JPS5945319A - Preparation of polyester resin - Google Patents

Abstract

PURPOSE:To prepare the titled novel resin having excellent dispersion stability to pigment, etc. and suitable as a binder for magnetic recording tape, by using a specific N-containing compound in addition to sulfo-sodium isophthalic acid as essential components for modification. CONSTITUTION:The objective resin is prepared by reacting (A) >=80mol%, based on the whole acid component, of terephthalic acid and/or isophthalic acid with (B) >=80mol%, based on the whole glycol component, of ethylene glycol and/or neopentyl glycol, (C) 0.2-5mol%, based on the whole acid component, of sulfo-sodium isophthalic acid, and (D) 3-10mol%, based on the whole glycol component, of a nitrogen-containing compound of formula I -III (R and R' are alkylene; R2 is alkyl or aryl; X and X' are carboxyl or OH) or ring-opened product of the compound of formula III.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a novel polyester resin that has particularly excellent dispersion stability for pigments, inorganic powders, and the like.

Polyester resins have traditionally been used in a wide range of fields such as binders, paints, and adhesives, and their uses are still increasing. Moreover, in recent years, in addition to such general uses, it is also expected to be used for special uses such as binders for magnetic tapes, and various reports have been made. For example, JP-A-51-2860
In JP-A No. 54-1514, polyester resin containing a sulfonic acid metal salt having a reduced viscosity of 0.2 or more is used as a magnetic recording medium, that is, as the binder.
The use of mixtures of polyester resins with sulfonic acid metal salts and thermoplastic and/or thermosetting resins as magnetic recording binders with a reduced viscosity of less than 17 KFi and 0.2 has been reported. That is, in the above-mentioned JP-A-Sho, by further introducing a sulfonic acid group such as sulfonatric isophthalic acid into a polyester resin consisting of an acid component such as terephthalic acid or isophthalic acid, and a glycol component such as ethylene glycol or neopentyl glycol. It has been shown to improve the properties of magnetic pines.

In such applications, the demand for video tapes and audio tapes is increasing in proportion to the spread of home video recorders and audio tape recorders, and higher-dimensional quality is required in various aspects such as image quality, sound quality, and wear resistance. However, since the performance of the binder, which plays the role of uniformly and densely filling the magnetic layer coated on the base film of the tape, plays a large role in the performance of the tape, various improvements have been made to the polyester resin. It is something that is being done.

However, according to research conducted by researchers at Kishi University, the above-mentioned polyester resin has remarkable properties in terms of binder and physical properties (7), but there are problems in terms of workability. Coating liquids prepared using this method have good dispersibility immediately after production, but the magnetic powder in the binder may settle over time and become unable to maintain a uniform dispersion state, or the magnetic powder may strongly aggregate and cause redispersion. It was found that there were many handling problems.From an industrial standpoint, where binders and magnetic powders are often handled in large quantities and stored for long periods of time, it is difficult to handle them. This is an important issue that cannot be ignored.

Such dispersibility problems are not limited to the use of binders for magnetic tapes as described above, but also for general uses such as paints and adhesives, although binders for magnetic tapes do not require any strict performance. When used in combination with other powders, problems must be solved in both cases.

However, in view of the above-mentioned problems, the inventors of the present invention have conducted extensive research and found that (a) terephthalic acid and (also Vi) isophthalic acid account for the total acid components of polyester 4'jI fat. (b) at least 80 mol% of ethylene glycol and/or neopentyl glycol, based on the total glycol component; (C) sulfonatrichumisophthalic acid, based on the total acid component; 0.2~5
Mol%, (d) based on the total glycol component, the following general formula (1) to 1) H,N-R-NH2 2) If X-R-N-R'-X' 1 is required, problems in Section 011 can be solved using the VC method, and in addition to each component of (a) to (dl), Polyester resins containing 0.1 to 1"0 mol% of polyhydric alcohol based on the total glycol components are of course Kokichi, which has significantly improved dispersion stability.
Due to the branched units of this resin, when a crosslinking agent such as isocyanate is added, it contributes to improving the coating strength and adhesive strength, and greatly improves abrasion resistance, resulting in even better performance in terms of physical properties. After discovering that this could be obtained, the water valve 11 was completed.

In other words, the new polyester resin in this invention J is characterized by containing the dl component in the molecule, and is useful not only for special purposes as a binder for magnetic tapes, but also for general paints and adhesives. It also exhibits excellent effects on various functions such as dispersion stability, abrasion resistance, and hardness, which are important properties for use in agents.

Among the acid components constituting the polyester resin used in the present invention, it is essential that (a) terephthalic acid and/or isophthalic acid be used in an amount of at least 80 mol% based on the acid component. If the content of carboxylic acid components other than these exceeds 20 mole%, the produced polyester resin tends to become soft, and at the same time its abrasion resistance decreases. Become a parishioner. Carboxylic acids other than terephthalic acid and isophthalic acid are not particularly limited, but typical examples include orthophthalic acid, I,5-naphthalic acid/l
/acid, P-oxybenzoic acid, succinic acid, adipic acid, azelaic acid, sepacic acid, etc. are used.

Furthermore, among the glycol components constituting the polyester resin, (b) ethylene glycol and/or neopentyl glycol must be used in an amount of at least 80 mol % or more based on the total glycol components. If glycol components other than these are present in the resin in an amount exceeding 20 mol %, the polyester resin becomes soft, which is not preferable.

Glycol components other than ethylene glycol and neopentyl glycol are not particularly limited, but commonly used ones include glopylene glycol, I,5-propanediol, 1,4-butanediol, 1,5-bentanediol, 1,6-hexanedio-I, dielene glycol, diglobylene glycol, triethylene glycol, cyclohexane dimetatool, bisphenol A1, hydrogenated bisphenol A, and the like.

It is essential to use 0.2 to 5 mol% of Cl sulfonatric isophthalic acid based on the total acid components.
If it is less than 2 mol %, the dispersibility of the so-called magnetic powder, face 11, etc. will be poor, and if it exceeds 5 mol %, the solubility of the polyester resin in solvents will deteriorate, which is unsuitable.

unexploded! As mentioned above, the biggest feature of y1 is that it has a structure similar to the above-mentioned (al acid component, (bl glycol component, (Cl sulfonatric cum isophthalic acid), as well as (dl nitrogen element-containing compound). The objective is to produce a polyester resin containing the essential components.The compound is used in an amount of 5 to 10 mol%, more preferably 4 to 7 mol%, based on the total glycol component.If it is less than 5 mol%, The dispersion effect is extremely low for powders such as pigments, fillers, and magnetic powders (7), gelation is likely to occur, and long-term storage is poor, and the desired effect of the original FJ-] cannot be obtained. On the other hand, if the amount exceeds 10 mol %, the polyester resin becomes stone-like and is not suitable for practical use. Only by adding within the above range can the greatest feature of dispersion stability be obtained. Examples of nitrogen element-containing compounds having the nrr structure include 1) ethylenediamine, trimethylenediamine, buto-1notsine, cadaverine, hexamethylenediamine, 2) 2-human lJxyethyl-p-toluidine, 2-carboxy1-tyl-p-toluidine. , 5) β-proviolaccum, T-petyloraccum,
Examples include T-parerolactam, ε-caprolactam, heptolactam, and ring-opened products of C), but are not particularly limited, and one or more of these can be used in combination as appropriate.

When the polyester resin of the present invention is used as a binder for magnetic tape, the part of the head that the tape directly binds and contacts is extremely hard. However, for this purpose, it is necessary to add (c) 0.1 to 10 mol% of a polyhydric alcohol of hexahydric or higher valence to the total glycol component in addition to the ingredients listed in I. If it is less than 0.1 mole, sufficient effect cannot be obtained, and if it is added in excess of 10 moles, it may cause gelation of the polyester resin or impair its solubility in the vehicle. I don't like it because it has a tendency. Alcohols with a valence of 5 or more include trimethylolethane, trimethylolpropane, glycerin, pentaerythritol, etc.
Any can be used.

(e) A polyester resin containing a polyhydric alcohol component having a valence of 5 or more is further improved in abrasion resistance when a compound reactive with hydroxyl groups is used in combination as a crosslinking agent. Such crosslinking agents include isocyanate compounds, melamine resins, epoxy resins, etc., but in particular incyanate compounds, eg JJf 2. Preferred examples include polyisocyanates such as a-), lylene diisocyanate, and xylylene diisocyanate.

The optimal amount of these crosslinking agents to be added depends on the application, so it cannot be absolutely specified, but it is usually desirable to use 1 to 5 equivalents based on the hydroxyl group of the polyester derived from the (e) polyhydric alcohol component of 5 or more valences. .

In producing the polyester resin of the present invention, usually (a
) Alcohol component (including (e) if a polyhydric alcohol with a filtration value or higher is used) is added to 1 mole of the total amount of the acid component and (C) sulfonatrichumisophthalic acid.
05-6 mol, (d) nitrogen element-containing compound f: 0.05
Charge the ester catalyst, heavy bond catalyst, and stabilizer together at a ratio of ~0.1 mole or in any order into a reaction vessel equipped with a stirrer, a total container, 4 containers per minute, and a torque meter, and bring the temperature to 1.
Esterification is carried out at 50-250°C. Esterification catalyst (!: 1~, digityltin oxide, zinc oxoxate,
Antimony trioxide or the like is used as a polycondensation catalyst, and phosphoric acid, triethyl phosphoric acid or the like is used as a stabilizer. It is more effective to place the reaction system under a reduced pressure of 500 to 10 Torr when esterification has progressed to about 9096 degrees. When the esterification progresses to approximately 97%, the vacuum is further increased, and finally 1.
At the same time, the reaction temperature is set to 250-26°C.
When aged at 0℃, the desired polyester 7 and chair 1j
You can get the effect.

The polyester resin obtained in this way has excellent dispersibility of powders such as magnetic powder and pigments, so it goes without saying that it exhibits very good performance when used as a binder for paints and adhesives, especially magnetic tapes. It also has excellent dispersion stability, so it has extremely advantageous properties industrially. Furthermore, plasticizers such as digtylphthalate and triphenyl phosphate, lubricating oil, and antistatic agents can be added as necessary. Furthermore, even when used as a paint, commonly used additives such as leveling agents are added. In addition to these uses, it is also useful as a glue for fibers, a paper processing agent, and a fiber processing agent.

The method of the present invention will be explained in more detail below with reference to Examples.

Production example of polyester resin (A) Terephthalic acid 0.4 mol, Inphthalic acid 90.44 mol,
Adipic acid 0. +5 mole, ethylene glycol 0.45
mol, neopentyl glycol [1.42 mol, sulfonatrichum isophthalic acid 0. OI moles, 2-0007 moles of rutin oxide were charged into an 11-volume flask equipped with a stirrer, a partial condenser, a total container, and a torque meter, and reacted at 150 to 250 C. Then, antimony trioxide Add .005 mol of o,001'-E-nyl phosphate and conduct the reaction at 250°C under reduced pressure of 1 torr or less,
Intrinsic viscosity: o, 68, hydroxyl value: 8KOHmy7. polyester resin k t'J k.

Thereafter, polyester resins (I31~) having compositions and physical properties as shown in Table 1 were obtained in the same manner. Furthermore, for comparison, resins (E) to (Ma) having the compositions shown in the same table were produced in the same manner.

Example 1 Each of the obtained polyester resin bodies) to (D+) was placed on a magnetic tape.
The performance when used as a binder for plastic wrap was evaluated by the method described below. However, [a 1:1 (volume ratio) mixed solvent of methyl isobutyl ketone and toluene was used as the two solvents. Furthermore, for resin (c) K, 2 is added as an isocyanate compound.
．． A similar evaluation was performed by adding 1 equivalent of 4-tolylene diisocyanate to the binder solution just before use (assuming that resin<c5').

The results are shown in Table 2.

Comparative Example 1 Evaluation was carried out in the same manner as for rotation except that resins (Ii,) to α() used in Example 1 were used instead of DJ.The results are shown in Table 2. Shown.

The evaluation items and methods are as follows.

Oa air stretchable binder solution + 00 * VC + oy T
- 7-Fe after dispersing iron dioxide (T-Fe203) in a ball mill, collecting 20 rne, and leaving it for 24 hours.
, 03 was measured.

0-minute stability: After the solution was allowed to stand for 24 hours, the solution was repeatedly turned upside down to redisperse it, and was evaluated based on ease of redispersion, overall length, and poor quality.

0 Abrasion resistance: The above dispersion was uniformly applied onto a polyester film and dried, and after curing, a test was conducted using a Tate type abrasion tester, and evaluation was made by the number of rotations at which the magnetic layer was removed.

0 Magnetic properties: The ratio BT/Bs (squareness) of the saturation magnetization Bs in the orientation direction to the residual magnetism of the obtained magnetic tape was measured.

Example 2 The performance of polyester resin bodies) to (DJ and the above (C)' when used as paint resins was evaluated by the method described below. However, toluene and cyclohexane were used as solvents.
:1 (volume ratio) mixed solution was used as a 40% by weight resin liquid. The results are shown in Table 2.

Comparative Example 2 Evaluation was carried out in the same manner as in the rotation except that resins (A) to (DJ) used in Example 2 were used instead of resins (E) to α().The results are shown in Table 5. Shown.

The evaluation items and methods are as follows.

0 Pigment dispersibility: 60PHR of titanium oxide in paint resin liquid
Disperse the liquid with a repaint conditioner and apply it to a polished mild steel plate with a regular thickness of 0.5" after passing through it at a temperature of 280.
Baked at ℃ for 60 seconds. The gloss rate of this coating film is 6 Uf
'-60° reflection gloss rate was determined to be 1111.

0 Dispersion stability: The above dispersion was allowed to stand for one week and the presence or absence of sediment was examined.

0 Paint film hardness: Based on JIS K5401 K, the hardness value of the pencil is shown when the pencil mark is erased and there are no scratches.

Table 2 Table 6 Patent applicant: Nippon Gosei Chemical Industry Co., Ltd. 142-

Claims (1)

[Claims] 1. (a) F L/phthalic acid and (also 1l-j'
) at least 80 mol % of isofucuric acid based on the total acid component
, (b) at least 80 mol % of ethylene glycol and/or neopentyl glycol based on the total glycol component, (c) 0.2 to 5 mol % of sulfonium isophthalic acid based on the total acid component, (dl below) 1) to 5) General formula % Formula % (However, R, R'[alkylene, R1 is an alkyl group or aryl group, x, x' are carboxyl groups or hydroxyl groups, and x, x' are the same group. A method for producing a polyester resin, comprising 6 to 10 mol% of at least one of the nitrogen element-containing compounds represented by (may be present or stationery) based on the total glycol component. 2. (a) at least 80 mol% of terephthalic acid and/or isophthalic acid based on the total acid component; (b) at least 80 mol% of ethylene glycol and/or neopentyl glycol based on the total glycol component; (c) 0.2 to 5 mol% of sulfonodium isophthalic acid based on the total acid components; (d) General formula % formula % of the following 1) to 3) (similar, R and R' are alkylene, R1 At least one of the nitrogen element-containing compounds represented by an alkyl group or an aryl group, x and x' are carboxyl groups or hydroxyl groups, and X and X' may be the same or different.
A method for producing a polyester resin, wherein the seed is 10% by mole based on the total glycol component, and (e) 0.1 to 10% by mole based on the total glycol component.