JP6769583B2 - Manufacturing method of molded products and resin film used in the manufacturing method - Google Patents

Description

The present invention relates to a method for producing a molded product and a resin film used in the method. More specifically, the present invention relates to a method for producing a molded product that has been subjected to an aging or annealing treatment using a specific resin film, and a specific resin film used in the production method.

In the manufacture of various molded products (plastic molded products, metal molded products, etc.), "post-heating" of the molded products may be performed.
As an example, especially in the production of molded articles using thermosetting resins, heating may be performed after the intention is to completely cure the uncured resin or inactivate unreacted chemical species. ..
As another example, post-heating may be performed to relieve strain and stress due to molding.
These heatings are sometimes referred to as "aging", "annealing" and the like.

As an example, Patent Document 1 describes a method for producing a molded product in which the residual stress of a resin molded product, particularly a thermoplastic resin molded product, is reduced by using far-infrared heating.

As another example, in Patent Document 2, in the annealing treatment of a plate-shaped resin molded product, a heat treatment capable of producing the annealed product with good yield, low cost, and labor saving and space saving can be performed. The method is described.

As yet another example, in Patent Document 3, a foamed resin sheet having a large number of foam-like holes formed on the surface of a base material having a predetermined shape and used as a suction surface is fixed, and the suction surface of the foamed resin sheet is fixed. Describes a method for annealing a thermoplastic resin plate, which comprises adsorbing and fixing the thermoplastic resin plate to the surface, integrating the thermoplastic resin plate, and heating and cooling the resin plate.

JP-A-3-268843 JP-A-11-172026 Japanese Unexamined Patent Publication No. 2008-55624

In post-heating of a molded product, the molded product is supported by a film from the viewpoints of efficient treatment of a small molded product, prevention of contamination during post-heating, prevention of contact with a heating device (heat source) of the molded product, and the like. A method of heat treatment (more preferably, the molded product is sandwiched between two films from the top and bottom) can be considered.
However, as far as the inventor knows, such a method has not yet been materialized. Moreover, there has been no film suitable for such a method.

The present invention has been made in view of such circumstances. One of the objects of the present invention is to provide a new method for post-heating (aging treatment, annealing treatment, etc.) of a molded product. Also, one of the objects of the present invention is to provide a film that is suitably applied to the new method.

As a result of the study, the present inventors have completed the inventions provided below.

According to the present invention
A method for manufacturing a molded product that has been aged or annealed.
The preparatory process for preparing the molded product and
A heating step of heating the molded product while supporting it with a resin film to perform an aging or annealing treatment is included.
The rate of change in thermal dimension from 23 ° C to 160 ° C in the vertical direction of the resin film is 10% or less.
Provided is a method for producing a molded product, wherein the resin film has a transmittance of light having a wavelength of 500 nm of 38% or more and a haze value of 40% or less.

Further, according to the present invention,
A resin film used to support a molded product when it is heated and subjected to an aging or annealing treatment.
The rate of change in thermal dimension from 23 ° C to 160 ° C in the vertical direction of the resin film is 10% or less.
Provided is a resin film having a transmittance of light having a wavelength of 500 nm of 38% or more and a haze value of 40% or less.

According to the present invention, a new method for post-heating (aging treatment, annealing treatment, etc.) of a molded product is provided. Also provided are films that are suitably applied to the new method.

The above-mentioned objectives and other objectives, features and advantages are further clarified by the preferred embodiments described below and the accompanying drawings below.

It is a figure which shows typically the example of the manufacturing method of a molded article.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the drawings, similar components are designated by the same reference numerals, and description thereof will be omitted as appropriate.
In order to avoid complication, when there are a plurality of the same components in the same drawing, only one of them may be coded and all of them may not be coded.
The drawings are for illustration purposes only. The shape and dimensional ratio of each member in the drawing do not necessarily correspond to the actual article.

In the present specification, the notation "a to b" in the description of the numerical range means a or more and b or less unless otherwise specified. For example, "1 to 5% by mass" means "1% by mass or more and 5% by mass or less".

In the notation of a group (atomic group) in the present specification, the notation that does not indicate whether it is substituted or unsubstituted includes both those having no substituent and those having a substituent. For example, the "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).
The notation "(meth) acrylic" herein represents a concept that includes both acrylic and methacrylic. The same applies to similar notations such as "(meth) acrylate".

<Manufacturing method of molded products>
The method for producing a molded product of the present embodiment is a method for producing a molded product that has been subjected to an aging or annealing treatment, and is a preparatory step for preparing the molded product and heating the molded product while supporting it with a resin film. Including a heating step of performing an aging or annealing treatment.
The thermal dimensional change rate of the resin film in the vertical direction from 23 ° C. to 160 ° C. is 10% or less, the transmittance of light having a wavelength of 500 nm is 38% or more, and the haze value is 40% or less. Is.

In this method for manufacturing a molded product, the molded product is heated while being supported by a disposable resin film. Therefore, there is an advantage that the molded product is less likely to get dirty. (It should be noted that the resistance to stains on the molded product can be further enhanced by sandwiching the molded product between two resin films, as described later.)
Further, the high transparency of the resin film (the transmittance of light having a wavelength of 500 nm is 38% or more and the haze value is 40% or less) has an advantage that the visibility of the molded product at the time of heating is excellent. Leads to. This is preferable in that it is easy to visually inspect the molded product.
In addition, since the resin film is not deformed or is small due to heating (the rate of change in thermal dimension of the resin film from 23 ° C. to 160 ° C. in the vertical direction is 10% or less), the weight of the molded product is particularly heavy during heating. By doing so, the resin film is prevented from bending. This is preferable in that the film and / or the molded product does not easily come into contact with the heat source in the heating device during the heating step.

The method for producing the molded product of the present embodiment will be described more specifically.

(Preparation process)
In the preparation process, a molded product is prepared.
The material of the molded product is typically metal or plastic.
An example of a molded product is an article (part, housing, etc.) obtained by press-molding a metal plate. More specifically, metal housings and parts for electronic devices, parts for automobiles, and the like can be mentioned.
Another example of a molded product is an article formed by pouring molten resin into a mold. More specifically, resin parts for automobiles and the like can be mentioned.
Of course, the molded product is not limited to the one specified above. For example, a molded product in which distortion and residual stress are generated by molding and an annealing treatment is required, and a molded product in which an aging treatment is required to complete the post-curing of the resin can be mentioned.

"Preparation" here is interpreted in a broad sense. That is, the mode in which the person who performs the heating step described later himself manufactures and prepares the molded product is naturally included in the "preparation step". Not only that, the "preparation" also includes a mode in which a molded product manufactured by a person different from the person performing the subsequent heating step is transferred and prepared.
The method for preparing the molded product is not particularly limited. For example, as a method for producing a molded product, various known molding techniques can be used.

(Heating step (FIG. 1 (A))
FIG. 1A is a diagram schematically showing an example of a heating step.
FIG. 1A schematically shows a state in which the molded product 5 supported by the resin film 3 (molded product 5 placed on the upper surface of the resin film 3) is heated in the heating device 1. ing.

The heating device 1 has, for example, a square tubular heating portion. In other words, the heating device 1 has a square tubular heating portion including at least four of the six surfaces of a prism or a rectangular parallelepiped, excluding two opposing surfaces. By inserting the molded product 5 supported by the resin film 3 into the tubular heating portion, the molded product 5 can be heated (note that in FIG. 1A, the corners are for illustration purposes. Of the four surfaces of the tubular heating unit, the front surface in the figure is omitted).
Of course, the shape of the heating portion of the heating device 1 is not limited to the square tubular shape. The heating device 1 can be arbitrary as long as it can heat the molded product 5 supported by the resin film 3.

In FIG. 1A, the resin film 3 on which the molded product 5 is placed has, for example, slack (deflection) due to its own weight and the weight of the molded product 5 due to tension being applied in the left-right direction of the drawing. It is in a suppressed state (means for applying tension from the left and right are not specified in FIG. 1 (A)).

The heating step may be performed by any method, for example, by infrared irradiation.
That is, as the heating device 1, a device having a mechanism for heating an article by infrared rays, preferably called an "IR oven" or the like, can be used.
The wavelength of infrared rays is not particularly limited as long as the molded product 5 can be heated. Infrared is typically far infrared.

In the heating step, the temperature at which the molded product 5 is heated is not particularly limited, and may be appropriately set according to the purpose of heating. As an example, in general aging or annealing, the part 5 is heated to 140-180 ° C.
The degree to which the molded product 5 is heated can be known by, for example, a radiation thermometer.

The time of the heating step is not particularly limited, and may be appropriately set according to the purpose of heating. As an example, in general aging or annealing, it takes about 1 to 120 minutes. More specifically, the time for the molded product 5 to be heated to 140 to 180 ° C. is about 10 to 60 minutes. Of course, this time is a guide.

In the heating step, the resin film 3 and the molded product 5 on the resin film 3 may be stationary or may be moving. In order to efficiently and continuously heat-treat a large amount of molded product 5, for example, the molded product 5 is heated while slowly moving the resin film 3 from the left direction to the right direction (or from the left direction to the right direction) in the drawing. Then, the molded product 5 coming out of the heating device 1 may be automatically or manually separated from the resin film 3.

・ Molded product 5
Examples of the molded product 5 include the above-mentioned molded product. Therefore, a new description will be omitted.

・ Resin film 3
As described above, the resin film 3 used in the heating step has the following properties.
(1) The rate of change in thermal dimensions of the resin film 3 from 23 ° C. to 160 ° C. in the vertical direction is 10% or less.
(2) The transmittance of light having a wavelength of 500 nm of the resin film 3 is 38% or more, and the haze value is 40% or less.

The term "vertical direction" in the present specification is used in the same meaning as "vertical direction" usually used in the technical field of resin films ("vertical direction" is an abbreviation for flow direction and MD direction (Machine Direction). ) Etc.). In FIG. 1 (A) and FIG. 1 (B) described later, the left-right direction of the figure, that is, the long side direction of the film is usually the “vertical direction”.

The thermal dimensional change rate of the above (1) may be 10% or less, but is preferably 8.5% or less, and more preferably 5% or less.

Specifically, the rate of change in thermal dimensions can be measured under the following conditions using a thermomechanical analyzer (Thermomechanical Analyzer). Then, when the length of the sample before measurement is L ₁ and the length of the sample after measurement is L ₂ , the value of {(L _2- L ₁ ) / L ₁ } × 100 is the thermal dimension change rate ( %).
・ Temperature: 23-160 ℃
・ Temperature rise: 5 ° C / min
・ Atmosphere: Nitrogen gas ・ Mode: Tensile / Load: 49mN
-Sample: A resin film 3 cut out in a length direction of 10 mm and a width direction of 4 mm is used.

The transmittance of the light having a wavelength of 500 nm in (2) may be 38% or more, but is preferably 42% or more, more preferably 44% or more. There is no particular upper limit, but in reality it is 95% or less.
The haze value may be 40% or less, but is preferably 35% or less, more preferably 30% or less.
By appropriately adjusting the transmittance and / or haze value of light having a wavelength of 500 nm, the visibility of the molded product can be further improved. In particular, as shown in FIG. 1 (B) described later, it is important that the molded product 5 has high visibility when it is sandwiched between the two resin films 3.

The transmittance of light having a wavelength of 500 nm can be measured by, for example, a known spectrophotometer.
The haze value can be measured by, for example, a commercially available haze meter based on JIS K 7361.

In terms of visibility of the molded product, the total light transmittance of the resin film 3 defined by JIS K 7361 is preferably 65% or more, more preferably 70% or more, still more preferably 75% or more.
From the level of visibility usually required, it is often sufficient for the resin film 3 to satisfy the above (1) and (2). However, when particularly high visibility is required, it is preferable to use the resin film 3 having a total light transmittance (that is, a light transmittance of the entire visible light) of 70% or more.

As one aspect, the resin film 3 includes at least two layers, a base material layer and a heat-resistant resin layer.
Furthermore, the resin film 3 may have a three-layer structure in which heat-resistant resin layers are present on both the front and back surfaces, and a base material layer is present between the two heat-resistant resin layers. Such a three-layered resin film 3 is preferable in that, for example, the front and back surfaces can be used without distinction during the heating step. Further, there may be an advantage that the resin film 3 can be turned over and reused (even if it is reused, it is easy to suppress the adhesion of dirt).

In the above-mentioned three-layered resin film 3, the materials and thicknesses of the heat-resistant resin layer on the front surface and the heat-resistant resin layer on the back surface may be the same or different. However, from the viewpoint of reusability described above, the heat-resistant resin layer on the front surface and the heat-resistant resin layer on the back surface contain the same resin material and have almost the same thickness (of one heat-resistant resin layer). The thickness of the other heat-resistant resin layer is preferably within ± 20% based on the thickness).

In the resin film 3, by forming the portion in contact with the molded product 5 as a heat-resistant resin layer (that is, increasing the heat resistance of the portion in contact with the molded product 5), contamination of the molded product 5 can be further reduced.
Further, since the resin film 3 has the heat-resistant resin layer, the heat resistance of the resin film 3 as a whole is further improved. This makes it easier to suppress the deformation of the resin film 3 during the heating step.

Regarding the "heat resistance" of the heat-resistant resin layer, for example, it means that the heat-resistant layer has a higher softening point than the base material layer.
From another point of view, it can be said that the heat-resistant resin layer itself has a small weight loss rate when heated. More specifically, when only the heat-resistant resin layer is simultaneously measured by thermogravimetric analysis and differential thermal analysis, the weight reduction rate before and after the measurement is preferably 2% or less, more preferably 1% or less, still more preferable. Is 0.5% or less. When this weight reduction rate is small, for example, it is possible to obtain an effect such as further suppressing contamination of the molded product 5.
[conditions]
Starting temperature: 25 ° C
Final temperature: 160 ° C
Temperature rise: 10 ° C / min
Hold: 160 ° C, 30 min
Atmosphere: Air

The material of the heat-resistant resin layer is not particularly limited. As the material constituting the heat-resistant resin layer, a resin having high heat resistance can be used from among polyolefin-based resins, polyester-based resins, and polyamide resins.
Specific examples of materials include polyalkylene terephthalates such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), and polyhexamethylene terephthalate (PHT), and poly-4-methyl1-pentene. Examples thereof include (TPX: hereinafter also referred to as polymethylpentene), syndiotactic polystyrene (SPS), polypropylene resin (PP), and a copolymer resin obtained by copolymerizing other components. Further, as the polyamide resin, one that is relatively heat-resistant can be selected and used from known nylon-based resins.
These may be used alone or in combination of two or more.
In particular, the heat-resistant resin layer preferably contains at least one resin selected from the group consisting of polymethylpentene and polybutylene terephthalate.

The thickness of the heat-resistant resin layer is, for example, 20 to 150 μm, preferably 22 to 110 μm, and more preferably 28 to 100 μm. When there are two or more heat-resistant resin layers, it is preferable that the thickness of each heat-resistant resin layer is within these numerical ranges.
When the thickness of the heat-resistant resin layer is 20 μm or more, the heat-resistant resin layer can achieve sufficient performance as the heat-resistant resin layer. That is, sufficient heat resistance can be obtained. Further, when the heat-resistant resin layer is appropriately thick, the rigidity of the resin film 3 as a whole can be increased. Due to the high rigidity of the resin film 3, the deflection of the resin film 3 during the heating step is sufficiently suppressed, and the film and / or the molded product is more difficult to touch the heat source in the heating device.
When the thickness of the heat-resistant resin layer is 150 μm or less, the thickness of the entire resin film 3 can be easily reduced, and the handleability of the resin film 3 can be improved, for example.

The material of the base material is not particularly limited.
Since the resin film 3 has two or more layers of a heat-resistant resin layer and a base material layer, the heat resistance of the resin film 3 as a whole is improved, and the suppleness and handleability of the film are improved, and the mechanical strength is improved. Can also be obtained. In addition, these characteristics can be further enhanced by appropriately selecting the material of the base material.

Examples of the material of the base material layer include polyolefins such as polypropylene. Further, engineering plastics such as α-olefin polymers other than polypropylene, α-olefin copolymers containing ethylene, propylene, butene, penten, hexene, methylpentene and the like as polymer components, polyether sulfone, polyphenylene sulfide and the like. Engineering plastics can also be mentioned.

From another viewpoint, the base material layer preferably contains an olefin-based copolymer (a copolymer of an olefin monomer and a non-olefin monomer). Examples of the olefin-based copolymer include a copolymer of an olefin such as ethylene and a (meth) acrylic acid ester (for example, an ethylene- (meth) methyl acrylate copolymer and an ethylene- (meth) ethyl acrylate copolymer. Etc.), a copolymer of ethylene and vinyl acetate, a copolymer of ethylene and (meth) acrylic acid, and a partially ionized crosslinked product thereof.

From a further viewpoint, it is preferable that the base material layer contains a resin having relatively high heat resistance as described above as a material example of the heat resistant resin layer. That is, the base material layer preferably contains one or more of the above-mentioned polyalkyleneene terephthalate such as polybutylene terephthalate (PBT) and polymethylpentene.

The base material layer may contain only one type of resin material, or may contain two or more types of resin material. In particular, the base material layer can further enhance heat resistance, suppleness, etc. by containing two or more of the above-mentioned materials (polyolefin, olefin copolymer, resin having relatively high heat resistance). ..
When the base material layer contains two or more kinds of resin materials, specific examples of preferable combinations are as follows, for example. Of course, the combination of the resin materials of the base material layer is not limited to these.
-Polypropylene, α-olefin- (meth) acrylic acid ester copolymer-Polypropylene, polybutylene terephthalate-Polypropylene, 1,4-cyclohexanedimethanol copolymer polyethylene terephthalate-Polypropylene, ethylene-methylmethacrylate copolymer (EMMA)
-Polypropylene, polybutylene terephthalate, ethylene-methylmethacrylate copolymer-Polypropylene, polybutylene terephthalate, ethylene-polyethylene, polybutylene terephthalate-polymethylpentene, polypropylene, ethylene-methylmethacrylate copolymer

When the film 3 includes a base material layer, the thickness of the base material layer is, for example, 10 to 100 μm, preferably 20 to 90 μm, and more preferably 30 to 80 μm.
When the thickness of the base material layer is 10 μm or more, the base material layer can fulfill sufficient performance as a base material layer. Further, when the base material layer is appropriately thick, the suppleness of the resin film 3 as a whole can be imparted. Since the resin film 3 becomes supple, wrinkles are less likely to occur during film transfer, and film transfer becomes easier.
When the thickness of the base material layer is 100 μm or less, the thickness of the entire resin film 3 can be easily reduced. Therefore, for example, the handleability of the resin film 3 can be improved.

The total thickness of the resin film 3 is, for example, 50 to 200 μm, preferably 55 to 120 μm, and more preferably 60 to 110 μm.
When the total thickness is 50 μm or more, sufficient strength, rigidity, mechanical durability and the like can be obtained. Since the resin film 3 has high rigidity, the deflection of the resin film 3 during the heating process can be suppressed. Then, the film and / or the molded product becomes more difficult to touch the heat source in the heating device.
When the total thickness is 200 μm or less, the handleability of the resin film 3 can be improved.

Previously, regarding the heat resistance of the heat-resistant resin layer, it was explained that it is preferable that the weight loss rate when heated is small. Similarly, it is preferable that the weight loss rate of the resin film 3 as a whole is small when heated.
Specifically, when the resin film 3 is simultaneously measured for thermogravimetric analysis and differential thermal under the following conditions (the same as the above-mentioned measurement conditions for heat resistance of the heat-resistant resin layer), the weight loss rate before and after the measurement is It is preferably 1% or less, more preferably 0.8% or less, and further preferably 0.5% or less.
When the resin film 3 has a multilayer structure, it should be noted that a sample reflecting the thickness (ratio) of each layer of the resin film 3 should be prepared as a sample for simultaneous measurement of thermogravimetric analysis and differential thermal analysis.
[conditions]
Starting temperature: 25 ° C
Final temperature: 160 ° C
Temperature rise: 10 ° C / min
Hold: 160 ° C, 30 min
Atmosphere: Air

As described above, the resin film 3 preferably has a structure of two or more layers.
On the other hand, as another aspect, the resin film 3 may have a single-layer structure. For example, a single-layer film having only a layer corresponding to the above-mentioned "heat-resistant resin layer" can be used as long as the molded product 5 can be supported.

As another viewpoint, the storage elastic modulus of the resin film 3 when viscoelasticity is measured at 160 ° C., a tensile mode, and a frequency of 1 Hz is preferably 20 MPa or more, and more preferably 35 MPa or more.
The fact that the storage elastic modulus at 160 ° C. is large to some extent means that the resin film 3 has a certain degree of rigidity even when heated to 160 ° C. That is, it means that the resin film 3 is not easily deformed even in a heating environment and can stably support the molded product 5.
There is no particular upper limit on the storage elastic modulus, but it is, for example, 700 MPa or less.

In the heating step, the surface roughness Ra of the surface of the resin film 3 in contact with the molded product 5 is preferably 1.0 μm or less, more preferably 0.8 μm. There is no particular lower limit, but it is, for example, 0.01 μm or more due to the usual manufacturing conditions of the resin film.
The surface roughness Ra is defined by JIS B 0601. Ra can be measured by a known surface roughness measuring machine.

More specifically, when the resin film 3 includes at least two layers, a heat-resistant resin layer and a base material layer, and the heat-resistant resin layer is in contact with the molded product 5, Ra on the surface of the heat-resistant resin layer has the above value. Is preferable.
As another example, when the resin film 3 is a single-layer film, it is preferable that Ra on at least one side has the above value, and that side is in contact with the molded product 5.

Since the surface roughness Ra of the surface of the resin film 3 in contact with the molded product 5 is small, the contact area between the resin film 3 and the molded product 5 becomes larger. This leads to the advantage that the molded product 5 is hard to slip on the resin film 3 and is hard to fall.
In addition, when the resin film 3 after the heating step is collected and made into a scroll, it also leads to an advantage that it is easy to wind up (it is difficult for winding deviation to occur).

The method for adjusting the surface roughness Ra (and / or light transmission, etc.) is not particularly limited, but for example, it is conceivable that the "embossing" that is often performed in the processing of a general resin film is not performed. Further, a method using an air knife, a method using a touch roll, and the like can also be considered.

The resin film 3 may contain additive components such as an anti-blocking agent, an antioxidant, a nucleating agent, an antistatic agent, a process oil, a plasticizer, a flame retardant, a flame retardant aid, and a pigment.

For example, when the resin film 3 includes two or more layers of a heat-resistant resin layer and a base material layer, the heat-resistant resin layer may or may not contain at least one of the above-mentioned additive components.

Specific examples of the additive components that the heat-resistant resin layer may contain.

Examples of the anti-blocking agent include the following inorganic particles or organic particles. Examples of the inorganic particles include IA, IIA, IVA, VIA, VIIA, VIIIA, IB, IIB, IIIB, and IVB element oxides, hydroxides, sulfides, nitrates, and halogens. Compounds, carbonates, sulfates, acetates, phosphates, phosphites, organic carboxylates, silicates, titanates, boronates and their hydrous compounds, as well as complex compounds and natural mineral particles centered on them. Can be mentioned.

Specific examples of the inorganic particles include Group IA element compounds such as lithium fluoride and borosand (hydrous salt of sodium borate); magnesium carbonate, magnesium phosphate, magnesium oxide (magnesia), magnesium chloride, magnesium acetate, and foot. Magnesium buffalo, magnesium titanate, magnesium silicate, magnesium silicate hydrous salt (talc), calcium carbonate, calcium phosphate, calcium phosphite, calcium sulfate (plaster), calcium acetate, calcium terephthalate, calcium hydroxide, calcium silicate, foot Group IIA element compounds such as calcium dioxide, calcium titanate, strontium titanate, barium carbonate, barium phosphate, barium sulfate, barium sulfite; titanium dioxide (titania), titanium monoxide, titanium nitride, zirconium dioxide (zirconia), one IVA group element compounds such as zirconium oxide; VIA group element compounds such as molybdenum dioxide, molybdenum trioxide and molybdenum sulfide; VIIA group element compounds such as manganese chloride and manganese acetate; Group VIII element compounds such as cobalt chloride and cobalt acetate; Group IB element compounds such as cuprous chemicals; Group IIB element compounds such as zinc oxide and zinc acetate; aluminum oxide (alumina), aluminum hydroxide, aluminum fluoride, alumina silicates (alumina silicate, kaolin, kaolinite), etc. Group IIIB element compounds; IVB group element compounds such as silicon oxide (silica, silica gel), stone ink, carbon, graphite, glass; particles of natural minerals such as carnal stone, kainite, mica (mica, kinunmo), baylose ore, etc. Be done.
Examples of the organic particles include Teflon (registered trademark), melamine-based resin, styrene-divinylbenzene copolymer, acrylic-based resin silicone, and crosslinked products thereof.
These can be used alone or in combination of two.
The average particle size of the inorganic particles and organic particles is preferably 0.1 to 10 μm.

Antioxidants include phosphorus-based antioxidants, phenol-based antioxidants, sulfur-based antioxidants, 2-[(1-hydroxy-3,5-di-t-pentylphenyl) ethyl] -4,6- Examples thereof include di-t-pentylphenyl acrylate.
The antioxidants can be used alone or in combination of two or more.

Examples of the nucleating agent include metal salts of carboxylic acids such as aluminum di (pt-butylbenzoate), metal salts of phosphoric acid such as methylenebis (2,4-di-t-butylphenol) acid phosphate sodium, talc, and phthalocyanine derivatives. And so on.
The nucleating agent can be used alone or in combination of two or more.

Examples of the plasticizer include polyethylene glycol, polyamide oligomer, ethylene bisstearoamide, phthalate ester, polystyrene oligomer, polyethylene wax, silicone oil and the like.
The plasticizer may be used alone or in combination of two or more.

Examples of the process oil include paraffin oil, naphthenic oil, and aroma oil. Among these, paraffin-based oil having a percentage of the total carbon number of carbons related to paraffin (straight chain) calculated by the nd-M method to 60% Cp or more is preferable.

The amount of the added component added is preferably 0.01 to 15% by weight based on the entire heat-resistant resin layer.

The base material layer may also contain various additive components. The substrate image is, for example, an antioxidant, a slip agent, an antiblocking agent, an antioxidant, a colorant such as a dye and a pigment, an additive such as a stabilizer, an impact resistance imparting agent such as a fluororesin and a silicone rubber, and the like. Of the inorganic fillers such as titanium oxide, calcium carbonate, and talc, one or more of them may be contained.
Further, the base material layer may contain a rubber component. Examples of the rubber component include styrene-based thermoplastic elastomers such as styrene-butadiene copolymers and styrene-isoprene copolymers, olefin-based thermoplastic elastomers, amide-based elastomers, and thermoplastic elastomer materials such as polyester-based elastomers, and natural rubber. , Isoprene rubber, chloroprene rubber, rubber materials such as silicon rubber and the like.

-Method of manufacturing the resin film 3 The resin film 3 can be manufactured by any method.
For example, it can be produced by using a known method such as a coextrusion method, an extrusion laminating method, a dry laminating method, or an inflation method.
When the resin film 3 has two or more layers of a heat-resistant resin layer and a base material layer, each layer may be manufactured separately and then bonded with a laminator or the like. However, it is preferable to collectively form a film by an air-cooled or water-cooled coextrusion inflation method or a coextrusion T-die method. Of these, the method of forming a film by the coextrusion T-die method is particularly preferable because it is excellent in controlling the thickness of each layer.
When each layer is manufactured separately and then joined, it may be joined as it is, or it may be joined via an adhesive layer.

From the viewpoint of further enhancing the light transmission, for example, it is considered better not to perform the "embossing" that is often performed in the processing of a general resin film.

(Heating step (FIG. 1 (B))
FIG. 1B is a diagram schematically showing an example of a heating process, which is different from FIG. 1A.
FIG. 1 (B) is different from FIG. 1 (A) in that the molded product 5 is sandwiched between the two resin films 3 from above and below. As a result, contamination of the molded product 5 during the heating process can be further suppressed.
By sandwiching the molded product 5 from above and below by the two resin films 3, the molded product 5 is more stable and the fall of the molded product 5 is sufficiently suppressed.

The resin film 3 is highly transparent (the transmittance of light having a wavelength of 500 nm is large and the haze value is small). Therefore, even if the molded product 5 is sandwiched between the two resin films 3, the visibility of the molded product 5 is sufficiently high. This is preferable in that it is easy to visually inspect the molded product.

When the molded product 5 is sandwiched between the two resin films 3 from above and below, an appropriate device or the like for imparting the sandwiching force may be used (not clearly shown in FIG. 1B). ).
Further, like the lower resin film 3, tension may be applied to the upper resin film 3 in the left-right direction of the drawing, for example.

The two resin films 3 in FIG. 1B may be the same or different.
The specific aspect of the upper resin film 3 can be the same as that of the resin film 3 (that is, the lower resin film 3) described with reference to FIG. 1 (A).
In FIG. 1B, when the upper resin film 3 includes at least two layers, a base material layer and a heat-resistant resin layer, the heat-resistant resin layer is usually in contact with the molded product 5.

(Other processes)
The method for producing a molded product of the present embodiment may include other steps in addition to the preparation step and the heating step.
For example, after the heating step, a cooling step of allowing the heated molded product 5 to cool may be included. The cooling step may be carried out at room temperature, or may be slowly cooled by an appropriate device. Various conditions of the cooling process may be appropriately adjusted according to the properties of the molded product 5.

<Resin film>
In addition to the concept of "a method for manufacturing a molded product" using a resin film having a specific configuration, the present invention has a concept of a "resin film" having a specific configuration, which is suitably applied to a method for manufacturing a molded product. You can also do it. That is, the present invention can also be regarded as a resin film used to support a molded product when the molded product is heated and subjected to an aging or annealing treatment.
The embodiment of this resin film is the same as that of the “resin film 3” described in the above <Method for manufacturing a molded product>, but just in case, the above items will be briefly described.

The resin film is used to support a molded product when it is heated and subjected to an aging or annealing treatment.
The rate of change in thermal dimension of the resin film from 23 ° C. to 160 ° C. in the vertical direction is 10% or less.
The transmittance of light having a wavelength of 500 nm of the resin film is 38 (approximate)% or more, and the haze value is 40% or less.
The total light transmittance of the resin film specified by JIS K 7361 is preferably 65% or more.

The resin film preferably includes at least two layers, a base material layer and a heat-resistant resin layer. The resin film is more preferably a three-layer structure in which heat-resistant resin layers are present on both the front and back surfaces, and a base material layer is present between the two heat-resistant resin layers.
Material preferably contained in each layer, thickness of each layer, overall thickness, weight reduction rate when heat weight and differential heat are simultaneously measured for heat-resistant resin layer, weight reduction rate when thermal weight and differential heat are simultaneously measured for resin film, resin The storage elastic modulus and the like when the film is measured for viscoelasticity are as described above.
When the resin film includes at least two layers of a base material layer and a heat-resistant resin layer, the resin film is preferably used so that the heat-resistant resin layer is in contact with the molded product to be aged or annealed.

The surface roughness Ra of at least one side of the resin film is preferably 1.0 μm or less.
The resin film is preferably used so that the surface having a surface roughness Ra of 1.0 μm or less is in contact with the molded product to be aged or annealed. When the resin film includes at least two layers, a base material layer and a heat-resistant resin layer, the surface roughness Ra of the heat-resistant resin layer is preferably 1.0 μm or less.

Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than the above can be adopted. Further, the present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the range in which the object of the present invention can be achieved are included in the present invention.

Embodiments of the present invention will be described in detail based on Examples and Comparative Examples. The present invention is not limited to the examples.

<Manufacturing of resin film>
First, as a material for each layer, the resin types shown in Table 1 below (for the base material layer, a mixture of a plurality of resin types except for Comparative Example 2) were prepared.
Using these materials, a three-layer or single-layer resin film was produced by an extrusion T-die method while applying wind from an air knife device (multi-die for a three-layer film and single-layer film for a single-layer film). A single die was used). At this time, the thickness of each layer was adjusted to the extrusion amount of the resin material and the film forming speed so as to have the values shown in Table 1.

In Comparative Example 1, when the film was formed, the film surface was roughened by embossing, which is often performed in the production of a release film.
Further, in Comparative Example 2, the wind from the air knife device was not applied during the film formation.

<Various properties and physical properties of resin film>
Various properties and physical properties of the above resin film (or its material, etc.) were measured as follows.
[Vertical thermal dimension change rate of resin film (23 to 160 ° C)]
A resin film cut out in a vertical direction of 10 mm and a horizontal direction of 4 mm was set in a thermomechanical analyzer EXSTAR TMA / SS6100 (formerly manufactured by Seiko Instruments, now manufactured by Hitachi High-Tech Science). Then, thermomechanical analysis was performed under the following conditions. When the length of the sample before measurement is L ₁ and the length of the sample after measurement is L ₂ , the value of {(L _2- L ₁ ) / L ₁ } × 100 is the thermal dimension change rate (%). And said.
・ Temperature: 23-160 ℃
・ Temperature rise: 5 ° C / min
・ Atmosphere: Nitrogen gas ・ Mode: Tensile / Load: 49mN

[Transmittance of light with a wavelength of 500 nm]
The measurement was performed using an ultraviolet-visible spectrophotometric intensity (product number: V-650) manufactured by JASCO Corporation.

[Haze value]
The measurement was performed using a turbidity meter (product number: NDH2000) manufactured by Nippon Denshoku Industries Co., Ltd.

[Total light transmittance]
The measurement was performed using a turbidity meter (product number: NDH2000) manufactured by Nippon Denshoku Industries Co., Ltd.

[Weight reduction rate of resin film]
Device name: TG / DTA6200 (formerly manufactured by Seiko Instruments, now manufactured by Hitachi High-Tech Science) was used, and the weight reduction rate was determined under the following conditions.
・ Starting temperature: 25 ° C
・ Final temperature: 160 ℃
・ Temperature rise: 10 ° C / min
・ Hold: 160 ℃, 30min
・ Atmosphere: Air

[Resilient storage modulus of resin film (160 ° C)]
Device name: DMS6100 (formerly manufactured by Seiko Instruments, now manufactured by Hitachi High-Tech Science) was used to measure viscoelasticity under the following conditions. From the obtained data, the storage elastic modulus at 160 ° C. was determined.
-Mode: Tension-Temperature: 23-250 ° C
・ Temperature rise: 5 ° C / min
・ Frequency: 1Hz
-Measurement sample: A resin film of each Example or Comparative Example cut into a size of 20 mm in the vertical direction x 4 mm in the horizontal direction.

[Surface roughness Ra of resin film]
According to JIS B 0601, the arithmetic mean roughness Ra (unit: μm) of the surface of the heat-resistant resin layer in contact with the molded product of each resin film was measured using the equipment "Handy Surf E-35B" manufactured by Tokyo Seimitsu Co., Ltd. ..
The measurement was performed three times near the center of each prepared resin film, and the average value of the three times was adopted as Ra.

<Preparation of molded products>
A commercially available phenolic resin-based molding material was poured into a mold heated to 160 ° C. and appropriately heated / cooled to obtain a resin molded product for evaluation.

<Heating process>
Two sheets of each resin film were prepared, and the procedure was as follows.
(1) One of the two resin films was stretched horizontally so as not to have slack as much as possible. At this time, when the resin film has a multi-layer structure, the heat-resistant resin layer is on the upper surface.
(2) A plurality of molded products were placed on the upper surface of the above resin film.
(3) Another resin film was put on the above-mentioned molded product, and the molded product was sandwiched between the two resin films from above and below. At this time, when the resin film has a multi-layer structure, the heat-resistant resin layer is brought into contact with the molded product. As a result, a molded product was obtained by being sandwiched between resin films from above and below.
(4) The above-mentioned molded product sandwiched between the resin films from above and below was placed in an infrared furnace together with the resin film and heated. The heating was performed at 160 ° C. for 30 minutes by adjusting the intensity of infrared rays.
(5) After heating, the molded product was naturally cooled to room temperature while being sandwiched between resin films.
(6) The resin film was removed to obtain a heat-treated molded product.

<Evaluation>
[Visibility]
After the completion of step (5) of the above <heating step>, the molded product in a state of being sandwiched between the two resin films was visually observed (this observation is referred to as "observation 1").
In addition, the molded product after removing the resin film was visually observed (this observation is referred to as "observation 2").
In Observation 1 and Observation 2, it was evaluated whether or not the appearance (color tone, surface texture, presence / absence of scratches and stains, etc.) of the molded product did not change.
◯ (Good): The appearance of the molded product is substantially the same between Observation 1 and Observation 2. That is, the visual inspection of the molded product can be sufficiently performed even through the resin film.
X (defective): The appearance of the molded product is observed differently in observation 1 and observation 2. That is, when the molded product is observed through the resin film, if the molded product is defective, it may be overlooked.

[Heat resistance / rigidity]
In the above <heating step>, it was confirmed whether the resin film was sagging. Specifically, by observing the resin film after the <heating process>, the resin film is loosened and wrinkles are not generated, or the resin film touches the inner wall of the infrared furnace and a part of the resin film is melted. I checked if it wasn't. Then, it was evaluated according to the following criteria.
○ (Good): Good heat resistance and rigidity (no wrinkles or melting of the resin film are observed)
× (Defective): There is room for improvement in heat resistance and rigidity (partial melting of the resin film was observed).

[Presence or absence of contamination of molded products]
The heat-treated molded product was observed and confirmed for dirt and impurities that did not exist before heating. Then, it was evaluated according to the following criteria.
◯ (Good): No stains or impurities that did not exist before heating were observed.
X (defective): Dirt that did not exist before heating, adhesion of impurities, etc. were observed.

Table 1 summarizes the materials used for each layer of the resin film, various properties (physical properties) such as thickness and transmittance, and evaluation results such as visibility.

In Table 1, the abbreviations of the resin types represent the following.
-TPX: Polymethylpentene resin (TPX (registered trademark)) (manufactured by Mitsui Chemicals, RT31)
-PP: Polypropylene resin (manufactured by Prime Polymer Co., Ltd., E-203GP)
-EMMA: Modified polyethylene resin (ethylene-methylmethacrylate copolymer) (manufactured by Sumitomo Chemical Co., Ltd., WD106)
-PBT: Polybutylene terephthalate resin (manufactured by Wintech Polymer, Duranex 201AC)

As described above, the resin film has a thermal dimensional change rate of 10% or less from 23 ° C. to 160 ° C. in the vertical direction, a light transmittance of 38% or more at a wavelength of 500 nm, and a haze value of 40% or less. The article was supported and the part could be heat treated. That is, it was possible to provide a new method for post-heating of the molded product (aging treatment, annealing treatment, etc.).

Specifically, as shown in Table 1, in Examples 1 to 7, the visibility, heat resistance / rigidity, and evaluation of the presence or absence of contamination of the molded product were all good. That is, by heating the molded product while supporting (holding) the molded product with a specific film, it is easy to visually inspect the molded product, and the film and / or the molded product does not easily come into contact with the heat source in the heating device. It was shown that there are advantages such as less contamination.

On the other hand, when the film of Comparative Example 1 was used, the evaluation result of visibility was poor, which was disadvantageous in terms of visual inspection of the molded product. It is considered that the cause of this is that the light transmittance was small and the haze value was large due to the embossing.
Further, when the film of Comparative Example 2 was used, the evaluation result of visibility was poor, and in addition, the evaluation result of heat resistance / rigidity was also poor. The causes of this were (1) the wind from the air knife device did not hit during film formation (this made the surface smoother slightly) and the total thickness was large, and (2) Comparative Example 2 It is considered that this film did not have a heat-resistant resin layer and had a large dimensional change rate (23 to 160 ° C.).

This application claims priority on the basis of Japanese application Japanese Patent Application No. 2018-160083 filed on August 29, 2018, the entire disclosure of which is incorporated herein by reference.

Claims (20)

A method for manufacturing a molded product that has been aged or annealed.
The preparatory process for preparing the molded product and
A heating step of heating the molded product while supporting it with a resin film to perform an aging or annealing treatment is included.
The rate of change in thermal dimension from 23 ° C to 160 ° C in the vertical direction of the resin film is 10% or less.
A method for producing a molded product, wherein the resin film has a transmittance of light having a wavelength of 500 nm of 38% or more and a haze value of 40% or less. The method for manufacturing a molded product according to claim 1.
The resin film includes at least two layers, a base material layer and a heat-resistant resin layer.
A method for producing a molded product in which the molded product and the heat-resistant resin layer of the resin film are in contact with each other in the heating step. The method for manufacturing a molded product according to claim 2.
A method for producing a molded product, wherein the heat-resistant resin layer contains at least one resin selected from the group consisting of polymethylpentene and polybutylene terephthalate. The method for producing a molded product according to claim 2 or 3.
A method for producing a molded product, wherein the heat-resistant resin layer has a thickness of 20 to 150 μm. The method for producing a molded product according to any one of claims 1 to 4.
A method for producing a molded product, in which the weight loss rate before and after the measurement of the resin film is 1% or less when the thermogravimetric analysis and the differential thermal are simultaneously measured under the following conditions.
<Conditions>
Starting temperature: 25 ° C
Final temperature: 160 ° C
Temperature rise: 10 ° C / min
Hold: 160 ° C, 30 min
Atmosphere: Air The method for producing a molded product according to any one of claims 1 to 5.
A method for producing a molded product, wherein the total thickness of the resin film is 50 to 200 μm. The method for producing a molded product according to any one of claims 1 to 6.
A method for producing a molded product, wherein the resin film has a storage elastic modulus of 20 MPa or more when viscoelasticity is measured at 160 ° C., a tensile mode, and a frequency of 1 Hz. The method for producing a molded product according to any one of claims 1 to 7.
A method for producing a molded product of the resin film, wherein the total light transmittance measured based on JIS K 7361 is 65% or more. The method for producing a molded product according to any one of claims 1 to 8.
A method for producing a molded product, wherein the surface roughness Ra of the surface of the resin film in contact with the molded product is 1.0 μm or less in the heating step. The method for producing a molded product according to any one of claims 1 to 9.
A method for manufacturing a molded product in which the heating step is performed by infrared irradiation. The method for producing a molded product according to any one of claims 1 to 10.
A method for producing a molded product, wherein the molded product is heated to 140 to 180 ° C. in the heating step. A resin film used to support a molded product when it is heated and subjected to an aging or annealing treatment.
The rate of change in thermal dimension from 23 ° C to 160 ° C in the vertical direction of the resin film is 10% or less.
A resin film having a transmittance of light having a wavelength of 500 nm of 38% or more and a haze value of 40% or less. The resin film according to claim 12.
A resin film comprising at least two layers, a base material layer and a heat-resistant resin layer. The resin film according to claim 13.
A resin film in which the heat-resistant resin layer contains at least one resin selected from the group consisting of polymethylpentene and polybutylene terephthalate. The resin film according to claim 13 or 14.
A resin film having a heat-resistant resin layer having a thickness of 20 to 150 μm. The resin film according to any one of claims 12 to 15.
A resin film having a weight reduction rate of 1% or less before and after the measurement when the thermogravimetric analysis and the differential thermal are simultaneously measured under the following conditions.
<Conditions>
Starting temperature: 25 ° C
Final temperature: 160 ° C
Temperature rise: 10 ° C / min
Hold: 160 ° C, 30 min
Atmosphere: Air The resin film according to any one of claims 12 to 16.
A resin film having an overall thickness of 50 to 200 μm. The resin film according to any one of claims 12 to 17.
A resin film having a storage elastic modulus of 20 MPa or more when measured in viscoelasticity at 160 ° C., a tensile mode, and a frequency of 1 Hz. The resin film according to any one of claims 12 to 18.
A resin film having a total light transmittance of 60% or more as measured based on JIS K 7361. The resin film according to any one of claims 13 to 19.
A resin film having a surface roughness Ra of at least one side of 1.0 μm or less.

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