JPS62235353A - Polyester composition - Google Patents

Abstract

PURPOSE:A polyester composition, obtained by containing calcium carbonate treated with a specific phosphorus compound in a linear polyester and having improved affinity of the calcium carbonate for the polyester as well as ready slipperiness, transparency and abrasion resistance. CONSTITUTION:A polyester composition obtained by adding calcium carbonate prepared by treating calcium carbonate with 0.1-30wt%, preferably 0.5-20wt% (based on the calcium carbonate) partial ester of phosphoric (phorphorous) acid expressed by the formula (R is 4-20C alkyl, aryl, hydroxyalkyl or alkoxyalkyl, bn is 0 or 1; l is 1 or 2; m is 1 or 2; l+m is 3), e.g. monobutyl phosphate, etc., and having preferably <=5mu average particle diameter in an amount of 0.01-3pts.wt. based on 100pts.wt. linear polyester thereto, e.g. in synthesizing the polyester or before completing the polycondensation. The calcium carbonate is added in the form of powder of a glycol slurry.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to polyester compositions useful in making molded articles such as improved polyester films and polyester fibers. More details on charcoal.

A film with excellent transparency and abrasion resistance by improving the affinity with polyester of fine particles mainly composed of calcium oxide.
This invention relates to a polyester composition that can be used to make molded articles such as fibers.

BACKGROUND OF THE INVENTION Generally, polyethylene terephthalate is widely used in films, fibers, etc. because of its excellent mechanical and chemical properties. However, when producing films or fibers that take full advantage of their transparency and brightness, process defects often occur during the molding and processing steps. The cause is often a high friction coefficient rj! This is due to Z'.

Conventionally, many methods have been proposed to reduce the friction coefficient of polyester, including the presence of fine particles in polyester, but the affinity between the fine particles and polyester is insufficient, and the transparency and abrasion of films and fibers have Neither gender was satisfactory.

Conventional methods for improving the surface properties of polyester include (1) a method in which part or all of the catalyst used during polyester synthesis is precipitated during the reaction process (internal particle precipitation method); ■ a method in which fine particles such as calcium carbonate or silicon oxide are precipitated Many methods (external particle addition method) of adding during or after polymerization have been proposed.

However, in the internal particle precipitation method (1), since the particles are metal salts of the polyester component, it has a certain degree of affinity with polyester, but on the other hand, it is a method in which particles are generated during the reaction, so the particle amount It is difficult to control the particle size and prevent the generation of coarse particles.

On the other hand, in method (2), if the particle size, amount added, etc. are appropriately selected, and fine particles from which coarse particles are removed by classification or the like are added, excellent slipperiness can be obtained. However, since the affinity between the inorganic particles and the organic component polyester is not sufficient, peeling occurs at the interface between the particles and the polyester during stretching, etc., and voids are generated. Because of this transparency.

This is a problem that needs to be solved in terms of wear resistance.

To improve the affinity between inorganic particles and polyester, surface treatment using a coupling reaction between silane-based compounds or titanate-based compounds and inorganic particles has been proposed, but the treatment process is complicated and the effects are not expected. There were various kinds of good luck, such as being out of place.

Purpose of the Invention In view of the above-mentioned circumstances, the present inventors have created a polymer with fine particles present therein to improve slipperiness and transparency.

As a result of intensive studies on polyester suitable for producing films and fibers with excellent abrasion resistance, we found that when calcium carbonate is treated with a specific phosphorus compound before use, the resulting films and m-fibers have good properties. The present invention has been achieved based on this discovery.

The purpose of the present invention is to provide a film with excellent transparency and abrasion resistance,
#J! The object of the present invention is to provide a polyester composition that can be used to make molded products such as textiles.

Structure of the Invention The present invention is a polyester composition characterized in that a linear polyester contains calcium carbonate treated with a phosphorus compound represented by the following chemical formula.

A feature of the present invention is the use of calcium carbonate treated in the presence of a phosphorus compound represented by the above chemical formula. The reason why the affinity of calcium carbonate for polyester is improved by treatment in the presence of a phosphorous compound is not clear, but the interaction between the two improves the affinity of calcium carbonate for polyester, especially for stretched polyester compositions. It is thought that it imparts excellent transparency and abrasion resistance to biaxially stretched films and stretched yarns.

The polyester used in the present invention may be any material as long as it can be formed into fibers or films, such as polyethylene terephthalate and polytetramethylene terephthalate.

Polyethylene-p-oxydipenzoate, poly-1,4
-cyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalene dicarboxylate, and the like. Of course, these polyesters may be homopolyesters or copolyesters,
An example of a copolymerization component is diethylene glycol.

Diol components such as neopentyl glycol and polyalkylene glycol, 7 divic acid, sepacic acid, phthalic acid,
Inphthalic acid, 2,6-naphthalene dicarboxylic acid, 5-
Dicarboxylic acid components such as sodium sulfoisophthalate;
Examples include polyfunctional carboxylic acid components such as trimellitic acid and pyromellitic acid in a range in which the polymer maintains a substantially linear shape.

Calcium carbonate in the present invention includes natural products and synthetic products, and crystal types of calcium carbonate include calcite, 7lagonite, and vaterite, and any of these may be used.

In addition, calcium carbonate is (1) pure calcium carbonate +
t2) Contains one or more of magnesium oxide, silicon oxide, calcium hydroxide, and other compounds, and has a calcium carbonate content of 50% or more.

The phosphorus compound referred to in the present invention is a partial ester of phosphoric acid or phosphorous acid represented by the following general formula.

(0)n Examples of the furkyl group for H in the above general formula include butyl, pentyl, hexyl, and octyl.

Indecyl, tesyl, F-decyl, tridecyl.

Examples of the aryl group include phenyl, naphthyl, cresyl, tolyl, xylyl, etc., and examples of the hydroxyalkyl group include hydroxybutyl, hydroxypentyl, hydroxyhexyl, and hydroxyoctyl. , hydroxydecyl, hydroxytetradosyl, hydroxyhexadecyl, etc. Further, examples of the flufukidialkyl group include butoxyethyl. Specific examples include motuputyl phosphate, digutyl phosphate, motuputyl 7-osphite, dioctyl phosphate, monoisodecyl phosphate, diphenyl phosphate, dicresyl phosphate, dihydroxyoctyl phosphate, dibutoxyethyl phosphate, etc. You may use a mixture of more than one species.

In the present invention, the method of treating calcium carbonate with a phosphorus compound is not particularly limited, but examples include (1) a method of adding a phosphorus compound to calcium carbonate powder and carrying out mixing or crushing treatment; (2) a method of treating calcium carbonate and a phosphorus compound; Examples include a method of adding it to a dispersion medium such as ethylene glycol and dispersing or crushing it. In this case, when calcium carbonate is treated with a phosphorus compound, it is preferable to carry out the treatment at room temperature or at a temperature of about 150° C. or lower.

The proportion of calcium carbonate and phosphorus compound used is preferably 0.1 to 30 parts by weight, more preferably 0.1 to 30 parts by weight, based on 100 parts by weight of calcium carbonate, in order to improve the affinity of calcium carbonate to polyester. 5-20
It is best to use within the range of parts by weight.

The average particle size of calcium carbonate after treatment is preferably 5 μ or less, more preferably 2 μ or less. Here, the average particle size refers to the particle size at 50% by weight of all particles measured.
"equivalent spherical diameter". "Equivalent spherical diameter" means the diameter of an imaginary sphere having the same volume as the particle, and can be calculated from an electron micrograph of a single particle or measurement by a conventional sedimentation method.

Regarding the particle size distribution of calcium carbonate having an average particle size of 5 μm or less, it is preferable that it contains almost no coarse particles of about 10 μm or more and has a sharp distribution on the fine side. For this reason, it is preferable to carry out a classification process before or after the treatment with the phosphorus compound.

Various methods can be used to add calcium carbonate treated with a phosphorus compound to the linear polyester. Typical methods include (1) adding it as a powder or glycol slurry before the completion of Mla synthesis during polyester synthesis; and (2) adding it to polyester, melting and kneading it.

In the present invention, the content ratio of calcium carbonate is preferably 0, Q1 to 3 times the weight of the polyester.
%, more preferably 0.05 to 2% by weight. If the amount of calcium carbonate added is extremely small (the resulting film will lack smoothness), if the amount of calcium carbonate added is extremely small (the amount added), various problems will occur such as the surface of the film becoming too rough and transparency decreasing. Undesirable.

The polyester composition of the present invention is effective in the field of fiber, film, and other molding fields, but especially in terms of transparency and
It can be preferably used in the fields of microfilms, vapor deposited films, and magnetic tapes that require abrasion resistance.

EXAMPLES The following examples will be used to specifically explain the present invention. Note that "parts" in the examples mean parts by weight. Further, each characteristic value in the Examples was measured according to the following method.

(1) Etching the affinity film between calcium carbonate and polyester to remove the surface polymer.
After exposing calcium carbonate, under a scanning electron microscope 2
Observation was made at 0,000x magnification.

The affinity is expressed by the following determination based on the ratio of the diameter of calcium carbonate (Da) to the diameter of voids (Db).

1st grade: l≦Db/Da<1.5 (that is, voids do not exist or are very small) 2nd grade: 1.5≦Db/Dc<2.0 3M: 2.0≦Db/Da<4. 0 (2) Film haze Measurement was carried out using a yim haze meter according to the method specified in ASTM D1003-59T.

(3) Abrasion resistance evaluation (calendar abrasion) The abrasion resistance of the film was evaluated using a 5-stage mini super calendar. The calender is a 5-stage calender made of nylon rolls and steel ρ-rolls, and the processing temperature is 80°C.
The linear pressure applied to the film was 200 kf/31, and the film speed was 507+1/min. After running the running film for a total length of 2000 m, the abrasion resistance of the base film was evaluated based on the dirt that adhered to the top roller of the calendar.

<5-level evaluation> O Nylon roll is not stained at all ○ Nylon roll is hardly stained Δ Nylon roll is stained X Nylon roll is very stained × × The film side of a 2-inch wide magnetic tape is attached to a 5-diameter stainless steel SUS back fixed bottle at a speed of 2 m/min for approximately 15 minutes.
It is reciprocated by about 1 cm to cause friction (at this time, the entrance tension T1 was set to 40I).

After repeating this operation and measuring 20 times, the extent of the scratches on the surface was visually determined.

At this time, if there are almost no scratches or only a few scratches, ○
Those that occur in large numbers on the entire surface are judged as ×, and those in between are judged as △.

Example-1 15 parts of calcium carbonate (average particle size 2.5μ) and 2 parts of dioctyl phosphate were added to 85 parts of ethylene glycol (hereinafter abbreviated as EC), mixed and stirred, and then ground in a sand grinder (manufactured by Igarashi Kikai ■, Media The average particle size was 0.6 by crushing using glass beads).
A calcium carbonate-treated product of μ was obtained.

Furthermore, 100 parts of dimethyl terephthalate and 3.4 parts of the EC slurry of lucium carbonate obtained above (calcium carbonate concentration: 20.5% by weight to polymer) were added under stirring as an EG catalyst and transesterified in a conventional manner. did. Then 0.03 parts of trimethyl phosphate, 0.0 parts of antimony trioxide.
03 parts were added thereto, and a polycondensation reaction was carried out in a conventional manner under high temperature vacuum to obtain polyethylene terephthalate having an intrinsic viscosity of 0.620.

Further, the obtained polyester was dried at 180°C, formed into a sheet using an extruder, and then stretched at 90°C at a longitudinal stretching ratio of 3.
Biaxially stretched to 5 times, 4.0 times transverse stretch ratio, and further 200 times
It was heat-set at ℃ to form a film with a thickness of 15μ. The properties of this film are shown in Table-1.

In the obtained film, there were mainly no voids around the calcium carbonate, and even if there were any voids, they were extremely small. The film also had good transparency and abrasion resistance.

Examples-2 to -5 All of Example-1 except that the compound shown in Table-1 was used as the compound in Example-1 (thickness 1
A 5μ film was obtained. The physical properties of the obtained film are shown below.
Show IK.

Comparison → 11 Examples-1 to -4 In Example-I, trimethyl phosphate and dimethyl phosphate were used as phosphorus compounds, respectively! A film with a thickness of 15 μm was obtained in exactly the same manner as in Example 1 except that +phenyl phosphate and no additives were added. The properties of this film are shown in Table-1. The resulting film had large voids around calcium carbonate, and was poor in both transparency and abrasion resistance.

Example-6 95 parts of lucium carbonate (average particle size 0.7 μm) and 5 parts of dioctyl phosphate were mixed and crushed using a ball mill (Ito Seisakusho) to produce a calcium carbonate treated product with an average particle size of 0.6 μm. I got it.

100 parts of polyethylene terephthalate pellets with an ultimate viscosity of 0.65 and 0.5 part of the above calcium carbonate treated product were mixed into 2
After melt-mixing using an axial type extruder, it is made into a sheet using an extruder, and then stretched at 90°C with a longitudinal stretching ratio of 3.5 times and a transverse stretching ratio of 4.0 times! K biaxially stretched and further IC2
Heat set at 00℃ and thick! It was made into a 5μ film. The properties of this film are shown in Table-1.

In the obtained film, there were mainly no voids around the calcium carbonate, and even if there were any voids, they were extremely small. The film also had good transparency and abrasion resistance.

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Claims (1)

[Scope of Claims] 1. A polyester composition characterized in that a linear polyester contains calcium carbonate treated with a phosphorus compound represented by the following chemical formula. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, R is an alkyl group having 4 to 20 carbon atoms, an aryl group, a hydroxyalkyl group, or an alkoxyalkyl group,
n is 0 or 1, l is 1 or 2, m is 1 or 2,
It is an integer such that l+m=3. ] 2 The ratio of phosphorus compound used to calcium carbonate is 0.
The polyester composition according to claim 1, characterized in that the content is 1% to 30% by weight.