JPH05287041A - Production of polyester containing urethane bond - Google Patents

Abstract

PURPOSE:To obtain the title polyester having practical strengths, a high melting point, and film-forming properties by using a very small amount of a catalyst. CONSTITUTION:A saturated polyester terminated substantially with hydroxyl and having an average molecular weight of 5000 or above is produced by using 0.0001-2 pts.wt., per 100 pts.wt. polyester to be formed, deglycolation catalyst. 100 pts.wt. this polyester in a molten state is reacted with 0.1-5 pts.wt. at least trifunctional polyisocyanate to obtain the title polyester of a number-average molecular weight of 10000 or above.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a saturated polyester having a practically sufficient high molecular weight and containing a small amount of a urethane bond. Very little usage,
The present invention relates to a method for producing a polyester containing a small amount of urethane bonds.

[0002]

2. Description of the Related Art When synthesizing polyethylene terephthalate having a practically sufficient number average molecular weight, it is used as a catalyst for a deglycolization reaction as an organic alkoxy compound of a heavy metal such as titanium, zinc, manganese, iron, lead, antimony, and It is well known to utilize metal salts of acids as catalysts. If these catalysts are used in a sufficient amount, it may be possible to increase the required number average molecular weight in a short time, and if so, there is no problem, for example, packaging materials used for foods, It is desired that the amount of these catalysts is as small as possible. Especially, it is necessary to avoid the use of the kind that is recognized to have harmful effects on the human body. Therefore, a metal compound that is not toxic is
If it is possible to synthesize a practical high-molecular-weight polyester using a small amount as much as possible, it is expected to be extremely desirable for food-related packaging materials.

In order to increase the molecular weight of the saturated polyester, it is possible to combine the saturated polyester with a diisocyanate to increase the molecular weight. For example, conventionally, the number average molecular weight of the terminal group is a hydroxyl group 2,000 ~
It is widely practiced to use about 2,500 saturated polyester as a raw material component of a polyurethane resin and react it with diisocyanate to prepare a rubber, foam, paint or adhesive.

However, the saturated polyester used in the existing polyurethane has a number average molecular weight of 2,000 to 2.5.
It is a so-called prepolymer of No. 00, and for obtaining 100% by weight of this low molecular weight saturated polyester, in order to obtain practical physical properties, it depends on the molecular weight of diisocyanate.
The amount of diisocyanate used is 10 parts by weight or more and 15 to 2
It is necessary to reach 0 parts by weight. However, for example, 1
When 0 part by weight or more of diisocyanate is added to melt-saturated polyester (depending on the type, it is approximately 150 ° C or higher),
If the saturated polyester has a low molecular weight, it will always gel, regardless of whether it is a saturated polyester having a high molecular weight, and a handleable resin cannot be obtained. In practice, the addition of 10 parts by weight or more of diisocyanate is carried out in solution in a solvent, or as in foam or RIM molding, to obtain the final cured resin in one go.

In the case of rubber, it has also been conducted to convert a hydroxyl group into an isocyanate group (adding diisocyanate) and further increase the number average molecular weight with glycol, but the amount of the isocyanate is as described above. The amount is 10 parts by weight or more. In such a case, when a heavy metal-based catalyst is used for the synthesis of the saturated polyester, it significantly accelerates the reactivity of the isocyanate group, resulting in poor storage stability and undesired crosslinking (branching). A low molecular weight saturated polyester as a raw material resin is synthesized without a catalyst. Therefore, even if the number average molecular weight is high, the limit is 2,500.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned conventional problems and uses a deglycolization catalyst and a polyfunctional isocyanate having three or more functional groups, and has practically sufficient strength and a melting point. It is an object of the present invention to provide a method for producing a polyester containing a urethane bond, which is high and which can use a very small amount of deglycolization catalyst.

[0007]

[Means for Solving the Problems] To a saturated polyester having a hydroxyl group as a terminal group and a number average molecular weight of 5,000 or more, a trifunctional or higher polyvalent isocyanate is added,
It is considered that if the reaction is carried out, it is common knowledge that a gelable and handleable polyester cannot be obtained, but the present inventors have found that a specific saturated polyester synthesized under controlled conditions,
The present invention has been completed by finding that the number average molecular weight of saturated polyester can be increased to a desired level without gelation by adding a polyfunctional isocyanate having a functionality of 3 or more and reacting it in a molten state. did it.

That is, the present inventors have synthesized a saturated polyester having a number average molecular weight of 5,000 or more, preferably 10,000 or more, using a catalyst for a deglycolization reaction, and further 100 parts by weight of the saturated polyester in a molten state. 0.
By adding and reacting 1 to 5 parts by weight of a polyfunctional isocyanate having a functionality of 3 or more, the saturated polyester (1) has a broader molecular weight distribution (weight average molecular weight / number average molecular weight) and improved processability. (2) The number average molecular weight is increased to 1.5 to 5 times, thereby eliminating the poor activity of the catalyst and the difficulty of increasing the molecular weight of the saturated polyester to a desired level based on it, (3) Volatility It was found that the use of a polyfunctional isocyanate having a low trifunctionality or higher makes it possible to complete the present invention by finding that the toxicity, which must be paid the most attention in handling the isocyanate, becomes almost zero.

In the present invention, (a) 0.0001 to 2 per 100 parts by weight of the polyester produced in the process of synthesizing a saturated polyester having a terminal hydroxyl group.
Using 10 parts by weight of a deglycolization catalyst, a saturated polyester having a number average molecular weight of 5,000 or more whose terminal group is substantially a hydroxyl group is synthesized, and (b) 0.1 part is added to 100 parts by weight of the saturated polyester in a molten state. The present invention provides a method for producing a polyester containing a urethane bond having a number average molecular weight of 10,000 or more, which comprises adding and reacting 5 to 5 parts by weight of a trifunctional or higher polyvalent isocyanate.

The present invention will be described in more detail below. (Saturated Polyester) In the present invention, the saturated polyester to be reacted with a trifunctional or higher polyvalent isocyanate is
It must be a saturated polyester having a number average molecular weight of 5,000 or more, preferably 10,000 or more, the end groups of which are substantially hydroxyl groups. When this is a low molecular weight saturated polyester, for example, a number average molecular weight of about 2,500, good physical properties can be obtained even when 0.1 to 5 parts by weight of a trifunctional or higher polyvalent isocyanate is used. In addition to not being able to obtain the final high-molecular-weight polyester, the addition of 0.1 to 5 parts by weight of the above-mentioned polyfunctional isocyanate in the melt addition of trifunctional or higher functional polyisocyanate may cause gelation during the reaction. It is recognized that the occurrence of Therefore, the terminal hydroxyl number is about 30.
If it is not higher than the rank, a safe reaction cannot be performed. The saturated polyester of the present invention having a number average molecular weight of 5,000 or more inevitably has a hydroxyl value of this level or lower, and by using a small amount of a trifunctional or higher polyvalent isocyanate, even under severe conditions such as a molten state. It is possible to safely synthesize high molecular weight polyester. Therefore, the saturated polyester referred to in the present invention has at least a number average molecular weight of 5,0.
It will contain one urethane bond per 00.

The number average molecular weight obtained by the present invention is 10,
A polyester containing urethane bonds of 000 or more, preferably 20,000 or more can be made into a tough film if it has a melting point of 60 ° C. or more and is crystalline, and can be used as a packaging material. Examples of glycols used for synthesizing the saturated polyester include ethylene glycol, butanediol 1,4, hexanediol 1,6, decamethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol,

[Chemical 1]

[Chemical 2] Etc. Ethylene oxide can also be utilized. Polybasic acids (or their anhydrides) that react with these glycols to form saturated polyesters include succinic acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, succinic anhydride, adipic anhydride, phthalic acid. Acids, isophthalic acid, terephthalic acid and the like are generally commercially available and can be used in the present invention. If the amount is small, a polyfunctional carboxylic acid having a functionality of 3 or more, a polyhydric alcohol, and a polyoxycarboxylic acid can be used as the cocondensation component. Examples of the polyvalent carboxylic acid include trimellitic acid and pyromellitic acid, examples of the polyvalent alcohol include trimethylolpropane and pentaerythritol, and examples of the polyvalent oxycarboxylic acid include malic acid, citric acid and tartaric acid. In particular, the combination of butanediol 1,4 and succinic acid (melting point 110-115 ° C.), and ethylene glycol and succinic acid (melting point about 97-102 ° C.) show a melting point similar to that of polyethylene, and are most suitable for the present invention. It is a desirable combination. As a matter of course, glycols and polybasic acids (or acid anhydrides thereof) can be used in combination with each other as long as the purpose is not impaired. Although the saturated polyester of the present invention has a terminal group substantially a hydroxyl group,
To this end, the glycols and polybasic acid (or their acid anhydrides) used in the synthesis reaction need to be used in a somewhat excess amount. The method for synthesizing the saturated polyester is not special, and it is generally made high molecular weight by a deglycolization reaction following esterification.

(Catalyst) The deglycolization catalyst used in the synthesis of the saturated polyester of the present invention is not particularly limited, and examples thereof include acetoacetoyl type chelate compounds,
Examples thereof include metal alkoxides and metal salts of organic acids.
Examples of the metal forming the acetoacetoyl type chelate compound, metal alkoxide or metal salt of an organic acid include iron, manganese, cobalt, zirconium, vanadium, yttrium, lanthanum, cerium, lithium and calcium,
Examples include titanium and zinc. Other metals such as aluminum, strontium, and barium can be used, but they are not particularly desirable in terms of weak catalytic action and toxicity. Among the above-mentioned metals, iron, cobalt, vanadium and zirconium are superior to acetoacetoyl type chelate compounds in terms of action, hue and the like, and vanadium is not practical unless it is vanadyl type acetylacetonate. .. Yttrium, lantern,
Cerium, lithium, calcium and the like are commercially available in the form of metal salts of organic acids, and it is not recognized that a chelate compound must be used. The proportion of these deglycolization catalysts used is 0.0001 to 2 parts by weight, preferably 0.
0005 to 1 part by weight, more preferably 0.001 to 0.
1 part by weight. These deglycolization catalysts may be added from the beginning of the esterification or immediately before the deglycolization reaction. The use ratio of deglycolization catalyst is 0.
If it is less than 0001 parts by weight, the action of the catalyst becomes weak and it is difficult to obtain a saturated polyester having a desired number average molecular weight. On the other hand, when the use ratio of the deglycolization catalyst is more than 2 parts by weight, the action does not change greatly and only the catalyst residue increases, which is not preferable.

(Trifunctional or higher polyvalent isocyanate) Further, the number average molecular weight 5, which is a constituent of the present invention, is 5,
There is no particular limitation on the trifunctional or higher polyvalent isocyanate added to the saturated polyester having 000 or more, and preferably 10,000 or more, end groups being substantially hydroxyl groups to further increase the molecular weight. The following types are listed. Tolylene diisocyanate trimer, hexamethylene diisocyanate trimer or an adduct of diisocyanate with a compound having polyvalent active hydrogen (for example, 3 mol of tolylene diisocyanate and 1 mol of trimethylolpropane, Or an adduct of 3 mol of hexamethylene diisocyanate and 1 mol of trimethylolpropane) or a burette type triisocyanate represented by the following formula

[Chemical 3] Etc. In particular, hexamethylene diisocyanate trimer and hexamethylene diisocyanate 3
An adduct of 1 mol of trimethylolpropane and 1 mol of trimethylolpropane is preferable from the viewpoint of the hue of the produced resin and the reactivity when the polyester is added. The amount of addition of these trifunctional or higher polyvalent isocyanates depends on the molecular weight, but saturated polyester 100
0.1-5 parts by weight, preferably 0.5-
3 parts by weight. If the amount of the trifunctional or higher polyvalent isocyanate added is less than 0.1 parts by weight, the effect of the present invention cannot be obtained, and if it is more than 5 parts by weight, there is a risk of gelation.

The addition of the trifunctional or higher polyvalent isocyanate is preferably carried out under a condition in which the saturated polyester is in a homogeneous molten state and does not contain a solvent and can be easily stirred. Separately, it is not impossible to add it to solid saturated polyester and melt and mix it through an extruder, but generally it is added to the saturated polyester manufacturing equipment or to the saturated polyester in a molten state (for example, in a kneader). It is practical to do so.

The polyester containing a small amount of urethane bond according to the present invention can be formed into a film, a sheet and the like and is mainly used for packaging. When used, a lubricant, a colorant, another polymer, a release agent, a filler and a reinforcing material are used. It goes without saying that the above can be used as necessary.

[0016]

EXAMPLES In order to facilitate understanding of the present invention, examples will be shown below.

The molecular weight was measured by GPC. The conditions are as follows. Model used Shodex GPC SYSTEM-11 (manufactured by Showa Denko KK) Eluent 5 mM CF ₃ COONa / HFIP (hexafluoroisopropanol) column Sample column HFIP-800P HFIP-80M × 2 columns Reference column HPIP-800R × 2 columns Temperature 40 ° C. Flow rate 1.0 ml / min Detector Shodex RI standard PMMA (Shodex STANDARD M-7
5)

Example 1 Ethylene glycol 2 was placed in a 1 liter separable flask equipped with a stirrer, a fractionating condenser, a thermometer, and a gas inlet tube.
After charging 48.7 g and 407.1 g of succinic acid and esterifying in a nitrogen stream at 160 to 195 ° C. to an acid value of 8.9, 0.027 g of tetraisopropyl titanate was added, and finally up to 0.1 Torr. Decompress, 210-220
Deglycol reaction at 7 ℃ for 7 hours, number average molecular weight 1
8,000; weight average molecular weight 41,300; molecular weight distribution
(Weight average molecular weight / number average molecular weight) 2.28 of saturated polyester (A) was obtained. When it was cooled to room temperature, it became a white wax and had a melting point of 97 to 102 ° C. and an acid value of almost 0.

400 g of the obtained saturated polyester (A) was heated to 190 to 200 ° C. to melt it, and 4.8 g of hexamethylene diisocyanate trimer was added thereto while stirring. The viscosity increased rapidly but no gelation occurred. The mixture was stirred for 20 minutes so as to be uniform and then cooled.
The resulting polyester (B) containing a urethane bond has a number average molecular weight of 27,800; a weight average molecular weight of 142,700;
Molecular weight distribution is 5.13, white waxy, melting point 1
It was 00-105 degreeC.

Example 2 A 1 l separable flask equipped with a stirrer, a fractionating condenser, a thermometer and a gas inlet tube was charged with ethylene glycol 2
Charge 48.7g and succinic acid 407.1g, and in a nitrogen stream 1
After esterification at 60 to 195 ° C. to make the acid value 9.2, 0.027 g of tetraisopropyl titanate was added, and finally the pressure was reduced to 0.1 Torr and 210 to 220.
Deglycol reaction at 7 ℃ for 7 hours, number average molecular weight 1
A saturated polyester (C) having a weight average molecular weight of 42,500 and a molecular weight distribution of 2.17 was obtained. When cooled to room temperature, it becomes a white wax and has a melting point of 97-102 ° C.
Met.

400 g of the obtained saturated polyester (C) is heated to 190 to 200 ° C. to melt it, and 9.6 g of hexamethylene diisocyanate trimer while stirring this.
Was added. The viscosity increased rapidly but no gelation occurred. The mixture was stirred for 20 minutes so as to be uniform and then cooled. The obtained polyester (D) containing a urethane bond is
Number average molecular weight 30,000; weight average molecular weight 200,60
0: The molecular weight distribution was 6.69, and it became a slightly yellowish white wax, and the melting point was 105 to 110 ° C.

From polyester (C) and polyester (D), a thickness of about 10 was obtained using a press molding machine.
A 0 μm film was made. Next, the thickness is about 1
A film of 00 μm was drawn at 40 ° C. using a stretching device for testing.
When a uniaxially stretched film having a thickness of about 30 μm was produced by stretching 3 times, the polyester (C) was broken and the uniaxially stretched film was not formed, but the polyester (D) was transparent. A uniaxially stretched film was formed. The tensile strength of this transparent film is 11.9kg / mm ² ~
It showed a value of 15.1 kg / mm ^{2 and was} extremely strong.

Example 3 Ethylene glycol 2 was placed in a 1 liter separable flask equipped with a stirrer, a fractionating condenser, a thermometer, and a gas inlet tube.
Charge 48.7g and succinic acid 407.1g, and in a nitrogen stream 1
After esterification at 60 to 195 ° C. to adjust the acid value to 8.3, 0.027 g of tetraisopropyl titanate was added, and finally the pressure was reduced to 0.1 Torr and 210 to 220.
When the glycol removal reaction was carried out at 7 ° C. for 7 hours, a saturated polyester (E) having a number average molecular weight of 19,300; a weight average molecular weight of 41,900; a molecular weight distribution of 2.17 was obtained.
When cooled to room temperature, it becomes a white wax and has a melting point of 97.
It was -102 degreeC.

400 g of the obtained saturated polyester (E) was heated to 190 to 200 ° C. to be melted, and 10 g of an adduct of 3 mol of hexamethylene diisocyanate and 1 mol of trimethylolpropane was added thereto with stirring. .. The viscosity increased rapidly but no gelation occurred. The mixture was stirred for 20 minutes so as to be uniform and then cooled. The resulting polyester (F) containing a urethane bond has a number average molecular weight of 2
9,500; weight average molecular weight 195,000; molecular weight distribution was 6.61, and it was a slightly yellowish white wax and had a melting point of 100 to 105 ° C.

Polyester (E) and polyester (F) were press-molded using a press molding machine,
A film having a thickness of 100 μm was produced. Next, each of the produced films having a thickness of about 100 μm was stretched 3 times at 40 ° C. using a stretching device for a test, and the thickness was about 30.
When an attempt was made to produce a uniaxially stretched film of μm, the polyester (E) was broken and a uniaxially stretched film was not formed, but the polyester (F) was formed as a transparent uniaxially stretched film. The tensile strength of the transparent film has a value of ^{11.3kg / mm 2 ~14.8kg / mm 2} , it was extremely strong.

[0026]

EFFECTS OF THE INVENTION The present invention provides a method for producing a polyester having a urethane bond having a film-forming ability, which has a practically sufficient strength, a high melting point, and a very small amount of a catalyst. It

Claims (1)

[Claims] 1. In the process of synthesis of (a) a saturated polyester in which the end group is substantially a hydroxyl group, 0.0001 to 2 parts by weight of a deglycolization catalyst is used with respect to 100 parts by weight of the polyester produced, and the end is prepared. A saturated polyester having a number average molecular weight of 5,000 or more in which the group is substantially a hydroxyl group is synthesized, and (b) 100 parts by weight of the saturated polyester in a molten state, and 0.1 to 5 parts by weight of a polyfunctional polyfunctional compound having a functionality of 3 or more. A number average molecular weight of 10,0 is obtained by adding and reacting an isocyanate.
A method for producing a polyester containing 00 or more urethane bonds.