KR102123151B1 - Eco-friendly Plasticizer and Resin Composition Comprising the Same - Google Patents

Abstract

상기 식에서, R₁ 및 R₂는 서로 독립적으로 치환 또는 비치환의 C₂-C₂₀ 지방족 알킬, 또는 치환 또는 비치환의 C₄-C₁₀ 시클로알킬이다. The present invention provides a plasticizer comprising a compound having the structure of the following formula, and a resin composition comprising the plasticizer and a polymer resin.

In the above formula, R ₁ and R ₂ are each independently substituted or unsubstituted C ₂ -C ₂₀ aliphatic alkyl, or substituted or unsubstituted C ₄ -C ₁₀ cycloalkyl.

Description

Eco-friendly Plasticizer and Resin Composition Comprising the Same

The present invention relates to an eco-friendly plasticizer and a resin composition comprising the same.

Plasticizer is a material that affects the thermal/mechanical properties of polymer resins by adding it to various consumer products, medical supplies, packaging materials, automobile parts, and toys.

A typical plasticizer is a phthalate-based compound obtained through an esterification reaction, and is added to various plastic materials to lower the melting temperature or viscosity of the material, thereby facilitating molding and processing. Gives flexibility.

As ortho-phthalate-based products have been mainly used as these plasticizers, but since ortho-phthalate-based plasticizers began to be suspected of endocrine disruption or potential carcinogenic factors, recently, iso- or tere-phthalate series and aromatic-free adipate A series of plasticizers have been developed and used.

However, since iso- or tere-phthalate-based plasticizers are still based on phthalate structures, it is difficult to say that they are completely free from potential dangers.

Therefore, products based on hydrogenated hydrogenated benzene rings in phthalate structures and converted to cyclohexane rings and products based on acyclic compounds have been developed and used, but have problems of high manufacturing cost and poor physical properties than conventional plasticizers.

The present invention aims to solve the problems of the prior art as described above and the technical problems requested from the past.

The inventors of the present application have undergone in-depth studies and various experiments, and as described later, a cyclohexane-based dihydric alcohol was reacted with a carboxylic acid to develop a novel ester compound as a plasticizer, and these ester compounds While sufficiently exerting the properties required for the silver plasticizer, it was confirmed that it did not cause any adverse effects on the human body, and the present invention has been completed.

Therefore, the eco-friendly plasticizer according to the present invention includes a compound having the structure of Formula 1 below.

(1)

(One)

In the above formula,

R ₁ and R ₂ are, independently of each other, substituted or unsubstituted C ₂ -C ₂₀ aliphatic alkyl, or substituted or unsubstituted C ₄ -C ₁₀ cycloalkyl.

In the plasticizer according to the present invention, the compound of Formula 1 has a basic structure consisting of a cyclohexane ring structure, which is harmless not only to the human body but also to the environment, and has a performance equal to or higher than that of a conventional plasticizer.

In one specific example, -CH ₂ -O(C=O)-R ₁ and -CH ₂ -O(C=O)-R ₂ are coupled to para positions opposite to each other around the cyclohexane ring. Can. These -CH ₂ -O(C=O)-R ₁ and -CH ₂ -O(C=O)-R ₂ may be the same or different.

In one specific example, the compound of Formula 1 may be a compound of Formula 2 or 3 below.

(2)

(2)

(3)

(3)

When R ₁ and R ₂ are each C ₂ -C ₂₀ aliphatic alkyl, and among them, aliphatic alkyl having 3 or more carbon atoms, alkyl includes branched alkyl in addition to linear alkyl. In addition, C ₄ -C ₁₀ cycloalkyl may be a structure further substituted.

In R ₁ and R ₂ , when C ₂ -C ₂₀ aliphatic alkyl is substituted and C ₄ -C ₁₀ cycloalkyl is substituted, the substituent is C ₁ -C ₆ alkyl, C ₄ -C ₁₀ cycloalkyl, halogen It may be one or more selected from the group consisting of elements, amino groups, nitro groups, sulfonic acid groups, sulfate groups, and hydroxy groups.

In one preferred example, the substituents when C ₂ -C ₂₀ aliphatic alkyl is substituted and when C ₄ -C ₁₀ cycloalkyl is substituted may be C ₁ -C ₆ alkyl. More preferably, R ₁ and R ₂ are each substituted C ₄ -C ₁₀ aliphatic alkyl, and one ethyl group is substituted with an alkyl main chain moiety (moiety) adjacent to the ester structure (-O(C=O)-). It may be a structure, in particular, the compound of formula 4 below is preferred.

(4)

(4)

According to experimentally confirmed by the inventors of the present application, when the compound of Formula 4 is used as a plasticizer, compared with the case of using the compound of Formula 5 having a similar structure as a plasticizer, surprisingly, the material of the plasticizer added material It has been confirmed that the cold-resistant property is remarkably excellent and exhibits a low softening temperature, so that the material properties can be sufficiently exhibited even at low temperatures. A material having a low cold resistance property, even if it has a soft property at room temperature, may become fragile at low temperature, and the soft property originally required may disappear, and may be easily destroyed even with a small impact. Therefore, in the plasticizer added to the material to impart plasticity properties, it can be said that the plasticizer provides excellent cold resistance properties to the material.

(5)

(5)

Under the condition that the scope of the present invention is not limitedly interpreted, the reason why the compound of Formula 4 can exert the above-mentioned special effect is that the plasticizer is added by including an ethyl group substituted in the alkyl main chain portion adjacent to the ester structure. It is presumed to increase the ordering disorder of the polymers at, and give high flexibility and elongation even at low temperatures.

Accordingly, as described later, when the plasticizer of the present invention is synthesized through the reaction of a cyclohexane-based dihydric alcohol with a carboxylic acid, the compound of Formula 4 uses 2-ethyl hexanoic acid as the carboxylic acid. , The 2-ethyl hexyl structure of these carboxylic acids is judged to be the best alkyl group in terms of increasing the degree of disorder, decreasing the efficiency of polymer packing, and increasing amorphousness, in order to improve the cold resistance, as compared with other alkyl groups. do.

Therefore, the present invention proposes the compound of Formula 4 as the most preferred plasticizer, whereas the C ₂ -C ₂₀ aliphatic alkyl is substituted with C ₁ -C ₆ alkyl, wherein a plurality of methyl groups are substituted at adjacent sites. Such compounds are excluded from the present invention in terms of cold resistance properties.

The compound of Formula 1 may be synthesized through a dehydration esterification reaction of a cyclohexane-based dihydric alcohol and a carboxylic acid, for example, as in the following scheme.

In the above reaction formula, for the purpose of simplifying the expression of the reaction scheme, the parts corresponding to R ₁ and R ₂ in Formula 1 are expressed as R.

The conditions for the reaction are, after adding a dihydric alcohol and carboxylic acid to an organic solvent such as toluene, and adding a catalyst such as para-toluene sulfonic acid, a temperature of 100° C. or higher, which is the boiling point of water It can proceed by heating slowly to the boiling point of the organic solvent.

The cyclohexane-based dihydric alcohol is known in the art, for example, as in the following reaction formula, prepared by reducing terephthalic acid or dimethyl terephalate obtained by oxidizing para-xylene separated in the distillation process of crude oil. The carboxylic acid is a variety of types are currently commercially available.

The present invention also provides a resin composition obtained by mixing the plasticizer with a polymer resin.

The type of the polymer resin is not particularly limited, but may be preferably polyvinyl chloride.

The content of the plasticizer in the resin composition may be 5 to 100 parts by weight, specifically 10 to 30 parts by weight based on 100 parts by weight of the polymer resin.

In one preferred example, the resin composition may have a composition comprising a compound of Formula 4 as a plasticizer.

In some cases, in addition to the compound of Formula 1, a known non-toxic plasticizer compound may be used together, and in this case, a mutually content range may be determined according to required physical properties.

In one specific example, the resin composition may further include additives such as fillers and stabilizers, and the content of the additive may range from 1 to 350 parts by weight based on 100 parts by weight of the polymer resin.

The filler is not particularly limited as long as it is a material known in the art, for example, barium sulfate, calcium hydroxide, aluminum hydroxide, magnesium hydroxide, aluminum silicate, magnesium silicate, calcium carbonate, magnesium carbonate, titanium dioxide, magnesium oxide , Silica, talc, and the like.

The stabilizer is also not particularly limited as long as it is a material known in the art, for example, stearic acid salt and the like.

As described above, the plasticizer according to the present invention has physical properties equal to or higher than that of the conventional plasticizer, and does not contain an aromatic ring in the basic structure, thereby having a harmless effect on the human body and the environment. In particular, the compound of Formula 4 can significantly improve the cold resistance properties of the material in which it is contained as a plasticizer.

In the following, description will be made with reference to examples of the present invention, but this is for easier understanding of the present invention, and the scope of the present invention is not limited thereto.

Preparation and preparation of plasticizer

<Example 1>

Cyclohexanedimethanol (CHDM) 187.5 g (1.3 mol), butyric acid (BA) 412 g (2.86 mol) (CHDM: BA molar ratio 1: 2.2 in a 4-neck 2 liter reactor equipped with a condenser, temperature controller, stirrer, and Dean-stark trap) ), 600 g of toluene was added as a solvent. After raising the temperature to 60° C. and stirring to dissolve the reactants uniformly, 6 g of para-toluenesulfonic acid (1 part by weight based on 100 parts by weight of solids) was added as an acid catalyst, and the boiling point of the solvent. The phosphorus was stirred while gradually warming to about 110° C., and the reaction was carried out for about 7 hours under normal pressure conditions and terminated.

After the reaction is completed, to remove the unreacted carboxylic acid raw material, neutralize it in a separatory funnel with 1200 mL of a 10% solution of sodium carbonate aqueous solution, separate the supernatant, and additionally wash with distilled water, then separate the supernatant again. Did. The reaction solution from which the acid had been removed was extracted under a reduced pressure with a solvent, toluene and trace water. 1,4-cyclohexanedimethanol dibutyl ester (compound of formula 1) was obtained as a plasticizer through vacuum distillation (pressure of 10 mmHg or less, temperature of 220°C or more) to obtain a cleaner reactant.

<Example 2>

A plasticizer (compound of formula 2) was prepared in the same manner as in Example 1, except that hexanoic acid was used instead of BA in the same molar ratio.

<Example 3>

A plasticizer (compound of formula 4) was prepared in the same manner as in Example 1, except that 2-ethyl hexanoic acid was used instead of BA in the same molar ratio.

<Comparative Example 1>

A plasticizer (compound of formula 5) was prepared in the same manner as in Example 1, except that 3,5,5-Trimethylhexanoic acid was used in the same molar ratio instead of BA.

<Comparative Examples 2 to 4>

DBP (Dibutyl phthalate) (Comparative Example 2) and DEHP (Bis(2-ethylhexyl) phthalate) (Comparative Example 3), which are commercially available ortho-phthalate plasticizers, were purchased, and BASF's DINCH (1, 2-Cyclohexane dicarboxylic acid diisononyl ester) (Comparative Example 4) was obtained.

Preparation of specimen using polyvinyl chloride resin composition

With respect to 100 parts by weight of polyvinyl chloride resin (KL-10, LG chem), 60 parts by weight of plasticizers of Examples 1 to 3 and Comparative Examples 1 to 4, Ba-Zn-based thermal stabilizer as additive (BZ-191, songwon industrial) ) 3 parts by weight were blended and degassed under reduced pressure under vacuum while stirring at 100 rpm for 30 minutes with a stirrer to prepare plastisol.

The prepared plastisol was placed in a mold and geled at 170°C for 5 minutes to 10 minutes in a hot press to prepare a specimen having a desired shape.

<Experimental Example>

Test Items

A. Hardness measurement

Shore hardness was measured at 25° C. using ASTM D2240.

B. Tensile strength measurement

After pulling to 50 mm/min by the ASTM D638 method, the point where the specimen was cut was measured. Tensile strength was calculated as follows:

Tensile strength (MPa) = rod value (N) / {thickness (m) × width (m)}

C. Elongation (elongation rate) measurement

After pulling at 50 mm/min according to the ASTM D638 method, the point of cut was measured and the elongation was calculated as follows.

Elongation(%) = Length at elongation/ Initial length × 100

D. Measurement of migration loss

A test piece in the form of a film having a thickness of 0.25 mm was obtained according to ASTM D1239, the test piece was placed in each solvent, left at 25° C. for 24 hours, then taken out and weighed to calculate the amount of transition loss.

Transfer loss (%) = {(Initial specimen weight at room temperature-Weight of specimen after standing in solvent) / Initial specimen weight at normal temperature} × 100

E. Volatility measurement

A specimen in the form of a film having a thickness of 0.25 mm was obtained by ASTM D1203, and after working in an oven at 70° C. for 24 hours with activated carbon, the weight was measured.

Volatile reduction (%) = {(Initial specimen weight-Weight after 24 hours of operation) / Initial specimen weight} × 100

F. Cold resistance test

After the specimen was stored at -20°C for 24h, after pulling at 100 mm/min using a UTM device, elastic modulus of 5% and 10%, tensile strength at the point where the specimen was cut, and elongation were measured. Elastic modulus, tensile strength and elongation were measured as follows.

Elastic modulus (N/mm) = tensile stress / strain

Tensile strength (MPa) = rod value (N) / {thickness (m) × width (m)}

Elongation (%) = Length at elongation / Initial length × 100

G. Measurement of softening temperature

The temperature when the stiffness coefficient value of the specimen molded into a T-die type was 310 MPa was measured using a Clash-Berg mechanism according to the method of JIS K 6773. The stiffness coefficient was measured as follows.

Stiffness coefficient (Mpa) = 270 × length of specimen (mm) × torque value (N × mm) / thickness ³ (mm ³ ) × (10-thickness)^angle

Experiment result

(Shore A)

[Table 1]

[Table 2]

(Tensile strength / Elongation)

[Table 3]

(Measurement of performance loss)

[Table 4]

[Table 5]

[Table 6]

[Table 7]

(Volatile loss)

[Table 8]

[Table 9]

Table 10

[Table 11]

As can be seen from the results of the experiment, it can be seen that the plasticizer according to the present invention has superior physical properties compared to conventional plasticizers on the market.

In particular, in Tables 10 and 11, looking at the experimental results for the compound of Example 3 (Formula 4) and the compound of Comparative Example 1 (Formula 5), despite these compounds having a similar molecular structure, Examples It can be seen that the compound of 3 is superior to the compound of Comparative Example 1, and the cold properties of the specimen are generally superior and the softening point is also remarkably low.

As described above with reference to the embodiments of the present invention, those skilled in the art to which the present invention pertains will be able to perform various applications and modifications within the scope of the present invention based on the above.

Claims (9)

Plasticizer characterized in that it comprises a compound of formula (4):

(4) delete delete delete delete delete A resin composition comprising a compound according to Formula 4 of claim 1 and a polymer resin as a plasticizer. 8. The resin composition according to claim 7, wherein the polymer resin is polyvinyl chloride. The resin composition according to claim 7, wherein the resin composition further comprises a filler and/or a stabilizer.