JP5080145B2 - Plasticizer for polyamide resin - Google Patents

Description

  The present invention relates to a plasticizer for polyamide resin and a polyamide resin composition.

  Polyamide resins that have been given flexibility by adding a plasticizer are used as construction machines, fuel hoses for automobiles, hydraulic and pneumatic tubes, and injection molded parts for automobile interiors.

  In general, butylbenzenesulfonamide and the like are known as plasticizers for polyamide resins. However, when this plasticizer is added to increase the plasticization efficiency, the surface of the molded product may bleed and become sticky, or these plasticizers may ooze out from the hose or tube and lose flexibility. There is. Furthermore, there is a problem that the heat resistance (volatility) is poor and the working environment at the time of molding deteriorates, and the plasticizer in the product volatilizes with time to deteriorate the plasticization efficiency.

In order to improve these problems, Patent Document 1 proposes a citrate ester in which a hydroxyl group is partially left as a plasticizer for polyamide resin having excellent plasticity and stability. However, the plasticizing efficiency is low for a large number of added plasticizers, and a sufficiently satisfactory polyamide resin composition has not been obtained.
JP-A-5-331368

  An object of the present invention is to provide a plasticizer for polyamide resin capable of imparting flexibility, bleed resistance and heat resistance, and a polyamide resin composition excellent in flexibility, bleed resistance and heat resistance. .

  The present invention provides a plasticizer for polyamide resin containing a (poly) glycerin fatty acid ester represented by the general formula (1), and a polyamide resin composition containing this plasticizer and a polyamide resin.

(Wherein R represents an alkyl group or alkenyl group having 5 to 9 carbon atoms, X represents a hydrogen atom or a group represented by RCO (R represents the above meaning), and a plurality of X may be the same. (It may be different, but at least one is a hydrogen atom. N represents an integer of 0 to 4.)

  The plasticizer of the present invention can impart flexibility, bleed resistance and heat resistance to the polyamide resin, and the polyamide resin composition of the present invention is excellent in flexibility, bleed resistance and heat resistance.

[Plasticizer]
The plasticizer of the present invention contains a (poly) glycerin fatty acid ester represented by the general formula (1).

  In the general formula (1), R represents an alkyl group or an alkenyl group having 5 to 9 carbon atoms from the viewpoint of obtaining excellent compatibility with polyamide, bleeding resistance and plasticizing efficiency, and 7 to 9 carbon atoms. An alkyl group or an alkenyl group is preferable, and an alkyl group or alkenyl group having 8 carbon atoms is more preferable. The alkyl group or alkenyl group may be linear or branched. X is a hydrogen atom or RCO (R represents the above meaning, and an alkyl group or alkenyl group having 7 to 9 carbon atoms is preferable from the viewpoint of obtaining excellent compatibility with polyamide, bleeding resistance and plasticizing efficiency. A plurality of Xs may be the same or different, but at least one is a hydrogen atom. n is an integer of 0 to 4, preferably 0 or 1, and more preferably 1, from the viewpoint of obtaining excellent compatibility with polyamide and heat resistance.

  The (poly) glycerin fatty acid ester represented by the general formula (1) is obtained by esterifying glycerin or polyglycerin (hereinafter referred to as (poly) glycerin) and a fatty acid having 6 to 10 carbon atoms.

  From the viewpoint of obtaining excellent compatibility with polyamide, bleeding resistance and plasticizing efficiency, the reaction ratio of glycerin and fatty acid having 6 to 10 carbon atoms is 1 fatty acid having 6 to 10 carbon atoms with respect to 1 mol of glycerin. It is preferable to react at a ratio of ˜2 mol, and the reaction ratio between diglycerin and a fatty acid having 6 to 10 carbon atoms is a ratio of 1 to 3 mol of fatty acids having 6 to 10 carbon atoms with respect to 1 mol of diglycerin. The reaction ratio between triglycerin and the fatty acid having 6 to 10 carbon atoms is preferably such that the fatty acid having 6 to 10 carbon atoms is reacted at a ratio of 1 to 4 mol with respect to 1 mol of triglycerin. The reaction ratio between tetraglycerin and a fatty acid having 6 to 10 carbon atoms is preferably such that a fatty acid having 6 to 10 carbon atoms is reacted at a ratio of 1 to 5 mol with respect to 1 mol of tetraglycerin. The reaction ratio of glycerin and a fatty acid having 6 to 10 carbon atoms, compared pentaglycerol 1 mole, preferably reacted at a ratio of 1-6 moles of fatty acid having 6 to 10 carbon atoms.

  The (poly) glycerin used in the present invention is at least one selected from the group consisting of glycerin, diglycerin, triglycerin, tetraglycerin and pentaglycerin, and from the viewpoint of more excellent plasticization efficiency, from glycerin and diglycerin. At least one selected is preferable, and glycerin is more preferable.

  The fatty acid used in the present invention has low volatility, has a carbon number of 6 or more from the viewpoint of obtaining a good working environment and kneading efficiency, is excellent in compatibility with the polyamide resin, and has good plasticization efficiency and bleed resistance. From the viewpoint of obtaining properties, the number of carbon atoms is 10 or less. The fatty acid may be a saturated fatty acid or an unsaturated fatty acid, and may be a linear or branched fatty acid. Specific examples of fatty acids having 6 to 10 carbon atoms include caproic acid, enanthic acid, caprylic acid, nonanoic acid, capric acid, 2-ethylhexanoic acid, 3,5,5-trimethylhexanoic acid, isocaproic acid and sorbic acid. And caprylic acid, nonanoic acid, 3,5,5-trimethylhexanoic acid and capric acid are preferred, and nonanoic acid and 3,5,5-trimethylhexanoic acid are more preferred.

  In addition to the (poly) glycerin fatty acid ester represented by the general formula (1), the plasticizer of the present invention is an unreacted component when producing this (poly) glycerin fatty acid ester, and other than this (poly) glycerin fatty acid ester The known plasticizer can be contained.

  The content of the (poly) glycerin fatty acid ester represented by the general formula (1) in the plasticizer of the present invention is preferably 50% by weight or more, more preferably 70% by weight or more from the viewpoint of achieving the object of the present invention. 90% by weight or more is more preferable.

[Polyamide resin]
The polyamide resin used in the present invention is a polymer having an amide group in the molecule, and α-pyrrolidone, α-piperidone, ε-caprolactam, 6-aminocaproic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, 12 -Polymer obtained by polymerizing aminododecanoic acid, ω-laurolactam, etc .; hexamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, metaxylylenediamine, 1,4-bis (aminomethyl) Examples thereof include polymers obtained by condensation polymerization of diamines such as cyclohexane and dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, cyclohexanedicarboxylic acid, terephthalic acid, and isophthalic acid.

  Specific examples of the polyamide resin used in the present invention include polyamide 6 obtained by polymerizing ε-caprolactam, polyamide 66 obtained by condensation polymerization of hexamethylenediamine and adipic acid, hexamethylenediamine and sebacic acid, and the like. Polyamide 610 obtained by condensation polymerization, polyamide 6T obtained by condensation polymerization of hexamethylenediamine and terephthalic acid, polyamide 6I obtained by condensation polymerization of hexamethylenediamine and isophthalic acid, diaminobutane and adipic acid Polyamide 46 obtained by polycondensation, polyamide MXD6 obtained by condensation polymerization of metaxylylenediamine and adipic acid, polyamide 11,12-aminododecanoic acid obtained by polymerizing 11-aminoundecanoic acid or ω- Polyamide obtained by polymerizing laurolactam 12 etc. are mentioned.

Among these, the polyamide resin used in the present invention is preferably polyamide 6, polyamide 66, polyamide 11, or polyamide 12, from the viewpoint of requiring more flexibility and the viewpoint of the plasticizer of the present invention exhibiting more effects. Polyamide 11 and polyamide 12 which are more flexible than polyamide 6 and 66 are preferable.
These polyamide resins can be used alone or in admixture of two or more.

[Polyamide resin composition]
The polyamide resin composition of the present invention contains a polyamide resin and the plasticizer of the present invention. From the viewpoint of achieving the object of the present invention, the content of the polyamide resin in the polyamide resin composition of the present invention is preferably 70% by weight or more, and more preferably 90% by weight or more.
The content of the plasticizer of the present invention in the polyamide resin composition of the present invention is preferably 1 part by weight or more, preferably 5 parts by weight or more from the viewpoint of imparting a plasticizing effect to 100 parts by weight of the polyamide resin. More preferred. Further, from the viewpoint of maintaining a good surface appearance, it is preferably 30 parts by weight or less, more preferably 20 parts by weight or less, and even more preferably 15 parts by weight or less. From this viewpoint, the content of the plasticizer of the present invention in the polyamide resin composition of the present invention is preferably 1 to 30 parts by weight, more preferably 5 to 20 parts by weight with respect to 100 parts by weight of the polyamide resin. More preferred is ˜15 parts by weight.

  The production method of the polyamide resin composition of the present invention is not particularly limited, and a method of adding the plasticizer of the present invention when the polyamide resin is produced by polymerization, and dry blending the plasticizer of the present invention to the polyamide resin after polymerization. And the like, a method of attaching the plasticizer of the present invention to the surface of the polyamide resin pellets, and a method of melt-kneading the plasticizer of the present invention to the polyamide resin. As a method of melt kneading, a known method, for example, a method of obtaining pellets of a mixture of a polyamide resin and a plasticizer by melt kneading using a Banbury mixer, a mixing roll, a single screw or a twin screw extruder, and the like can be given. It is done.

  The polyamide resin composition of the present invention has other components such as other polyamide components, heat stabilizers, weathering agents, inorganic fillers, reinforcing agents, antioxidants, and impact resistance as long as the moldability and physical properties are not impaired. An improver, pigment, lubricant, flame retardant, etc. can be added and introduced.

  The polyamide resin composition of the present invention can be formed into a monofilament, a sheet, a tube, a hose or the like by a known method such as extrusion molding or injection molding.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these Examples.

Synthesis example 1
In a 500 ml glass four-necked flask, 138.0 g (1.5 mol) of glycerin (trade name: purified glycerin, manufactured by Kao Corporation) and 3,5,5-trimethylhexanoic acid (reagent name manufactured by Wako Pure Chemical Industries, Ltd.) 237.3 g (1.5 mol) was weighed and heated to 225 ° C. with nitrogen blowing to react for 5 hours. At this time, water was distilled out of the system to obtain 3,5,5-trimethylhexanoic acid partial ester of glycerin (hereinafter referred to as ester compound 1).

Synthesis example 2
Under the same conditions as in Synthesis Example 1, except that 259.5 g (1.5 mol) of capric acid (trade name: LUNAC 10-98, manufactured by Kao Corporation) is used instead of 3,5,5-trimethylhexanoic acid. Thus, a capric acid partial ester of glycerin (hereinafter referred to as ester compound 2) was obtained.

Synthesis example 3
Instead of 3,5,5-trimethylhexanoic acid, 282.8 g (1.95 mol) of caprylic acid (trade name: LUNAC 8-98, manufactured by Kao Corporation) was used, and the amount of glycerin was 119.6 g (1 .30 mol), and glycerin caprylic acid partial ester (hereinafter referred to as ester compound 3) was obtained under the same conditions as in Synthesis Example 1.

Synthesis example 4
Diglycerin (trade name: Diglycerin S, manufactured by Sakamoto Yakuhin Co., Ltd.) 166.2 g (1.0 mol) instead of glycerin, caprylic acid (trade name: LUNAC) instead of 3,5,5-trimethylhexanoic acid Diglycerin caprylic acid partial ester (hereinafter referred to as ester compound 4) was obtained under the same conditions as in Synthesis Example 1 except that 216.9 g (1.5 mol) (8-98, manufactured by Kao Corporation) was used.

Synthesis example 5
Synthetic Example 1 except that 237.3 g (1.5 mol) of n-nonanoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of 3,5,5-trimethylhexanoic acid and the reaction time was 6 hours. Under the same conditions, nonanoic acid partial ester of glycerin (hereinafter referred to as ester compound 5) was obtained.

Comparative Synthesis Example 1
Weigh 192 g (1.0 mol) of citric acid, 650 g (5.0 mol) of n-octyl alcohol and 0.42 g of dibutyltin oxide (IV) (manufactured by Kanto Chemical) into a 1000 ml glass four-necked flask, and blow nitrogen. The temperature was raised to 180 ° C. and reacted for 8 hours. At this time, water was distilled out of the system. Then, after cooling to 90 ° C. once again, it was replaced with a vacuum device, the temperature was raised again to 190 ° C., and n-octyl alcohol that had been excessively blended at 400 Pa for 2 hours was distilled out of the system to give n-octyl alcohol. Of citric acid ester (hereinafter referred to as comparative ester compound 1) was obtained.

Comparative Synthesis Example 2
In a 1000 ml glass four-necked flask, 124.7 g (0.75 mol) of diglycerin (trade name: diglycerin S, manufactured by Sakamoto Yakuhin Co., Ltd.) and caprylic acid (trade name: LUNAC 8-98, Kao Corporation )) 434.0 g (3.00 mol) was weighed out, and diglycerin caprylate (completely esterified product, hereinafter referred to as comparative ester compound 2) was obtained under the same conditions as in Synthesis Example 1.

Comparative Synthesis Example 3
Comparative Synthesis Example 2 except that 166.2 g (1.0 mol) of diglycerin and 414.6 g (1.5 mol) of oleic acid (trade name: LUNAC O-LL, manufactured by Kao Corporation) are used. Under conditions, diglycerin oleic acid partial ester (hereinafter referred to as comparative ester compound 3) was obtained.

Comparative Synthesis Example 4
Under the same conditions as in Synthesis Example 1, except that 301.7 g (1.5 mol) of lauric acid (trade name: LUNAC L-98, manufactured by Kao Corporation) is used instead of 3,5,5-trimethylhexanoic acid. Thus, glycerin lauric acid partial ester (hereinafter referred to as comparative ester compound 4) was obtained.

  The compositions of the reaction products obtained in Synthesis Examples 1 to 5 and Comparative Synthesis Examples 1 to 4 are summarized in Table 1.

Examples 1-6, Comparative Examples 1-6
The ester compound obtained in Synthesis Examples 1 to 5 and Comparative Synthesis Examples 1 to 4, or butylbenzenesulfonamide (manufactured by Wako Pure Chemical Industries, Ltd.), which is a known plasticizer, is a polyamide 12 resin (UBE3030U: Ube Industries, Ltd.) ) Was set to a cylinder temperature of 230 ° C. using a twin screw extruder (Laboplast Mill, manufactured by Toyo Seiki Seisakusho Co., Ltd.), and then added in the dropping funnel in the amount shown in Table 2 (80 at room temperature solid product). The mixture was allowed to stand in a warm bath at 10 ° C. for 10 minutes to dissolve) and pelletized. Next, a test piece was prepared by an injection molding machine (J75E-D type injection molding machine, manufactured by Nippon Steel Co., Ltd.) set at a cylinder temperature of 240 ° C. and a mold temperature of 25 ° C., and a flat plate piece (70 mm × 40 mm × 3 mm). ) And prismatic test pieces (63 mm × 12 mm × 5 mm) and No. 1 dumbbell-shaped piece. The obtained test piece was evaluated for flexibility, bleed resistance and heat resistance by the following methods. The results are shown in Table 2.

<Flexibility evaluation method>
For a prismatic test piece (125 mm x 12 mm x 6 mm), based on JIS-K7191, measure the flexural modulus of five test pieces using a thermal deformation temperature measuring machine (B-32 manufactured by Toyo Seiki Seisakusho). The average value of five samples is shown. The smaller this value, the better the flexibility.

<Bleed resistance evaluation method>
The injection-molded flat plate (70 mm × 40 mm × 3 mm) was allowed to stand for one week under constant temperature and humidity at 80 ° C., and the presence or absence of bleeding on the surface was observed with the naked eye and evaluated according to the following criteria.
A: Bleed is not seen.
○: Slight bleeding is observed.
Δ: Bleed is observed.
X: Bleed is considerably observed and clouding occurs on the surface.
XX: Bleed is severely observed and oil droplets are generated on the surface.

<Evaluation method of heat resistance>
The injection-molded test piece (JIS K7113, No. 1 dumbbell type) was stored in a constant temperature dryer adjusted to 100 ° C. for 3 days, and the weight loss was determined by the following formulas (2) and (3).
The volatilization weight loss 1 represented by the formula (2) indicates the volatilization weight loss (%) with respect to the plasticizer contained in the test piece, and the volatilization weight loss 2 represented by the formula (3) indicates the volatilization weight loss (% %). It can be said that the smaller these values, the less the plasticizer is volatile and the higher the heat resistance.

In the above formulas (2) and (3), W ₀ and W ₁ have the following meanings.
W ₀ : Test piece weight before storage (g)
W ₁ ; test piece weight after storage for 3 days (g)

  As is apparent from the results in Table 2, the polyamide resin composition of the present invention has excellent moldability and good heat resistance even when compared with the polyamide resin composition of Comparative Example 2 using a conventionally known plasticizer. It can be confirmed that there is almost no bleeding of the plasticizer on the molding surface without impairing the flexibility.

Claims (5)

A plasticizer for polyamide resin containing a (poly) glycerin fatty acid ester represented by the general formula (1).

(Wherein R represents an alkyl group or alkenyl group having 5 to 9 carbon atoms, X represents a hydrogen atom or a group represented by RCO (R represents the above meaning), and a plurality of X may be the same. (It may be different, but at least one is a hydrogen atom. N represents an integer of 0 to 4.)   The plasticizer according to claim 1, wherein, in the general formula (1), R is an alkyl group or alkenyl group having 7 to 9 carbon atoms, and n is 0 or 1.   A polyamide resin composition comprising a polyamide resin and the plasticizer according to claim 1.   The polyamide resin composition according to claim 3, wherein the content of the plasticizer is 1 to 30 parts by weight with respect to 100 parts by weight of the polyamide resin.   The polyamide resin composition according to claim 3 or 4, wherein the polyamide resin is at least one selected from the group consisting of polyamide 11 and polyamide 12.