JP2001030351A - Manufacture of thermoplastic resin sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an oriented thermoplastic resin film free from a surface flaw and excellent in surface easy slip properties and surface easy adhesiveness. SOLUTION: A thermoplastic resin sheet is produced by applying a thermoplastic resin B layer to at least the single surface of a thermoplastic resin A layer by coextrusion to form a laminated sheet and stretching the laminated sheet longitudinally and peeling the B layer from the A-layer to laterally stretching and/or heat-treating the thermoplastic resin A layer in a substantial non-contact state to produce a sheet comprising the thermoplastic resin A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a semiconductor device having no surface defects.
The present invention relates to a method for producing a thermoplastic resin sheet such as a stretched thermoplastic resin film having excellent surface characteristics.

[0002]

2. Description of the Related Art In a method for producing a thermoplastic resin sheet such as a thermoplastic resin film, a stretching step is indispensable. In general, stretching is performed in a longitudinal direction using a roll and in a width direction using a tenter. Stretching is taking place.

In such a case, when performing uniaxial stretching or biaxial stretching only in the longitudinal direction, it is necessary to heat and stretch the sheet by bringing the sheet into contact with the roll. The seat speed does not match,
The surface of the roll is often scratched due to the slip of the sheet on the roll.

[0004] For this purpose, efforts are made to adjust the peripheral speed of the roll, or the surface of the roll is cleaned so as not to damage the sheet. However, in reality, it is impossible to obtain a sheet which can be said to be flawless. Not too much.

[0005] Therefore, it has been proposed to laminate a releasable resin sheet on the surface layer and stretch it. Alternatively,
There has been proposed a method using a simultaneous biaxial stretching machine that stretches in the longitudinal direction by gripping with a clip.

[0006]

However, when stretched and heat-treated with another resin layer laminated on the surface layer, even if additives such as a lubricant are contained, the surface of the resin sheet after peeling is easily smooth and smooth. In addition to not being able to form a stable surface, surface defects due to surface transfer of the resin B layer occur, coating liquid cannot be coated in-line in film formation, and the thickness detection of the resin sheet A layer becomes difficult, and further lamination is performed. It had fatal drawbacks such as difficulty in recovering only the resin.

[0007]

In the simultaneous biaxial stretching machine, it is practically impossible to change the magnification in the longitudinal direction, the film formation speed is abnormally low, and the upper limit of the thickness of the stretchable sheet is too small. It had significant disadvantages in productivity.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The inventors of the present invention have conducted intensive studies on a method of forming a resin sheet A which can be said to have no surface defects under conditions close to ordinary film forming conditions.
After forming a thermoplastic resin B layer on at least one surface of the layer into a laminated sheet made of A / B by a co-extrusion method, stretching the laminated sheet in the longitudinal direction, peeling off the B layer from the A layer, This is a method for producing a sheet made of a thermoplastic resin A, wherein the thermoplastic resin A layer is stretched in the width direction and / or heat-treated in a non-contact manner.

In the present invention, the thermoplastic resin is a resin which exhibits a melt flow upon heating, and is typically a resin selected from polyester, polyamide, polyolefin, polyphenylene sulfide, vinyl polymer, and a mixture or modified product thereof. It is a target.

[0010] Polyester is a high molecular compound having an ester bond in the molecular main chain, and examples thereof include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, liquid crystal polyester, and copolymers thereof. Among them, polyethylene terephthalate, polyethylene naphthalate and a copolymer thereof are preferable, and polyethylene terephthalate and a copolymer thereof are particularly preferable. The number of repeating units of these polymer compounds is 80 or more, preferably 120 or more.

The intrinsic viscosity is preferably 0.4 (dl / g) or more, and more preferably 0.55 (dl / g) or more, as measured in orthochlorophenol (OCP). As a method for producing a polyester resin, a polymerization method in which the residue of the metal catalyst is reduced as much as possible is preferable,
Specifically, not the transesterification method but the direct polymerization method of directly polymerizing from carboxylic acid is preferred. The polymerization catalyst at this time, such as germanium oxide or antimony oxide, is preferably as small as possible, and magnesium oxide, manganese oxide, which is usually used as a transesterification catalyst,
It is preferable not to contain zinc oxide, aluminum oxide, and the like.

As the liquid crystal resin, polyester liquid crystal resin, polyester amide liquid crystal resin, polyamide liquid crystal resin and the like can be used. In the case of the present invention, although not particularly limited, polyester liquid crystal resins are preferable among them, for example, aromatic diols such as biphenol, terephthalic acid, aromatic dicarboxylic acids such as naphthalenedicarboxylic acid, and further parahydroxybenzoic acid A polyester liquid crystal polymer containing a hydroxycarboxylic acid such as hydroxynaphthoic acid as a main component, and a liquid crystal resin containing an aliphatic diol such as ethylene glycol or an ether binding unit may be used. Each resin is characterized by having a regular structure even in a molten state.

Needless to say, these polyester resins may be used in combination with various additives such as slipping agents, stabilizers, antioxidants, viscosity modifiers, antistatic agents, coloring agents, pigments, and liquid crystal polyesters. However, it is preferable that the additive be as small as possible.

The polyamide resin is a high molecular compound having an amide bond in the main chain, and typical examples thereof include nylon 6, nylon 66, nylon 610, nylon 12, nylon 11, nylon 7, nylon 7, / Paraxylylene adipamide, polyhexamethylene terephthalamide / isophthalamide, and their related copolymers, mixtures and the like.

The polyolefin resin includes polyethylene, polypropylene, methylpentene polymer, cyclic polyolefin, and copolymers and blends thereof with butene, hexene, vinyl acetate and the like. Propylene butene C ₂ C ₃ C
₄ copolymer or the like is preferable, and the melt melt index M
I is preferably as high as 4 to 15 (g / min).

Of course, various additives are added to these resins.
For example, sliding materials, stabilizers, antioxidants, viscosity modifiers,
An antistatic agent, a colorant, a pigment, and the like can be used in combination, but it is preferable to use the minimum necessary additives.

As the thermoplastic resin A, a polyester resin, a polyphenylene PPS resin, a polyamide resin and the like are preferable, and as the thermoplastic resin B, a polyolefin resin and a polyester resin are preferable. At this time, in order to improve the releasability, a silicone oil modified with an amino group, a carboxyl group, a polyoxyalkylene group, an aliphatic hydrocarbon, a higher fatty acid and a salt thereof, a fatty acid amide, a fatty acid Esters, fatty acid ketones, aliphatic alcohols, nonionic surfactants and the like may be contained in an amount of about 0.001 to 1% by weight.

As a combination of the thermoplastic resins A and B,
Polyester resin A and polyolefin resin B, polyphenylene resin A and polyester resin B, polyamide resin A
And a combination of polyolefin resin B and the like are particularly preferable from the viewpoint of surface formation.

As a method of laminating the thermoplastic resin B layer on at least one surface of the thermoplastic resin A layer by the coextrusion method, the respective molten resins are laminated into two or three layers by a lamination adapter, and then the T resin is laminated. After being expanded in the width direction by a die such as a die, the melt is extruded and cooled to obtain a laminated sheet. Of course, it is obvious that lamination may be carried out after being expanded in the width direction in the die, or a method of laminating each other immediately after melt extrusion from the die may be employed. Although lamination may be performed on one side, lamination of layer B on both sides of layer A is preferable because both surfaces of thermoplastic resin A can be made defect-free.

When the thus obtained two-layer, preferably three-layer laminate film is stretched in the longitudinal direction using a roll, the thermoplastic resin A layer is not laminated on the surface of the thermoplastic resin A layer. When the sheet is heated and cooled by directly contacting the layer on the roll, the sheet surface speed rubs against the roll surface because the sheet linear velocity and the roll peripheral velocity do not always match due to thermal expansion and thermal contraction of the sheet,
As a result, surface defects such as scratches and transfer occur on the sheet surface. Therefore, a thermoplastic resin B layer is formed on at least one surface of the thermoplastic resin A layer by the co-extrusion method.
A film is formed as a laminated sheet composed of B or B / A / B.
The layer is peeled off, and then the thermoplastic resin A layer is stretched and / or heat-treated in the width direction without contact. As described above, after the stretching in the longitudinal direction, it is essential to peel off the thermoplastic resin B layer before heat treatment.

If the heat treatment is performed while the layer B is laminated, the surface of the layer A cannot be formed, and not only surface properties such as slipperiness, smoothness, abrasion resistance, and blocking resistance cannot be obtained, but also, A sheet having a uniform thickness, in which surface treatment such as corona discharge treatment, plasma treatment, coating of a coating liquid, or the like cannot be performed in-line during film formation, and it is difficult to detect the thickness of the resin sheet A layer during film formation. Is not obtained,
In addition, there is a serious drawback in that the recovery of the release resin B layer becomes difficult because the recovery of the release resin B layer becomes contaminant in the resin A and the resin A is easily mixed.

Therefore, in the present invention, it is essential to peel off the release resin B layer before the heat treatment step performed near the melting point of the thermoplastic resin A.

For example, MD in the longitudinal direction and TD in the width direction
Then, (1) lamination → MD stretching → B layer peeling → TD stretching →
Heat treatment, (2) lamination → MD stretching → B layer peeling → coating → TD stretching → heat treatment, (3) lamination → MD stretching → TD stretching →
MD stretching again → B layer peeling → TD stretching → heat treatment, (4) lamination → MD stretching → TD stretching → MD stretching again → B layer peeling →
Coating → TD stretching → heat treatment, (5) lamination → TD stretching → MD stretching → B layer peeling → heat treatment, (6) lamination → TD stretching →
Various processes such as MD stretching → B layer peeling → coating → heat treatment can be applied.

The delamination force at room temperature is 1 m / mi.
0.1 to 5 when peeled by 180 ° peeling method at speed n
It is preferably about 00 g / cm, preferably about 1 to 100 g / cm, and if it is too light, it is not preferable because delamination occurs during the film forming process.

After the layer B is peeled off after the stretching in the longitudinal direction, preferably, a water-soluble or water-dispersible coating liquid is coated on at least one surface of the layer A of the thermoplastic resin immediately after the peeling to easily slide the surface of the layer A. Properties such as adhesiveness, easy adhesion, antistatic properties, and abrasion resistance.

The resin used for coating includes acrylic resin, urethane resin, polyester resin, polyolefin resin, polyamide resin, urethane acrylic resin,
A resin containing a polyester urethane resin and a copolymer or blend thereof as a main component can be used. As a coating method, any method such as a gravure roll, a metering bar, a reverse roll, and a die coater can be used.

The method for peeling is not particularly limited.
The layer B after peeling is recovered and reused again as a raw material for coextrusion.

Next, an example of a method for producing the thermoplastic resin A sheet according to the present invention will be described.

A polyester resin is prepared as the thermoplastic A layer resin used for the coextrusion, and a propylene copolymer resin obtained by copolymerizing ethylene and butene is prepared as the thermoplastic B layer resin. At this time, when it is desired to reduce the peeling force, a modified silicone oil, a hydrocarbon, or the like is added to the propylene copolymer as an additive.

Of course, in each of these resin layers, a slip additive, a heat stabilizer, a viscosity modifier, an anti-blocking agent, a coloring agent, an antioxidant, various stabilizers, etc., as a polymer additive, A raw material or the like prepared by mixing the raw material for collecting the resin sheet of the A layer or the B layer is prepared, dried and dehydrated if necessary, and then heated and melted in the respective extruders to a temperature equal to or higher than the melting point of the resin. It is laminated by a lamination adapter so as to have three layers of thermoplastic resin B layer / thermoplastic resin A layer / thermoplastic resin B layer, extruded from a T-die die into a sheet, and is a conventionally known adhesion means. The electrostatic charge is applied, the air knife, a vacuum chamber, a close contact means such as a press roll, or the like is used to adhere to the cooling medium and solidify by cooling. Of course, an appropriate filter, for example, a commonly used filter such as a sintered metal, a porous ceramic, a sand, or a wire mesh may be used to remove foreign matters of the resin in a molten state.

The laminated sheet thus obtained is stretched according to an arbitrary stretching method such as longitudinally uniaxial stretching or sequential biaxial stretching. The stretching temperature is equal to or higher than the glass transition temperature of the thermoplastic resin, and the stretching ratio is about 3 to 7 times in the longitudinal direction and the width direction, respectively. At this time, the layer A is always B
Must be done protected by layers.

After stretching in the longitudinal direction, the layer B is peeled off, and a lubricant is contained in an aqueous solution or an aqueous dispersion of an acrylic resin or a urethane resin in order to impart lubricity or easy adhesion to both surfaces of the layer B. Coat the coating liquid.

Thereafter, stretching in the width direction and / or
Alternatively, heat treatment is performed to obtain a film made of a stretched and oriented polyester A resin. The heat treatment needs to be performed after the layer B has been peeled off.
Is preferably in the range of Tm to Tm-100 ° C.

The thermoplastic resin sheet A thus formed
Has various excellent properties such as surface no defect, easy lubricity, transparency as well as strength, heat resistance, low linear expansion coefficient, insulation, low water absorption, high gas barrier properties, It can be used for various uses such as an optical base sheet, a magnetic recording medium sheet, a packaging use, and an electric insulation use.

[0035]

[Measurement method of physical properties] Next, the method of measuring physical properties used in the present invention will be described below. 1. Melt index MI (g / 10 minutes) Based on JIS K7210 condition 4, the temperature is 190 ° C for polyethylene and 210 ° C for polypropylene.
Under a load of 2.16 kgf. 2. Thermal properties (Tm, Tg, Tmc) Using a DSC-II type measuring device manufactured by PerkinElmer, sample weight 10 mg, heating rate 20 ° C. /
The temperature at which the deviation of the baseline started was Tg, the exothermic peak at the further increase in temperature was Tcc, and the endothermic peak temperature accompanying crystal melting was the melting point Tm.
After holding at Tm + 20 ° C. for 1 minute, the melt was cooled at a cooling rate of 20 ° C./min.
mc.

[0036]

EXAMPLES Examples and comparative examples are shown below to make the present invention easier to understand. Example 1 Ethylene / propylene / butene C ₂ C as a resin for layer B
₃ C ₄ copolymer (C ₂ 2 mol%, butene C ₄ 8 mol%)
Was used, and polyethylene terephthalate PET (direct polymerization method using 55 ppm of polymerization catalyst antimony trioxide) was used as the resin of the A layer, and the PET resin was dried at 180 ° C. for 2 hours in a vacuum. Each resin is supplied to a usual single screw extruder, and the PET resin is melted at 285 ° C., the C ₂ C ₃ C ₄ copolymer resin is melted at 300 ° C., and then the C ₂ C ₃ C ₄ resin layer / PE is melted.
It was laminated with a lamination adapter so as to have three layers of T resin layer / C ₂ C ₃ C ₄ resin layer, and this was extruded from a T die die into a sheet.

In order to bring the molten sheet into close contact with a casting drum, which is a moving cooling medium maintained at 25 ° C.,
Apply 10 KV electrostatic charge from the tape-shaped electrode to 10 m
/ Min. And tightly cooled and solidified. The three-layer laminated sheet thus obtained was heated to 100 ° C. by a roll-type longitudinal stretching machine, stretched five-fold in multiple steps, and cooled to room temperature. The roll material is made of chrome plating, Teflon, alumina ceramic, silicon rubber. The B layers on both surfaces were peeled off from the three-layer laminated longitudinally stretched film thus obtained. The resin of the layer B was directly supplied to an extruder for recovery, and was extruded into pellets for reuse.

An aqueous solution of ethylene acrylic acid resin (0.8% by weight of silicon oxide having an average particle diameter of 0.3 nm was added as an additive) was coated on both surfaces of the peeled layer A sheet.
It is supplied to a stenter and heated to 95 ° C., stretched 4 times in the width direction, and once cooled to around 100 ° C., heat-fixed at 200 ° C., cooled to 160 ° C., and 5% in the width direction at this temperature. Once the stretched sheet is removed from the clip of the stenter, the edges of the product are slit, and the center product is removed from the inside of the drum with an air can that blows heated air to 170 (toward the outer periphery of the drum). With an external heating device that blows out heated air at 170 ° C.) while relaxing 3% in the longitudinal direction.

The biaxially oriented PET thus obtained having a width of 5 m.
The thickness of the resin sheet is 188 μm, and there are almost no foreign substances and defects on the PET surface and inside,
It was an uncolored and highly transparent sheet, and had excellent winding properties. Further, the distribution of the refractive index, the heat shrinkage, and the elastic modulus in the width direction of the sheet in the width direction was within 8%, and the sheet was uniform in the width direction. Since it has properties such as no defect on the surface and inside, easy surface adhesion (surface wetting tension of 65 dynes / cm), easy sliding (static friction coefficient 0.25), transparency, etc., it is used for optical applications and packaging. It can be used for various purposes such as applications and electrical insulation. Comparative Example 1 Without using the C ₂ C ₃ C ₄ copolymer resin used in Example 1,
Extensive heat treatment was carried out in the same manner as in Example 1 except that stretching was performed using a single PET resin sheet, to obtain a stretched sheet having a thickness of 188 μm.

On the surface of the sheet thus obtained,
Since surface defects such as scratches, transfer patterns, and scratches were observed, they could not be used for severe applications such as optical applications. Comparative Example 2 A three-layer laminated sheet was produced in exactly the same manner as in Example 1 except that the PET resin layer A used in Example 1 contained 0.8% by weight of silicon oxide having an average particle diameter of 0.3 μm as a slipping agent. Is extruded and cooled, stretched in the longitudinal direction, and then supplied to the stenter as it is without peeling the layer B, stretched in the width direction in the same manner as in Example 1, cooled once, and then heat-fixed and relaxed. After processing, once the stretched sheet is removed from the clip of the stenter and the layer B is peeled off at this stage, both edges of the layer A are slit, and only the center product part is 3% in the longitudinal direction by an air can. Heat treatment was performed while relaxing, to obtain a biaxially oriented sheet having a thickness of 188 μm.

The surface of the sheet thus obtained has scratches.
No transfer flaw was present, but the wetting tension was 41 dynes / c
In addition to the poor adhesion with m, the coefficient of static friction was 0.8 and the slipperiness was poor. In addition, when the sheet was rolled up, the sheet was meandering and the winding appearance was poor. Was. In addition, aggregates considered to be additives were scattered in the inside, and the transparency was slightly deteriorated.

On the surface of the sheet thus obtained,
Not only surface defects such as abrasions, transfer scratches, and scratches, but also poor adhesion and lubricity, and foreign substances and defects are found inside, so it cannot be used for severe applications such as optical applications. Was something.

[0043]

According to the present invention, it is possible to produce a thermoplastic resin sheet such as a stretched thermoplastic resin film having substantially no surface defects and extremely excellent surface properties as compared with conventional ones. Can be.

Such a thermoplastic resin sheet has various defects such as strength, heat resistance, low coefficient of linear expansion, insulation, low water absorption, and high gas barrier properties, as well as surface defect-free, easy slippage, and transparency. Excellent characteristics can also be exhibited, and by utilizing these characteristics, they can be usefully used in various industrial applications such as optical base sheets, magnetic recording medium sheets, packaging applications, and electrical insulation applications.

Continued on the front page F-term (reference) 4F100 AK01A AK01B AK01C AK03A AK03C AK41B BA03 BA06 BA10A BA10C BA15 EH20 EJ38 JB16A JB16B JB16C JL14 4F210 AA03 AA09 AA21 AE01 AG01 QA01 QA03 Q08 QA03 Q08

Claims (6)

[Claims] 1. A laminated sheet is formed by co-extruding a thermoplastic resin B layer on at least one surface of a thermoplastic resin A layer, and the laminated sheet is stretched in the longitudinal direction.
Peeling the layer B from the layer, and subsequently stretching the thermoplastic resin A layer in the width direction in a substantially non-contact manner and / or heat-treating to produce a sheet made of the thermoplastic resin A. A method for manufacturing a resin sheet. 2. The method for producing a thermoplastic resin sheet according to claim 1, wherein the film stretched in the width direction is stretched in the longitudinal direction, and subsequently, the layer B is separated from the layer A of the stretched film. 3. The film stretched in both the longitudinal and width directions in the axial direction is stretched again in the longitudinal direction, and the layer A is separated from the layer A of the stretched film. A method for producing a sheet comprising a thermoplastic resin A. 4. A method in which a water-soluble or water-dispersible coating liquid is coated on at least one surface of the thermoplastic resin A layer after the layer B is peeled off from the layer A, and then the film is stretched and / or stretched in a non-contact manner in a practical manner. Or a heat treatment.
4. The method for producing a thermoplastic resin sheet according to 2 or 3. 5. The laminate sheet according to claim 1, wherein the laminate sheet is a three-layer sheet composed of B / A / B.
A method for producing a thermoplastic resin sheet comprising the thermoplastic resin A described above. 6. The method for producing a thermoplastic resin sheet according to claim 1, wherein the thermoplastic resin A is a polyester resin and the thermoplastic resin B is a polyolefin resin.