KR100682398B1 - Polyurethane foam having shock absorption and resilience and the method for preparing thereof - Google Patents

Abstract

The present invention relates to a polyurethane foam having excellent shock absorbency and restoring force and a method for producing the same. More specifically, the polyurethane foam of the present invention uses an organometallic catalyst such as bismuth carboxylate, zirconium carboxylate, and the like to produce a fine and uniform cell structure while maintaining a high density of 0.2 g / cm 3 or more. It shows shock absorbency and restoring force.

Polyurethane foam * Shock absorbing * Resilience * Organometallic catalyst * Bismuth carboxylate * Zirconium carboxylate

Description

Polyurethane foam having excellent shock absorption and resilience and manufacturing method thereof

The present invention relates to a polyurethane foam having excellent shock absorbency and restoring force and a method for producing the same. More specifically, the polyurethane foam of the present invention uses an organometallic catalyst such as bismuth carboxylate, zirconium carboxylate, and the like to produce a fine and uniform cell structure while maintaining a high density of 0.2 g / cm 3 or more. It shows shock absorbency and restoring force.

In general, polyurethane foam is widely used for electronic devices such as computers, communications, sports and medical, and cushions and dustproof materials for automobiles because it is easy to manufacture and mass-produced into a product having various density ranges.

Resilience is important for producing a polyurethane foam having excellent shock absorption in the polyurethane foam. This depends on how quickly the shock is absorbed and mitigated when the impact is applied to the polyurethane foam, the slower recovery rate against the impact of the polyurethane foam, the better the absorption. In order to exhibit such characteristics, the lower the resilience of the polyurethane foam (resilience) is 5% or less, the better, and the recovery rate is also slowly recovered and maintained for more than 3 seconds to have excellent shock absorption.

However, when the polyurethane foam is used for various purposes, the polyurethane foam must maintain a certain strength in order to exhibit proper characteristics, and in order to maintain this strength, the crosslinking density of the polyurethane foam must be increased. However, since the crosslinking density and impact absorbency are inversely related, it is necessary to find the optimal point of these two elements.

Therefore, the present inventors have studied to prepare a polyurethane foam excellent in shock absorption while maintaining a certain strength, when using the organometallic compound-based catalyst as a catalyst, the cell formation time is kept long, the cell is fine and uniformly organized It has been found that a polyurethane foam having excellent shock absorbency and resilience can be produced, and completed the present invention.

Accordingly, it is an object of the present invention to provide a polyurethane foam having excellent shock absorption and restoring force.

Another object of the present invention is to provide a method for producing the polyurethane foam.

In order to achieve the above object, the polyurethane foam of the present invention is prepared by adding a filler, a catalyst, a crosslinking agent, a surfactant, and the like to a polyol component having an average molecular weight of 200 to 8000, and then adding an isocyanate compound and stirring to react. It is prepared as, the catalyst is characterized in that using an organometallic compound-based catalyst.

Hereinafter, the present invention will be described in more detail.

The polyol component used in the production of the polyurethane foam of the present invention includes polyester polyols, polyether polyols and the like. Specifically, the polyester-based polyol is composed of dicarboxylic acid and diol, the dicarboxylic acid as succinic acid, glutaric acid, adipic acid, pimelic acid, subberic acid, azeline acid, sebacic acid, phthalic acid, terephthalic acid , Isophthalic acid, maleic acid, fumaric acid, itaconic acid, tetrabromophthalic acid, trimellitic acid or ester derivatives thereof, acid anhydrides thereof and the like, and these may be used alone or in combination of two or more thereof. In addition, as the diol constituting the polyester-based polyol, ethylene glycol, propylene glycol, butanediol, pentanediol, 1,6-hexanediol, 1,8-octanediol, neopentyl glycol, trimethylolpropane, glycerin, pentaerythrate Lithol, Quinitol, Diethylene Glycol, Triethylene Glycol, Tetraethylene Glycol, Polyethylene Glycol, Polyfluoroethylene Glycol, Diglycerin, Dextrose, Sorbitol, etc., may be used alone or in combination of two or more thereof. .

In addition, examples of the polyether polyols include blocks or random alkaline oxide adducts such as alcohols and amines. Specifically, diols of polyoxyethylene and polyoxypropylene, triols and polyols, polyoxytetramethylene glycol and mixtures thereof and the like.

Examples of the compound having two or more active hydrogens in the compound used for preparing the polyether polyol include ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, butylene glycol, and neopentyl glycol. , 1,4-butanediol, 1,6-hexanediol, cyclohexanedimethanol, glycerin, trimethylolpropane, pentaerythritol, 1,2,6-hexanetriol, 1,2,4-butanetriol, tri Ethylol ethane, diglycerin, dextrose, sucrose, bisphenol A, ethylenediamine, modified substances thereof, and the like, and these may be used alone or in combination. In addition, the alkylene oxide includes ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, styrene oxide and the like.

In the present invention, the polyol component maintains an appropriate viscosity and improves workability, and an average molecular weight of 200 to 8000, preferably 1000 to 5000, is preferable from the viewpoint of maintaining the strength of the polyurethane foam.

In the polyol component, 40 to 80% by weight of a polyester-based polyol having 2 functional groups and an average molecular weight of 1000 to 5000, and 20 to 60% by weight of a polyester polyol having a functional group of 3 and an average molecular weight of 1000 to 5000 It is preferable to use one or two or more of the polyol components containing at least in view of the viscosity at the time of work and the physical properties of the desired foam molded body.

On the other hand, as an isocyanate compound used for manufacture of the polyurethane foam of this invention, the aromatic type, alicyclic type, aliphatic polyisocyanate which has 2 or more isocyanate groups, the mixture thereof, the modified polyisocyanate obtained by modifying this, etc. are mentioned. . Specific examples thereof include ethylene diisocyanate, toluene diisocyanate, tolylene diisocyanate, methylene diphenyl diisocyanate, tetramethyl xylene diisocyanate, naphthalene diisocyanate, xylene diisocyanate, polymethylene polyphenylene isocyanate, hydrogenated methylene diphenyl diisocyanate, Hydrogenated tolylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate and mixtures thereof or modified substances thereof. Examples of the modified product include prepolymer-modified products, nurate-modified products, urea-modified products, carbodiimide-modified products, arophanate-modified products, and biuret-modified products which are reaction products of polyisocyanates and polyols.

The isocyanate component has a molecular weight of 300 to 500, 30 to 70% by weight of a polymeric methylene diphenyl diisocyanate having an isocyanate content of 25 to 50%, and a modified methylene diphenyl diisocyanate having a isocyanate content of 25 to 50% of 70 to 30 It is preferable to use one or two or more isocyanates containing% by weight.

On the other hand, as the catalyst used in the production of the polyurethane foam of the present invention, an organometallic compound catalyst is used. Specific examples thereof include organometallic compounds except mercury and lead, and organometallic compounds such as dibutyl tin dilaurate, first tin oleate, cobalt naphthenate, bismuth compounds, and zirconium compounds. Particularly, it is preferable to use bismuth carboxylate, which is a bismuth-based compound, and zirconium carboxylate, which is a zirconium-based compound, and the carboxylate portion of the bismuth carboxylate and zirconium carboxylate is saturated or composed of 2 to 30 carbon atoms. Is composed of unsaturated hydrocarbyl substituents, and possible substituents include alkyl groups such as methyl, ethyl, propyl, isopropyl, octyl, neopentyl and neodecyl; Cycloalkyl group; Aryl groups such as phenyl and naphthyl; Aralkyl group; Alkylaryl groups such as tolyl; and the like. In addition, bismuth carboxylate and zirconium carboxylate are composed of a salt with a carboxylic acid having 2 to 30 carbon atoms, and specifically, a carboxylic acid having 8 to 12 carbon atoms, versatinic acid, octophosphoric acid, neodecanoic acid, 2- Ethylhexanophosphoric acid, propionic acid and the like and mixtures thereof are also possible. The catalyst may be used alone or in combination of two or more thereof, and is used in an amount of 0.1 to 5.0 parts by weight based on 100 parts by weight of the polyol component. At this time, the organometallic catalyst is preferably used in the range of 0.1 to 2.0 parts by weight of bismuth catalyst and 0.2 to 2.0 parts by weight of zirconium catalyst in terms of the proper reaction rate and pot life of the polyurethane and the physical properties of the foam to be achieved. .

On the other hand, the surfactant used in the production of the polyurethane foam of the present invention is an anionic interface such as a silicone-based surfactant having a polydimethylsiloxane and polyoxyalkylene chain, fatty acid salt, sulfuric acid ester salt, phosphate ester salt, sulfonate Active agents and the like. The surfactant is used in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the polyol component.

The crosslinking agent used in the production of the polyurethane foam of the present invention includes a low molecular weight compound having two or more active hydrogen-containing groups capable of reacting with hydroxyl groups, primary amino groups, secondary amino groups, and other isocyanate groups. Specific examples of the crosslinking agent are not particularly limited, but ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, glycerin, trimethylol propane and triethanol Polyamines such as amines and alkylene oxide adducts of bisphenol A, polyamines such as diethyltoluenediamine, chlorodiaminobenzene, ethylenediamine, 1,6-hexanediamine, and the like. The said crosslinking agent can be used individually or in mixture of 2 or more types.

On the other hand, the filler used in the production of the polyurethane foam of the present invention includes a particulate filler, a layer filler, and a fibrous filler. Specific examples include particulate fillers such as calcium carbonate, barium sulfate, silica, clay, talc, aluminum hydroxide, melamine; Layer fillers such as mica, wollastonite, and aluminum flakes; And fibrous fillers such as various glass fibers, carbon fibers, alumina fibers and potassium titanate. The filler increases the hardness of the foam, improves thermal stability, and improves elastic modulus, which is effective for energy absorption.

Moreover, in order to make a color appear at the time of manufacture of the polyurethane foam of this invention, you may use colored pigments and dyes, such as titanium dioxide and carbon black.

The polyurethane foam of the present invention can be produced by mixing, stirring and foaming an isocyanate compound in a polyol mixed solution prepared by mixing and stirring a polyol component, a catalyst, a blowing agent, a filler, an additive, and the like in advance. More specifically, the polyol solution is mixed and agitated using a tank or the like, and the temperature is usually adjusted to 20 to 45 ° C., followed by isocyanate compound and air using a foaming machine such as an automatic mixing injection foaming machine or an automatic mixing injection foaming machine. And by injecting the inert gas is prepared by the foaming method by the Proth (Froth) method. At this time, it is preferable to adjust the ratio of a polyol component and an isocyanate compound so that an isocyanate index may be 50-110.

The density of the obtained molded article is adjusted to be 0.2 to 0.8 g / cm 3 in view of the improvement of the compression characteristics of the polyurethane foam in consideration of use as a cushioning material and a dustproof material, wherein the molded article density can be adjusted by adjusting the blowing agent and the catalyst. , The obtained molded body is subjected to heat treatment at a temperature of 60 ~ 200 ℃, heat treatment to the molded body by the excellent effect that the tensile strength and tear strength of the molded body is improved and the compression characteristics are further improved, the polyaddition reaction Effectively promotes and promotes the high molecular weight of polyurethane foam. At this time, the temperature of the heat treatment is 60 ~ 200 ℃, preferably 80 ~ 180 ℃ from the viewpoint of preventing the molded body from thermal deformation.

However, excessive heat treatment causes discoloration (yellowing) or thermal deformation of the polyurethane foam, so that the polyurethane foam is not discolored or thermally deformed in consideration of suppressing the occurrence of the problem and improving workability (productivity). It is preferable to heat-treat at the time which accelerates molecular weight and the temperature of heat-treatment.

Polyurethane foam of the present invention obtained by the above manufacturing method maintains a density of 0.2 g / cm 3 or more, the cell structure is fine (average 100 microns) and uniformly organized, the resilience is less than 5% excellent energy absorption It has a characteristic of excellent shock absorption.

The polyurethane foam of the present invention can be preferably used for cushioning and dustproof materials for electronic devices such as computers, communications, sports and medical, and automobiles.

Hereinafter, although an Example and a test example are given and this invention is demonstrated in detail, this invention is not limited only to these examples.

In the following Examples and Comparative Examples, the content is parts by weight, hereinafter referred to as 'parts'.

The measuring method used below is as follows.

Density : Tested by the method of ASTM D3574-01, the density of the polyurethane foam prepared in the following examples and comparative examples was prepared in the range of 0.4 ± 0.05g / ㎠. This is to compare the test results under the same density condition to increase the accuracy of the evaluation.

Pot life : Measure the time until the viscosity of the stirred solution reaches 12,000 cps (No. 6 spindle, 20 rpm) or higher than the temperature of the mixed solution at 48 ° C or higher with a Brookfield viscometer. In this case, the longer the pot life, the more excellent the productivity, and about 15 minutes or more is good.

Resilience : Tested by the method of ASTM D2632-92, the lower the better the shock absorption.

Recovery rate : After pressing the polyurethane foam with a force of 5kgf, measure the time it takes to recover.

[Examples 1-4 and Comparative Examples 1-4]

As a polyol composition, 35 parts of diols of molecular weight 3000, 21 parts of triols of molecular weight 2000, 7 parts of triols of molecular weight 3000, 4 parts of diethylene glycol, and 3 parts of 2,4-butanediol were mixed. 11 parts of aluminum trihydrate, 1 part of carbon black, 0.4 parts of silicon surfactant (DC-5125, Air Products), a bismuth catalyst (BiCAT 8, Shepherd Chemical) and a zirconium catalyst ( BiCAT Z, Shepherd Chemical) was added to the content in Table 1 and stirred. 18 parts of isocyanate compounds (Polymeric MDI) were added thereto, followed by stirring with a high speed stirrer to prepare polyurethane foam. Next, the pot life, the restoring force and the recovery rate of the obtained polyurethane foam were measured and shown in Table 1 below.

Measurement results of pot life, recovery force and recovery rate according to bismuth and zirconium input Bismuth (part) Zirconium (part) Pot life (minutes) dynamic stability(%) Recovery speed Example One 0.10 0.30 29 5 3.0 2 0.15 0.20 19 5 3.3 3 0.15 0.30 38 3 3.7 4 0.20 0.30 25 4 3.1 Comparative example One 0.10 0.00 6 55 0.2 2 0.10 0.10 9 41 0.9 3 0.15 0.10 10 20 2.0 4 0.20 0.10 10 10 1.1

As can be seen in Table 1 above, by adjusting the range of the catalyst used in the case of the embodiment according to the present invention according to the reaction rate, pot life, the desired foam properties of the polyurethane, restoring force, recovery rate, etc. It was confirmed that this excellent polyurethane foam can be produced.

[Example 5 and Comparative Examples 5-6]

Except for mixing the polyol component in the method of Examples 1 to 4 and Comparative Examples 1 to 4 20 parts of diol having a molecular weight of 3000, 43 parts of triol having a molecular weight of 3000, 4 parts of diethylene glycol, 3 parts of 2,4-butanediol And it manufactured by the same method as the said Examples 1-4 and Comparative Examples 1-4. Next, the pot life, the restoring force and the recovery rate of the obtained polyurethane foam were measured and shown in Table 2 below.

Measurement results of pot life, recovery force and recovery rate according to bismuth and zirconium input Bismuth (part) Zirconium (part) Pot life (minutes) dynamic stability(%) Recovery speed Example 5 0.15 0.30 39 3 3.7 Comparative example 5 0.10 0.00 6 49 0.2 6 0.10 0.10 10 37 0.5

As described above, the polyurethane foam according to the present invention is excellent in the restoring force and the recovery speed in the density region of 0.2 g / cm 3 or more by using an organometallic compound-based catalyst at the time of manufacture, and excellent in shock absorption, such as computers, communication It can be used as cushions and dustproof materials for electronic devices, sports and medical, and automobiles.

Claims (5)

(1) adding and stirring a filler, a catalyst, a crosslinking agent, a surfactant, and a blowing agent to the polyol component having an average molecular weight of 200 to 8000; And (2) adding an isocyanate compound to the solution prepared in (1) and stirring the reaction; In the manufacturing method of the polyurethane foam consisting of, The catalyst is an organometallic compound catalyst composed of bismuth carboxylate and zirconium carboxylate, The blowing agent is introduced into the gaseous state as air or inert gas, The density of the polyurethane foam is a method of producing a polyurethane foam, characterized in that produced in 0.2 ~ 0.8 g / ㎠. delete The method of claim 1, wherein the polyol component is selected from the group consisting of polyester-based polyols and polyether-based polyols. The method of claim 1, wherein the organometallic compound-based catalyst is prepared by using a polyurethane foam, characterized in that 0.1 to 2.0 parts by weight of bismuth carboxylate and 0.2 to 2.0 parts by weight of zirconium carboxylate are used in combination with 100 parts by weight of the polyol component. Way. Polyurethane foam, characterized in that produced by the first method.