JPH03199222A - Urethane composition - Google Patents

Abstract

PURPOSE:To obtain the title composition suitable for semirigid mold urethane foam, shortening curing time, being made into a lightweight material, preventing cure shortage during removal of mold, comprising an active hydrogen-containing compound using specific plural polyols in a specific ratio. CONSTITUTION:The objective composition comprising (A) a polyisocyanate, (B) an active hydrogen-containing compound and optionally (C) a catalyst, (D) a blowing agent and (E) another additive wherein the component B is composed of (i) bifunctional polyol A having 2,000-6,000 molecular weight and (ii) tri- to octafunctional polyol B having 1,000-3,000 OH equivalent molecular weight consisting of 60-95% component (i) and 5-40% component (ii) based on total amounts of the component (i) and the component (ii). The component (i) and the component (ii) preferably contain 5-30wt.% polyoxyethylene chain at the molecular end in the polyols, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to urethane compositions. More specifically, the present invention relates to a urethane composition suitable for producing semi-rigid molded urethane foam.

[Prior Art] Integrated foam molded products made of a skin material such as polyvinyl chloride (PVC) and semi-rigid polyurethane foam are often used for automobile interior materials such as crash pads, armrests, headrests, console boxes, and knee pads (for example, (Japanese Unexamined Patent Publication No. 146909/1983). These utilize semi-rigid foams obtained by reacting organic polyisocyanates with polyol components whose main components are polyether polyols, crosslinking agents, blowing agents, catalysts, etc.

[Problem to be solved by the invention] However, in recent years, there has been a strong demand for lighter automobiles, improved productivity, and softer interior materials. desired. This reduction in foam weight (lower density) and shortening of curing time can reduce problems such as deformation of the foam molded product due to lack of initial 1Tll hardness when removing the foam from the mold, and molding defects due to insufficient liquid flow. However, there was a problem of insufficient meat.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a urethane composition that can reduce the density of the foam, shorten the curing time, and has excellent moldability.

[Means for Solving the Problems] The urethane composition of the present invention is a urethane composition comprising a polyisocyanate, an active hydrogen-containing compound, a catalyst, a blowing agent, and other additives, and the composition comprises a polyisocyanate, an active hydrogen-containing compound, a catalyst, a blowing agent, and other additives. teeth,
Polyol A is difunctional and has a molecular weight of 2000 to 6000, and polyol A is 3 to 8 functional and has an OH equivalent molecular weight of 1000 to 3.
000, polyol A is 60 to 95% based on the total weight of polyol A and polyol B.
, containing 5 to 40% of polyol B.

Examples of polyol A include alkylene oxide adducts of compounds containing two active hydrogens. Compounds containing two active hydrogens include compounds having a hydroxyl group, amine group, and imino group. For example, compounds having a hydroxyl group include ethylene glycol, propylene glycol, 1°2-12,3-11,4- Examples include alcohols such as butylene glycol, and phenols such as resorcinol, catechol, and bisphenol 8. Examples of compounds having an amine group and an imino group include monomethylamine, monoethylamine, N1N=dimethylethylenediamine, and the like. Examples of the alkylene oxide added to the compound containing active hydrogen include ethylene oxide (hereinafter referred to as EO), propylene oxide (hereinafter referred to as PO), 1,2-12,3-1 and 1,3-brene oxide, styrene oxide, Epichlorohydrin, etc., and two or more of these are used in combination.

When two or more alkylene oxides are used, they may be used in a block, random, or combination format. In particular, it is preferable to use blocks or random adducts of EO and PO.

Polyol A usually has a molecular weight of 2000 to 6000.
, preferably 3,000 to 5,000.

If the molecular weight of polyol A is less than 2000, the resulting polyurethane will become too hard, which is not preferable. Moreover, if the molecular weight exceeds 6,000, the viscosity of polyol A becomes too high, which is not preferable.

Polyol A has a polyoxyethylene chain at the end of the molecule, and its content in the molecule is 5 to 30% by weight, preferably 10 to 20% by weight. If the content of polyoxyethylene chains is less than 5% by weight, the reactivity of polyol A becomes low and demolding time cannot be shortened, which is not preferable. Moreover, if it exceeds 30% by weight, the reaction becomes too fast and molding defects tend to occur, which is not preferable.

Examples of polyol B include polyether polyols that are obtained by adding alkylene oxide to a compound containing 3 to 8 active hydrogens and have 3 to 8 hydroxyl groups in the molecule.

As the above-mentioned compound containing 3 to 8 active hydrogens,
Alcohols (1), phenols (2), and amines (3) with active hydrogens such as OH, N-2, and N-position; (1) chain or cyclic aliphatic and aromatic saturated and unsaturated Saturated tri- to octahydric alcohols, such as glycerin, trimethylolpropane, trimethylolethane, hexanetriol, pentaerythritol, diglycerin, α-methylglucoside, sorbitol, xylit, mannitol, glucose, fructose, sucrose;
(2> Phenols, for example, trivalent to octavalent phenols such as phenol-formaldehyde condensates (intermediates of novolac resins and resol resins); (3) Chained or cyclic aliphatic, aromatic, and polyhydric ring polyamines,
For example, alkanolamines such as ammonia, triethanolamine, and tripropateuramine, alkylene diamines (ethylene diamine with 2 to 6 carbon atoms, hexamethylene diamine, etc.), polyalkylenes (with 2 to 6 carbon atoms, etc.),
~6) Polyamines such as aliphatic amines such as diethylenetriamine and triethylenetetramine, aromatic amines such as phenylenediamine, diaminotoluene, xylylenediamine, methylenedialanine, diethyltolylenediamine, and diphenyl ether diamine, isophoronediamine, and dicyclohexylmethanediamine Alicyclic amines such as aminoethylpiperazine and others
Examples include the heterocyclic amines described in No. 044 and mixtures of two or more thereof.

Examples of the alkylene oxide added to the compound containing 3 to 8 active hydrogens include EO, POll, 2-2
．． 3-1 and 1,3-butylene oxide, styrene oxide, epichlorohydrin, etc. and these 2
More than one species can be used in combination. When two or more alkylene oxides are used, the addition format may be block, random, or a combination thereof. Among these, EO, P of compounds containing 3 to 8 active hydrogens
Blocks or random adducts of O are preferred.

The 01-1 equivalent molecular weight of polyol B is 1000 to 30
00 preferably from 1500 to 2500.

The molecular weight of the O mouthpiece is expressed as (molecular weight)/(number of 0 mouthpieces in the molecule). If the OH equivalent molecular weight is less than 1000, the resulting polyurethane will become too hard, which is not preferable. Moreover, if the O equivalent molecular weight exceeds 3000, the viscosity of the polyol becomes too high and it becomes difficult to handle, which is not preferable.

Polyol B has a polyoxyethylene chain at the end of the molecule, and the content of the polyoxyethylene chain in the molecule is 5 to 30% by weight, like polyol A, preferably 10 to 2% by weight.
It is 5% by weight. If the content of the polyoxyethylene chain at the molecular terminal of polyol B is 5% by weight, it is not preferable because the reactivity of polyol B becomes low and demolding time cannot be shortened. Moreover, if it exceeds 30% by weight, the reaction becomes too fast, which tends to result in poor molding, which is not preferable.

The ratio of polyol A and polyol B used is 60 to 95% for polyol A and 5 to 40% for polyol B, based on the total heavy protein of both. If polyol A is less than 60% and polyol B is more than 40%, molding will be poor and this is not preferred. In addition, polyol A exceeds 95% and polyol B
If it is less than 5%, the curing properties will deteriorate, which is not preferable.

In the present invention, active hydrogen-containing compounds that can be used together with polyol A and polyol B if necessary include:
Examples include the following graft polyols and crosslinking agents.

As the graft polyol, one that has a hydroxyl value of 20 to 40 and is obtained by polymerizing monomers such as styrene and acrylonitrile in a long-lasting ether polyol can be used. The amount of graft polyol used is 30% by weight or less based on the total amount of all active hydrogen-containing compounds.

If the graft polyol exceeds 30% by weight, the resulting polyurethane will become too hard, which is not preferable.

In addition, as a crosslinking agent, low-molecular polyols such as ethylene glycol, diethylene glycol, propylene glycol, glycerin, trimethylolpropane, triethanolamine, jetanolamine, PO-attached IJn products, EO adducts, PO/EO blocks, etc. and/or random adducts, P of polyamines such as ethylenedidiamine, propylenediamine, diethylenetriamine, etc.
O adduct, EO adduct, PO/EO block and/or random adduct with hydroxyl value between 200 and 100
0 and mixtures of two or more of these.

The amount of crosslinking agent used is 5% by weight or less based on the total of all active hydrogen-containing compounds. If the amount of the crosslinking agent exceeds 5% by weight, the resulting polyurethane will become too hard, which is not preferable.

The total hydroxyl number of the active hydrogen-containing compound containing polyol A and polyol B used in the present invention is 20
It is preferably in the range of 200 to 200. If the total hydroxyl number is less than 20, the resulting urethane foam will be too soft, and if it exceeds 200, it will be too hard and cannot be used as a semi-rigid foam, which is not preferred.

As the catalyst used if necessary in the present invention, 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-methylmorpholine, N-■ Examples include amine catalysts such as tilmorpholine, 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 other blowing agents include trichloromonofluoromethane and methylene chloride. 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 be added.

As the organic polyisocyanate used in the present invention, those conventionally used in polyurethane production can be used. Such polyisocyanates include
Aromatic polyisocyanates having a carbon number of 6 to 20 (excluding carbon in NCOJ3), such as 2, 4 and/or 2
, 6-tolylene diisocyanate (TDI), crude TD
I, 2°4- and/or 4,4'-diphenylmethane diisocyanate (MD I ), crude MDI [crude diaminophenylmethane (condensation product of formaldehyde and aromatic amines or mixtures thereof, diaminodiphenylmethane and small amounts (e.g. ~20% by weight) of trifunctional or higher functional polyamines), polyallyl polyisocyanate (PAPI), etc.], aliphatic polyisocyanates having 2 to 18 carbon atoms, such as hexamethylene diisocyanate, lysine diisocyanate, etc. Alicyclic polyisocyanates having 4 to 15 carbon atoms, such as isophorone diisocyanate, dicyclohexylmethane diisocyanate, aromatic aliphatic polyisocyanates having 8 to 15 carbon atoms, such as xylylene diisocyanate, and modified products of these polyisocyanates (urethane groups, Carbodiimide group, allophanate group,
modified products containing urea group, biuret group, uretdione group, isocyanurate group, oxazolidone group, etc.), polyisocyanates described in Japanese Patent Application No. 1991-160@, and mixtures of two or more of these. Among these, commercially readily available polyisocyanates include, for example, 2,4 and 2,6-TDI and mixtures of these isomers, crude TDI, 4.4" and 2,4'MDI, and mixtures of these isomers,
PAPI, also called crude IMDI, and urethane groups, carbodiimide groups, allophanate groups, urea groups, billet groups derived from these polyisocyanates,
They are modified polyisocyanates containing isocyanurate groups.

In the present invention, the isocyanate index [NCO/active hydrogen-containing group equivalent ratio x 1001] during polyurethane production is 8
0-140, preferably 85-120, particularly preferably 95-115.

Note that the active hydrogen-containing group here is the total of hydroxyl groups and amino groups other than carboxyl groups. Also, the isocyanate index is significantly higher than the above range (for example, 300 to 10
00 or higher), it is also possible to incorporate polyisocyanurates into the polyurethane.

Polyurethane can be produced by a conventional method, and known methods such as a one-shot method, a semi-prepolymer method, and a prepolymer method can be applied. Conventional manufacturing equipment can be used to manufacture polyurethane. In the case of no solvent, it is also possible to use a device such as a binder or an extruder. Various types of foamed polyurethane can be produced in closed or open molds. Polyurethane is usually produced by mixing and reacting raw materials using low-pressure or high-pressure mechanical equipment. The method of the present invention is useful for manufacturing mold forms. It is also possible to use the RIM (reaction injection molding) method.

The resulting polyurethane may be in either a soft or semi-rigid foam, but a semi-rigid foam is preferred.

The density of the obtained polyurethane is 0.05-0. 25g
/cm3 is preferable. Density is 0.05
If it is less than 9/cm3, moldability will deteriorate, which is not preferable. Moreover, if it exceeds 0.259/cm'', the polyurethane becomes too hard, which is not preferable.

[Example] Hereinafter, the present invention will be specifically explained using examples, but the present invention is not limited thereto. Note that parts in the examples are parts by weight.

Examples 1 to 3, Comparative Examples 1 to 4 Raw materials were mixed in the composition ratios shown in Table 1, and free foaming and mold foaming were performed to produce polyurethane foams. Mold foaming is performed by injecting raw materials with the composition ratio shown in the table into a mold and foaming them into a semi-rigid polyurethane foam. The cell condition (form filling property) was investigated.

(Raw materials used) Polyol A1: Block adduct of propylene glycol with propylene oxide/ethylene oxide, ethylene oxide content 120%, molecular weight 4000, hydroxyl value 28.0 Polyol B1: Propylene oxide/glycerin
Block adduct of ethylene oxide, ethylene oxide content 18%, molecular weight 5000, hydroxyl value 34
．． 0 Polyol B2: Block adduct of propylene oxide/ethylene oxide of pentaerythritol, ethylene oxide content 14%, molecular weight 6500, hydroxyl value 34.5 Polyol B3: Block adduct of propylene oxide/ethylene oxide of sucrose, ethylene oxide content 12 %, molecular weight "16000, hydroxyl value 28.
0 DEA diethanolamine U-CAT: U-CATIoo Tetramethylhexamethylenediamine DABCO: DAB manufactured by San-Apro Co., Ltd.
CO33LV 33% dipropylene glycol solution of triethylene diamine manufactured by Sankyo Air Products MR-200: Millionate MR200 Polymeric diphenylmethane diisocyanate manufactured by Nippon Polyurethane Co., Ltd. (foaming conditions) Mold shape: 200X200X5a++, Material: Iron, Mold temperature: 40±2 ℃, Cure time 2 minutes at room temperature 4 minutes (Evaluation) GT Nigel time, Time when the foam surface foamed from stirring the composition starts to pull strings with a matchstick (seconds)
(Including stirring time of 10 seconds) Time from stirring of the composition to completion of foaming of urethane foam (seconds) (
(including stirring time of 10 seconds) Density: Density of free form (g/CCm3) Density: Total density of molded form ('j/cml) C Hardness -1: C during demolding using Shore C type hardness tester
Hardness (on the form) C hardness -2: Final C hardness measured by Shore C type hardness tester (on the form) Cure property: Injection - demolding After 4 minutes, press the form with your finger and visually judge the degree of marks left O mark ( No trace〉 Δ mark (
Marked with × (obviously marked) Cell condition: Visually judge the cell condition and filling properties at the end of the form O mark (good cell condition) Δ mark (slight cell leakage) Mark X (obvious cell damage or (Results) As shown in Table 1 (Examples 1 to 3 and Comparative Examples 1 to 4), the foams obtained with the compositions of Examples 1 to 3 had low densities, and C As shown by the hardness of 1, the degree of C during demolding was high, the curing property was good, and the cell state was excellent.It also had an appropriate gelation time and had excellent productivity.On the other hand, in Comparative Example 1, polyol B Comparative Examples 2 to 4 are cases in which polyol A is not included, and the polyol contains a large amount of active hydrogen, resulting in a high crosslinking density and hardness. ,
Cell conditions were also inadequate. Therefore, by using the composition of the present invention, a semi-rigid urethane foam having a low density and a short curing time and excellent moldability can be obtained.

(The following is a blank space) [Effects of the Invention] In the present invention, by using two types of polyols having compositions in a specific range in a specific ratio, it is possible to shorten the curing time and reduce the weight of a molded semi-rigid polyurethane foam.

In addition, it is possible to solve problems such as insufficient curing (deformation) or poor molding during demolding, and insufficient filling in the mold (underfilling), which conventionally occur when molding semi-rigid urethane foam.

Claims (1)

[Scope of Claims] 1. A urethane composition comprising a polyisocyanate, an active hydrogen-containing compound, and, if necessary, a catalyst, a blowing agent, and other additives, wherein the active hydrogen-containing compound is difunctional and has a molecular weight of Polyol A is 2000 to 6000, and polyol A is 3 to 8 functional and has an OH equivalent molecular weight of 1000.
-3000, polyol A is 60-9 based on the total weight of polyol A and polyol B.
5% and polyol B of 5 to 40%. 2 The active hydrogen-containing compounds polyol A and polyol B each have 5 to 30 carbon atoms at the molecular end in each polyol molecule.
The urethane composition according to claim 1, characterized in that it contains % by weight of polyoxyethylene chains. 3. The urethane composition according to claim 1 or 2, wherein the active hydrogen-containing compound has a total hydroxyl value of 20 to 200.