JP2830137B2 - Polyester composition - Google Patents

Description

The present invention relates to a polyester composition, and particularly to a film,
The present invention relates to a polyester composition capable of simultaneously satisfying the surface characteristics and the slipperiness of a molded article such as a fiber.

[Prior art] Polyester, especially polyethylene terephthalate, has excellent mechanical properties and chemical properties, so it is widely used as a film for clothing, industrial fibers, magnetic tapes, photographs, capacitors, etc. ing.

In these applications, smoothness is required from the viewpoint of workability at the time of forming a molded article such as a film or fiber and handling property of the product as well as the flatness of the surface.

Conventionally, as a method of improving lubricity, a method of adding inert particles such as silicon oxide, titanium dioxide, calcium carbonate, talc, and clay (external particles), a catalyst component used in the synthesis of polyester, and a coloring prevention agent. There has been proposed a method of generating fine particles (internal particle method), and a method of improving the slipperiness by forming protrusions on the surface by fine particles in polyester has been known. However, when such particles are used, the problem that the surface flatness is impaired by the incorporation of coarse particles or aggregated particles is unavoidable, and there is a limit to imparting slipperiness while maintaining the surface flatness. Was.

Also, methods using various organic polysiloxanes as additives other than particles (JP-A-50-92949, JP-A-58-2322)
5) has been proposed. However, in the case of ordinary organic polysiloxane, since it is not compatible with polyester, dispersion is poor and coarse crater-like irregularities occur on the surface of the molded product. Further, in the case of polydimethylsiloxane having hydroxyl groups at both molecular terminals disclosed in JP-A-58-2323, the flatness of the surface of the molded article is relatively good, but the sliding property is insufficient. That is, even when these organic polysiloxanes were used as additives other than the particles, it was difficult to simultaneously satisfy the surface flatness and the slipperiness.

[Problems to be Solved by the Invention] An object of the present invention is to solve the above-mentioned drawbacks of the prior art, and to provide a polyester composition which can simultaneously satisfy the smoothness and the slipperiness of the surface of a molded article. To provide.

[Means for Solving the Problems] An object of the present invention is to provide a polyester-based oligomer having two or more organic polysiloxane chains in a pendant form (however, a polybasic acid represented by the following general formula (A): (Excluding a polyester resin obtained by polycondensation with a polyhydric alcohol)) to a polyester composition.

(In the formula, n is an integer of 3 to 130.) The polyester in the present invention refers to a polyester obtained from a dicarboxylic acid or a derivative thereof and a glycol.

The main object of the dicarboxylic acid or its derivative is terephthalic acid or its lower alkyl ester, and other acid components such as isophthalic acid and p-
β-oxyethoxybenzoic acid, diphenylsulfone 4,
4'-dicarboxylic acid, diphenyl ether 4,4'-dicarboxylic acid, diphenoxyethane 4,4'-dicarboxylic acid, adipic acid, sebacic acid, dodecane diacid, azelaic acid,
One or two or more kinds of 5-sodium sulfoisophthalic acid or esters of lower alkyl or glycol thereof can be used in combination.

Glycols are mainly ethylene glycol and tetramethylene glycol-1,4, but other glycol components such as propylene glycol, trimethylene glycol, neopentyl glycol, hexamethylene glycol-1,6, and pentaethylene glycol -1,5,1,4-cyclohexanediol, 1,4
One or more of cyclohexanedimethanol, 1,4-bisoxyethylene glycol, bisphenol A, and polyoxyethylene glycol may be used in combination.

To produce a polyester comprising the above dicarboxylic acid or its derivative and a glycol, any method is employed. For example, to describe polyethylene terephthalate comprising a terephthalic acid component and an ethylene glycol component, a direct esterification reaction of terephthalic acid and ethylene glycol, a transesterification reaction of dimethyl terephthalate and ethylene glycol, or a reaction with terephthalic acid It is produced by a first stage reaction of reacting with ethylene oxide to produce a glycol ester of terephthalic acid or a low polymer thereof, and a second stage of subjecting the reaction product of the first stage to a polycondensation reaction. Is the most common.

The polyester composition of the present invention is obtained by blending a specific organic polysiloxane with the polyester described above,
The compound is a polyester oligomer having at least two or more organopolysiloxane chains in a pendant form via an ester bond (provided that the above-mentioned general formula (A)
(Excluding polyester resins obtained by polycondensation of the polybasic acid represented by the formula (1) and a polyhydric alcohol).

As is clear from the above, the polyester-based oligomer having an organic polysiloxane chain used in the present invention has substantially no reactive functional group at one end with respect to one organic polysiloxane chain, that is, is blocked. The other molecular terminal has two ester-bonding functional groups, and has a chemical structure in which at least two or more organic polysiloxane chains are connected in a pendant manner by the ester bonding of the functional groups.

A typical example of the polyester oligomer having the pendant organopolysiloxane chain is represented by the following general formula:
And (II).

(Where R ₁ is a hydrogen atom, an alkyl group or —CH ₂ CH ₂ OH
It is. R ₂ is an alkyl group. R ₃ and R ₄ are an alkyl group,
One selected from a phenyl group and a fluorine-containing alkyl group,
R ₃ and R ₄ may be the same or different. X is a trivalent organic group. x ₁ is an integer of 2 to 20. y ₁ is 0-20
Is an integer. n1 is an integer of ₃ to 100. ) (Where R ₅ is a hydrogen atom, an alkyl group or —CH ₂ CH ₂ OH
It is. R ₆ is an alkyl group. R ₇ and R ₈ are an alkyl group,
One selected from a phenyl group and a fluorine-containing alkyl group,
R ₇ and R ₈ may be the same or different. Y is a trivalent organic group. x2 is an integer of ₂ to 20. y ₂ is 0 to 20
Is an integer. n2 is an integer of ₃ to 100. In formulas (I) and (II), when R ₃ , R ₄ , R ₇ , and R ₈ are alkyl groups, the number of carbon atoms is not particularly limited, but is usually 4 or less such as methyl and ethyl. Is preferably a lower alkyl group or a phenyl group. In the case of a fluorine-containing alkyl group, there is no particular limitation, but a normal trifluoropropyl group is preferred.

n ₁ and n ₂ are 3 to 100. If n ₁ and n ₂ are smaller than 3,
The effect of improving slipperiness is not sufficiently exhibited, which is not preferable. On the other hand, if n ₁ and n ₂ are more than 100, the compatibility with the polyester becomes insufficient, and the surface smoothness of a molded product is impaired. x ₁ and x ₂ are integers of ₂ to 20, y ₁ and y ₂
Is an integer of 0 to 20, preferably x ₁ and x ₂ are 3 to 10,
y ₁ and y ₂ are 0 to 10.

X and Y are organic chains connecting the ester-forming functional group and the siloxane moiety, and may be any of an aliphatic chain, an aromatic chain or an alicyclic chain, and may contain an ether bond. .

Specific examples of these organic chains are represented by X As Y, (R ₉ and R ₁₀ are each hydrogen or an alkyl group, p ₁ , q ₁ , r
₁ , p ₂ , q ₂ , and r ₂ are each an integer of 0 to 10. ) And the like.

In the present invention, the compounding amount of the polyester oligomer having an organic polysiloxane chain in a pendant form is preferably 0.01 to 30 parts by weight based on 100 parts by weight of the polyester,
0.05-10 parts by weight is more preferred. If the amount is less than 0.01 part by weight, the lubricity of the film is insufficient, and if it is more than 30 parts by weight, the mechanical strength of the film or fiber is inferior.

Further, a part of the polyester-based oligomer may be present in combination with the polyester.

The compound can be added to the polyester at any time.A method of adding the compound during the polycondensation reaction or a method of kneading with an extruder can be used. In order to improve the dispersion, the addition reaction is preferably performed before the completion of the polycondensation reaction. Alternatively, a method of preparing a high-concentration master polymer in advance and diluting it with an unadded polyester can be used.

In the polyester composition of the present invention, the polyester-based oligomer may be used alone, or the above-mentioned external particles and internal particles may coexist. An object of the present invention is to simultaneously satisfy the flatness and smoothness of the surface of a film or fiber, which cannot be achieved by the conventional method of applying fine particles, but satisfy the flatness required for a molded article such as a film or a fiber. Providing fine projections on the surface within the range described above synergistically enhances the effects of the present invention.

The fine particles used may be any of external particles and internal particles such as calcium carbonate, titanium oxide, kaolin, silica, and calcium terephthalate, but are not limited thereto. Further, in the polyester composition of the present invention, additives such as a colorant and a stabilizer can be used in combination.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples.

 In addition, the physical property in an Example was measured as follows.

A. The intrinsic viscosity of the polymer is a value measured at 25 ° C. using o-chlorophenol as a solvent.

B. The number of foreign substances in the polymer was represented by the number of foreign substances visible to the naked eye in a range of 30 × 40 cm of the ribbon on a piece of white paper when the polymer was taken out in a ribbon shape at the time of ejection.

C. The coefficient of friction of the film is a value measured according to the ASTM-D-1894-63 method.

D. The surface roughness of the film was indicated by the center line average roughness Ra.

Example 1 5 parts by weight of a polyester-based oligomer having an organic polysiloxane chain represented by the formula, 100 parts by weight of dimethyl terephthalate, 70 parts by weight of ethylene glycol, and 0.1 part of calcium acetate.
09 parts by weight and 0.03 parts by weight of antimony trioxide were added,
A transesterification reaction was carried out by a conventional method, and 0.04 parts by weight of trimethyl phosphate was added to the obtained product. Thereafter, the temperature was gradually increased and the pressure was reduced, and finally polymerization was performed at 290 ° C. and 1 mmHg or less. 3 hours after the start of pressure reduction
617 polyester compositions were obtained.

This composition was melt-extruded at 280 ° C. to prepare an unstretched sheet. Next, the film is stretched 3.5 times in one direction at a temperature of 80 ° C., further stretched 3.6 times in a right angle direction at a temperature of 110 ° C., and is heat-set at 200 ° C. for 5 seconds to obtain a biaxially stretched film having a thickness of 15 μm. Was. The surface roughness and slipperiness of the film are as shown in Table 1, which indicates that the film has excellent performance in surface flatness and slipperiness. In general, desired values in the film field are a surface roughness Ra of 0.03 μm or less and a dynamic friction coefficient of 1.0 or less.

Comparative Examples 1-4, Examples 2, 3 As shown in Table 1, a biaxially stretched film was obtained in the same manner as in Example 1, except that the polyester-based oligomer having an organic polysiloxane chain was changed.

The results, as shown in Table 1, show that when the polyester-based oligomer having the organic polysiloxane chain of the present invention was blended, both the surface flatness and the slipperiness of the film were good.

Example 4 90 parts by weight of polyethylene terephthalate having an intrinsic viscosity of 0.615 containing 1 part by weight of calcium carbonate having an average particle size of 0.5 μm was blended with 10 parts by weight of the polyester composition obtained in Example 1, and Similarly, a biaxially stretched film was obtained. The resulting film had a surface roughness of 0.01 μm and a kinetic friction coefficient of 0.4, and the surface flatness and slipperiness were extremely good.

[Effects of the Invention] In the present invention, when the polyester is formed into a molded article such as a film or a fiber by using a polyester composition containing a polyester oligomer having a pendant organic polysiloxane chain, the surface smoothness is improved. Not only can improve the lubricating properties, but also exhibit excellent water and oil repellency.

Therefore, the polyester composition of the present invention is effectively used in the field of films, fibers and the like, and in particular, magnetic tapes with strict demands for surface smoothness and lubricity, films such as release paper utilizing water and oil repellency. When used in the field, the effect is more remarkably exhibited.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ identification code FI C08L 83:10) C10N 30:06 50:08 (58) Investigated field (Int.Cl. ⁶ , DB name) C08L 67/00 -67/08 C08L 83/00-83/16 C08G 63/00-63/91 C08G 77/00-77/62 C10M 107/50

Claims (1)

(57) [Claims] 1. A polyester oligomer having two or more organic polysiloxane chains in a pendant form (excluding a polyester resin obtained by polycondensing a polybasic acid and a polyhydric alcohol represented by the following general formula): A) a polyester composition obtained by blending the above with a polyester. (In the formula, n is an integer of 3 to 130.)