JP6185368B2 - Thermoplastic cellulose ester composition - Google Patents

Description

  The present invention relates to a thermoplastic cellulose ester composition.

  Since cellulose esters such as cellulose acetate generally have poor thermoplasticity, they are usually used as a composition containing a plasticizer. Furthermore, a flame retardant is mix | blended when a flame retardance is requested | required according to a use.

Patent Document 1 is an invention relating to a resin composition composed of a cellulose ester having an average substitution degree of 2.7 or less, a plasticizer, and a filler. As a plasticizer, it is described that a phosphate ester or the like can be used (paragraph number 0020). In the examples, TPP (triphenyl phosphate) is used.
Patent Documents 2 and 3 describe that various phosphate esters can be used as flame retardants and plasticizers for cellulose esters.

  However, the balance of thermoplasticity, flame retardancy, mechanical strength and transparency of the cellulose ester composition is not yet sufficient.

JP-A-2005-194302 JP 05-271471 A JP 09-52979 A

  An object of the present invention is to provide a thermoplastic cellulose ester composition that has a high thermoplasticity and from which a molded article having excellent flame retardancy, mechanical strength, and transparency can be obtained.

  As a means for solving the problems, the present invention provides a thermoplastic cellulose ester composition containing (A) a cellulose ester and (B) a phosphate ester compound represented by the following formula (1).

（式中、
Ｒ¹およびＲ²は、各々独立して炭素原子数１〜５の直鎖または分岐状のアルキル基であり、
ｍおよびｋは、各々独立して０〜５の整数であり、
Ａは、炭素原子数１〜５の直鎖または分岐状のアルキレン基であり、
ｑは、１〜５の整数であり、
ｎは、１または２である。）

(Where
R ¹ and R ² are each independently a linear or branched alkyl group having 1 to 5 carbon atoms,
m and k are each independently an integer of 0 to 5;
A is a linear or branched alkylene group having 1 to 5 carbon atoms,
q is an integer of 1 to 5,
n is 1 or 2. )

  The composition of the present invention has high thermoplasticity, and a molded product having excellent flame retardancy, mechanical strength, and transparency can be obtained.

<(A) component>
The cellulose ester of the component (A) used in the composition of the present invention is a known one (for example, those described in Patent Document 1), cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate propio. Nate, cellulose acetate butyrate, and the like.
Other examples include polycaprolactone-grafted cellulose acetate, acetyl methyl cellulose, acetyl ethyl cellulose, acetyl propyl cellulose, acetyl hydroxyethyl cellulose, acetyl hydroxypropyl cellulose, and the like. Of these, cellulose acetate, cellulose acetate propionate and cellulose acetate butyrate are preferred.
These cellulose esters can be used alone or in combination of two or more.

The cellulose ester as the component (A) is particularly preferably cellulose acetate. From the viewpoint of moldability and mechanical properties, the average degree of substitution is preferably 2.7 or less, more preferably 2 to 2.7, and even more preferably 2 to 2.5.
The degree of polymerization of the cellulose ester as the component (A) is not particularly limited, and the viscosity average degree of polymerization is preferably 100 to 1000, more preferably 100 to 500, and still more preferably 100 to 400.

<(B) component>
The component (B) used in the composition of the present invention is a phosphate ester compound represented by the following formula (1).
The component (B) is a component that can impart flame retardancy to the molded product obtained from the composition of the present invention and can impart thermoplasticity to the composition.

In formula (1), R ¹ and R ² are each independently a linear or branched alkyl group having 1 to 5 carbon atoms, preferably a linear or branched alkyl group having 1 to 3 carbon atoms. An alkyl group, more preferably an alkyl group having 1 carbon atom.
In formula (1), m and k are each independently an integer of 0 to 5, preferably an integer of 0 to 2, and more preferably 0.
In formula (1), A is a linear or branched alkylene group having 1 to 5 carbon atoms, preferably a linear or branched alkylene group having 2 to 4 carbon atoms, and more preferably. An alkylene group having 2 carbon atoms.
In Formula (1), q is an integer of 1 to 5, preferably an integer of 1 to 3, and more preferably 1.
In the formula (1), n is 1 or 2, and preferably 1.

  The content ratio of the component (A) and the component (B) in the composition of the present invention is 5 for the component (B) with respect to 100 parts by mass of the component (A) from the viewpoint of the thermoplasticity and flame retardancy of the composition. -50 mass parts is preferable, and 10-30 mass parts is more preferable.

<(C) component>
The composition of this invention can contain the adipic acid ester type compound of (C) component.
The (a) component adipic acid ester compound is a component that acts as a plasticizer, and can be used in combination with the component (B) to further improve fluidity and impact strength.
The component (C) adipic acid ester compound includes an ester of adipic acid and an aromatic alcohol, an ester of adipic acid and an aliphatic alcohol, and a mixed group ester of adipic acid with an aromatic alcohol and an aliphatic alcohol. A single compound or a mixture of mixed esters of adipic acid with an aromatic alcohol and an aliphatic alcohol is preferable.

As the mixed ester of adipic acid and aromatic alcohol and aliphatic alcohol, benzylalkyl diglycol adipate is preferable, benzylalkyldiglycol adipate may be used alone, or adipic acid containing benzylalkyldiglycol adipate Mixtures of esters of bis and aromatic alcohols and / or esters of adipic acid and aliphatic alcohols may be used.
When a mixture containing benzylalkyldiglycol adipate is used, it is preferable that the content of benzylalkyldiglycol adipate is 35% by mass or more.
The alkyl group of benzylalkyldiglycol adipate may be either linear or branched, but is preferably linear.
Moreover, 1-20 are preferable, as for carbon number of an alkyl group, 1-8 are more preferable, and 1-4 are still more preferable.
Particularly preferred are benzyl methyl diglycol adipate, benzyl ethyl diglycol adipate, benzyl n-propyl diglycol adipate, and benzyl n-butyl diglycol adipate having a linear alkyl group having 1 to 4 carbon atoms.

  Examples of esters of adipic acid and aliphatic alcohols include dibutyl adipate, dioctyl adipate, dimethoxyethoxyethyl adipate, dibutoxyethoxyethyl adipate, and the like.

  Examples of the ester of adipic acid and aromatic alcohol include diphenyl adipate, dibenzyl adipate, dicresyl adipate, and dixylyl adipate.

  As for the content rate of (C) component in the composition of this invention, 3-40 mass parts is preferable, and (C) component is more preferable 10-30 mass parts with respect to 100 mass parts of (A) component.

The total content of the component (B) and the component (C) when the component (C) is contained is preferably 20 to 50 parts by mass, more preferably 25 to 45 parts by mass with respect to 100 parts by mass of the component (A). .
The content ratio of the component (B) and the component (C) when the component (C) is contained is preferably 30 to 70% by mass of the component (B), 70 to 30% by mass of the component (C), and the component 40 (B). -65 mass% is more preferable, and (C) component 60-35 mass% is more preferable.
By containing (B) component and (C) component in the said range, especially fluidity | liquidity and impact strength can be improved with sufficient balance.

Moreover, the composition of this invention can also contain another well-known plasticizer as needed in the range which does not inhibit the characteristic of this invention.
For example,
Aromatic carboxylic acid esters [dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, di-2-ethylhexyl phthalate, etc. C 1-6 Alkyl C 1-12 Alkyl Esters such as C 1-6 Alkyl C 1-12 Alkyl Esters, Phthalates, C 1-12 Alkyl Aryl-C 1-3 Alkyl Esters such as Ethyl Phthalyl Ethylene Glycolate, Butyl Phthalyl Butylene Glycolate 6 alkylphthalyl C2-4 alkylene glycolate, trimethyl trimellitic acid, triethyl trimellitic acid, trioctyl trimellitic acid, trimellitic acid tri C1-12 alkyl ester, pyromellitic acid tetraoctyl such as trimellitic acid tri-2-ethylhexyl Such as Pyromellitic acid tetra C1-12 alkyl ester etc.],
Fatty acid ester [Azelaic acid ester such as diethyl azelate, dibutyl azelate, dioctyl azelate, sebacate such as dibutyl sebacate, dioctyl sebacate, butyl oleate, methylacetyl ricinoleate, etc.]
Lower fatty acid esters of polyhydric alcohols (glycerin, trimethylolpropane, pentaerythritol, sorbitol, etc.) [triacetin, diglycerin tetraacetate, etc.]
Glycol esters (such as dipropylene glycol dibenzoate),
Citrate esters such as acetyltributyl citrate,
Amides [N-butylbenzenesulfonamide, etc.]
An ester oligomer (such as a caprolactone oligomer) may be contained.
These plasticizers can be used alone or in combination of two or more.

The composition of this invention can contain a well-known thermoplastic resin according to a use.
Known thermoplastic resins include styrene resins such as ABS resin and AS resin, polycarbonate resins, polyolefin resins such as polyethylene and polypropylene, polyamide resins such as polyamide 6, polyamide 66, polyamide 610, and polyamide 612, and acrylic. Resin, methacrylic resin, polyester resin, polyacetal resin, polyphenylene sulfide resin and the like.
40 mass% or less is preferable in the total amount with the cellulose ester of (A) component, and, as for the content rate of a well-known thermoplastic resin, 20 mass% or less is more preferable.

The composition of the present invention may further contain a filler as necessary.
Examples of the filler include fibrous fillers and non-fibrous fillers (powdered or plate-like fillers). Examples of fibrous fillers include organic fibers (natural fibers, papers, etc.), inorganic Examples thereof include fibers (glass fibers, asbestos fibers, carbon fibers, silica fibers, silica / alumina fibers, zirconia fibers, potassium titanate fibers, etc.), metal fibers, and the like. These fibrous fillers can be used alone or in combination of two or more.
Non-fibrous fillers include, for example, mineral particles (talc, mica, zeolite, diatomaceous earth, calcined siliceous earth, kaolin, sericite, bentonite, smectite, clay, silica, quartz powder, glass beads, glass powder, Glass flakes, milled fiber, wollastonite, etc.), boron-containing compounds (boron nitride, boron carbide, titanium boride, etc.), metal carbonates (magnesium carbonate, heavy calcium carbonate, light calcium carbonate, etc.), metal silicates ( Calcium silicate, aluminum silicate, magnesium silicate, magnesium aluminosilicate, etc.), metal oxides (alumina, silica, zinc oxide, titanium dioxide, iron oxide, magnesium oxide, zirconium oxide, etc.), metal hydroxides (aluminum hydroxide, water) Calcium oxide, magnesium hydroxide, etc.) Metal sulfate (calcium sulfate, barium sulfate, etc.), metal carbide (silicon carbide, aluminum carbide, titanium carbide, etc.), metal nitride (aluminum nitride, silicon nitride, titanium nitride, etc.), white carbon, various metal foils, etc. It is done. These non-fibrous fillers can be used alone or in combination of two or more.
As for the content rate of a filler, 5-50 mass parts is preferable with respect to 100 mass parts of cellulose ester of (A) component, More preferably, it is 5-40 mass parts, More preferably, it is 5-30 mass parts.

  The composition of this invention can contain stabilizers, such as an epoxy compound and an organic acid, a thioether, and a phosphite compound, further as needed.

  Examples of the epoxy compound include an alicyclic epoxy compound, a glycidyl ester compound, a glycidyl ether compound, a glycidyl amine compound, and a long chain aliphatic epoxy compound. These epoxy compounds can be used individually or in combination of 2 or more types.

  As the organic acid, a weak organic acid having a pKa value of 1 or more (preferably 2 or more) is used. For example, monocarboxylic acids [C2-10 such as aliphatic carboxylic acids (formic acid, acetic acid, propionic acid, butyric acid, caprylic acid, etc. Aliphatic carboxylic acids, etc.), alicyclic carboxylic acids (cyclohexane carboxylic acids, etc.), aromatic carboxylic acids (benzoic acids, C7-12 aromatic polycarboxylic acids such as naphthoic acid, etc.)], polycarboxylic acids [aliphatic Saturated polycarboxylic acids (such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid and other C2-10 aliphatic saturated polycarboxylic acids), aliphatic unsaturated polycarboxylic acids (maleic acid, fumaric acid, C4-10 aliphatic unsaturated polycarboxylic acids such as itaconic acid and sorbic acid), alicyclic polycarboxylic acids (1,4-cyclohexanedicarboxylic acid, tetrahydrophthalate) C8-10 alicyclic polycarboxylic acids such as phosphoric acid), aromatic polycarboxylic acids (such as C8-12 aromatic polycarboxylic acids such as phthalic acid and trimellitic acid)], oxycarboxylic acids [aliphatic oxy C7-12 aromatic oxycarboxylic acids such as carboxylic acids (glycolic acid, lactic acid, oxybutyric acid, C2-10 aliphatic oxycarboxylic acids such as glyceric acid), aromatic oxycarboxylic acids (salicylic acid, oxybenzoic acid, gallic acid, etc.) Etc.], oxypolycarboxylic acids [aliphatic oxypolycarboxylic acids (such as C2-10 aliphatic oxypolycarboxylic acids such as tartaric acid, citric acid, malic acid, etc.)], heterocyclic carboxylic acids (pyridine carboxylic acid, etc.) ), And aromatic sulfonic acids (C6-10 aromatic polycarboxylic acids such as benzenesulfonic acid and toluenesulfonic acid). These organic acids may be anhydrides or hydrates. These organic acids can be used alone or in combination of two or more.

  Examples of the thioether compound include dilauryl-3,3′-thiodibropionate, ditridecyl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, dipalmityl-3,3 ′. -Dialkyl- such as thiodipropionate, distearyl-3,3'-thiodibropionate, laurylstearyl-3,3'-thiodipropionate, palmitylstearyl-3,3'-thiodipropionate Thiodicarboxylate can be used. These thioether compounds can be used alone or in combination of two or more.

  Examples of the phosphite compound include triaryl phosphites (triphenyl phosphite, tricresyl phosphate, trixylenyl phosphite, trinaphthyl phosphite, etc.), diaryl alkyl phosphites (diphenyl isooctyl phosphite, diphenyl). Diaryl C1-18 alkyl phosphite such as decyl phosphite), aryl dialkyl phosphite (such as aryl C1-18 dialkyl phosphite such as phenyl diisooctyl phosphite), trialkyl phosphite (trimethyl phosphite, triethyl phosphite) Tri-n-butyl phosphite, triisooctyl phosphite, tridecyl phosphite, triisodecyl phosphite and other tri-C1-18 alkyl phosphites), di Rualkyl phosphites (such as diC1-18 alkyl phosphites such as dilauryl phosphite), phosphites containing alkylaryl units [tris (2,4-t-butylphenyl) phosphite, tris (nonylphenyl) phosphite, Tris (C 1-18 alkyl-aryl) phosphite such as tris (dinonylphenyl) phosphite, dinonylphenyl-o-biphenyl phosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl Phosphites, etc.], aliphatic carboxylic acid phosphites (C1-18 aliphatic carboxylic acid phosphites such as tristearyl phosphite), phosphites containing alkylene oxide units (polydipropylene glycol nonylphenyl phosphate, tetraphenyl) Dipropylene grease Phosphites containing cyclic neopentane units, such as cyclic neopentanetetraylbis (octadecyl) phosphite, cyclic neopentanetetraylbis (2,4-di-t-butylphenyl) phosphite, cyclic Click neopentanetetraylbis (2,6-t-butyl-4-methylphenyl) phosphite], diphosphites (diisodecylpentaerythritol diphosphite, didodecylpentaerythritol diisocyanate, 4,4'-isopropylidenediphenyldiphenyl Dodecyl diphosphite, etc.), triphosphites [heptasis dipropylene glycol triphosphite, hexa-tridecyl-1,1,3-tri (3-t-butyl-6-methyl-4-oxyphenyl)- 3-methylpropane triphosphite] and the like. These phosphite compounds can be used alone or in combination of two or more.

  The composition of the present invention contains conventional additives such as other stabilizers (for example, antioxidants, ultraviolet absorbers, heat stabilizers, light stabilizers, etc.), colorants (dyes, pigments) depending on applications. Etc.), flame retardants other than the component (B), antistatic agents, lubricants, antiblocking agents, dispersants, fluidizing agents, anti-dripping agents, antibacterial agents and the like may be included.

The composition of the present invention may be prepared by, for example, mixing each component in a dry or wet manner using a mixer such as a tumbler mixer, a Henschel mixer, a ribbon mixer, or a kneader.
Furthermore, after premixing with the mixer, a method of kneading with an extruder such as a single-screw or twin-screw extruder to prepare pellets, or a method of melting and kneading with a kneader such as a heating roll or a Banbury mixer is applied. can do.

  The composition of the present invention can be molded into various molded products by injection molding, extrusion molding, vacuum molding, profile molding, foam molding, injection press, press molding, blow molding, gas injection molding and the like.

Since the molded product obtained from the composition of the present invention has excellent flame retardancy and mechanical strength, for example, OA / home appliance field, electrical / electronic field, communication field, sanitary field, transportation of automobiles, etc. It can be used for various parts, housings, etc. in the vehicle field, housing-related fields such as furniture and building materials, and sundries fields.
Moreover, the molded object obtained from the composition which consists of (A) and (B) component of this invention or (A), (B) and (C) component is described in an Example with a flame retardance and mechanical strength. Since the total light transmittance measured by this method can be 80% or more, it can also be used in applications where transparency and design are required in conventional applications.
In addition, flame retardancy and mechanical strength can be obtained by blending other optional components to the composition comprising the components (A) and (B) or the components (A), (B) and (C) of the present invention. Further, the application range can be expanded while adjusting the level of transparency. For example, by blending other additives such as inorganic fillers, the molded body is opaque, but the mechanical strength can be increased while maintaining the flame retardancy level.

  The present invention will be described more specifically with reference to the following examples, comparative examples and production examples. However, the scope of the present invention is not limited by these examples.

Production Example 1 (benzyl methyl diglycol adipate as component (C))
In a 1 liter four-necked flask equipped with a thermometer, a stirrer, a condenser and a water separation device, 146.1 g (1 mol) of adipic acid, 129.8 g (1.2 mol) of benzyl alcohol, 144.2 g of diethylene glycol monomethyl ether ( 1.2 mol), 0.95 g of paratoluenesulfonic acid, and 120 g of toluene were added, and the reaction was performed by refluxing for 8 hours while extracting water produced using a water separation apparatus.
After neutralizing with 2.9 g of sodium carbonate and water, the residual solvent and residual alcohol were removed by washing with water, solvent removal, and steam distillation to obtain benzylmethyldiglycol adipate with an acid value of 0.03 KOHmg / g in a yield of 96. Obtained at 9%.

Production Example 2 (2-phenoxyethyl diphenyl phosphate as component (B))
In a 1 liter four-necked flask equipped with a thermometer, a stirrer, a condenser, a hydrogen chloride recovery device, and a decompression device, 268.5 g of DPC (1 mol, manufactured by Daihachi Chemical Industry Co., Ltd.), 138.0 g of 2-phenoxyethanol ( 1 mol), 0.24 g of magnesium chloride and 92 g of toluene were added, and after stirring for 2 hours at 100 ° C. under normal pressure while recovering hydrogen chloride generated by a hydrogen chloride recovery device, the pressure was reduced to 67 kPa at 120 ° C. And reacted with stirring.
The resulting reaction mixture was washed with dilute hydrochloric acid, neutralized, washed with water, solvent removed, and steam distilled to remove residual solvent, etc., and 2-phenoxyethyl diphenyl phosphate having an acid value of 0.02 KOH mg / g was obtained at a yield of 94%. Obtained.

Examples and Comparative Examples A Henschel mixer was used to stir and mix the composition comprising the components shown in Table 1 so that the frictional heat in the mixer would be 70 ° C or higher, and then a twin screw extruder (cylinder temperature: 200 ° C). , Die temperature: 220 ° C.) and extruded to be pelletized.
The obtained pellets were supplied to an injection molding machine, and a test piece was injection molded under the conditions of a cylinder temperature of 210 ° C., a mold temperature of 50 ° C., and a molding cycle of 30 seconds (injection 15 seconds, cooling time 15 seconds), Used for each evaluation test.

<Use ingredients>
Component (A) Cellulose acetate: manufactured by Daicel Corporation, trade name “L50”, substitution degree 2.5, viscosity average polymerization degree 180

(B) component (B-1) 2-phenoxyethyl diphenyl phosphate obtained in Production Example 2 (in formula (1), m and k = 0, A = ethylene group, q = 1, n = 1)
(B) Component comparison component (B-2) Trade name “PX-200”, condensed phosphate ester, manufactured by Daihachi Chemical Industry Co., Ltd. (B-3) Trade name “CR-741”, condensed phosphorus Acid ester, manufactured by Daihachi Chemical Industry Co., Ltd. (B-4) Trade name “PX-110”, monomer type phosphate ester, manufactured by Daihachi Chemical Industry Co., Ltd. (B-2), (B-3), (B-4) is widely used as a flame retardant.

(C) Component Benzylmethyldiglycol adipate obtained in Production Example 1

<Measurement method>
(1) Evaluation of thermoplasticity
Each component shown in Table 1 is put into a batch-type kneading device “Lab Plast Mill” manufactured by Toyo Seiki Seisakusho Co., Ltd. and kneaded under the conditions of a preset temperature of 210 ° C., a blade rotation speed of 100 r / m, and a kneading time of 3 minutes. did. In this kneading process, thermoplasticity was evaluated.
The thermoplasticity is determined by visually observing the state after kneading under the above conditions, and evaluating the case where the kneaded product is in a uniform lump as “◯” (with thermoplasticity). The case where the cellulose acetate was still in powder form was evaluated as “x” (no thermoplasticity).

(2) MFR
Based on ISO 1133, measurement was performed at 200 ° C. and a load of 5 kg.
(3) Tensile strength Based on ISO527, the tensile strength of the test piece was measured (tensile strength unit: MPa).
(4) Flexural strength and flexural modulus Measured according to ISO178 (unit: MPa).
(5) Charpy impact Measured according to ISO 179 / 1eA (unit: KJ / m ² )
(6) Heat distortion temperature (HDT)
It was measured at a load of 1.80 MPa in accordance with ISO75 (unit: ° C.).
(7) Transparency (total light transmittance)
The total light transmittance of a test piece (3 mm thickness) was measured according to ASTM D1003 (unit:%).
(8) Combustion test The vertical combustion test prescribed | regulated to UL-94 was done. The thickness of the test piece is 1.5 mm.

As is clear from the comparison between Examples 1 and 2 and Examples 3 to 6, by using the component (B), both flame retardancy and thermoplasticity are excellent even when a plasticizer is not added to the cellulose ester. Composition was obtained.
Further, as apparent from Examples 3 to 6, even when the content of the component (B) is reduced by using the adipic acid ester compound of the component (C) that acts as a plasticizer, high fluidity and impact are achieved. The strength could be obtained.
As is clear from Comparative Examples 1, 2, and 3, when a known phosphate ester was used as a flame retardant, thermoplasticity was not obtained and molding could not be performed.

Claims (4)

(A) For 100 parts by mass of cellulose ester , (B) a thermoplastic cellulose ester composition containing 10 to 30 parts by mass of a phosphate compound represented by the following formula (1) ,
Thermoplastic cellulose ester composition having a total light transmittance (measured in accordance with ASTM D1003 of the total light transmittance of a test piece (3 mm thickness)) of 80% or more of a molded product obtained from the thermoplastic cellulose ester composition .

(In the formula, m and k = 0, A = ethylene group, q = 1, and n = 1. ) Furthermore, (A) 3-40 mass parts of (C) adipic acid ester type compound is contained with respect to 100 mass parts of component ,
(B) The sum total content of a component and (C) component is 25-50 mass parts with respect to 100 mass parts of (A) component,
(B) component and (C) content of the component (B) component 40 to 65 wt%, (C) a component 60-35% by weight, according to claim 1 the thermoplastic cellulose ester composition. The thermoplastic cellulose ester composition according to claim 1 or 2 , wherein the cellulose ester as the component (A) is selected from cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate. The thermoplastic cellulose ester composition according to any one of claims 1 to 3 , wherein the cellulose ester as the component (A) is a cellulose acetate having a substitution degree of 2.7 or less.