KR20150024464A - Functional polyurethane foam - Google Patents

Abstract

The present invention relates to functional polyurethane foam and, more specifically, to polyurethane foam containing a reactant of a resin premix and an isocyanate component, wherein the resin premix includes a polyol component and a foaming agent, and the isocyanate component, based on the total isocyanate component weight, includes 4-70 wt% of monomeric methylene diphenyl diisocyanate (MMDI); 5-70 wt% of carbodiimide methylene diphenyl diisocyanate (CMDI); and 10-80 wt% of polymeric methylene diphenyl diisocyanate (PMDI). The same can be applied to a vehicle sheet and the like to absorb a considerable part of vibration generated during driving so that vibration transfer rate can be minimized.

Description

Functional polyurethane foam

The present invention relates to a polyurethane foam, and more particularly, to a functional polyurethane foam which can be applied to an automobile seat or the like, and absorbs a substantial portion of vibration generated during operation to minimize vibration transmission rate.

With the development of the automobile industry, the time for staying in the automobile has increased, and the importance of the ride quality of the automobile has been recently increasing. Accordingly, the demand for the comfort of the automobile is also increasing.

Generally, a polyurethane foam is produced by a reaction between a resin premix and an isocyanate. The resin premix is a stock solution containing a polyol, a crosslinking agent, a catalyst, a foaming agent, and other additives. The isocyanate reacts with the resin premix to form a urethane bond It is the main raw material of polyurethane reaction to form.

Such a polyurethane foam is widely known for various compositions. For example, Korean Patent Publication No. 10-0883514 discloses a polyurethane foam composition having excellent durability and hydrolysis resistance. However, polyurethane foam, which is conventionally used, Is applied to an automobile seat, it does not affect during a short-time operation. However, when a driver rides for a long time, the vibration of the vehicle is continuously transmitted to cause inconvenience.

It is an object of the present invention to solve the above problems by applying modified methylene diphenyl diisocyanate (MDI) and polyols having a molecular weight of about 3000 to 7000 without using toluene diisocyanate (TDI) And an object of the present invention is to provide a functional polyurethane foam having improved vibration absorbing ability.

In order to achieve the above object, the functional polyurethane foam of the present invention is a polyurethane foam containing a reaction product of a resin premix and an isocyanate component, wherein the resin premix comprises a polyol component and a foaming agent, and the isocyanate component is a total isocyanate 4 to 70% by weight of monomeric methylenediphenyl diisocyanate (MMDI) relative to the component weight; 5 to 70% by weight of carbodiimide methylene diphenyl diisocyanate (CMDI); And 10 to 80% by weight of polymeric methylene diphenyl diisocyanate (PMDI); And a control unit.

The polyol component preferably has OH-V of 10 to 60 mgKOH / g, OH-V of 20 to 40 mgKOH / g, 20 to 50 mgKOH / g, 20 to 60 mgKOH / mg KOH / g, and the polyol component preferably comprises 40 to 75% by weight of a polyol having an OH-V of 20 to 40 mg KOH / g, based on the total weight of the polyol component; 10 to 40% by weight of a polyol having 20 to 50 mg KOH / g; And 3 to 40% by weight of a polyol having 10 to 30 mg KOH / g.

Meanwhile, the resin premix may further include a curable catalyst, a foamable catalyst, a crosslinking agent, a chain extender, and a foam stabilizer.

The blowing agent may be used in an amount of from 0.1 to 2 parts by weight, the blowing agent may be used in an amount of from 1 to 5 parts by weight, and the blowing agent may be used in an amount of from 1 to 5 parts by weight based on 100 parts by weight of the polyol component. , 0.1 to 5 parts by weight of the crosslinking agent, 1 to 10 parts by weight of a chain extender having OH-V of 1500 to 2500 mgKOH / g, and 0.1 to 5 parts by weight of a chain extender 0.1 to 500 kg of OH-V To 1 part by weight, and the foaming agent is preferably 0.1 to 3 parts by weight.

By using a functional polyurethane foam satisfying such a composition, an automotive sheet can be produced by a conventionally known method.

The functional polyurethane foam according to the present invention having the above-described structure is advantageous in that it has excellent vibration absorption ability compared to polyurethane foam.

In addition, when the automobile seat is manufactured using the functional polyurethane foam, a substantial portion of the vibration generated in the road can be absorbed to improve the comfort.

In addition, since only methylene diphenyl diisocyanate (MDI) is used as a curing agent except for toluene diisocyanate (TDI) used in conventional polyurethane foam, stress reduction of the sheet foam is minimized, Can be increased for a long time.

1 is a time-stress graph of a sheet foam made with TDI and a sheet foam made with MDI according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

In one aspect, the present invention relates to a functional polyurethane foam having greatly improved vibration absorption capability.

Generally, a polyurethane foam to be applied to an automobile seat or the like is a flexible foam obtained by reacting a urethane foam composition containing a polyol, an isocyanate, a catalyst, a crosslinking agent, a foam stabilizer and a foaming agent, wherein the polyol has a hydroxyl functional group (- OH), and isocyanate has an isocyanate functional group (-NCO) in the molecule.

The polyol is classified into monol, diol, and triol according to the number of functional groups in the molecule. The isocyanate may be monoisocyanate, diisocyanate or the like depending on the number of functional groups per molecule. And the like.

Typically, a urethane bond is formed by combining an alcohol having an active hydroxyl group and an isocyanate having an isocyanate group, as shown in Formula 1 below.

[Chemical Formula 1]

R-NCO + R'-OH -> [R-NH-COO-R '

Such polyurethane foam is widely used as an automotive component material due to its excellent properties such as low density, high mechanical properties and high heat resistance, and is widely used as a low density and excellent durability And is widely used particularly in automobile seats.

The present invention relates to a polyurethane foam containing a reaction product of a resin premix and an isocyanate component, wherein the resin premix comprises a polyol component and a blowing agent, wherein the isocyanate component is a monomeric methylenediphenyl diisocyanate (MMDI) 4 to 70% by weight; 5 to 70% by weight of carbodiimide methylene diphenyl diisocyanate (CMDI); And 10 to 80% by weight of polymeric methylene diphenyl diisocyanate (PMDI); , And the isocyanate component is used in an amount of 40 to 70 parts by weight based on 100 parts by weight of the polyol component.

Hereinafter, the present invention will be described in detail with reference to Table 1 below.

Component Furtherance Remarks The first polyol 40.0 to 75.0 wt% Glycerol,
OH-V = 20 to 40 mg KOH / g The second polyol 10.0 to 40.0 wt% Glycerol,
OH-V = 20 to 50 mg KOH / g The third polyol 5.0 to 30.0 wt% Glycerol,
OH-V = 20 to 60 mg KOH / g Fourth polyol 3.0 to 40.0 wt% Glycerol,
OH-V = 10 to 30 mg KOH / g,
Solid 30 ~ 50% The first chain extender 1.0 to 10.0 parts by weight Diethanolamine,
OH-V = 1500 to 2500 mg KOH / g The second chain extender 0.1 to 1.0 part by weight 1,4-butanediol,
OH-V = 500 to 1500 mg KOH / g Cross-linking agent 0.1 to 5.0 parts by weight Triethanolamine,
OH-V = 1500 to 2500 mg KOH / g Water (foaming agent) 1.0 to 5.0 parts by weight OH-V = 6000 to 7000 mg KOH / g Curable catalyst
(Dabco 33LV)
(Air Products, USA) 0.1 to 3.0 parts by weight 33% triethylenediamine
67% dipropylene glycol Effervescent catalyst
(Dabco BL-11)
(Air Products, USA) 0.1 to 2.0 parts by weight 70% Bis (2-dimethylaminoethl) ethem
30% dipropylene glycol Foaming agent
(Niax L-3002)
(Momentive, USA) 0.1 to 3.0 parts by weight Polyether-modified polysiloxane
(Polyether modified polysiloxane) Sum The weight portion is based on 100 parts by weight of the polyol component.

(1) The polyol component

In order to produce a polyurethane foam, a polyol component is used in an amount of at least 60 wt% or more, and a variety of polyols are used in accordance with the characteristics and production conditions of the product without using only a single polyol. The polyol is formed by chemical bonding of an initiator with propylene oxide (PO) and ethylene oxide (EO).

The use of initiators such as glycerol, glycerin, trimethylol propane, triethanolamine, 1,2,6-hexyllithiol, phosphoric acid, and triisopropanolamine produces triols with three hydroxyl groups (-OH). In this case, the OH-V is determined depending on the degree of capping of PO / EO, which is related to the molecular weight of the chemically bonded polyol. The polyol component of the present invention has OH-V of 10 to 60 mgKOH / g .

Preferably, the polyol component according to the present invention comprises at least one polyol component selected from the group consisting of 20 to 40 mg KOH / g, 20 to 50 mg KOH / g, 20 to 60 mg KOH / g and 10 to 30 mg KOH / g, .

From the viewpoint of the composition, it is preferable that the polyol (first polyol) having OH-V of 20 to 40 mgKOH / g is contained in an amount of 40 to 75% by weight based on the total weight of the polyol component. When it exceeds 75% by weight, the hardness is lowered.

The polyol (second polyol) having an OH-V of 20 to 50 mgKOH / g is preferably contained in an amount of 10 to 40% by weight based on the total weight of the polyol component. When the polyol is less than 10% by weight, The permanent compressive strain rate is lowered.

It is preferable that the polyol (third polyol) having an OH-V of 20 to 60 mgKOH / g is contained in an amount of 5 to 30% by weight based on the total polyol component weight. When the polyol is less than 5% The elasticity and the permanent compressive strain rate are lowered.

It is preferable that the polyol (fourth polyol) having OH-V of 10 to 30 mgKOH / g is contained in an amount of 3 to 40% by weight. When the content is less than 3% by weight, the hardness is excessively low. The comfort is poor.

(2) Isocyanate Component

In general, the isocyanates used in the preparation of polyurethane foams include methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), or a combination thereof, wherein the isocyanate component according to the present invention is a toluene di From 4 to 70% by weight of monomeric methylenediphenyl diisocyanate (MMDI) relative to the total isocyanate component weight without the use of isocyanate; 5 to 70% by weight of carbodiimide methylene diphenyl diisocyanate (CMDI); And 10 to 80% by weight of polymeric methylene diphenyl diisocyanate (PMDI); .

Specifically, the monomeric methylene diphenyl diisocyanate and the carbodiimide methylene diphenyl diisocyanate are preferably 4 to 70% by weight and 5 to 70% by weight, respectively. If the amount is less than the recommended amount, If the recommended amount is exceeded, the foam is not generated due to excessive cell opening and the defect rate is increased.

The polymeric methylene diphenyl diisocyanate (PMDI) is preferably 10 to 80% by weight, and if it is less than 10% by weight, the tensile and tear strengths drop sharply, and when it exceeds 80% by weight, the hardness increases sharply.

In other words, except for the TDI which is generally applied to the seat foam, the maximum supporting force of the driver's body is maximized because the MDI has a polymer structure relatively to TDI to increase the supporting force of the foam, It prevents the sagging phenomenon.

Meanwhile, the resin premix according to the present invention preferably further comprises a curable catalyst, a foamable catalyst, a crosslinking agent, a chain extender, and a foam stabilizer.

(3) a chain extender and a crosslinking agent

Chain extenders and cross-linkers are reactive monomers that are used to enhance intermolecular bonding. Chain extenders serve to extend the main chain. Divalent alcohols or amines are mainly used. Cross-linkers Is used to make the network structure of the mesh or branch structure, and alcohol or amines of trivalent or more are mainly used.

Since the chain extender and the cross-linking agent increase the cross-linking force between molecules, they play an important role in improving general properties such as tensile and tear, and at the same time, improve the hydrolysis resistance and maintain the properties of the product under high temperature and high humidity conditions.

However, if only the required characteristics of the final product are satisfied, the productivity is somewhat lowered due to problems such as closed cells and flowability.

1 to 10 parts by weight of a chain extender (first chain extender) having an OH-V of 1,500 to 2,500 mgKOH / g, and a chain having an OH-V of 500 to 1,500 mgKOH / g based on 100 parts by weight of the polyol component The amount of the extender (second chain extender) is preferably 0.1 to 1 part by weight.

If the amount of the first chain extender is less than 1 part by weight, the tensile and tearing decreases. If the amount of the first chain extender is less than 10 parts by weight, the occurrence of closed cells is excessively decreased, And the flowability is lowered when the amount is more than 1 part by weight.

The amount of the cross-linking agent is preferably 0.1 to 5 parts by weight, and if it is less than 0.1 parts by weight, the effect to be added is insignificant. When the amount is more than 5 parts by weight, the flowability decreases and the percentage of defects increases.

(4) Curable catalysts and foamable catalysts

The curable catalyst and the foamable catalyst serve to lower the activation energy of the isocyanate and polyol reaction. Depending on the degree of use of these two catalysts, it is possible to produce stable products of polyurethane foam.

Typically, the curable catalyst may be triethylenediamine, dimethylpiperidine, etc. The expandable catalyst may be triethylamine, N, N'-dimethylcyclohexylamine or the like, but is not particularly limited. In most production conditions, there is a time for demolding. In order to terminate the production of the product within this limited time range, it is preferable to use the curable catalyst in a maximum of 3 parts by weight and the foamable catalyst in a maximum of 2 parts by weight.

From the viewpoint of the composition, it is preferable that the curable catalyst is 0.1 to 3 parts by weight based on 100 parts by weight of the polyol component and 0.1 to 2 parts by weight of the foamable catalyst. When the amount is less than the recommended amount, If the recommended amount is exceeded, the flowability may be lowered and porosity may be caused.

(5) Foaming agent

The foaming agent is classified into a physical foaming agent and a chemical foaming agent. In the case of the present invention, it is preferable to use a chemical agent. Since the reaction rate, the curing property and the free rise density are determined according to the amount of the blowing agent used, the usage amount is determined according to the production conditions within a maximum of 5 parts by weight. Particularly, it is preferable to use water as a chemical foaming agent applied to an automobile seat.

From the viewpoint of the composition, it is preferable that the foaming agent is 1 to 5 parts by weight based on 100 parts by weight of the polyol component. When the amount is less than 1 part by weight, the foaming ratio is lowered and it is difficult to match the density of the sheet to be etched. The physical properties are lowered due to foaming.

(6) Repelling agent

 Generally, it is preferable to use a silicone agent, for example, a foam stabilizer such as a polyether-modified polysiloxane, and emulsify the surface of the MDI to assist the reaction between the MDI and the polyol, to lower the surface tension, It serves to stabilize fine bubbles.

From the viewpoint of the composition, the foaming agent is preferably 0.1 to 3 parts by weight based on 100 parts by weight of the polyol component. When the amount is less than 0.1 part by weight, urethane foam is not formed. When the amount is more than 3 parts by weight, The productivity is lowered.

The functional polyurethane foam having the above composition can be applied to an automobile seat or the like using a conventionally known process in the art, and it is possible to manufacture an automobile seat with minimized vibration transmission rate and improved comfort.

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these embodiments are merely illustrative of the present invention and that the scope of the present invention is not construed as being limited by these embodiments.

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example 1 Example 2 The first polyol 80 wt% 60 wt% 60 wt% 60 wt% 60 wt% 60 wt% The second polyol - - 20 wt% 20 wt% 20 wt% 20 wt% The third polyol - 20 wt% - - - - Fourth polyol 20 wt% 20 wt% 20 wt% 20 wt% 20 wt% 20 wt% MMDI 70 wt% 70 wt% 80 wt% 15 wt% 20 wt% 30 wt% CMDI - - 15 wt% 80 wt% 40 wt% 30 wt% PMDI - - 5 wt% 5 40 wt% 40 wt% TDI derivative 30 wt% 30 wt% - - - -

In Table 2, the weight percentages of the first polyol to the fourth polyol are based on the total weight of the polyol component, and the weight percentages of the MMDI, CMDI, PMDI, and TDI derivatives are based on the total isocyanate component weight, The isocyanate component was mixed in an amount of 60 parts by weight based on 100 parts by weight.

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example 1 Example 2 Hardness
(kgf / m ³ ) 27 30 31 29 27 30 Hysteresis loss
(%) 29 34 26 23 19 21 The tensile strength
(kgf / cm ² ) 2.1 1.85 2.3 1.9 1.94 2.1 Elongation (%) 120 122 90 105 116 120 Phosphorus strength
(kgf / cm ² ) 0.94 0.72 0.85 0.65 0.72 0.79 Permanent Compression Ratio (%) 3.2 12.5 5.7 8.5 7.7 9.5 Vibration transmission rate 6.5 5.7 5.5 4.5 3.2 3.9 Stress relaxation
(%) 25 23 22 22 21 20

Table 3 is a table for measuring mechanical properties of the polyurethane foam prepared with the composition shown in Table 2 above.

Transmissivity is the value of all vibrations transmitted to the seat during operation divided by the vibrations received by the driver. The lower this value is, the more vibration is absorbed by the seat and the dynamic comfort is improved. In the case of vibration transmission rate, the vibration absorption of the urethane foam was measured by transmitting vibration to the urethane foam by artificially generating vibration through the vibration generator during the operation of the vehicle.

The stress relaxation means that the stress inside the object decreases with time when the quasi-deformation is kept constant for a moment. When the result of stress relaxation is smaller, the seat foam Can be maintained.

As can be seen from the above table, when the MDI alone is used, the vibration transmission rate is lower than that of the conventional TDI derivative. In particular, when the composition according to the present invention is satisfied, the vibration transmission rate is the lowest value of 3.2 to 3.9, The losses were also generally low.

1 is a time-stress graph of a sheet foam made of TDI and a sheet foam made of MDI according to the present invention. As shown in FIG. 1, a sheet foam made of MDI It is possible to confirm that the supporting force for supporting the driver's body is high because the stress is not reduced even when the motor 200 is driven for a relatively long time. This is because the MDI shows a relatively polymer-like structure than the TDI.

Although the present invention has been described in connection with the specific embodiments of the present invention, it is to be understood that the present invention is not limited thereto. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents. Various modifications and variations are possible.

100: sheet foam made with TDI
200: Sheet foam made from MDI

Claims (13)

A polyurethane foam containing a reaction product of a resin premix and an isocyanate component,
Wherein the resin premix comprises a polyol component and a blowing agent,
The isocyanate component comprises 4 to 70% by weight of monomeric methylene diphenyl diisocyanate (MMDI) relative to the total isocyanate component weight;
5 to 70% by weight of carbodiimide methylene diphenyl diisocyanate (CMDI); And
10 to 80% by weight of polymeric methylene diphenyl diisocyanate (PMDI); Functional polyurethane foam.
The method according to claim 1,
Wherein the polyol component has OH-V of 10 to 60 mgKOH / g.
3. The method of claim 2,
Wherein the polyol component is at least one polyol component selected from the group consisting of 20 to 40 mg KOH / g, 20 to 50 mg KOH / g, 20 to 60 mg KOH / g and 10 to 30 mg KOH / g, Polyurethane foam.
The method of claim 3,
The polyol component comprises 40 to 75% by weight of a polyol having an OH-V of 20 to 40 mgKOH / g based on the total weight of the polyol component; 10 to 40% by weight of a polyol having 20 to 50 mg KOH / g; And 3 to 40% by weight of a polyol having 10 to 30 mg KOH / g.
The method according to claim 1,
Wherein the resin premix further comprises a curable catalyst, a foamable catalyst, a crosslinking agent, a chain extender, and a foam stabilizer.
6. The method of claim 5,
Wherein the isocyanate component is 40 to 70 parts by weight based on 100 parts by weight of the polyol component.
6. The method of claim 5,
Wherein the curable catalyst is 0.1 to 3 parts by weight based on 100 parts by weight of the polyol component.
6. The method of claim 5,
Wherein the foaming catalyst is 0.1 to 2 parts by weight based on 100 parts by weight of the polyol component.
The method according to claim 1,
Wherein the foaming agent is 1 to 5 parts by weight based on 100 parts by weight of the polyol component.
6. The method of claim 5,
Wherein the crosslinking agent is 0.1 to 5 parts by weight based on 100 parts by weight of the polyol component.
6. The method of claim 5,
Wherein the chain extender is 1 to 10 parts by weight of a chain extender having an OH-V of 1500 to 2500 mgKOH / g and 0.1 to 10 parts by weight of a chain extender having an OH-V of 500 to 1500 mgKOH / g based on 100 parts by weight of the polyol component. 1 < / RTI > parts by weight of a polyurethane foam.
6. The method of claim 5,
Wherein the foaming agent is 0.1 to 3 parts by weight based on 100 parts by weight of the polyol component.
A sheet for use in an automobile, which is produced by using the functional polyurethane foam of any one of claims 1 to 12.

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