JP2009039956A - Evaluation method for extrusion lamination formability of synthetic resin and quality control process using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for evaluating the extrusion lamination formability, especially the neck-in, using a small quantity of a sample. <P>SOLUTION: The neck-in of a synthetic resin in extrusion lamination is evaluated from the ratio (η<SB>DF</SB>/η<SP>+</SP>) of the degree of viscosity η<SB>DF</SB>calculated from the melt tension F to the degree of viscosity η<SP>+</SP>(t) calculated based on the storage elastic modulus G' and the loss modulus G" measured at the same temperature as when the degree of viscosity η<SB>DF</SB>is measured. The evaluation results of the neck-in are used for quality control. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for evaluating extrusion laminate moldability of a synthetic resin for extrusion laminate molding and a quality control method using the same.

  Extrusion laminate molding is a method of bonding paper, metal foil, plastic film and synthetic resin, and is widely used in industry. In recent years, high productivity has been demanded in each industry, and the same applies to the extrusion laminate field. One of the indexes representing productivity in extrusion lamination is neck-in. Neck-in is a phenomenon in which the width of the film-like molten resin extruded from the T-die decreases until it comes into contact with the cooling roll, and is determined by subtracting the cooled film width from the die opening width. It is known that the larger the neck-in, the more loss called edge beads and the lower the productivity, and it is very important for extrusion laminate molders to predict the neck-in level of the synthetic resin used in advance and control the quality. It has been studied for some time.

  Honkanen et al. Have proposed that the neck-in of high-pressure low-density polyethylene is determined by the molecular weight distribution and the degree of long-chain branching (see Non-Patent Document 1), but these measurement methods are complicated and expensive. It is difficult to obtain an accurate value of the molecular weight component, and it is not suitable as a quality control method that requires a simple method. Chai et al. Have proposed that the storage elastic modulus obtained by a conical disk type rheometer shows a good relationship with neck-in (see Non-Patent Document 2). However, this method can only predict the neck-in of some limited samples. This is presumably because the extrusion laminate formability reflects the viscoelasticity in the nonlinear region, not the linear viscoelasticity like the storage elastic modulus. Further, in this document 2, it is proposed that the melt tension also shows a good correlation with the neck-in, but this method can also predict the extrusion laminate processability only for some samples with similar linear viscoelasticity. Not too much.

Polymer Engineering Science, Vol. 18, 985 (1978) ANTEC, 225 pages (2004)

  The present invention has been made in view of the above circumstances, and does not require evaluation by an extrusion laminating apparatus. Extrusion of a synthetic resin capable of evaluating extrusion laminating property, particularly neck-in, with a small amount of sample. A laminate moldability evaluation method and a quality control method using the same are provided.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor has obtained a melt tension F measured using a capillary viscometer, a storage elastic modulus G ′ and a loss elastic modulus G ″ measured using a conical disk type viscometer. From the viscosity ratio calculated from the above, it was found that the neck-in level of the synthetic resin can be evaluated, and the present invention has been completed.

That is, in the present invention, the viscosity η _DF (Pa · sec) calculated from the melt tension F (mN) of the synthetic resin by the equation (1), the storage elastic modulus G ′ (Pa), and the loss elastic modulus G ″ (Pa ) To a viscosity ratio (η _DF / η ⁺ ) calculated with the formula η ⁺ calculated from the formula (2), and an evaluation method of extrusion laminate formability and a quality control method of a synthetic resin using the same .

ここで、溶融張力Ｆは毛管粘度計を用い測定することにより得られ、ａは溶融張力を測定した際の巻取り部における合成樹脂ストランドの断面積（ｍ^２）、ｖ_ｃ−ｒは合成樹脂ストランドの巻き取り速度（ｍ／秒），ｖ_ｄｉｅは毛管粘度計のダイにおける合成樹脂の流速（ｍ／秒）、Ｌはダイから押出されたストランドの径が変化している距離（ｍ）である。

Here, the melt tension F is obtained by measurement using a capillary viscometer, a is the cross-sectional area (m ² ) of the synthetic resin strand in the winding portion when the melt tension is measured, and v _c−r is the synthetic resin. The winding speed of the strand (m / sec), v _die is the flow rate of the synthetic resin in the capillary viscometer _die (m / sec), and L is the distance (m) at which the diameter of the strand extruded from the die changes. is there.

ここで、貯蔵弾性率Ｇ’と損失弾性率Ｇ’’は円錐円板型粘度計を用い粘度η_ＤＦと同一温度で測定することにより得られ、ωは角速度（ラジアン／秒）、ｔは時間（秒）であり、式（３）より求められる。

Here, the storage modulus G 'and loss modulus G''is obtained by measuring at the same temperature and viscosity eta _DF using a cone disc viscometer, omega is the angular velocity (rad / sec), t is the time (Seconds), which is obtained from equation (3).

ｒ_ｃ−ｒは巻取り部における合成樹脂ストランドの直径、ｒ_ｄｉｅはダイの直径である。 以下に、本発明について詳細に説明する。

rc _-r is the diameter of the synthetic resin strand in the winding portion, and r _die is the diameter of the die. The present invention is described in detail below.

  The melt tension F constituting the present invention is described in Polymer, Vol. 42,8,663 pages It is a well-known method described in 2001 or JP-A-2006-43911, and can be determined by using a capillary viscometer.

From this melt tension F, the viscosity η _DF is determined using the equation (1).

ａはストランド巻き取り部における合成樹脂ストランドの断面積（ｍ^２）、Ｌはダイから押出されたストランドの径が変化している距離（ｍ）であり、それぞれ実測により求めることができる。また、ｖ_ｃ−ｒは合成樹脂ストランドの巻き取り速度（ｍ／秒）であり装置に設備されている速度計から求めることができる。さらに、ｖ_ｄｉｅは毛管粘度計のダイにおける合成樹脂の流速（ｍ／秒）であり、ダイの内径とダイを通過する樹脂の押出量から算出することができる。溶融張力Ｆの測定温度は、特に限定するものではないが、測定する樹脂の融点より２０℃以上高い方が好ましい。ポリエチレンの場合、１３０℃から２５０℃の範囲が好ましく、ポリプロピレンの場合は１６０℃から２５０℃の範囲が好ましい。

a is a cross-sectional area (m ² ) of the synthetic resin strand in the strand winding portion, and L is a distance (m) in which the diameter of the strand extruded from the die changes, and can be obtained by actual measurement. Moreover, vc _-r is a winding speed (m / sec) of the synthetic resin strand, and can be obtained from a speedometer installed in the apparatus. Furthermore, v _die is the flow rate (m / sec) of the synthetic resin in the _die of the capillary viscometer, and can be calculated from the inner diameter of the die and the extrusion amount of the resin passing through the die. The measurement temperature of the melt tension F is not particularly limited, but is preferably higher by 20 ° C. or more than the melting point of the resin to be measured. In the case of polyethylene, a range of 130 ° C. to 250 ° C. is preferable, and in the case of polypropylene, a range of 160 ° C. to 250 ° C. is preferable.

The storage elastic modulus G ′ and the loss elastic modulus G ″ constituting the present invention can be obtained by a known method using a conical disk type viscometer. From the storage elastic modulus G ′ and the loss elastic modulus G ″ at each angular frequency obtained at the same temperature as the measurement of the melt tension F, the equation (2) proposed in Journal of Japanese Society of Rheology 1976 No. 4, page 166 is obtained. Use viscosity η ⁺ .

ここで、ωは角速度（ラジアン／秒）、ｔは時間（秒）であり、式（３）より求められる。

Here, ω is an angular velocity (radian / second), t is a time (second), and is obtained from equation (3).

ｒ_ｃ−ｒは巻取り部における合成樹脂ストランドの直径（ｍ）、ｒ_ｄｉｅはダイの直径（ｍ）である。すなわち、ｔはダイにおける合成樹脂の押出速度とダイの径、ストランドの引き取り速度と径により決定される。

rc _-r is the diameter (m) of the synthetic resin strand in the winding portion, and r _die is the diameter (m) of the die. That is, t is determined by the synthetic resin extrusion speed and die diameter in the die, and the strand take-up speed and diameter.

The neck-in of the synthetic resin can be evaluated from the ratio (η _DF / η ⁺ ) of the viscosity η _DF and the viscosity η ⁺ thus determined. Viscosity eta _DF and viscosity eta ⁺ ratio (η _DF / η ⁺⁾ is the higher neck-in reduced neck-in large enough viscosity eta _DF and viscosity eta ⁺ ratio (η _DF / η ⁺⁾ is small. The method of the present invention can be evaluated if there is a small amount (several tens of grams) of synthetic resin, and is very useful as a quality control method at the time of shipment at the resin manufacturer and at the time of acceptance of the synthetic resin at the laminate molding manufacturer. It is beneficial. Quality control is possible by setting the value of the ratio (η _DF / η ⁺ ) of the viscosity η _DF to the viscosity η ^{+ in} a certain range as the standard width. In this case, the preferable range of the ratio of the viscosity η _DF to the viscosity η ⁺ (η _DF / η ⁺ ) varies depending on the lamination molding conditions, and can be set as appropriate.

  The synthetic resin constituting the present invention is not particularly limited, but low density polyethylene, high density polyethylene, ethylene / 1-butene copolymer, ethylene / 1-hexene copolymer used for extrusion lamination molding, Ethylene / 1-octene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, ethylene / acrylic acid Ester copolymer, ethylene polymer such as ethylene / methacrylic acid ester copolymer, polypropylene, propylene polymer such as propylene / ethylene copolymer, propylene / 1-butene copolymer, poly 1-butene, poly Polyolefins such as 1-hexene and poly-4-methyl-1-pentene, polyethylene terephthalate, etc. Polyesters, polyamides, polyvinyl alcohol, ethylene-vinyl acetate copolymer saponification product, and the like can be exemplified polycarbonate.

  The neck-in evaluation method of the present invention does not need to be evaluated by an extrusion laminating apparatus, and can be evaluated for extrusion lamination processability, particularly neck-in, with a small amount of sample, and is very useful.

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

  The measurement methods and evaluation methods for physical properties and workability are shown below.

(1) Melt mass flow rate (MFR)
It measured based on JISK6922-1 (1997).

(2) Density The density was measured in accordance with JIS K6922-1 (1997).

(3) Neck-in An extrusion laminator (manufactured by Musashinokikai Co., Ltd.) having a screw of 25 mmφ was used. The neck-in was determined by measuring the width of the polyethylene film at a take-up speed of 40 m / min and a polyethylene extrusion rate of 6 kg / hour, and calculating the difference in die opening width (300 mm). The resin temperature was 320 ° C.

(4) Melt tension F
A capillary viscometer (trade name: Capillograph, manufactured by Toyo Seiki Seisakusho Co., Ltd.) having a barrel diameter of 9.55 mm was attached to a die having a length of 8 mm, a diameter (r _die ) of 2.095 mm, and an inflow angle of 90 °. The measurement temperature is set to 190 ° C., the piston lowering speed is set to 10 mm / min, the winding speed of the strand is set to (v _c−r ) 0.167 (m / sec), and the load (mN) necessary for take-up is set. The melt tension was F. L was 0.05 m by actual measurement, r _cr was 0.0003 m, v _die was 0.0035 m / sec, and t was 1.2 sec.

(5) Storage elastic modulus G ′ and loss elastic modulus G ″
Using a conical disk type viscometer (trade name MR-500, manufactured by Rheology Co., Ltd.), the angular velocity dependence of dynamic viscoelasticity at an angular velocity of 0.03 to 28.9 (radians / second) and a temperature of 190 ° C. It was measured. The strain was measured in a linear region of 1% or less.

Example 1
As synthetic resins having different neck-in values, low density polyethylene (trade name Petrocene 205, manufactured by Tosoh Corporation) having an MFR of 3 g / 10 min and a density of 924 kg / m ³ , an MFR of 8 g / 10 min, and a density of 919 kg / m ³ Low density polyethylene (trade name Petrocene 203, manufactured by Tosoh Corporation), low density polyethylene (Made by Tosoh Corporation, trade name Petrocene 213), MFR 8 g / 10 min, density 918 kg / m ³ , MFR 13 g / 10 min. Neck-in, melt tension F, storage elastic modulus G ′, and loss elastic modulus G ″ were measured using low-density polyethylene having a density of 919 kg / m ³ (trade name Petrocene 212 manufactured by Tosoh Corporation). The measurement results and the results of calculating η _DF / η ⁺ are shown in Table 1. Smaller sample of neck-η _{DF /} η ⁺ large, was possible quality control of neck-by η _{DF /} η ^+. On the other hand, conventional methods such as MFR and melt tension have no correlation with the neck-in value, and are not suitable for neck-in quality control.

Claims (3)

From the viscosity η _DF (Pa · sec) calculated from the melt tension F (mN) of the synthetic resin according to the equation (1), the storage elastic modulus G ′ (Pa), and the loss elastic modulus G ″ (Pa), the equation (2) The extrusion laminate formability evaluation method by calculating the ratio (η _DF / η ⁺ ) of the viscosity η ⁺ (t) (Pa · sec) calculated by

Here, the melt tension F is obtained by measurement using a capillary viscometer, a is the cross-sectional area (m ² ) of the synthetic resin strand in the winding portion when the melt tension is measured, and v _c−r is the synthetic resin. The winding speed of the strand (m / sec), v _die is the flow rate of the synthetic resin in the capillary viscometer _die (m / sec), and L is the distance (m) at which the diameter of the strand extruded from the die changes. is there.

Here, the storage modulus G 'and loss modulus G''is obtained by measuring at the same temperature and viscosity eta _DF using a cone disc viscometer, omega is the angular velocity (rad / sec), t is the time (Seconds), which is obtained from equation (3).

rc _-r is the diameter of the synthetic resin strand in the winding portion, and r _die is the diameter of the die. 2. The extrusion laminate formability evaluation method according to claim 1, wherein the synthetic resin is a polyolefin. A synthetic resin quality control method according to the extrusion laminate formability evaluation method according to claim 1.