JPH0525888B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for producing polyurethane and a polyol composition. More specifically, the present invention relates to a method for producing polyurethane suitable for producing semi-rigid molded polyurethane foam. [Prior technology] PVC (polyvinyl chloride) skin material or PVC (polyvinyl chloride) skin material is used for automobile interior materials such as crash pads, armrests, head rests, console boxes, knee pads, etc.
Integral foam molded products with PVC/ASB resin skin material and semi-rigid polyurethane foam are often used.
It is well known that a semi-rigid foam is used in which a polyol component mainly consisting of a polyether polyol, a crosslinking agent, a blowing agent, a catalyst, etc. is reacted with an organic polyisocyanate. Polyether polyols are used as polyol components for these applications, and amine polyols such as triethanolamine, ethylenediamine, and aminoethylpiperazine with alkylene oxide attached have also been used because of their high activity. [Problems to be solved by the invention] However, recently there has been a strong demand for higher productivity, but conventional amine-based polyols still have insufficient activity and cannot satisfy these demands. I couldn't do it. Therefore, polyols with even higher activity have been strongly desired. Furthermore, in recent years there has been a strong demand for lighter weight automobiles, improved productivity, softer interior materials, etc., and there is a strong desire to reduce the weight and shorten the curing time of the semi-rigid polyurethane foams used. Such a reduction in foam density and shortening of curing time has become a major drawback in that when the foam is removed from the mold, the foam molded product is deformed due to insufficient initial hardness of the foam. Furthermore, when increasing the amount of catalyst used to shorten the curing time, there was a drawback that the heat discoloration (vinyl stain) of the skin material worsened. [Means for Solving the Problems] The present inventors have solved the following problems: (1) Insufficient initial hardness when the density of polyurethane is lowered and the curing time is shortened, (2) Deterioration of heat discoloration of the skin material, etc. As a result of intensive studies to solve these problems, the present invention has been arrived at. That is, the present invention provides a method for producing polyurethane by reacting a polyisocyanate and an active hydrogen atom-containing compound in the presence of a catalyst, a blowing agent, and other additives if necessary. As general formula (1) (In the formula, R ₁ is an alkyl group having 1 to 4 carbon atoms, A is an alkylene group having 2 to 4 carbon atoms, and R ₂ is an alkyl group having 1 to 4 carbon atoms.
4 alkyl group or (AO) _o H, A' has 2 carbon atoms
~4 alkylene group, m is an integer of 0 to 4, n is 1
is an integer greater than or equal to ) This is a method for producing polyurethane characterized by using the polyol (a) shown below. In general formula (1), examples of the alkyl group having 1 to 4 carbon atoms for R ₁ include methyl, ethyl, propyl and butyl groups. Preferred are methyl and ethyl groups. Examples of the alkylene group having 2 to 4 carbon atoms for A include ethylene, propylene, and 1,2-, 2,3- and 2,3-butylene groups. Preferred are ethylene and propylene groups. Examples of the alkyl group having 1 to 4 carbon atoms for R ₂ include the same groups as for R ₁ . Examples of the alkylene group having 2 to 4 carbon atoms for A' include ethylene, trimethylene, and tetramethylene groups. Preferred are ethylene and trimethylene groups. m is preferably 0-1. Preferably n is 4-100. The polyol (a) includes dimethylaminoethylamine, dimethylaminopropylamine, dimethylaminobutylamine, diethylaminoethylamine, diethylaminopropylamine, dimethylaminobutylamine, methylethylaminoethylamine, methylethylaminopropylamine, methylethylaminobutylamine, dibutylaminoethylamine. , dialkylaminoalkylamines such as dibutylaminopropylamine, N,N-
Alkylene oxides of active hydrogen atom-containing amine compounds such as dialkyl polyalkylene polyamines such as dimethyldiethylenetriamine and N,N-dimethyldipropylenetriamine [ethylene oxide (hereinafter also referred to as EO), propylene oxide (hereinafter also referred to as PO), 1,2-,2,3
- and 1,3-butylene oxide, styrene oxide, epichlorohydrin, etc., and adducts of two or more of these in combination. When two or more alkylene oxides are used, the addition format may be block, random, or a combination thereof. Among these, preferably
PO of the above active hydrogen atom-containing amine compound and
It is a block or random adduct of EO. The polyol (a) preferably has at least 5% by weight of polyoxyethylene chains. 5% by weight of polyoxyethylene chains
If it is less than that, the urethane foam will not be sufficiently cured and will collapse. The number of functional groups in polyol (a) is usually 2 to 4. If the number of functional groups is less than 1, the strength of the foam will be significantly reduced, and if it is more than 4, the foam will shrink significantly. The hydroxyl value of polyol (a) is usually 15-200,
Preferably it is 15-200. If the hydroxyl number of polyol (a) is less than 15, the effects of the present invention cannot be obtained, and if the hydroxyl number exceeds 200, the elongation and tear strength of the foam will decrease. The tertiary nitrogen content of polyol (a) is usually 0.3 to 15
%, preferably 0.5-10%. If the tertiary nitrogen content is less than 0.3%, the effect of the present invention cannot be fully expected because the reactivity decreases, and if it exceeds 15%, the liquid flow within the mold during foaming will be inhibited and it should not be used. hard. A specific example of the polyol (a) is a PO/EO block adduct of dimethylaminoethylamine (EO
Content 10%, molecular weight 3500, hydroxyl value 32.0),
PO/EO block adduct of dimethylaminopropylamine (EO content 18%, molecular weight 4000, hydroxyl number 28.0), PO/EO block adduct of N,N-dimethyldiethylenetriamine (EO content
15%, molecular weight 5000, hydroxyl value 33.0), etc. In the present invention, the following polyethers, crosslinking agents, etc. can be mentioned as active hydrogen atom-containing compounds that can be used if necessary together with the polyol (a). Polyethers are made by adding alkylene oxide to active hydrogen atom-containing compounds [compounds having active hydrogen atom-containing groups such as OH, NH ₂ , NH, and COOH, such as alcohols, phenols, amines, phosphoric acids, and carboxylic acids]. Examples include polyethers (polyether monools and polyether polyols) having one or more hydroxyl groups in the molecule, which are obtained by addition. Active hydrogen atom-containing compounds used in the production of the above polyethers include (1) aliphatic, cycloaliphatic and aromatic, saturated and unsaturated, monohydric and polyhydric alcohols, such as: methanol, ethanol, Monohydric alcohols (2 to 20 carbon atoms) such as n-butanol, octyl alcohol, 2-ethylhexanol, lauryl alcohol, stearyl alcohol, oleyl alcohol, cyclohexanol, and benzyl alcohol; alkylene glycols (2 to 6 carbon atoms) [ethylene Glycol, propylene glycol, 1,4-butanediol, 1,3
-butylene glycol, neopentyl glycol, 1,6-hexanediol, etc.], cyclohexanediol, cyclohexanedimethanol, etc.; glycerin, trimethylolpropane, trimethylolethane, hexanetriol, pentaerythritol, diglycerin, α-methyl Tri- to octahydric alcohols such as glucosides, sorbitol, xylitol, mannitol, glucose, fructose, sucrose; (2) Phenols, such as: phenols, mono- or di-alkyl (1 to 20 carbon atoms) phenols (cresol, dinonylphenol, etc.),
Monovalent phenols such as naphthol; hydroquinone, catechol, resorcinol, pyrogallol, bisphenols (bisphenol A, bisphenolsulfon, bisphenol F, etc.), phenol-formaldehyde condensates (novolak resin, resol resin intermediate) (3) Aliphatic, alicyclic, aromatic and heterocyclic,
Mono- and polyamines, such as; ammonia; mono-, di- and tri-alkanolamines such as ethanol and/or propanolamine; mono- and di-alkyl (1 to 20 carbon atoms) amines, alkylene diamines (carbon Aliphatic amines such as number 2 to 6) (ethylenediamine, hexamethylenediamine, etc.), polyalkylene (carbon number 2 to 6) polyamines (diethylenetriamine, triethylenetetramine, etc.); aniline, phenylenediamine, diaminotoluene, xylylenediamine , methylene dianiline, diethyltolylene diamine, diphenyl ether diamine, and other aromatic amines; isophorone diamine, dicyclohexylmethane diamine, and other cycloaliphatic amines; piperazine, aminoethyl piperazine, and others
-21044; (4) Aliphatic, cycloaliphatic and aromatic, saturated and unsaturated, mono- and polyhydric carboxylic acids, such as: acetic acid, propionic acid, butyric acid, octane; acid,
Monocarboxylic acids (1 to 20 carbon atoms) such as lauric acid, stearic acid, oleic acid, and benzoic acid;
Dicarboxylic acids such as adipic acid and phthalic acid; (5) Phosphoric acids, such as orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, polyphosphoric acid, and phosphorous acid; and acidic esters thereof (dibutylpyrophosphoric acid, etc.); Examples include mixtures of more than one species. Among these, preferred are alcohols, especially divalent to trivalent alcohols. Examples of alkylene oxides added to active hydrogen-containing compounds include EO, PO, 1,2-, 2,3-
and 1,3-butylene oxide, tetrahydrofuran, styrene oxide, epichlorohydrin, etc., and two or more of these (e.g. EO and
PO) combination (random and/or block)
can be mentioned. Preferred are PO, EO and
Combination of PO/EO [random, block, and mixed systems of both (e.g., random, block, and mixed systems of both (e.g., random addition followed by EO
chip). The number of moles of alkylene oxide added is usually 5 to 100, preferably 10 to 100 per active hydrogen atom.
80, particularly preferably 15-50. The molecular weight of these polyethers usually ranges from 500 to
20,000, preferably 1,500 to 10,000, more preferably 3,000 to 8,000. Additionally, a graft polyol may be used as a part of the polyether, such as one with a hydroxyl value of 20 to 40 obtained by polymerizing monomers such as styrene and acrylonitrile in polyol (a) represented by general formula (1). be able to. In the present invention, the amount of polyol (a) used is based on 100 parts by weight of the active hydrogen-containing compound.
is usually 2 to 80 parts, preferably 5 to 50 parts. 2
If the amount is less than 80%, the effect of the present invention will not be sufficiently obtained;
If it is used in excess of 50%, the liquid flowability during foaming of the semi-rigid foam will deteriorate, resulting in adverse effects such as molding defects. Crosslinking agents that can be used in the present invention include ethylene glycol, diethylene glycol, propylene glycol, glycerin, trimethylolpropane, triethanolamine, diethanolamine, and/or their PO adducts, EO adducts, PO/EO blocks. ,and/
or ethylene diamine, propylene diamine,
PO adduct, EO adduct of diethylenetriamine,
Examples include PO/EO blocks and/or random adducts with a hydroxyl value of 200 to 1000. The total hydroxyl value of the active hydrogen-containing compound containing polyol (a) used in the present invention is usually 40.
~200. If the total hydroxyl number is less than 40, the resulting urethane foam will be too soft, and if it exceeds 200, the resulting urethane foam will be too hard.
Difficult to use as a semi-rigid foam. Catalysts that may be used as necessary in the present invention include:
Known amine catalysts and metal catalysts used for foaming urethane foam can be used. For example, triethylamine, triethylenediamine,
N,N,N',N'-tetramethylethylenediamine, tetramethylhexamethylenediamine, tetramethylpropylenediamine, pentamethyldiethylenetriamine, dimethylbenzylamine, N
Examples include amine catalysts such as -methylmorpholine, N-ethylmorpholine and dimethylethanolamine, and metal catalysts such as stannath octoate and dibutyltin dilaurate. The amount used may be the same as that used for foaming general urethane foam. Examples of the blowing agent include water and/or other blowing agents, and examples of the water and/or other blowing agents include trichloromonofluoromethane and methylene chloride in addition to water. The amounts used for these may be those used for foaming general urethane foam. Furthermore, other additives such as flame retardants such as trischloroethyl phosphate, pigments such as carbon black, foam stabilizers, and other auxiliary agents may also be used. As the polyisocyanate used in the present invention,
Polymeric diphenylmethane diisocyanate, mixture of polymeric diphenylmethane diisocyanate and toluene diisocyanate, mixture of polymeric diphenylmethane diisocyanate and pure diphenylmethane diisocyanate, NCO-terminated prepolymer of toluene diisocyanate, pure diphenylmethane Examples include NCO-terminated prepolymers of diisocyanates. The method for producing polyurethane may be the same as conventional methods, and either the one-shot method or the prepolymer method (semi-prepolymer method) can be applied, but the one-shot method is preferred. Further, polyurethane can be used as polyurethane foam, elastomer, etc., but polyurethane foam is preferred. The foaming method is the slab method,
Mold method {Hot mold method, HR (high elasticity)
It can be applied to any of the molding methods, etc. The polyurethane foam may be ultra-soft, soft, or semi-rigid, but semi-rigid foam is preferred. The density of polyurethane foam is usually at least 0.05
g/cm ³ or more. [Examples] Hereinafter, the present invention will be further explained with reference to Examples, but the present invention is not limited thereto. Parts in the examples are parts by weight. Examples 1 to 3, Comparative Examples 1 to 4 Using the foaming formulations shown in Tables 1 and 2, the urethane foam stock solution was injected into the mold to foam the semi-rigid urethane foam, and then the C-hardness when the foam was removed from the mold. And the foam deformation and foam physical properties were measured. (Foaming conditions) Mold shape: 100mm x 200mm x 50mm Material: Iron Mold temperature: 40±2℃ Raw material stirring time: 10 seconds Cure time: 4 minutes at room temperature (Measurement conditions) C-Hardness: Shore C type hardness tester by. Cream time: Time from stirring to foaming Gel time: Time from stirring to when the foam surface begins to pull when touched with a mallet stick Rise time: Time from stirring to completion of foaming (both include 10 seconds of stirring time) Cure properties: Injection Demolding After 4 minutes of demolding, press the form with your finger and visually judge the extent of marks ○ mark (no marks) △ mark (some marks left) × mark (obvious marks left) Vinyl stain ΔE: slush PVC skin with foam at 110℃
Represents the skin color difference after 400hrs aging (raw materials used) Polyol A: propylene oxide/ethylene oxide adduct of propylene glycol,
Ethylene oxide content 25%, molecular weight 4000, hydroxyl number 28.0 Polyol B; propylene oxide/ethylene oxide adduct of dimethylaminopropylamine, ethylene oxide content 18%, molecular weight
4000, hydroxyl number 28.0 Polyol C: propyleoxide/ethylene oxide adduct of aminoethylpiperazine,
Ethylene oxide content 14%, molecular weight 6000, hydroxyl number 28.0 U-CAT1000: Tetramethylhexamethylene diamine DABCO 33LV, manufactured by San-Apro Co., Ltd. Millionate 33% dipropylene glycol solution of triethylene diamine, manufactured by Sankyo Air Products Co., Ltd. MR100: Polymer diamine manufactured by Nippon Polyurethane Co., Ltd. Diphenylmethane diisocyanate

【table】

[Table] [Effects of the invention] The manufacturing method of the present invention solves the problem of insufficient curing (deformation) during demolding and deterioration of heat discoloration of the skin, which are problems when trying to shorten curing time and reduce weight. It is. That is, the following effects are recognized. 1. No shortage of cure (deformation) of the foam was observed after shortening the hardening time. 2 As shown in Example 3, the density of the foam was reduced. 3. Curing time could be shortened without causing deterioration of heat resistance change (vinyl stain) of the epidermis.

Claims (1)

[Claims] 1. A method for producing polyurethane by reacting a polyisocyanate and a compound containing an active hydrogen atom, optionally in the presence of a catalyst, a blowing agent, and other additives, in which the compound containing an active hydrogen atom is reacted. At least as part of general formula (1) (In the formula, R ₁ is an alkyl group having 1 to 4 carbon atoms, A is an alkylene group having 2 to 4 carbon atoms, and R ₂ is an alkyl group having 1 to 4 carbon atoms.
4 alkyl group or (AO) _o H, A' has 2 or more carbon atoms
4 is an alkylene group, m is an integer of 0 to 4, and n is an integer of 1 or more. ) A method for producing polyurethane characterized by using the polyol (a) shown below. 2. The method according to claim 1, wherein the polyurethane is a polyurethane foam having a density of at least 0.05 g/cm ³ or more. 3. The method according to claim 1 or 2, wherein the polyol (a) is a polyether polyol containing at least 5% by weight of polyoxyethylene chains in the polyol (a). 4. The method according to any one of claims 1 to 3, wherein the polyol (a) is a polyether polyol having a hydroxy value of 15 to 200.