JP2000017068A - Polyol for polyurethane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyol for a polyurethane which has no tendency toward crystal deposition, has good curing operability and gives a strong cured material having a wide range of strength and also to contribute resource saving and industrial recycling by using a polyethylene terephthalate scrap such as used PET bottles. SOLUTION: (A) Terephtalic acid, its ester or a polyester and (B) a branched diol having not less than 7 carbon atoms are the essential source materials and this polyol is obtained by reacting them. Otherwise, (A) a polyethylene terephthalate, (B) a branched diol having not less than 7 carbon atoms and (C) an ethyleneglycol oligomer are the essential source materials and the polyol is obtained by reacting them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyol for polyurethane useful as a paint, an adhesive, a sealing agent, a floor material, a structural material, a clothing material, a cushion material, a sealing material for electronic parts and the like. More specifically, the present invention relates to a polyol for polyurethane obtained by recycling a bottle made of polyethylene terephthalate known as PET.

[0002]

2. Description of the Related Art US Pat. No. 4,469,824 describes a method for producing a polyol by reacting PET with diethylene glycol and one or more oxyalkylene glycols. JP-A-60-8333 discloses that PE
It describes a method for producing a polyol in which T and an active hydrogen compound having 2 to 4 functional groups, and optionally a polycarboxylic acid or an anhydride thereof are added and reacted. However,
These polyols have difficulties in handling such as being easily crystallized at room temperature, and having a high curing rate and high heat generation. Further, when used in combination with phthalic acid or the like, there is a disadvantage that the cured product becomes brittle.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyol which uses PET as one component of a raw material and gives a polyurethane which is easy to handle and has high performance.

[0004]

Means for Solving the Problems The present inventors have made intensive studies on polyols having good handleability and excellent polyurethane performance using waste PET as a raw material. As a result, they have reached the present invention. That is, the present invention provides (A) a polyol for polyurethane obtained by reacting (A) terephthalic acid or an ester or polyester thereof and (B) a branched hydrocarbon diol having 7 or more carbon atoms as essential raw materials, and (A)
The present invention relates to a polyurethane polyol obtained by using polyethylene terephthalate, (B) a branched hydrocarbon diol having 7 or more carbon atoms and (C) an ethylene glycol oligomer as essential raw materials, and reacting them.

[0005] (A) Terephthalic acid is produced in large quantities as a polyethylene phthalate (PET) raw material. As the terephthalate, dimethyl terephthalate is industrially produced. These can be used as raw materials of the present invention as they are. As the polyester of terephthalic acid, polyethylene terephthalate, polybutylene terephthalate and the like can be used. In particular, from the viewpoint of resource saving, it is preferable to use waste PET bottles, recycled products of other PET products, and extraordinary products produced as a by-product in PET production.

Examples of the branched hydrocarbon diol having 7 or more carbon atoms include methylhexane-1,6-diol, dimethylpentane-1,5-diol, and methylheptane-1,7-diol.
Diol, dimethylhexane-1,6-diol, methyloctane-1,8-diol, dimethylheptane-
1,7-diol, methylnonane-1,9-diol,
One or more selected from dimethyloctane-1,8-diol and the like can be used.

(B) The ethylene glycol oligomers include diethylene glycol, triethylene glycol,
Distillation for the production of polyethylene glycol and ethylene oxide cooligomers such as tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, heptaethylene glycol, octaethylene glycol, nonaethylene glycol, decaethylene glycol, etc., as well as diethylene glycol, triethylene glycol or tetraethylene glycol It can be selected from the residue, and among these high-boiling cut fractions by distillation. Among them, the molecular weight of polyethylene glycol is preferably 2000 or less. The ethylene oxide cooligomer is a copolymer of ethylene oxide and at least one of propylene oxide and butylene oxide, and preferably has a molecular weight of 2000 or less.
Distillation residue in the production of diethylene glycol, triethylene glycol or tetraethylene glycol is the distillation residue in the step of producing ethylene glycol by reacting ethylene oxide with water. These usually contain an alkaline non-volatile catalyst and a non-adherent colored material, and are particularly preferable because removing them by flash distillation or the like can extend the pot life and reduce the color.

In producing the polyol of the present invention by reacting the above (A), (B) and (C), no catalyst may be added, but antimony trioxide, calcium acetate, titanates, tin When a known transesterification catalyst such as a compound is used, the reaction time can be reduced. (A),
The charging ratio of (B) + (C) can be determined based on the molar number (a) of terephthalic acid contained in (A). Usually, the charged mole number (b) of (B) + (C) is b / a = 1.
The range of ~ 2 is appropriate. The ratio between (B) and (C) is selected according to the purpose. The reaction can be advanced by stirring at a reaction temperature of 200 to 300 ° C. for about 0.5 to 5 hours.
Injecting nitrogen gas or the like is preferable because the reaction time can be shortened while preventing the hue from being deteriorated. Adhered water such as PET flakes, water generated by the reaction, alcohol and ethylene glycol are removed by a distillation tube. The progress of the reaction can be monitored by GPC or the like. Finally, ethylene glycol and excess polyol may be removed by distillation under reduced pressure or the like, and if necessary, removal or inactivation of the catalyst may be performed by a known method. It is considered that a complex random type polyester poly (di) ol structure composed of terephthalic acid, branched hydrocarbon diol, ethylene glycol, and ethylene glycol oligomer is generated in this reaction.

Other reactive components include polycarboxylic acids such as phthalic acid, isophthalic acid or phthalic anhydride, succinic acid, maleic acid, maleic anhydride, adipic acid, sebacic acid, and diethylene glycol, propylene glycol, dipropylene glycol, Polyols such as propylene glycol, tetrapropylene glycol, polypropylene glycol, butanediol, pentanediol, hexanediol, nonanediol, and decanediol, and hydroxys such as ricinoleic acid, 12-hydroxystearic acid, lescleric acid, and 14-hydroxyeicosanoic acid Carboxylic acids or butyrolactone,
Lactones such as caprolactone may be used as long as the effects of the present invention are not impaired. In addition, the polyol of the present invention does not crystallize even when stored at room temperature, and thus is excellent in handleability.

[0010] The polyols of the present invention form polyurethane compositions with polyisocyanates. As the polyisocyanates, tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and the like and modified products thereof are used. Other known polyol compounds such as polyester polyols, polyether polyols, and hydrocarbon polyols may be used in combination. The ratio of the polyol of the present invention to the polyisocyanate together with other active hydrogen compounds is determined based on the stoichiometric amount. The mixture is cast, applied, sprayed, injected,
It is sent to a required place by a method such as injection, and is cured by heating or ambient temperature. The polyol of the present invention is reacted with a polyisocyanate in a ratio less than the stoichiometric amount to form a modified polyisocyanate having an isocyanate group at a terminal, and mixed with various polyol compounds and polyamine compounds to form urethane bonds and urea bonds. And a cured product containing

The polyol of the present invention contains known additives,
For example, a urethanization promoting catalyst, a foaming agent, a surfactant, and a plasticizer may be used. In addition, asphalt, coal tar, petroleum resin, and by-product residue in the production of phenols such as phenol, cresol, and resorcin may be mixed for the purpose of improving waterproofness and corrosion resistance and reducing costs. In addition, talc, clay, silica, alumina, calcium carbonate, iron oxide, titanium oxide,
It may contain carbon black, glass and the like.

The polyol of the present invention can be used for heat insulating materials, adhesives, sealing agents, flooring materials, road paving materials, synthetic tatami materials, bumpers, structural materials, clothing materials, footwear materials, cushion materials, sealing of electronic parts. It covers a wide range of industries such as materials and insulating materials.

[0013]

The embodiments of the present invention will be described with reference to the following Examples, but it should not be construed that the invention is limited thereto. Acid value in the examples,
The hydroxyl value was measured by the standard oil and fat analysis test method established by the Japan Oil Chemical Association. In each case, the unit is mg-KOH / g. The 25 ° C. viscosity was measured with an E-type rotational viscometer. Hue was measured by the Gardner method. Further, the polyol sample was stored at room temperature for 2 weeks, and the storage stability was determined as follows. ：: liquid state, △: slight crystallization, ×: large crystallization The physical properties of the polyurethane were evaluated as follows.

<Evaluation Method of Physical Properties of Polyurethane> (a) Curing: total amount of polyol and polyisocyanate (carbodiimide-modified diphenylmethane diisocyanate: MDI-LL manufactured by Mitsui Chemicals: MDI-LL): 20 g, NCO / OH =
A polymethylpentene petri dish (diameter: 85 mm) is weighed so that the ratio becomes 1.05 (mol / mol). Mix quickly, leave at room temperature under reduced pressure, and cure at room temperature until fluidity is lost. Next, it was post-cured at 80 ° C. for 3 hours to obtain a test sheet. (B) Mechanical property test The following test was performed using the sheet of (a). (B-1) Hardness: JISK-2215 (b-2) Bending strength: A test piece was cut out from a sheet and determined by the following equation. Bending strength = 3PL / 2bh ² P: Load (read on a table only) L: Distance between branches (20 mm) b: Width (mm) of test piece, h: Thickness (mm) of test piece (b-3) Tensile strength: A test piece is cut out from a sheet, the upper part is fixed, the plastic tank is fixed at the lower part, and water is injected at a rate of 1 kg / min. The load when the test piece was cut was divided by the initial area of the neck portion of the test piece to obtain the tensile strength. (B-4) Elongation at break: At the time of tensile strength measurement, a mark of 5 mm width was previously marked on the neck portion of the test piece, and the width at the time of break was divided by the initial width. Reference Example 1 Table 1 shows the result of analyzing 466 g of triethylene glycol distillation residue.

Reference Example 2 432 g of a colorless and transparent distillate (31 g of black liquid in the bottom) was obtained by the simple distillation under reduced pressure of Reference Example 1 (bath temperature: 167 to 210 ° C., tower temperature: 130 to 205 ° C., pressure: 7 mmHg). Obtained. The analysis results of the distillate are shown in Table 1.

[0016]

[Table 1]

EXAMPLE 1 500 ml of 4 with a stirrer, thermometer, distilling tube and cooler
96 g of PET flake (0.5 mol as terephthalic acid) and mixed nonanediol (ND
65: methyloctanediol 65%, nonane-1,9
Diol 35%), 76 g (0.475 mol), 67 g (0.475 mol) of triethylene glycol and 0.02 g of tetrapropyl titanate, and 220 to 2
The reaction was performed at 60 ° C. for 1 hour. During this time, ethylene glycol produced by transesterification was distilled off. 130
Volatile components were removed at 10 ° C. and 10 mmHg, and polyol 205 was removed.
g was obtained. Hydroxyl value 245, acid value 0.4, viscosity 4506
0 cp and hue 1 or less. The product became translucent at room temperature, but did not undergo sedimentation separation even after long-term storage. Table 2 shows the results of examining the curing workability and the cured physical properties after polyurethane conversion.

Example 2 In the same apparatus as in Example 1, 96 g of PET flake, 24 g of mixed nonanediol (ND65 manufactured by Kuraray), 120 g (0.8 mol) of triethylene glycol and 0.02 g of tetrapropyl titanate were added, and the same operation was carried out. Thus, 189 g of a polyol was obtained. Hydroxyl value 221, acid value 0.2,
The viscosity was 4120 cp and the hue was 1.5. This one is
Even when stored for a long period of time, there was no precipitation or precipitation of crystals and the like, and it was a uniform transparent liquid. Table 2 shows the results of examining the curing workability and the cured physical properties after polyurethane conversion.

Example 3 In the same apparatus as in Example 1, 96 g of PET flakes, 24 g of mixed nonanediol (ND65 manufactured by Kuraray), 143 g (0.8 mol) of a simple distillation distillate of Reference Example 2 and 0.02 g of tetrapropyl titanate And 196 g of a polyol was obtained in the same manner. Hydroxyl value 210, acid value 0.2,
The viscosity was 5640 cp and the hue was 1. This was a homogeneous transparent liquid without precipitation or precipitation of crystals even after long-term storage. Table 2 shows the results of examining the curing workability and the cured physical properties after polyurethane conversion.

Example 4 In the same apparatus as in Example 1, 96 g of PET flakes and 93 g of branched nonanediol (Kyowadiol PD-9) (0.9 g) were used.
58 mol) and 0.02 g of tetrapropyl titanate
Was added, and the same operation was performed to obtain 170 g of a polyol.
Hydroxyl value 87, acid value 0.4, viscosity at 50 ° C 9010c
p, hue 1 This was a homogeneous transparent liquid without precipitation or precipitation of crystals even after long-term storage. Table 2 shows the results of examining the curing workability and cured physical properties of polyurethane.
It was shown to.

Comparative Example 1 96 g of PET flake, 112 g of hexane-1,6-diol and 0.02 g of tetrapropyl titanate were placed in the same apparatus as in Example 1, and reacted similarly to obtain 173 g of a polyol. It was found that this product became a hard solid by crystallization at 80 ° C. and had difficulty in handling.

Comparative Example 2 Diethylene glycol and adipic acid were prepared according to a conventional method.
A polyester polyol was synthesized. Table 2 shows the results of evaluation in the same manner as in the examples.

Comparative Example 3 A polyester polyol was synthesized from methylpentanediol and terephthalic acid by a conventional method. Evaluation was performed in the same manner as in the examples, and the results are shown in Table 2.

[0024]

[Table 2]

[0025]

EFFECT OF THE INVENTION By using the polyol of the present invention, a low-viscosity and low-crystallinity, excellent handleability and storage stability, and a tough polyurethane cured product can be obtained. Use can contribute to industrial resource saving.

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Claims (2)

[Claims] 1. A polyol for polyurethane obtained by reacting (A) terephthalic acid or an ester or polyester thereof and (B) a branched hydrocarbon diol having 7 or more carbon atoms as essential raw materials, and reacting them. 2. An essential raw material comprising (A) polyethylene terephthalate, (B) a branched hydrocarbon diol having 7 or more carbon atoms and (C) an ethylene glycol oligomer,
Polyol for polyurethane obtained by reacting these.