanate compound may be an aromatic diisocyanate.

In one embodiment, the aromatic diisocyanate may be 1,5-naphthalene diisocyanate.

In one embodiment, the polyalkylene adipate may be poly (1,4-butylene adipate) or poly (1,4-butylene ethylene adipate).

In order to achieve the above object, another aspect of the present invention provides a foamable composition for a polyurethane foam, which comprises foaming and heating in the presence of a mixture comprising a catalyst, a foaming agent, a chain extender, a foam stabilizer, And the polyurethane foam is produced.

In one embodiment, the polyurethane foam may have a glass transition temperature (Tg) of from -40 占 폚 to -30 占 폚.

Further, in order to achieve the above object, another aspect of the present invention provides a jounce bumper including the polyurethane foam.

According to one aspect of the present invention, by specifying the kind of polyol which is one component of the foamable composition for a polyurethane foam, by controlling the OH value of the polyol and the molecular weight of the polyol that can be calculated from the OH value, It is possible to improve not only the mechanical properties of the polyurethane foam prepared by foaming and heating the foaming foamable composition but also the cold resistance and moisture absorption resistance.

Further, the jounce bumper including the polyurethane foam is excellent in moisture absorption resistance, and can be applied directly to a vehicle without a separate protective cover, which is economically advantageous.

It should be understood that the effects of the present invention are not limited to the effects described above, but include all effects that can be deduced from the description of the invention or the composition of the invention set forth in the claims.

1 is a graphical representation of the relationship between glass transition temperature (Tg) and tan delta of a polyurethane foam according to an embodiment of the present invention and a comparative example.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements, not excluding other elements unless specifically stated otherwise.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

A1. Foamable composition for polyurethane foam

The foamable composition for a polyurethane foam according to one aspect of the present invention comprises 100 parts by weight of a polyisocyanate compound and 350 to 450 parts by weight of a polycaprolactone polyol having an OH value of 50 mgKOH / g to 70 mgKOH / g .

The foamable composition for a polyurethane foam may be a polyurethane prepolymer produced by reacting a polyisocyanate compound with a polyol.

As used herein, the term "prepolymer" refers to a polymer having a relatively low degree of polymerization, in which the polymerization reaction is terminated in the middle stage to facilitate molding of the final polymer. The synthesis route through such a prepolymer is advantageous in that a part of the reaction heat is already generated in the synthesis of the prepolymer to reduce the exothermic effect of the substantial polymer synthesis.

As the polyisocyanate compound, an aromatic diisocyanate may be used so that the prepared polyurethane prepolymer can cause an additional crosslinking reaction. The aromatic diisocyanate is superior in physical properties and processability to aliphatic diisocyanates.

The aromatic diisocyanate may be one selected from the group consisting of diphenylmethane diisocyanate, toluene diisocyanate, paraphenyl diisocyanate, 1,5-naphthalene diisocyanate, and mixtures of two or more thereof, 1,5-naphthalene diisocyanate, but is not limited thereto.

On the other hand, the polycaprolactone polyol may be polycaprolactone diol or polycaprolactone triol, and may preferably be polycaprolactone diol, but is not limited thereto.

If the content of the polycaprolactone polyol relative to 100 parts by weight of the polyisocyanate compound is less than 350 parts by weight, mechanical properties such as hardness and tensile strength may be deteriorated. If the content is more than 450 parts by weight, the cold resistance and moisture absorption resistance may be deteriorated .

The OH value of the polycaprolactone polyol may be 50 mgKOH / g to 70 mgKOH / g, and preferably 55 mgKOH / g to 65 mgKOH / g. When the OH value of the polycaprolactone polyol is out of the above range, it is difficult to control the molecular weight of the polycaprolactone polyol, specifically, the number average molecular weight (Mn) to the required range (3,000 or more).

A2. Foamable composition for polyurethane foam

The foamable composition for polyurethane foam according to another aspect of the present invention comprises 100 parts by weight of a polyisocyanate compound and 300 to 400 parts by weight of a polyalkylene adipate having an OH value of 30 mgKOH / g to 50 mgKOH / g .

The polyisocyanate compound is the same as that described above in connection with "A1 foamable composition for polyurethane foam ".

On the other hand, the polyalkylene adipate may be poly (1,4-butylene adipate) or poly (1,4-butylene ethylene adipate), preferably poly (1,4- Adipate).

If the content of the polyalkylene adipate is less than 300 parts by weight based on 100 parts by weight of the polyisocyanate compound, mechanical properties such as hardness and tensile strength may be deteriorated. If the content is more than 400 parts by weight, the cold resistance and moisture absorption resistance have.

The OH value of the polyalkylene adipate may be from 30 mgKOH / g to 50 mgKOH / g, and preferably from 35 mgKOH / g to 40 mgKOH / g. When the OH value of the polyalkylene adipate, specifically, poly (1,4-butylene ethylene adipate) is out of the above range, the molecular weight of the poly (1,4-butylene ethylene adipate) It is difficult to control the average molecular weight (Mn) to the required range (3,000 or more).

B. Polyurethane foam

The polyurethane foam according to another aspect of the present invention can be produced by foaming and heating the foamable composition for polyurethane foam in the presence of a mixture comprising a catalyst, a foaming agent, a chain extender, a foam stabilizer, and an antioxidant.

The foaming composition for polyurethane foam is prepared by mixing 350 parts by weight to 450 parts by weight of a polycaprolactone polyol having OH value of 50 mgKOH / g to 70 mgKOH / g, or OH value (OH value) of 100 parts by weight of a polyisocyanate compound, And 300 to 400 parts by weight of a polyalkylene adipate having a hydroxyl value of 30 mgKOH / g to 50 mgKOH / g, and the polyisocyanate compound, polycaprolactone polyol, and polyalkylene adipate are as described above.

The foaming step of the foaming composition for polyurethane foam for producing the polyurethane foam may be carried out in the presence of a mixture comprising a catalyst, a foaming agent, a chain extender, a foaming agent, and an antioxidant.

The catalyst may be a high activity catalyst in order to prevent the degradation of the reactivity of the polyisocyanate compound during foaming of the foamable composition. The highly active catalyst may be an organic based metal catalyst, preferably an organic tin catalyst or an organic based lead catalyst mixed with a diazabicycloalkene catalyst (DBU), for example 1,5-diazabicyclo 5,4,0) -undecyne-7, but is not limited thereto.

The blowing agent may be one selected from the group consisting of water, hydrogen fluoride (HCFC), cyclopentane, methylene chloride, and a mixture of two or more thereof.

The chain extender is a material introduced to improve the molding stability and reactivity of the polyurethane foam and the shrinkage due to the promotion of the curing property and increase the amount of the polyisocyanate compound to be used according to the use of the low molecular weight chain extender.

The chain extender may be selected from the group consisting of 1,4-butanediol, hydroquinone-bis-hydroxyethyl ether, 1,4-cyclohexanedimethanol, trimethylolpropane, ethylenediamine, Aminopropane, 1,4-diaminobutane, 2,3-diaminobutane, 1,5-diaminopentane, 1,6-hexamethylenediamine, 1,4-cyclohexanediamine, and mixtures of two or more thereof And may be an aliphatic diol such as 1,4-butanediol, hydroquinone-bis-hydroxyethyl ether, 1,4-cyclohexanedimethanol, trimethylolpropane, But is not limited thereto.

The foam stabilizer is a substance introduced to control the cell uniformity and size of the polyurethane foam, and may preferably be a silicone foam stabilizer.

The antioxidant is a substance introduced to prevent discoloration of the polyurethane foam, and may be a phenol-based antioxidant. The phenol-based antioxidant may be a 2-equivalent phenol-based antioxidant having two phenolic groups in one molecule, and may be a benzene propanonic acid, 3,5-bis (1,1-dimethylethyl) (3-t-butyl (3-tert-butyl) -4-hydroxyphenyl) propionate, triethylenecol- -4-hydroxy-5-methylphenyl) propionate, and mixtures of two or more thereof, but is not limited thereto. The phenolic antioxidant may be used singly or in combination with a phosphorus-based or sioester-based antioxidant, which is a secondary antioxidant.

In addition, the mixture may further comprise at least one additive component selected from the group consisting of ultraviolet absorbers, ultraviolet stabilizers, and hydrolysis stabilizers.

Meanwhile, the polyurethane foam may have a glass transition temperature (Tg) of -40 ° C to -30 ° C. If the glass transition temperature of the polyurethane foam is less than -40 캜, the elasticity may deteriorate and the impact absorbability may be deteriorated. When the glass transition temperature is higher than -30 캜, it is difficult to realize cold resistance required in a cryogenic environment.

C. Zauns  The jounce bumper

A jounce bumper according to another aspect of the present invention may include the polyurethane foam.

A bumper bumper (also referred to as a bump stop, rebound bumper, end-of-travel bumper, strike-out bumper, suspension bumper, or compression bumper) And is a consumable part that plays a role of absorbing and mitigating the impact between the vehicle and the metal spring.

Suitable materials for the muffle bumper should be resilient, i. E. Be able to withstand impact without excessive permanent demoulding or rupture, and have good stretch life.

Since the porcelain bumper is manufactured by casting the foamable composition for polyurethane foam in a mold, the porcelain bumper may be made of the polyurethane foam.

Since the polyurethane foam has excellent mechanical and dynamic properties, the ride comfort of the vehicle equipped with the ZOUNS bumper can be improved as well as the life time, cold resistance and moisture absorption of the ZOON bumper including the same.

In addition, although the conventional Zooness bumper is insufficiently hygroscopic, it is mounted on the vehicle in a form in which a separate protective cover is placed on the vehicle. However, since the Zoonus bumper is highly hygroscopic, It is advantageous.

Hereinafter, embodiments of the present invention will be described in detail.

Example  One

100 parts by weight of 1,5-naphthalene diisocyanate in a nitrogen atmosphere was heated to 125 DEG C in a stirring flask and defoamed under vacuum for 30 minutes. Then, 408 parts by weight of polycaprolactone diol having an OH value of 56 mgKOH / Gt; NCO < / RTI > to prepare a polyurethane prepolymer of 4.5% NCO.

100 parts by weight of the prepared polyurethane prepolymer was deaerated at 80 to 100 ° C under vacuum while stirring until the bubbles were removed, and 15 parts by weight of a resin mixture containing polyol, blowing agent, catalyst, And at a speed of 3000 rpm to 5000 rpm for 10 seconds to 15 seconds, followed by foaming in a mold heated to 110 DEG C and heating for 24 hours to prepare a polyurethane foam test piece.

Example  2

100 parts by weight of 1,5-naphthalene diisocyanate in a nitrogen atmosphere was heated to 125 DEG C in a stirring flask and defoamed under vacuum for 30 minutes. Thereafter, a poly (1,4-butylene Ethylene adipate) and 360 parts by weight of a polyurethane prepolymer of 4.5% NCO were prepared by stirring for 1 hour.

100 parts by weight of the prepared polyurethane prepolymer was deaerated at 80 to 100 ° C under vacuum while stirring until the bubbles were removed, and 25 parts by weight of a resin mixture containing a polyol, a foaming agent, a catalyst, a foaming agent and an additive heated to 40 ° C And at a speed of 3000 rpm to 5000 rpm for 10 seconds to 15 seconds, followed by foaming in a mold heated to 110 DEG C and heating for 24 hours to prepare a polyurethane foam test piece.

Comparative Example  One

100 parts by weight of 1,5-naphthalene diisocyanate in a nitrogen atmosphere was heated to 125 DEG C in a stirring flask and defoamed under vacuum for 30 minutes. Then, 408 parts by weight of polyethylene adipate having an OH value of 56 mgKOH / g heated to 70 DEG C and 408 parts by weight of 1 hour To prepare a polyurethane prepolymer having 4.5% NCO.

100 parts by weight of the prepared polyurethane prepolymer was deaerated at 80 to 100 ° C under vacuum while stirring until the bubbles were removed, and 15 parts by weight of a resin mixture containing polyol, blowing agent, catalyst, And at a speed of 3000 rpm to 5000 rpm for 10 seconds to 15 seconds, followed by foaming in a mold heated to 110 DEG C and heating for 24 hours to prepare a polyurethane foam test piece.

Comparative Example  2

100 parts by weight of 1,5-naphthalene diisocyanate in a nitrogen atmosphere was heated to 125 DEG C in a stirring flask and defoamed under vacuum for 30 minutes. Thereafter, a poly (1,4-butyleneethylene Adipate) and 408 parts by weight of a polyurethane prepolymer of 4.5% NCO were prepared by stirring for 1 hour.

100 parts by weight of the prepared polyurethane prepolymer was deaerated at 80 to 100 ° C under vacuum while stirring until the bubbles were removed, and 15 parts by weight of a resin mixture containing polyol, blowing agent, catalyst, And at a speed of 3000 rpm to 5000 rpm for 10 seconds to 15 seconds, followed by foaming in a mold heated to 110 DEG C and heating for 24 hours to prepare a polyurethane foam test piece.

The composition, content and properties of the polyurethane prepolymer according to Examples 1 to 2 and Comparative Examples 1 to 2 are shown in Table 1 below.

Polyisocyanate Polyol OH
(mgKOH / g) Kinds Weight portion Kinds Weight portion Example 1 1,5-naphthalene diisocyanate 100 Polycaprolactone diol 408 56 Example 2 Poly (1,4-butylene ethylene adipate) 360 37.4 Comparative Example 1 Polyethylene adipate 408 56 Comparative Example 2 Poly (1,4-butylene ethylene adipate) 408 56

Experimental Example

The mechanical and dynamic properties of the polyurethane foam specimens prepared according to Examples 1 to 2 and Comparative Examples 1 and 2 were measured according to the following test methods and the results are shown in Table 2 and FIG.

- Hardness: durometer hardness, ASTM D2240-05

- Tensile strength: ASTM D412-06a

- Moisture absorption rate: ASTM D3575-14

- Tanδ: ASTM D5992

- 500,000 repetitive compression ratios: twice or more per second with a force of 4.9 kN, 500,000 repetitions,

- Hydrolysis change rate: Measurement of change in initial tensile property after storage at 80 ° C, 95% relative humidity, 610 hours

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Weight (g) 55 55 55 55 Density (kg / m ³ ) 500 500 500 500 Hardness (shore A) 58 57 53 54 Tensile Strength (MPa) 6.39 5.05 5.53 5.21 Elongation (%) 570 530 520 530 Moisture absorption rate (%) 3.9 4.5 9.3 8.8 Tg (占 폚) -35 -38 -21 -25 Tanδ (@ Tg) 0.63 0.72 0.73 0.73 Durability (cycles) 500,000 500,000 500,000 500,000 500,000 times repeated compression rate (%) 5 4.5 4.2 4.3 Hydrolysis change rate (? Tb,%) 15 8.7 - -

First, comparing the mechanical and dynamic properties of the polyurethane foam specimen based on the type of polyol from Example 1 and Comparative Example 1, it was found that when the polycaprolactone diol was used, the hardness and the tensile strength Are improved or improved, and the moisture absorptive rate is improved, so that it can be seen that it has suitability for a high humidity environment. 1, it was confirmed that the glass transition temperature (Tg) of Example 1 was lower than that of Comparative Example 1 by 14 占 폚 and had a cold resistance suitable for a cryogenic environment of (-35 占 폚) -30 占 폚 or lower.

On the other hand, when comparing the physical properties and the mechanical and dynamic properties of polyurethane foam specimens based on the OH of the polyol (which is interpreted as including the number average molecular weight that can be calculated therefrom) through Example 2 and Comparative Example 2, (Number average molecular weight: 3,000) poly (1,4-butylene ethylene adipate) having a K value of 37.4 mg KOH / g was used as the poly (1,4-butylene ethylene adipate) The moisture absorptive rate is improved as compared with the case of using the water-in-oil emulsions and the water-insoluble emulsions. 1, it was confirmed that the glass transition temperature (Tg) of Example 2 was lower than that of Comparative Example 2 by 13 占 폚 and had cold resistance suitable for a cryogenic environment of about -40 占 폚.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

Claims (7)

100 parts by weight of a polyisocyanate compound and 350 to 450 parts by weight of a polycaprolactone polyol having an OH value in a range of 50 mgKOH / g to 70 mgKOH / g were mixed with a diazabicycloalkene And having an internal moisture absorption rate of 3.9% or less and a glass transition temperature of -30 占 폚 or lower, wherein the polyurethane foam is produced by foaming and heating in the presence of a catalyst and a silicone foam stabilizer.
The method according to claim 1,
Wherein the polyisocyanate compound is an aromatic diisocyanate.
3. The method of claim 2,
Wherein the aromatic diisocyanate is 1,5-naphthalene diisocyanate.
The method according to claim 1,
Wherein the polycaprolactone polyol is a polycaprolactone diol or a polycaprolactone triol.
The method according to claim 1,
Characterized in that said foaming and heating is carried out in the presence of a mixture comprising a catalyst, a foaming agent, a chain extender, a foaming agent, and an antioxidant.
The method according to claim 1,
Wherein the polyurethane foam has a glass transition temperature (Tg) of from -40 占 폚 to -30 占 폚.
A jounce bumper comprising a polyurethane foam according to any one of claims 1 to 6.

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