CN1121091A - Integral skin polyurethane foam, its preparation method and its use - Google Patents

Abstract

The invention discloses a method for preparing integral skin polyurethane foam by using a carbon dioxide foaming system, which comprises using boric acid and/or ester thereof or a mixture of the boric acid and/or ester thereof and organic carboxylic acid and/or ester thereof as a foaming agent, and the integral skin polyurethane foam prepared by the method has low free foaming density, good moldability and no foaming phenomenon.

Description

Integral skin polyurethane foam, its preparation method and its use

The present invention relates to continuous skin polyurethane foam, its preparation method and its use. Integral skin polyurethane foam is used in automotive parts such as steering wheels and spoilers as well as furniture such as armrests and chair legs.

The integral skin polyurethane foam is characterized in that the skin layer and the foam layer are formed simultaneously by pouring the active ingredient into the mold, foaming, curing and subsequent demolding. Integral skin polyurethane foam has excellent elasticity and abrasion resistance, so it is widely used as a cushioning material in the fields of automobiles and furniture. In order to form the skin layer, low-boiling organic compounds need to be used as blowing agents, among which trichlorofluoromethane (code name CFC-11) is particularly commonly used.

However, so-called trifluoromethane-based compounds represented by trichlorofluoromethane (hereinafter abbreviated as CFC compounds) have been considered to destroy the ozone layer in the atmosphere in recent years. Therefore, laws restricting CFC compounds have been successively enacted in the world.

As a second-generation substitute of CFC compounds, hydrochlorofluorocarbons (hereinafter abbreviated as HCFCs) having a low ozone destruction coefficient (hereinafter referred to as ODP) have been proposed.

Available HCFCs include, for example, chlorodifluoromethane (code name HCFC-22), 2,2-dichloro-1,1,1-trifluoroethane (code name HCFC-123), 1,1-dichloro-1- Fluoroethane (code name HCFC-141b) and 1-chloro-1,1-difluoroethane (code name HCFC-142b).

Furthermore, as a third-generation substitute, hydrofluorocarbons (hereinafter abbreviated as HFCs) having an ODP of zero have been proposed. Examples of HFCs include 1,1,1,2-tetrafluoroethane (codename HFC-134a).

However, it is still considered that these HCEC and HFC blowing agents cannot be used absolutely safely from the viewpoint of protecting the earth's atmosphere.

That is, although HCFC has a low ODP, it is still a class of compounds that can destroy the ozone layer. Although the ODP of HFC is zero, there is no need to worry about the destruction of the ozone layer, but it has a strong greenhouse effect, and the greenhouse effect coefficient (hereinafter referred to as GWP) is high, so it cannot be used with confidence.

As mentioned above, the so-called HCFC substitutes are only a short-term response to HCFC regulations. Therefore, it is desired to develop a permanent and completely non-chlorofluorocarbon foaming technology, the so-called carbon dioxide gas foaming technology.

In the usual polyurethane foam field, carbon dioxide gas blowing technology using water as a blowing agent has been independently developed in the fields of flexible foam, semi-rigid foam and rigid foam. In the prior art, so-called water-blown foams have been mass-produced.

On the other hand, in the field of integral skin polyurethane foams, the use of low boiling blowing agents is advantageous in view of the mechanism of skin formation. Using water as a blowing agent has many problems, so it has not been practically used.

That is, "water blowing technology" refers to a technology of blowing foamed plastics with carbon dioxide gas generated by the reaction of water and isocyanate groups in raw materials. Thereby, when adopting the water foaming technology that does not use CFC to carry out the process that uses CFC-11 (boiling point 27.5) as blowing agent conventionally to prepare the continuous skin polyurethane foam plastics, produce carbon dioxide gas on the mold surface, that is to say, in The polyurethane foam surface forms a foam layer without forming a skin layer. As a result, the continuous skin structure cannot be formed. As a countermeasure against this phenomenon, Japanese Patent Laid-Open No. Hei 3-32811 proposes to maintain the mold temperature at 15-40° C., and to use a temperature-sensitive catalyst strongly dependent on temperature in the reaction of water and isocyanate. On the other hand, it has been proposed to use a catalyst with low temperature dependence for the reaction between isocyanate and hydroxyl-containing compound. Japanese Patent Laid-Open No. Hei 3-33120 discloses examples of temperature-sensitive catalysts. However, even high-density skin formation using a temperature-sensitive catalyst delays curing of the polyurethane surface due to a decrease in mold surface temperature, and impairs the appearance and quality of the resulting foam.

In addition, the high closed cell content and the resulting low foaming damping factor tend to cause foaming and cracking of the polyurethane foam at the demoulding stage, and as a result, temperature-sensitive catalysts have the disadvantage of requiring a longer demoulding time.

In addition, the water blowing technique causes another problem in that the urea bond formed by the reaction of water and isocyanate constitutes a very hard segment, resulting in increased hardness of the resulting polyurethane foam and impairing the tactile feel of the resulting foam.

On the other hand, a reaction mechanism capable of similarly generating carbon dioxide by the reaction of isocyanate but not forming a urea bond has been considered. For example, Japanese Patent Laid-Open No. Hei 3-24108 discloses a method in which isocyanate groups are reacted with each other to form carbodiimide groups and carbon dioxide released from the reaction is used as a blowing agent. Japanese Patent Laid-Open No. Hei 3-152111 proposes to react a cyclic carbonate with an isocyanate to form an oxazolidinone group and to use the carbon dioxide produced by the reaction as a blowing agent.

However, these methods have problems such as difficulty in adjusting the reaction rate, use of expensive catalysts, and the need to use chlorofluorocarbons in combination in order to provide a sufficient degree of foaming. Therefore, the problems of carbon dioxide foaming technology cannot be solved essentially by these technologies.

As mentioned above, the method of producing integral skin polyurethane foams by using carbon dioxide gas blowing technology instead of chlorofluorocarbons or substitutes HCFC and HFC has not been realized, although it is a problem that those skilled in the art are eager to solve. The reason for this is that this technology has the following disadvantages compared with the use of chlorofluorocarbons or substitutes HCFC and HFC:

(1) The need to prolong the demoulding time impairs productivity.

(2) Thick-walled molded products are prone to blistering and perforation during the demoulding stage.

(3) Polyurethane foam expands during the demoulding stage, and it is easy to retain the imprint of the mold surface on the product surface.

(4) Foamed plastics are hard and have poor touch.

(5) The cortex is thin.

Countermeasures have been found to overcome the disadvantages of (1)-(5) above, respectively. However, no carbon dioxide gas foaming technology capable of simultaneously solving all of the problems (1)-(5) and capable of being used in an actual production line has been developed.

Japanese Patent Laid-Open No. Hei 2-199136 proposes the use of organic carboxylic acids as blowing agents. However, in this method, the use of an organic carboxylic acid as a blowing agent creates a problem of stability over time in the isocyanate active ingredient. As a solution thereof, Japanese Patent Laid-Open No. Hei 3-153721 proposes to use an organic carboxylate of a nitrogen base having at least one N—H bond as a blowing agent. However, this method is difficult to control the reaction rate of the whole system, because the nitrogen base with N-H bond reacts too fast with isocyanate.

The object of the present invention is to provide a method for preparing continuous-skin polyurethane foams by using carbon dioxide as a blowing agent.

We have carried out in-depth research on the use of carbon dioxide gas as a blowing agent for continuous skin polyurethane foam, and found that the continuous skin polyurethane foam made of boric acid or its esters as a blowing agent can eliminate all the above-mentioned shortcomings, provide productivity and A molded article that is excellent in moldability and has a good touch. The present invention has thus been accomplished.

That is to say, content of the present invention is:

(1) Integral skin polyurethane foam with a molded product density of 0.3-0.8g/ ^cm3 , which is obtained by pouring a reaction mixture of aromatic polyisocyanate, high molecular weight isocyanate reactive compound, blowing agent and other additives into a mold Yes, including the use of boric acid and/or its esters as blowing agents.

(2) The integral skin polyurethane foam of (1) above, wherein the blowing agent is a mixture of boric acid and/or its ester and an organic carboxylic acid and/or its ester.

(3) A method of preparing an integral skin polyurethane foam with a molded product density of 0.3-0.8 g/ ^cm3 by pouring a reaction mixture of an aromatic polyisocyanate, a high-molecular-weight isocyanate-reactive compound, a blowing agent, and other additives into a mold , including the use of boric acid and/or its esters as blowing agents.

(4) The method for producing the integral skin polyurethane foam of the above (3), wherein the blowing agent is a mixture of boric acid and/or ester thereof and organic carboxylic acid and/or ester thereof.

(5) The production method of the integral skin polyurethane foam of (1) or (2) above, wherein the production method is a reaction injection molding method.

(6) Automobile steering wheels, interior decoration materials or furniture manufactured by the preparation method of (3), (4) or (5) above.

The present invention uses:

(1) boric acid and/or its esters, or

(2) The mixture of boric acid and/or its ester and organic carboxylic acid and/or its ester is used as blowing agent.

In processes using water as a blowing agent, the moldability of the reaction composition comprising an aromatic polyisocyanate, a high molecular weight isocyanate-reactive compound, a blowing agent, and other additives is generally poor. As a result, the amount of water used as a blowing agent must be increased in order to improve the potting ability. However, increasing the amount of water has the disadvantage that excessive expansion of polyurethane foam tends to leave mold surface imprints on the product surface and cause blistering and perforation during the demoulding stage.

Prolonging the demoulding time can effectively overcome the above disadvantages, but it will reduce the productivity of foamed plastics, and because water reacts with isocyanate to form urea bonds, the foamed plastics are hard and have poor touch.

The reaction composition comprising the blowing agent of the present invention and aromatic polyisocyanate, high-molecular weight isocyanate reactive compound and other additives has excellent potting ability and mold release ability compared with the composition using water as the blowing agent. Therefore, the integral skin polyurethane foam of the present invention which does not leave mold surface marks on the product surface and does not generate air bubbles and perforations at the molding stage can be produced with high productivity. Foams with excellent haptics are also obtained, since the carbon dioxide produced by the reaction of the isocyanate with the blowing agent forms the foam and rarely forms urea linkages.

As described above, in the present invention, water is not used as a blowing agent at all or only a small amount is used as a co-blowing agent, and therefore, the present invention can overcome the disadvantages of the method of using water as a blowing agent.

Furthermore, the foaming agent used in the present invention does not corrode metals, as opposed to organic carboxylic acid foaming agents typified by formic acid, which corrode metals.

The continuous-skin polyurethane foam of the present invention can be prepared by pouring the polyurethane raw material mixture into a mold by reaction injection molding. During the molding process, the expansion of the foam is suppressed in the portion that contacts the inner surface of the mold, forming an elastomeric skin. Thus, the skin layer and the foam layer are formed simultaneously to form an integral structure. The continuous skin polyurethane foam obtained by the present invention has excellent elasticity and touch, and is suitable for use as automotive interior parts such as steering wheel, horn button, squeeze pad, instrument panel, control box and glove box cover, headrest, armrest and air spoilers; and furniture such as seats, legs and arms of chairs.

The present invention will be explained below.

Known aromatic polyisocyanates are useful in the present invention. Preferred isocyanates are diphenylmethane diisocyanate, polymethylene polyphenyl diisocyanate, isocyanate group-terminated prepolymers obtained by reacting the above polyisocyanates with active hydrogen-containing compounds, and urethonimine-modified of polyisocyanates.

A particularly preferred aromatic polyisocyanate is a polymethylene polyphenylisocyanate having a high content of three or more benzene rings, more specifically, a content of three or more benzene rings of not less than 60 % (weight) of polymethylene polyphenylisocyanate. Furthermore, preference is also given to using a mixture thereof with a prepolymer of urethane-modified diphenylmethane diisocyanate or a urethaneimine-modified liquid diphenylmethane diisocyanate.

High molecular weight isocyanate-reactive compounds useful in the present invention are polyols obtained by mixing propylene oxide alone or propylene oxide and ethylene oxide with active hydrogen-containing compounds such as water, propylene glycol, glycerol, trimethylolpropane, pentaerythritol , sorbitol, sucrose, triethanolamine, ethylenediamine, toluenediamine, diaminodiphenylmethane or a mixture of the above compounds for polyaddition, so that the resulting average functionality is 2-4. The hydroxyl value of the polyol is 24-55 mg KOH/g, the oxyethylene content is 10-25% (weight) of the polyol, and the terminal primary hydroxyl content is 70-95% (mol).

Also preferred are polymeric polyols (trademark) obtained by grafting ethylenically unsaturated monomers such as styrene, acrylonitrile or methyl methacrylate on the above-mentioned polyols.

When the ethylene oxide content is less than 10% by weight, the terminal primary hydroxyl group content is also reduced to 70% by mole and the productivity is deteriorated due to decreased activity.

On the other hand, when the ethylene oxide content exceeds 25% by weight or the terminal primary hydroxyl content exceeds 95% by mole, the reaction is too fast, resulting in foaming in the thick-walled portion of the resulting foam or occurrence of cracks in the thickness of the foam. Dents appear on the changed part, which is disadvantageous.

Blowing agents usable according to the invention are boric acids and/or esters thereof, or mixtures of these compounds with organic carboxylic acids and/or esters thereof.

Boric acid and/or esters thereof include, for example, boric acid, methyl borate, ethyl borate, dimethyl borate, diethyl borate, trimethyl borate, triethyl borate, and other borate esters. These compounds can be used alone or in combination.

The organic carboxylic acids and their esters include, for example, formic acid, acetic acid, propionic acid, lauric acid, stearic acid, oleic acid, 2-ethylhexanoic acid, oxalic acid, itaconic acid, adipic acid, maleic acid, acetyl Dicarboxylic acid, acetone dicarboxylic acid, malonic acid, succinic acid, tartaric acid, diglycolic acid, cyclopropanediglycolic acid, glutaconic acid, tartronic acid, aconic acid, citric acid, trimellitic acid, Nitrilotriacetic acid, pyromellitic acid and mellitic hexacarboxylic acid, and methyl malonate, ethyl malonate, butyl malonate, methyl maleate, ethyl maleate, butyl maleate, Methyl malate, ethyl malate, butyl malate, methyl succinate, ethyl succinate, butyl succinate, methyl adipate, ethyl adipate, butyl adipate, methyl tartrate esters, ethyl and butyl tartrate, methyl benzoate, ethyl benzoate, methyl phthalate, ethyl phthalate. These organic carboxylic acids can be used alone or in combination.

The blowing agent is used in an amount of not more than 10 parts by weight, preferably 0.5-2.5 parts by weight, per 100 parts by weight of the high molecular weight isocyanate reactive compound.

The blowing agent of the present invention can also be used in combination with conventional blowing agents. Examples of useful conventional blowing agents include water and hydrocarbons such as pentane. Hydrocarbons have a relatively low boiling point, and must not contain chlorine and fluorine from the viewpoint of the present invention as a countermeasure against the disadvantages of chlorofluorocarbons.

Various known catalysts for urethane production can be used in the present invention. Examples of catalysts include organometallic catalysts such as dibutyltin dilaurate and dimethyltin dilaurate, or tertiary amines such as triethylenediamine, N,N,N',N'-tetramethylhexane-1, 6-diamine, N, N, N', N'', N'''-pentamethyldiethylenetriamine, N, N'-di(N", N"-dimethyl-3- Aminopropyl)-N', N'-dimethylethylenediamine, N-methyl-N'-(2-dimethylamino) ethylpiperazine, N-ethylmorpholine, 1- Methylimidazole, 1,2-dimethylimidazole, 3-(dimethylamino)propylimidazole, dimethylaminoethanol, bis(2-dimethylaminoethyl)ether and 1-isobutyl- 2-Methylimidazole. A particularly preferred tertiary amine is 1-isobutyl-2-methylimidazole. These catalysts can be used alone or in combination.

The tertiary amine can also be added to the reaction system in the form of a preformed salt with boric acid or its ester or organic carboxylic acid or its ester. In addition, when the salt is solid, the salt may be added to the reaction system in the form of a solution dissolved in a crosslinking agent such as diethylene glycol.

The following crosslinking agents, surfactants and other additives are used as necessary in the present invention.

The present invention can also be used with known crosslinking agents commonly used in the preparation of integral skin polyurethane foams. Examples of crosslinking agents include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol and other polyalkylene glycols; diethylene glycol, dipropylene glycol, triethylene glycol and others Polyoxyalkylene glycols; diethanolamines, triethanolamines, and other alkanolamines; and alkylene oxides added to polyols such as trimethylolpropylene and glycerol with the equivalent of 1-2 moles of active hydrogen groups low molecular weight polyols, and amines such as ethylenediamine and 2,4-/2,6-toluenediamine isomer mixtures. These crosslinking agents can be used alone or in combination. A particularly preferred crosslinking agent is diethylene glycol.

Useful surfactants include, for example, Nippon Unicar's L-5430 and L-3601; Toray Silicone's SRX-274C, SF-2961 and SF-2962; and other organosilicone surfactants.

Other possible additives are colorants, antioxidants, flame retardants, viscosity reducers and internal mold release agents. Known additives can be used.

Both open mold and reaction injection molding can be used for molding integral skin polyurethane foam. Particular preference is given to reaction injection molding.

The present invention will be further described in detail by way of Examples and Comparative Examples below.

In these Examples and Comparative Examples, the following aromatic polyisocyanates, polyols, crosslinking agents, catalysts and blowing agents were used.

Aromatic polyisocyanate (A): a polyisocyanate with an NCO content of 27.5%, which is obtained by modifying a mixture of diphenylmethane diisocyanate and polymethylene polyphenylisocyanate (70:30) urethane with dipropylene glycol of. Among them, the NCO content of polymethylene polyphenyl isocyanate is 31.5% and contains 70% (weight) of triphenyl ring or polyphenyl ring compound.

Aromatic polyisocyanate (B): a polyisocyanate with an NCO content of 29.2%, which is a mixture (70:30) of carbodiimide-modified diphenylmethane diisocyanate and polymethylene polyphenylisocyanate. Among them, the NCO content of polymethylene polyphenyl isocyanate is 31.5% and contains 70% (weight) of triphenyl ring or polyphenyl ring compound.

Polyol (A): a polyol having an average functionality of 3, an average molecular weight of 6000 and an ethylene oxide content of 15% by weight.

Crosslinking agent (A): diethylene glycol.

Catalyst (A): 33% solution of triethylenediamine in dipropylene glycol.

Catalyst (B): 1-isobutyl-2-methylimidazole.

Catalyst (C): bis(2-dimethylaminoethyl) ether.

Catalyst (D): dibutyltin dilaurate.

Blowing agent (A): boric acid.

Blowing agent (B): 2-ethylhexanoic acid.

Blowing agent (C): methyl borate.

Blowing agent (D): trichlorofluoromethane (CFC-11).

Blowing agent (E): water. Example 1

Prepared by mixing 100 parts of polyol (A), 10 parts of crosslinking agent (A), 0.7 parts of catalyst (B), 0.72 parts of catalyst (C), 0.01 part of catalyst (D) and 0.58 parts of blowing agent (A) Polyol composition. The above-mentioned aromatic polyisocyanate (B) and the above-mentioned polyol component were mixed at a ratio of NCO/OH of 1.05. Perform free foaming and mold foaming.

The time from the mixing of the polyisocyanate and polyol components to the start of foam rise (cream period) and the time to the end of foam rise (rise time) in free foaming were measured. The density of the resulting foam (free foam density) was also determined.

In mold foaming, a mold with dimensions 400×100×10 mm was preheated to 40°C.

Pour the urethane raw material mixture into the mold, close the mold cover, and leave the mold at room temperature for 3 minutes. Then the molded product was taken out from the mold, and the surface hardness at the time of demolding was measured with a Asker-Type-C hardness tester. The final hardness was measured after the product was left to stand for 24 hours after demoulding. There is no foaming phenomenon, and the mold filling ability (the ability to conform to the inner surface configuration of the mold) is strong, as shown in Table 1. Example 2

The same procedure as in Example 1 was carried out except that 0.2 part of blowing agent (E) was added. There is no foaming phenomenon, and the mold filling ability is strong, as shown in Table 1. Example 3

The same procedure as in Example 1 was carried out, except that blowing agent (A) was replaced with 1.0 parts of blowing agent, and catalysts (B) and (C) were replaced with 1.0 parts of the corresponding catalysts, respectively. There is no foaming phenomenon, and the mold filling ability is strong, as shown in Table 1. Example 4

Carry out the same process as Example 1, except that foaming agent (A) will be replaced with 0.58 parts of foaming agent (C), no foaming phenomenon occurs, and the filling ability is strong, as shown in Table 1. Example 5

Carry out the process identical with embodiment 1, difference is blowing agent (A) will replace with 0.3 part of blowing agent (A), and 0.47 part of catalyzer (B) and (C) will replace with 0.53 part of corresponding catalyzer respectively . There is no foaming phenomenon, and the mold filling ability is strong, as shown in Table 1. Example 6

Carry out the process identical with embodiment 1, difference is blowing agent (A) will replace with 0.47 part of blowing agent (B), and 0.3 part of blowing agent (B) and catalyzer (C) will use 0.53 part corresponding respectively catalyst instead. There is no foaming phenomenon, and the mold filling ability is strong, as shown in Table 1. Comparative example 1

Carry out the process identical with embodiment 1, difference is blowing agent (A) and catalyzer (B), (C) and (D) will replace with 16 parts of blowing agent (D), 1.5 parts of catalyzer (A) And 0.01 parts of catalyst (D) and aromatic polyisocyanate (B) are to be replaced by aromatic polyisocyanate (A). Free foam density decreases. There is no foaming phenomenon, and the mold filling ability is strong, as shown in Table 1. Comparative example 2

Carry out the process identical with embodiment 1, difference is blowing agent (A) and catalyzer (B), (C) and (D) will use 0.3 part of blowing agent (E) and 1.0 part of catalyzer (B), 1.0 part of catalyst (C) and 0.01 part of catalyst (D) were substituted. Free foam density decreases. There is no foaming phenomenon, and the mold filling ability is poor, as shown in Table 1. Comparative example 3

The same procedure as in Comparative Example 2 was carried out except that the foaming agent (E) was replaced with 0.6 parts of the foaming agent. The free foam density decreased and blistering occurred in the foam, the results were poor, as shown in Table 1.

Table 1 comparative example Example 1 2 3 1 2 3 4 5 6 Polyol (A) 100 100 100 100 100 100 100 100 100 Cross-linking agent (A) 10 10 10 10 10 10 10 10 10 Catalyst (A)(B)(C)(D) 1.50.01 1.01.00.01 1.01.00.01 0.70.720.01 0.70.720.01 1.01.00.01 0.70.720.01 0.70.530.01 0.70.530.01 Blowing agent (A)(B)(C)(D)(E) 16 0.3 0.6 0.58 0.580.2 1.0 0.58 0.30.47 0.470.3 Aromatic polyisocyanate equivalent ratio (NCO/OH) (A)1.05 (B)1.05 (B)1.05 (B)1.05 (B)1.05 (B)1.05 (B)1.05 (B)1.05 (B)1.05 Free foaming milky period (seconds) rising time (seconds) density (g/cm ³ ) 14300.10 13260.29 13300.20 16320.24 16340.20 16330.23 15300.22 16290.23 16330.22 Molding (10mm sheet) Density (g/cm ³ ) Hardness Final when demoulding 0.604575 0.596877 0.607081 0.637383 0.627078 0.627380 0.626778 0.606776 0.616977 Demoulding time (minutes) 3 3 3 3 3 3 3 3 3 bubbling ○ ○ x ○ ○ ○ ○ ○ ○ Molding ability ○ x ○ ○ ○ ○ ○ ○ ○ Note) Blistering: ○No Blistering×Blistering

Filling capacity: ○ good × poor

Claims (6)

1. (1) moulding product density is 0.3-0.8g/cm ³Integral-skin polyurethane foam, it is to pour in the mould by the reaction mixture with aromatic polyisocyanate, high molecular isocyanate activity compound, whipping agent and other additive to obtain, and comprises using boric acid and/or its ester to make whipping agent.
2. (2) integral-skin polyurethane foam of claim (1), wherein whipping agent is the mixture of boric acid and/or its ester and organic carboxyl acid and/or its ester.
3. (3) pour into by reaction mixture that to prepare moulding product density in the mould be 0.3-0.8g/cm with aromatic polyisocyanate, high molecular isocyanate activity compound, whipping agent and other additive ³The method of integral-skin polyurethane foam, comprise and use boric acid and/or its ester to make whipping agent.
4. (4) method of the integral-skin polyurethane foam of preparation claim (3), wherein whipping agent is the mixture of boric acid and/or its ester and organic carboxyl acid and/or its ester.
5. (5) preparation method of the integral-skin polyurethane foam of claim (3) or (4), wherein this preparation method is the reaction injection molding(RIM) method.
6. (6) vehicle steering, indoor hardware fitting or the furniture of preparation method's manufacturing of usefulness claim (3), (4) or (5).