JPH08143344A - Embossing roll and production of intermediate film for sandwich glass using the same - Google Patents

Abstract

PURPOSE: To obtain an embossing roll having an excellent release property and excellent productivity of intermediate films for sandwich glass by controlling the contact angle of water expressing the characteristics of the roll surface to a prescribed range by a plasma treatment or corona treatment. CONSTITUTION: The embossing roll 9 subjected to embossing on the surface is arranged within a glass vessel 3 of a plasma treating device 1 having a plasma generating system 2, an electrode 8, etc. A gaseous mixture composed of CF4 and oxygen is then introduced into the glass vessel 3 and the surface of the embossing roll is subjected to the plasma treatment, by which the roll surface is controlled to 50 to 110 deg. in the contact angle of the water. The corona treatment is usable in place of the plasma treatment. A base material for the intermediate film is then rolled by using a pair of the resulted embossing rolls, by which both surfaces of the base material for the intermediate film are embossed and the intermediate film for the sandwich glass is produced. As a result, the property to release the base material for the intermediate film from the embossing rolls in an embossing stage is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an embossing roll and a method for producing an interlayer film for laminated glass using the embossing roll. More specifically, the releasing property of the interlayer film base material from the embossing roll in the embossing step is improved. However, the present invention relates to an embossing roll capable of increasing productivity and a method for producing an interlayer film for laminated glass using the embossing roll.

[0002]

BACKGROUND OF THE INVENTION Laminated glass in which an interlayer film composed of a thermoplastic resin such as polyvinyl acetal resin and a plasticizer is adhered between two transparent glasses is widely used for window glass of automobiles, aircrafts, buildings and the like. It's being used. In this type of laminated glass, an interlayer film is sandwiched between transparent glass plates, and while heating it, it is passed between pressure rolls, or put in a rubber bag and suctioned under reduced pressure to remove the interlayer film between the glass plate and the interlayer film. It is manufactured by performing preliminary pressure bonding while deaerating air, then heating and pressurizing in an autoclave to finally make it completely transparent, and performing main pressure bonding.

When manufacturing laminated glass, it is required that the interlayer film has a good degassing property in the preliminary pressure bonding step in order to reduce the residual of bubbles in the laminated glass. To meet these demands,
Fine embossments (irregularities) are formed on the surface of the intermediate film. As a method of forming this emboss, a thermoplastic resin is formed into a sheet using an extruder, a calendar roll, or the like, the sheet is held at a constant temperature, and the sheet is passed between a pair of upper and lower embossing rolls to form a sheet on both sides. The method of transferring the emboss is widely adopted.

[0004]

Usually, the surface of an embossing roll is coated with a thermosetting resin such as a silicone type or a fluorine type as a releasing agent for the purpose of imparting a releasing property. Prevents adhesion to the embossing roll.
However, in the coating method such as the spray coating method which has been conventionally used, the coating thickness of the thermoplastic resin becomes non-uniform, or coating unevenness occurs such that there are uncoated portions.

A portion where the release agent is thinly coated is likely to be broken when stressed, and the releasability is easily deactivated in a short period of time. On the other hand, since the thermoplastic resin adheres to and grows on the part where the release agent is not applied, it causes mold release failure in a short period. For this reason, it is necessary to frequently apply the release agent to the embossing roll, which causes a problem that the production line stops each time.

The present invention is intended to solve the above problems, and an object of the present invention is to provide a method for efficiently producing an interlayer film with an embossing roll having an improved releasability.

[0007]

The inventors of the present invention have made extensive studies in view of the above problems, and as a result, by producing an intermediate film by using an embossing roll whose roll surface has been subjected to a specific treatment, The present inventors have completed the present invention by finding that the release treatment of the rolls is performed less frequently than in the past and the productivity is improved.

That is, according to the present invention, the surface of the roll has a contact angle of water of 50 ° to 50 ° by plasma treatment or corona treatment.
An embossing roll characterized by being controlled at 110 °.

Further, the present invention is a method for producing an interlayer film for laminated glass, which comprises a step of rolling an intermediate film base material with a pair of embossing rolls to give embossing on both sides, wherein the embossing roll is used. Provided is a method for producing a characteristic interlayer film for laminated glass.

Next, the present invention will be described in more detail.

The method of controlling the contact angle by plasma treatment or corona treatment on the surface of the embossing roll of the present invention uses a mixed gas in which a fluorine-containing compound which imparts hydrophobicity to the surface and a gas which imparts hydrophilicity are mixed, The contact angle can be easily controlled by changing the mixing ratio.

As the fluorine-containing compound, any gaseous compound at room temperature or at the temperature of plasma (corona) treatment can be used, but it is preferably a saturated fluorocarbon compound or saturated fluorocarbon compound which is low in toxicity and nonflammable. A sulfur compound that is gas at room temperature or gasifies at the temperature during discharge processing is used. Examples of such compounds include CF ₄ and C ₂ F ₆ which are low toxic and nonflammable, and SF ₆ and NF ₃ which are nonflammable and noncorrosive.

Examples of the gas that imparts hydrophilicity by plasma or corona treatment include oxygen, nitrogen, hydrogen, an inert gas such as argon, helium and neon, or a mixture thereof.

The plasma discharge preferably used in the plasma treatment is divided according to the plasma generation method.
DC glow discharge and low frequency discharge by internal electrode method,
Examples include, but are not limited to, high frequency discharge by an internal electrode system, external electrode system and coil system, microwave discharge by a waveguide system, electron cyclotron resonance discharge (ECR discharge), and the like. Other methods can be used as long as they cause a reaction on the surface.

The corona treatment is a tip pole discharge and may be either a low frequency discharge or a high frequency discharge as long as the dissociation reaction of the fluorinated compound is sufficient.

The roll surface of the embossing roll which has been subjected to plasma treatment or corona treatment has a water contact angle of 50.
It is controlled in the range of ° to 110 °. If this value is smaller than 50 °, it becomes difficult to release the thermoplastic resin from the embossing roll, which is not preferable. On the other hand, if it exceeds 110 °, the friction between the thermoplastic resin and the roll becomes too small, and the thermoplastic resin will not bite into the embossing roll, which is not preferable. The contact angle is an angle formed by the liquid surface and the solid surface at a place where the free surface of the stationary liquid contacts the solid wall, and is an acute angle when the liquid wets the solid and an obtuse angle when the liquid does not wet.

When embossing the interlayer film, embossing rolls having different contact angles of water may be used above and below, if necessary, unless the effects of the present invention are impaired.

The shape, size, and material of the embossing roll are not particularly limited, and a roll that is usually used for embossing the surface of a sheet, film or the like can be used. Further, the embossed shape of the surface can be given an arbitrary shape by the existing processing method.

Next, the interlayer film for laminated glass produced by the present invention is mainly composed of a thermoplastic resin and a plasticizer. Examples of the thermoplastic resin include polyvinyl butyral, polyurethane, polyvinyl chloride-ethylene copolymer, vinyl chloride-ethylene-glycidyl methacrylate copolymer, vinyl chloride-ethylene-glycidyl acrylate copolymer, vinyl chloride-glycidyl acrylate. Copolymer, polyvinylidene chloride, polyvinylidene chloride-acrylonitrile copolymer, polyvinyl acetate, ethylene-vinyl acetate copolymer, polyvinyl acetal-
A polyvinyl butyral mixture etc. can be mentioned.

Among these, polyvinyl butyral, polyurethane, vinyl chloride-ethylene-glycidyl methacrylate copolymer, ethylene-vinyl acetate copolymer are particularly preferably used.

The plasticizer is not particularly limited, but for example, dioctyl phthalate, dibutyl phthalate, diisododecyl adipate, epoxy fatty acid monoester, triethylene glycol-di-2-ethylbutyrate, triethylene glycol-diester. Examples thereof include 2-ethylhexoate, tetraethylene glycol-di-2-ethylbutyrate, tetraethylene glycol-di-heptaate, dihexyl adipate, dibutyl sebacate, dibutyl sebacate and the like.

Further, the intermediate film may contain various additives (ultraviolet absorbers, antioxidants, etc.), pigments, dyes, etc. within a range that does not impair the effects of the present invention.

The temperature of the intermediate film when imparting an embossed shape to the intermediate film with the embossing roll of the present invention is 90 ° C. to 140 ° C.
The temperature is in the range of 0 ° C, and preferably in the range of 108 ° C to 125 ° C. The surface temperature of the roll is 100 ° C.
It is set in the range of 170 ° C. If this temperature is too low, residual stress during rolling is large, and variations in the thickness of the interlayer film and thermal contraction increase. On the other hand, if the temperature is too high, the intermediate film is less likely to bite into the roll, which causes troubles such as winding of the intermediate film around the roll.

[0024]

The embossing roll of the present invention, to which the mold releasability is imparted by the plasma treatment or the corona treatment, has a release layer having a uniform thickness and no coating unevenness on the surface as compared with the conventional coating method. , The life of the release layer is extended. Therefore, the frequency of the mold release treatment applied to the embossing roll can be reduced, so that the production efficiency of the interlayer film is improved.

[0025]

EXAMPLES Next, the method for producing an interlayer film for laminated glass according to the present invention will be described in more detail with reference to Examples.

Example 1 An embossing roll was subjected to plasma treatment using the plasma treatment apparatus shown in FIG. In this plasma processing apparatus 1, an electrode 8 connected to a plasma generation system (high-frequency power source and impedance matching circuit) 2 is arranged in a glass container 3 serving as a plasma reaction system, and an electrode 8 is placed at a distance of 1.5 cm from the electrode 8. The embossing roll 9 to be processed is arranged. The embossing roll 9 is grounded and functions as an electrode itself. Further, the glass container 3 are each supplied CF ₄ and oxygen from the CF ₄ gas supply passage 4 and the oxygen gas supply path 5 is supplied through the mixed gas supply passage 6, after the reaction is exhausted from the exhaust passage 7 It The embossing roll 9 is controlled to rotate at an arbitrary constant speed during the discharge treatment, and a uniform release surface can be formed on the roll surface.

The embossing roll 9 to be treated has a diameter of 30c.
m, width 70 cm, made of carbon steel, and embossed on the surface. The embossing roll 9 was set in the plasma processing apparatus 1 as described above, and the roll surface was subjected to electric discharge treatment under the following conditions. That is, the ratio of CF ₄ to oxygen is 3:
A mixed gas of 1 (volume ratio) is used at a pressure of 3 Torr for 20 times.
It is introduced into the glass container 3 which is a plasma reaction system via the gas supply paths 4, 5 and 6 at a flow rate of 0 cm / min, and an effective power of 50 W and high frequency power of 13.56 MHz are supplied to the electrodes 8 and 50.
A voltage was applied between the embossing roll 9 and the rotating embossing roll 9 to cause discharge, and the surface of the embossing roll 9 was plasma-treated for 20 minutes.

The contact angle of water on the roll surface of the embossing roll 9 thus obtained was visually measured using a protractor.
It was 83 °. Next, the obtained embossing roll was used to impart embossing to the interlayer film, and the life of releasability was evaluated. That is, as shown in FIG.
A pair of embossing rolls 9 and 9 is installed in the mold, and an interlayer film substrate 12 made of polyvinyl butyral resin and triethylene glycol-di-2-ethyl butylate as a plasticizer is melt-extruded from a mold 11, and this is extruded. It was passed between the embossing rolls 9 and rolled, and embossed on both surfaces. At this time, the surface temperature of the intermediate film substrate 12 is 114 ° C., and the temperatures of the embossing rolls 9 are 150 respectively.
The temperature was 120 ° C. The linear velocity at that time is 10m.
/ Min.

While continuously performing the embossing treatment on the intermediate film as described above, the change in the releasability of the embossing roll was observed. Usually, when the mold releasability is lost, a mold release defect such as a yarn pulling from the interlayer film to the roll surface occurs. However, the embossing roll in the case of Example 1 has a mold release defect only after 720 hours have passed. There has occurred.

Example 2 The ratio of CF _{4 as a} mixed gas to oxygen was 4: 1 (volume ratio).
Then, the embossing roll was surface-treated in the same manner as in Example 1 to prepare an embossing roll having a surface water contact angle of 95 °. Further, when the time until the mold release failure was measured by the same method as in Example 1, the mold release failure occurred after 840 hours.

Example 3 The ratio of CF _{4 as a} mixed gas to oxygen was 5: 1 (volume ratio).
Then, the embossing roll was surface-treated in the same manner as in Example 1 to prepare an embossing roll having a surface water contact angle of 102 °. Further, when the time until the mold release failure was measured by the same method as in Example 1, the mold release failure occurred after 940 hours.

Comparative Example 1 The ratio of CF _{4 as a} mixed gas to oxygen is 7: 1 (volume ratio).
Then, the embossing roll was surface-treated in the same manner as in Example 1 to prepare an embossing roll having a surface contact angle of water of 120 °. Further, although it was tried to form an emboss on the intermediate film by the same method as in Example 1, the embossing could not be performed because the intermediate film did not penetrate into the roll.

Comparative Example 2 The ratio of CF _{4 as a} mixed gas to oxygen is 1: 1 (volume ratio).
Then, the embossing roll was surface-treated in the same manner as in Example 1 to prepare an embossing roll having a surface water contact angle of 40 °. Further, although it was tried to form an emboss on the intermediate film by the same method as in Example 1, the intermediate film was wrapped around the roll due to lack of releasability, and the embossing could not be performed.

Comparative Example 3 Shin-Etsu Chemical Co., Ltd. thermosetting silicone resin (trade name KS-
770A) was diluted with toluene to prepare a 1% solution.
For 100 parts of this solution, a curing catalyst (trade name CAT-P
L-8) 1 part was added to prepare a thermosetting silicone resin coating material. This coating material was applied onto the surface of an untreated embossing roll similar to that in Example 1 by using a sprayer so as to have a solid content thickness of about 1 μm, and then at 80 ° C. for 1 hour and 120 ° C. for 1 hour.
Further, it was cured at 150 ° C. for 30 minutes.

Using the obtained embossing roll, Example 1
Similarly to the above, embossing was applied to the interlayer film, and the life of releasability of the embossing roll was evaluated. As a result, defective release occurred at 350 hours.

Table 1 collectively shows the mixed gas ratio, the contact angle, and the time until defective release of each example and comparative example.

[0037]

[Table 1]

[0038]

As described above, according to the present invention, the life of releasability is longer than that of the conventional embossing roll, so that the frequency of the releasing treatment can be reduced and the production efficiency of the interlayer film is greatly improved. To do.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view of a plasma processing apparatus used in an embodiment of the present invention.

FIG. 2 is a cross-sectional explanatory view of an intermediate film rolling apparatus used in an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plasma processing apparatus 2 Plasma generation system 3 Glass container 8 Electrode 9 Embossing roll 10 Intermediate film rolling device 11 Die 12 Intermediate film substrate

Claims (2)

[Claims] 1. An embossing roll, wherein the roll surface is controlled to have a contact angle of water of 50 ° to 110 ° by plasma treatment or corona treatment. 2. A method for producing an interlayer film for laminated glass, which comprises a step of rolling an intermediate film base material with a pair of embossing rolls to give embossing to both surfaces, wherein the embossing roll according to claim 1 is used. A method for producing an interlayer film for laminated glass, which comprises: