JPH09238731A - Hair curler comprising polyester elastomer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve flexibility, heat resistance and chemical resistance by forming a hair curler of a polyester block copolymer having a specific m.p. and a block copolymer of polytetramethylene terephthalate. SOLUTION: The polyester block copolymer compsn. consisting of 100 pts.wt. polyester block copolymer consisting of 20 to 70wt.% hard segment consisting essentially of the specific polytetramethylene terephthalate and 80 to 30wt.% soft segment consisting of the specific polyester and 0 to 200 pts.wt. polytetramethylene terephthalate is used as the molding material. The m.p. T of the polyester block copolymer is specified to T0 -5>T>T0 -60 T>T'+50. (T0 : the m.p. of the polymer consisting of the component constituting the hard segment, T': the m.p. of the copolymer polymer consisting of the entire component constituting the soft segment).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a hair curler comprising a specific polyester block copolymer or a composition of the polyester block copolymer and polytetramethylene terephthalate.

[0002]

Conventionally, crosslinked rubber, thermoplastic olefin elastomer, polypropylene, polyethylene, etc. have been used for hair curlers,
No resin material was found that was satisfactory in terms of heat resistance such that it was not deformed by the heat of the hair dryer, and that it was not discolored or deteriorated by the hair styling agent. In other words, it is a thermoplastic resin that has flexibility near 0 ° C., does not deform even in an atmosphere of 100 ° C., does not thermally deteriorate even when exposed to an atmosphere of 150 ° C., and has excellent chemical resistance to alcohol and the like. Resin is required.

[0003]

An object of the present invention is to provide a hair curler using a thermoplastic polyester elastomer having excellent flexibility, heat resistance and chemical resistance.

[0004]

Means for Solving the Problems As a result of repeated studies to find out a thermoplastic resin excellent in flexibility, heat resistance and chemical resistance as described above, the present inventors have found that a specific polyester block copolymer may be polytetratetrafluoroethylene. It has been found that these characteristics are satisfied by blending methylene terephthalate, and the present invention has been completed.

That is, in the present invention, terephthalic acid and tetramethylene glycol are 20 to 70% by weight of a hard segment containing 60 mol% or more of polytetramethylene terephthalate as a main component per dicarboxylic acid component, an aromatic dicarboxylic acid and HO ( CH ₂ CH ₂ O) _n H (n = 2 to
Soft segment 8 consisting of polyester in which the long-chain diol of 5) is 60 mol% or more per dicarboxylic acid component
0 to 30% by weight, the melting point (T) of the polymer
Is a polyester block copolymer (A) in which is within the following range
A hair curler comprising a polyester block copolymer composition comprising 100 parts by weight and 0 to 200 parts by weight of polytetramethylene terephthalate (B) as a molding material.

T ₀ -5>T> T ₀ -60 T> T '+ 10 (T ₀ : melting point of polymer composed of components constituting hard segment T': composed of all components constituting hard segment and soft segment) Melting point of copolymer)

The present invention will be described. The polyester block copolymer used in the present invention has a hard segment whose main component is polytetramethylene terephthalate, but other than terephthalic acid, an aromatic dicarboxylic acid containing a benzene or naphthalene ring and a carbon number of 4 to 12 Aliphatic dicarboxylic acids, aliphatic diols having 2 to 12 carbon atoms other than tetramethylene glycol, and diols such as alicyclic diols such as cyclohexanedimethanol may be copolymerized, and the copolymerization ratio is all dicarboxylic acids. Per 4
It is less than 0 mol%, preferably less than 30 mol%. The smaller the copolymerization ratio, the higher the melting point, which is preferable, but copolymerization is also performed to increase flexibility. However, if the proportion of copolymerization increases, it becomes difficult to crystallize and the moldability deteriorates. This copolymerization ratio is difficult to specify in the block copolymer of the present invention, but the melting point of the crystal is 150 ° C. or higher, preferably 16
It is applicable when the temperature is 0 ° C or higher.

On the other hand, as the soft segment, a polyester containing terephthalic acid and a long chain diol of HO (CH ₂ CH ₂ O) _n H (n = 2 to 5) as main constituents is used. It may be a copolymer of a group dicarboxylic acid, an aliphatic or alicyclic dicarboxylic acid or a short chain diol. The copolymerization ratio of the dicarboxylic acid and the short chain diol is preferably 40 mol% or less based on the total dicarboxylic acid including terephthalic acid.

The copolymerizable aromatic dicarboxylic acid, aliphatic dicarboxylic acid and alicyclic dicarboxylic acid which can be used here include, for example, isophthalic acid, phthalic acid, naphthalene dicarboxylic acids, straight chain having 4 to 12 carbon atoms. Dicarboxylic acids, especially linear dicarboxylic acids having 8 to 12 carbon atoms, cyclohexanedicarboxylic acid and the like. Examples of the copolymerizable short-chain diol include linear aliphatic diols having 2 to 12 carbon atoms. The polyoxyalkylene glycol has a molecular weight of 1200 or less, preferably 1
Those having a relatively low molecular weight of 000 or less are used.

In the polyester block copolymer of the present invention, the amount ratio of the hard segment and the soft segment is 20 to 70:80 to 30, preferably 25 to 50:75 to 50. The amount ratio of these is not preferable because the resulting polyester block copolymer is hard when there are more hard segments and problems such as curling occur, and when there are many soft segments, the crystallinity decreases, and as a polyester elastomer. It is difficult to use.

The segment length of the soft segment and the hard segment of the polyester block copolymer is expressed as a molecular weight of about 500 to 700.
It is 0, preferably 800 to 5000, but is not particularly limited. Although it is difficult to directly measure this segment length, for example, the composition of the polyester that constitutes each of the soft and hard segments, the melting point of the polyester composed of the components that constitute the hard segment, and the obtained polyester block copolymer It can be estimated from the melting point using the Flory equation.

In the present invention, a method of producing a soft segment and a hard segment, respectively, and melt-mixing them so that the melting point of the copolymer is 2 to 40 ° C. lower than that of the polyester component constituting the hard segment can be mentioned. Since this melting point changes depending on the mixing temperature and time, it is preferable that the catalyst is deactivated by adding a catalyst deactivator such as phosphorus oxyacid when the desired melting point is reached.

As the polyester block copolymer of the present invention, one having an intrinsic viscosity of 0.6 or more, preferably 0.8 to 1.5, measured in orthochlorophenol at 35 ° C. can be applied. This is because if the intrinsic viscosity is lower than this, the mechanical strength will be low, which is not preferable.

On the other hand, the polytetramethylene terephthalate used in the present invention is a polyester mainly composed of terephthalic acid and tetramethylene glycol, but contains up to 30 mol% of other dicarboxylic acid or glycol. You can As the copolymerizable dicarboxylic acid, the same as those shown as the copolymerizable dicarboxylic acid of the soft segment can be used, on the other hand, as the glycol, the same as the above except tetramethylene glycol and HO (CH ₂ CH ₂ O) _n H similar to that used for the soft segment is used.

The polytetramethylene terephthalate used has an intrinsic viscosity of 0.6 or more (the measuring method is the same as that of the polyester block copolymerization), preferably 0.7 to 1.5.

The composition of the present invention is a mixture of 100 parts by weight of the above polyester block copolymer (A) and 0 to 200 parts by weight of polytetramethylene terephthalate (B), preferably 100 parts by weight of the polyester block copolymer. And 5 to 100 parts by weight of polytetramethylene terephthalate.

In addition to the polyester block copolymer and polytetramethylene terephthalate, the polyester block copolymer composition used in the present invention contains stabilizers, reinforcing fillers, pigments, dyes, flame retardants, nucleating agents, lubricants and other additives. The agent may be contained within a range in which the effect of the present invention is not impaired, and other polymers may be blended. As the other polymer, for example, 0.01 to 50 parts by weight of a glycidyl-modified polyolefin is blended for the purpose of improving impact resistance at low temperature.

The composition of the present invention can be produced by a usual melt mixing method, and for example, a screw type continuous extruder can be used.

In the present invention, the polyester block copolymer or the composition containing the copolymer as a component is molded and used as a hair curler. Generally, the molding is performed by a melt molding method. As an example, the injection molding method is the most common.

Further, the molding may be carried out independently, and only the hair curler may be molded, or the other parts may be simultaneously molded by two-color molding or insert molding.

The hair curler according to the present invention is of a type which is wound around hair alone to supply heat or warm air from the outside, a type having a mechanism for generating heat or storing heat inside the curler, and which is attached to another device and wound around hair. There are types, but they are applicable regardless of these.

[0022]

The present invention will be described in detail with reference to examples. In the examples, “parts” means “parts by weight”.

Reference Example 1 Dimethyl terephthalate 194
And 160 parts of triethylene glycol, were subjected to a transesterification reaction with a dibutyltin diacetate catalyst, and then polycondensed under reduced pressure to obtain a starch-like polyester (A) having an intrinsic viscosity of 0.76. To this polyester, a polytetramethylene terephthalate (a) chip having an intrinsic viscosity of 0.98, which was separately obtained by polycondensation, was dried and added at 107 parts at 250 ° C.
After further reacting for 75 minutes, 0.1 part of phenylphosphonic acid was added to stop the reaction. This polyester block copolymer was taken out and made into chips to be used as a raw material. This chip has a melting point of 176 ° C and an intrinsic viscosity of 0.8.
It was 3.

Reference Example 2 Dimethyl terephthalate 180
Part, dimethyl sebacate 20 parts, tetraethylene glycol 140 parts and diethylene glycol 30 parts were transesterified with a dibutyltin diacetate catalyst and then polycondensed under reduced pressure to obtain a polyester having an intrinsic viscosity of 1.06.
This polyester was blocked in the same manner as in Reference Example 1 and then made into chips (polyester block copolymer).

Reference Example 3 Dimethyl terephthalate 65
Parts, polytetramethylene glycol (average molecular weight 200
0) 126 parts and 61 parts of tetramethylene glycol were polymerized by a conventional method using tetrabutoxide titanate as a catalyst to obtain a polyester block copolymer having an intrinsic viscosity of 1.42.

Example 1 To 100 parts of the polyester block copolymer of Reference Example 1, 50 parts of polytetramethylene terephthalate (intrinsic viscosity 1.02) was melt extruded at 250 ° C. by an extruder. The extruded polyester block copolymer is made into chips, dried at 130 ° C, and then injection molded at a mold temperature of 20 ° C and a cylinder temperature of 240 ° C.
A hair curler having an STM test piece and a cylindrical protrusion having a diameter of 1 mm and a length of 3 mm on the surface of a circular cylinder was obtained. ASTM
From the test piece, the tensile breaking strength, breaking elongation, Izod impact value with notch at −20 ° C. and flexural modulus were measured.

Further, from the hair curler molded article, the presence or absence of breakage of the protrusions after exposure for 100 hours at 0 ° C. and 150 ° C. was measured. As a result, no breakage of the protrusion was observed under both test conditions. Further, as the chemical resistance, the presence or absence of whitening or swelling was measured after 24 hours of immersion in methanol. As a result, no bleaching or swelling was observed with the naked eye after 24 hours. The results are shown in Tables 1 and 2.

[Example 2] The same evaluation as in Example 1 was carried out using the polyester block copolymer of Reference Example 2, and no particular problem was observed.

Example 3 In Example 1, 10 parts by weight of glass fiber was added to 100 parts by weight of the resin component,
The same evaluation as in Example 1 was performed. As a result, although the flexural modulus was improved, a good result was obtained in which the bendability was not reduced.

Comparative Example 1 Using the polyester block polymer of Reference Example 3, the same evaluation as in Example 1 was performed.
As a result, the chemical resistance was poor and whitening swelling was observed. It also has poor heat resistance, and after being exposed at 150 ° C for 100 hours,
The protrusion was broken due to heat deterioration.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

By carrying out the present invention, it is possible to obtain a hair curler comprising a polyester block copolymer composition which is excellent in chemical resistance and heat resistance and in which projections are not easily broken.

Claims (1)

[Claims] 1. Hard segment 20 to 70% by weight of terephthalic acid and tetramethylene glycol whose main component is polytetramethylene terephthalate in an amount of 60 mol% or more per dicarboxylic acid component, aromatic dicarboxylic acid and HO (CH ₂ CH ₂ O) _n H (n = 2 to 5) long-chain diol is 60 mol% or more with respect to dicarboxylic acid component Soft segment composed of polyester of 80 to 30 wt%
A block copolymer composed of 100 parts by weight of (A) polyester block copolymer and (B) 0 to 200 parts by weight of polytetramethylene terephthalate, the melting point T of which is within the following range. A hair curler using the composition as a molding material. T ₀ -5>T> T ₀ -60 T> T ′ + 10 (T ₀ : Melting point of polymer composed of components constituting hard segment T ′: Copolymer composed of all components constituting hard segment and soft segment segment Melting point)