JP7340990B2 - Surface material - Google Patents

Description

The present invention relates to a surface material.

BACKGROUND ART Conventionally, as a surface material for preparing interior and exterior materials for vehicles such as automobiles, for example, a surface material in which a binder is applied to a fiber aggregate such as a nonwoven fabric, a woven fabric, or a knitted fabric has been used. Then, by subjecting the surface material to a thermoforming process in which heat or heat and pressure is applied to the surface material using a heating means such as a heating plate such as a mold or a heating roller, the surface material is formed into a desired shape and used for various interior decorations. Materials and various exterior materials are being prepared.

As such a surface material, for example, Japanese Unexamined Patent Publication No. 2016-156120 (Patent Document 1) discloses a nonwoven fabric for molding in which a fiber binding binder is applied to a fiber web. Note that Patent Document 1 discloses that by employing an acrylic resin as a binder for fiber binding, a nonwoven fabric for molding with excellent moldability can be provided.

JP 2016-156120 (Claims, 0028, etc.)

The applicant of the present application has studied "a surface material comprising a fiber aggregate and a binder resin" with reference to the above-mentioned prior art.
However, when a surface material having such a configuration is subjected to a thermoforming method with a deeper draw (hereinafter sometimes referred to as a higher expansion rate) than a general thermoforming method, the prepared interior material There were large and small wrinkles on the surface of the surface material and the exterior material, which were thought to be caused by the inability to follow the depth of drawing, and the formability of the surface material was still insufficient.
Therefore, in order to find a surface material with excellent moldability, we investigated reducing the amount of binder resin provided to the surface material, and found that there was a tendency for moldability to be improved. However, inversely proportional to the improvement in formability, when the surface of the prepared interior or exterior material comes into contact with other interior or exterior materials such as pillars, or when conveyed items such as luggage come into contact with the surface of the prepared interior or exterior material, A new problem has arisen in that the surfaces of interior and exterior materials are scratched and raised, resulting in poor appearance retention.

The present invention provides ``(Claim 1) A surface material comprising a fiber aggregate and a binder resin,
The binder resin is a versatic acid vinyl ester copolymerized acrylic resin with a glass transition temperature lower than -38°C,
A surface material having a 20% modulus in the vertical direction of less than 45 N/30 mm, a 20% modulus in the horizontal direction of less than 22 N/30 mm, and a weight loss calculated by subjecting to the following measurement of less than 72.8 mg.
The mass reduction in the surface material was determined by subjecting the surface material to the JISL1096:20108.19.3C method (Taber method).
・Used wear wheel No.: H-18,
・Load: 9.8N,
・Test rotation number: 100 times,
・Rotational friction speed: 70 r/min.

As a result of continued studies, the applicant of the present application found that by focusing on the 20% modulus of the surface material in the vertical and horizontal directions, it is possible to provide a surface material that can be molded into interior and exterior materials with better moldability. Specifically, a surface material whose 20% modulus in the vertical direction is less than 45 N/30 mm and whose 20% modulus in the horizontal direction is less than 22 N/30 mm is used when subjected to thermoforming means with a high expansion rate. It has also been found that the moldability is even better.
Furthermore, by subjecting the surface material to the above-mentioned measurement and focusing on the weight loss determined, it was discovered that it is possible to provide a surface material that can be used to prepare interior and exterior materials with better appearance retention. Specifically, it has been found that an interior material or an exterior material using a surface material whose weight loss is less than 72.8 mg has better appearance retention.
From the above, a surface material that satisfies the configuration according to the present invention has better moldability even when subjected to a thermoforming method with a high expansion rate, and can produce interior and exterior materials that have excellent appearance retention. can.

In the present invention, various configurations can be selected as appropriate, for example, the following configurations.
Note that the various measurements described in the present invention were performed under normal pressure and 25° C. unless otherwise specified. Further, unless otherwise specified, various measurement results described in the present invention were obtained by measurement to a value one digit smaller than the obtained value, and the obtained value was calculated by rounding off the value. As a specific example, if the desired value is to the first decimal place, the value to the second decimal place is determined by measurement, and the value to the first decimal place is calculated by rounding the obtained value to the second decimal place. This value was used as the value to be determined.

The surface material of the present invention includes a fiber aggregate and a binder resin.
Here, the fiber aggregate is a member that mainly plays a role in forming the skeleton of the surface material. The binder resin binds and integrates the constituent fibers of the fiber aggregate to prevent unintentional deformation of the shape of the fiber aggregate and improves various physical properties such as the rigidity of the fiber aggregate. take charge Further, it can play a role of supporting additives as described below on the fiber aggregate (on the surface of the fibers constituting the fiber aggregate or in the voids of the fiber aggregate).

The fiber aggregate as used in the present invention is, for example, a fiber web, a nonwoven fabric, or a sheet-like fabric such as a woven fabric or a knitted fabric. The surface material of the present invention contains a fiber aggregate (particularly a nonwoven fabric in which all constituent fibers are randomly entangled), so it is flexible, and has good moldability and surface smoothness for interior and exterior materials. We can provide surface materials that can be prepared. In addition, surface materials with fiber aggregates (especially nonwoven fabrics) in which all constituent fibers are randomly entangled are more flexible, and can be used as interior and exterior materials with better moldability and surface smoothness. This is preferred because it provides a surface material that can be prepared.

The constituent fibers of the fiber assembly are, for example, polyolefin resins (e.g., polyethylene, polypropylene, polymethylpentene, polyolefin resins with a structure in which a portion of the hydrocarbon is replaced with a cyano group or a halogen such as fluorine or chlorine), styrene, etc. resins, polyvinyl alcohol resins, polyether resins (e.g., polyether ether ketone, polyacetal, modified polyphenylene ether, aromatic polyether ketone, etc.), polyester resins (e.g., polyethylene terephthalate, polytrimethylene terephthalate, polybutylene) terephthalate, polyethylene naphthalate, polybutylene naphthalate, polycarbonate, polyarylate, fully aromatic polyester resin, etc.), polyimide resin, polyamide-imide resin, polyamide resin (e.g., aromatic polyamide resin, aromatic polyetheramide resin, nylon resin, etc.), resins with nitrile groups (e.g., polyacrylonitrile, etc.), urethane resins, epoxy resins, polysulfone resins (e.g., polysulfone, polyethersulfone, etc.), fluorine resins (e.g., polytetrafluorocarbon resins, etc.) ethylene, polyvinylidene fluoride, etc.), cellulose resins, polybenzimidazole resins, acrylic resins (e.g., polyacrylonitrile resins copolymerized with acrylic esters or methacrylic esters, copolymerized acrylonitrile with vinyl chloride or vinylidene chloride) It can be constructed using a known resin such as a modacrylic resin (modacrylic resin, etc.).

Note that these resins may be made of either a linear polymer or a branched polymer, and the resin may be a block copolymer or a random copolymer. However, there is no particular limitation. Furthermore, a mixture of multi-component resins may be used. Further, fibers prepared by kneading pigments or dyed fibers such as dyed fibers may be used.

In addition, when flame retardancy is required for the surface material, it is preferable that the constituent fibers of the fiber assembly contain a flame retardant resin. Examples of such flame-retardant resins include modacrylic resins, vinylidene resins, polyvinylidene chloride resins, polyvinylidene fluoride resins, novoloid resins, polyclar resins, polyester resins copolymerized with phosphorus compounds, and copolymerized halogen-containing monomers. Examples include acrylic resin, aramid resin, and resin into which halogen-based, phosphorus-based, or metal compound-based flame retardants are kneaded. Alternatively, the surface material may support a flame retardant by using a binder or the like.

The constituent fibers can be produced by, for example, melt spinning, dry spinning, wet spinning, direct spinning (melt blowing, spunbond, electrostatic spinning, etc.), or by removing one or more resin components from composite fibers. It can be obtained by known methods such as a method of extracting fibers with a small fiber diameter and a method of obtaining split fibers by beating the fibers.

The constituent fibers may be composed of one type of resin or multiple types of resin. The fibers composed of a plurality of types of resins may be in a form generally referred to as a composite fiber, such as a core-sheath type, an island-in-the-sea type, a side-by-side type, an orange type, or a bimetallic type.

Furthermore, the constituent fibers may include irregular cross-section fibers in addition to substantially circular fibers and elliptical fibers. In addition, the irregular cross-section fibers include hollow shapes, polygonal shapes such as triangular shapes, alphabetic character shapes such as Y-shapes, symbol-type shapes such as irregular shapes, multilobed shapes, and asterisk shapes, or multiple shapes of these shapes. The fibers may have a fiber cross section such as a bonded shape.

If the fiber aggregate contains heat-fusible fibers as constituent fibers, the fibers are heat-fused together to give strength and morphological stability to the fiber aggregate and suppress the occurrence of scraping and fuzzing. It's good to be able to do it. Such heat-fusible fibers may be fully-fusible heat-fusible fibers or partially-fusible heat-fusible fibers such as the above-mentioned composite fibers. Also good. As a component exhibiting heat fusibility in the heat fusible fiber, for example, heat fusible fiber containing a low melting point polyolefin resin or a low melting point polyester resin can be appropriately selected and used.

It is preferable that the fiber aggregate contains crimpable fibers, as this increases elasticity and provides excellent mold followability. As such crimpable fibers, for example, crimpable fibers that have crimped latent crimpable fibers, fibers that have crimps, etc. can be used. Further, the fiber aggregate may include latent crimpable fibers that develop crimp when heated.

When the fiber aggregate is a fiber web or nonwoven fabric, for example, a dry method in which the fibers are intertwined by subjecting them to a carding device or an airlay device, or a method in which the fibers are dispersed in a solvent and formed into a sheet to intertwine the fibers. Wet method, direct spinning method (melt blow method, spunbond method, electrospinning method, method of spinning by discharging a spinning stock solution and a gas flow in parallel (for example, the method disclosed in JP 2009-287138A), etc.) It can be prepared by spinning fibers using a fiber and collecting the fibers.

A nonwoven fabric can be prepared by entangling and/or integrating the constituent fibers of the prepared fibrous web. Methods for entangling and/or integrating the constituent fibers include, for example, entangling them with a needle or water stream, or subjecting the fiber web to heat treatment to bond and integrate the constituent fibers with a binder resin or adhesive fibers. Examples include a method of melting and integrating.
The method of heat treatment can be selected as appropriate, but for example, heating with a roll or heating and pressurizing, heating by applying to a heating device such as an oven dryer, far infrared heater, dry heat dryer, hot air dryer, etc., and heating using infrared rays under no pressure. A method of heating the contained resin by irradiating the resin can be used.

When the fiber aggregate is a woven or knitted fabric, the woven or knitted fabric can be prepared by weaving or knitting the fibers prepared as described above.

In addition to the fiber web, a fiber aggregate such as a nonwoven fabric, a woven fabric, or a knitted fabric may be subjected to the method of intertwining and/or integrating the constituent fibers described above.

The fineness of the constituent fibers of the fiber aggregate is not particularly limited, but may be 0.1 dtex or more, 1.5 dtex or more, 2 dtex or more so as to improve appearance retention. be able to. On the other hand, in order to be able to prepare interior and exterior materials with good moldability and excellent surface smoothness, it can be 100 dtex or less, 50 dtex or less, 30 dtex or less, and 10 dtex or less. Something can happen.

Further, the fiber length of the constituent fibers of the fiber aggregate is not particularly limited, but may be 20 mm or more, 25 mm or more, and 30 mm or more so as to improve appearance retention. Can be done. On the other hand, if the fiber length exceeds 110 mm, fiber aggregates tend to be formed during the preparation of the fiber aggregate, which may make it difficult to prepare interior and exterior materials with good moldability and excellent surface smoothness. Therefore, it is preferably 110 mm or less, and can be 70 mm or less. Note that "fiber length" refers to a value measured according to JIS L1015 (2010), 8.4.1c) direct method (C method).

Various configurations of the fiber aggregate, such as thickness and basis weight, are not particularly limited and may be adjusted as appropriate.
The thickness of the fiber aggregate can be 0.5-5 mm, 1-3 mm, 1.1-1.9 mm. In the present invention, the thickness refers to the length in the vertical direction when a compressive load of 20 g/cm ² is applied in the direction perpendicular to the main surface.
Further, the basis weight of the fiber aggregate can be, for example, 50 to 500 g/m ² , 80 to 300 g/m ² , or 100 to 250 g/m ² . In addition, in the present invention, the basis weight refers to the mass per 1 m ² on the surface (principal surface) having the widest area of the object to be measured.

Binder resins that can be used in the present invention are appropriately selected, and include, for example, polyolefin resins (modified polyolefins, etc.), ethylene-vinyl alcohol copolymers, ethylene-acrylate copolymers such as ethylene-ethyl acrylate copolymers, and various rubbers. and its derivatives (styrene-butadiene rubber (SBR), fluororubber, urethane rubber, ethylene-propylene-diene rubber (EPDM), etc.), cellulose derivatives (carboxymethylcellulose (CMC), hydroxyethylcellulose, hydroxypropylcellulose, etc.), polyvinyl alcohol ( PVA), polyvinyl butyral (PVB), polyvinylpyrrolidone (PVP), polyurethane, epoxy resin, polyvinylidene fluoride (PVdF), vinylidene fluoride-hexafluoropropylene copolymer (PVdF-HFP), acrylic resin (e.g. Versatic Acrylic acid vinyl ester copolymerized acrylic resin) etc. can be used.

It is preferable to use an acrylic resin as the binder resin, since it softens appropriately during thermoforming, thereby providing a surface material that has excellent conformability to the mold.
In particular, the acrylic resin is preferably an acrylic resin having a branched carboxylic acid moiety having a total carbon number of 9 or more and 11 or less (so-called versatile acrylic acid vinyl ester copolymerized acrylic resin). As specific examples, acrylic resins such as VANORA manufactured by Kusumoto Chemicals and Sumikaflex manufactured by Sumika Chemtex can be used. By using such acrylic resin, it is possible to create interior and exterior materials with excellent moldability and excellent appearance retention even when subjected to thermoforming methods with high expansion rates. We can provide surface materials that can

The glass transition temperature (hereinafter sometimes referred to as Tg) of the binder resin can be adjusted as appropriate as long as the above configuration is satisfied, and the glass transition temperature should be in the range of -60°C to less than 0°C. Can be done. Since the glass transition temperature is preferably lower, it is preferably lower than -38°C, and more preferably lower than -40°C. Further, the lower limit of the glass transition temperature can be adjusted as appropriate, but it can be set to -60°C or higher. In addition, the glass transition temperature as used in the present invention is defined as the point between the tangent line of the baseline in the DTA curve measured by subjecting the resin to be measured to a differential thermal analyzer (DTA), and the steeply descending position of the endothermic region due to the glass transition. The temperature at the point of intersection with the tangent.

Binder resins include, for example, flame retardants, fragrances, pigments, antibacterial agents, antifungal materials, photocatalyst particles, inorganic particles such as silica, hollow particles such as particles that foam when heated or foamed particles, emulsifiers, dispersants, surfactants, etc. may contain additives.

The basis weight of the binder resin contained in the surface material is appropriately selected. Specifically, the binder resin can have a basis weight of 2 g/m ² or more. Further, the basis weight of the binder resin can be 50 g/m ² or less, 30 g/m ² or less, and 20 g/m ² or less.

The mode in which the binder resin is present in the fiber aggregate can be adjusted as appropriate, and may be a mode in which it is present uniformly throughout the fiber aggregate, a mode in which it is unevenly distributed in a part of the fiber aggregate, or the like.

Preferably, the binder resin exists uniformly in the fiber aggregate. As a specific example, the density and dispersion state of the binder resin existing on one main surface side of the fiber aggregate, the density and dispersion state of the binder resin existing on the other main surface side of the fiber aggregate, and the fiber aggregate It is preferable that the density and dispersion state of the binder resin present between both main surfaces of the body are the same (more preferably the same).
As described below, the manner in which the binder resin is present can be achieved by applying a binder liquid containing a binder resin to one main surface of the fiber aggregate, or by impregnating the fiber aggregate with a binder liquid containing a binder resin. It can be prepared by

The surface material according to the present invention has a 20% modulus in the vertical direction of less than 45 N/30 mm, and a 20% modulus in the horizontal direction of less than 22 N/30 mm. By providing the surface material with the above-mentioned physical properties, the surface material has better moldability even when subjected to thermoforming means with a high expansion rate.

Note that the 20% modulus in the vertical and horizontal directions is determined by subjecting the surface material to the following measurements.
(Method for measuring 20% modulus in vertical and horizontal directions)
(1) A total of three strip-shaped samples A (long side: 200 mm, short side (perpendicular to the long side): 30 mm) were collected from the measurement object such as a surface material. In addition, when the production direction of the measurement target was known, the production direction and the long side direction were made to be parallel.
(2) The sample A was fixed to the chuck (distance between chucks: 100 mm) of a tensile strength testing machine (manufactured by Orientec, Tensilon UTM-III-100 (registered trademark)), and the tensile speed was set at 200 mm/min. The stress at the time of 20% elongation with a distance between chucks of 120 mm was measured. The stress was measured for each of the three prepared samples A, and the arithmetic mean thereof was taken as the 20% modulus (unit: N/30 mm) in the vertical direction of the measurement object.
(3) A total of three strip-shaped samples B (long side: 200 mm, short side (perpendicular to the long side): 30 mm) were collected from the measurement target. In addition, when the production direction of the measurement target was known, the production direction and the short side direction were made to be parallel.
(4) The stress at 20% elongation was measured by subjecting the sample B to the same measurement as in (2) above. The stress was measured for each of the three prepared samples B, and the arithmetic mean thereof was taken as the 20% modulus (unit: N/30 mm) in the horizontal direction of the measurement object.
In addition, if the production direction of the measurement target is unknown, remove strip-shaped samples (long side: 200 mm, short side (perpendicular to the long side): 30 mm) from various directions of the measurement target. Three pieces were collected. Then, each stress of three samples taken from each direction was measured, and the arithmetic mean value was determined. Among the calculated arithmetic average values, the long side direction of the sample showing the highest value was taken as the production direction of the measurement target.

The lower the 20% modulus, the more flexible and soft the surface material is, and the surface material has better moldability even when subjected to thermoforming means with a high expansion rate. Therefore, the 20% modulus of the surface material in the vertical direction is preferably 44 N/30 mm or less, preferably 40 N/30 mm or less, and preferably 30 N/30 mm or less. Further, the 20% modulus of the surface material in the horizontal direction is preferably 21 N/30 mm or less, preferably 18 N/30 mm or less, and preferably 14 N/30 mm or less.

The surface material according to the present invention was subjected to the following measurements and had a calculated weight loss of less than 72.8 mg. By having the above-mentioned physical properties, the surface material can be used to prepare interior materials and exterior materials with excellent appearance retention.
(Method for measuring mass loss)
The mass reduction in the measurement target, such as a surface material, was determined by subjecting the measurement target to JIS L1096:2010 8.19.3 C method (Taber type method).
・Used wear wheel No.: H-18
・Load: 9.8N
・Test rotation speed: 100 times ・Rotational friction speed: 70r/min

The smaller the weight loss, the more difficult it is for the surface to be scraped and the more the generation of naps is prevented, which means that it is possible to provide interior and exterior materials with excellent appearance retention. Therefore, the weight loss in the surface material is preferably 70 mg or less, preferably 60 mg or less, and preferably 50 mg or less.

In addition, it is thought that there is a trade-off relationship between the moldability of the surface material and the maintenance of the appearance of the interior material or exterior material made of the surface material.
in particular,
・Surface materials with excellent moldability are highly flexible and soft, so interior and exterior materials made of these surface materials tend to be prone to scratching and napping.
- Surface materials that can be used to create interior and exterior materials with excellent appearance retention are hard (the surface is hard to scrape and is hard to raise), so the moldability of the surface materials tends to be poor.

Since the surface material according to the present invention satisfies both the above-mentioned 20% modulus range in the horizontal and vertical directions and the mass loss range, it is suitable for use in thermoforming means with a high expansion rate. Also, it is possible to prepare interior and exterior materials that have better moldability and better appearance retention.

The physical properties of the surface material, such as the basis weight and thickness, can be adjusted as appropriate to achieve the purpose of the present invention. For example, the basis weight can be 140 to 260 g/m ² , 150 to 250 g/m ² , or 160 to 250 g/m ² . Also, the thickness can be 1-2 mm, 1.5-1.8 mm, 1.6-1.7 mm.

Although the surface material of the present invention has the above structure, the surface material may further have a print layer or a top coat layer on at least one main surface.

The print layer here refers to a layer containing a pigment and resin that mainly plays the role of imparting a pattern or color to the surface material, and the same resin as the binder resin described above can be used. In particular, the resin constituting the print layer contains acrylic resin because it softens appropriately during thermoforming such as heat press using a mold, so it can provide a surface material that has excellent conformability to the mold. is preferable, and it is more preferable that the resin constituting the print layer is only an acrylic resin. Note that the print layer may contain the above-mentioned additives in addition to the pigment and its resin.

In addition, the form of the print layer can be selected as appropriate, such as a form in which it covers the entire main surface of the surface material, a pattern with a pattern such as a lattice, a pattern in the form of lines, dots, or an irregular shape. It may be in an embodiment in which it covers a part of the main surface. Furthermore, the print layer may include one type of layer containing pigment and resin, or may include multiple layers containing one or more types of pigment and resin. , a plurality of printed layers containing the same or different resins and substances may be provided. Note that the printed layer may be present on both main surfaces of the surface material.

The basis weight of the printed layer is selected as appropriate, and can be, for example, 2 to 50 g/m ² , or 10 to 30 g/m ² .

The top coat layer here refers to a layer containing an organic resin that mainly plays a role in protecting the surface material, and the same organic resin as the binder resin described above can be used. In particular, it is preferable that the organic resin constituting the top coat layer contains an acrylic resin, since it softens appropriately during thermoforming and can provide a surface material with excellent conformability to the mold. It is more preferable that the constituting organic resin is only an acrylic resin. Note that the top coat layer may contain the above-mentioned additives in addition to the organic resin. In addition, the glass transition temperature of the organic resin constituting the top coat layer is adjusted appropriately, but the glass transition temperature is preferably lower than 0°C.

A surface material having a top coat layer is preferable because it can provide a surface material that can be used as an interior material or exterior material with excellent wear resistance. Although the form of the top coat layer can be selected as appropriate, it is preferable that the top coat layer be present so as to cover the entire main surface of the surface material so that interior and exterior materials with better wear resistance can be prepared.

The basis weight of the top coat layer is selected as appropriate, and can be, for example, 2 to 50 g/m ² , or 10 to 30 g/m ² .

The surface material can be submitted to the thermoforming process as is, but there are also processes such as punching out shapes according to the purpose and usage, and processes such as Reliant press treatment that adjust physical properties such as thickness and surface smoothness. After being subjected to various secondary processes such as, etc., it may be subjected to a thermoforming process. Alternatively, it may be laminated and integrated with other members (another fiber aggregate, film, etc.) and then subjected to the thermoforming process.

Next, a method for manufacturing the surface material of the present invention will be explained. It should be noted that explanation of the points having the same configuration as the above-mentioned items will be omitted.
Although the manufacturing method of the surface material according to the present invention can be selected as appropriate, as an example,
(1) Step of preparing a fiber aggregate;
(2) a step of preparing a solution formed by dissolving the binder resin in a solvent or a dispersion liquid formed by dispersing it in a dispersion medium (hereinafter sometimes referred to as a binder liquid);
(3) applying the binder liquid to the fiber aggregate;
(4) a step of heating the fiber aggregate to which the binder liquid has been applied to remove the solvent or dispersion medium in the binder liquid and bonding and integrating the constituent fibers of the fiber aggregate with a binder resin;
A method for producing a surface material can be mentioned.

Step (1) will be explained.
As the fiber aggregate, for example, a sheet-like fabric such as a fiber web, a nonwoven fabric, a woven fabric, or a knitted fabric is prepared. Note that the fineness and fiber length of the constituent fibers in the fiber aggregate, and the thickness and basis weight of the fiber aggregate can be adjusted as appropriate.

Step (2) will be explained.
The type of solvent or dispersion medium can be selected as appropriate, such as water, but in order to suitably apply the binder liquid to the fiber aggregate, a solvent that can dissolve the binder resin but does not dissolve the fiber aggregate should be used; It is preferable to use a solvent that can disperse the binder resin and does not dissolve the fiber aggregate. Further, the concentration of the binder resin in the binder liquid is appropriately adjusted so that the binder liquid can be suitably applied to the fiber aggregate.
Further, additives may be dissolved or dispersed in the print liquid.

Step (3) will be explained.
The method of applying the printing liquid to the fiber aggregate can be selected as appropriate, but methods include spraying or applying the printing liquid to one main surface of the fiber aggregate as it is or in a foamed state using a spray or impregnated roll; A method of immersing one main surface of the fiber, a method of impregnating the fiber aggregate in the printing liquid, etc. can be adopted.

Step (4) will be explained.
The method for removing the solvent or dispersion medium can be selected as appropriate, but examples include heating the product by heating it in a heating device such as an oven dryer, far-infrared heater, dry heat dryer, or hot air dryer, or leaving it still at room temperature or under a reduced pressure atmosphere. The solvent or dispersion medium can be removed by evaporation. The lower limit of the heating temperature when removing the solvent or dispersion medium is adjusted to a temperature at which the solvent or dispersion medium can volatilize, and at the same time, the lower limit of the heating temperature is adjusted so that the constituent fibers of the fiber assembly can be bonded and integrated with the binder resin. . In addition, the upper limit of the heating temperature is adjusted so that the shape and function of the fiber aggregate and additives do not deteriorate unintentionally.
In addition, when particles that foam when heated are included, the particles may be foamed in this step.

In this way, a surface material can be prepared in which the binder resin is mixed in the voids of the fiber aggregate.

The surface material can be prepared by going through the above steps, but after the above steps,
(5) Forming a patterned printed layer on at least one main surface or a printed layer on the entire surface of at least one main surface by applying a solution or dispersion capable of forming a printed layer to the surface material. ,
You can also offer it to

Furthermore, after step (4) or after step (5),
(6) forming a top coat layer on the entire surface of at least one main surface by applying a solution or dispersion capable of forming a top coat layer to the surface material;
You can also offer it to

By subjecting the surface material prepared as described above to thermoforming means, interior materials and exterior materials can be prepared. Note that before and after being subjected to thermoforming, the surface material, interior material, or exterior material may be subjected to secondary processing, such as punching or cutting out, or giving a three-dimensional shape.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but these are not intended to limit the scope of the present invention.

(Preparation of fiber aggregate)
Using 100% spun-dyed polyester fibers (fineness: 2.2 dtex, fiber length: 51 mm), the fibers were opened using a card machine to form a fiber web, and then needle punched from one side at a needle density of 400 needles/ ^cm2 . Then, nonwoven fabric 1 (fabric weight: 190 g/m ² , thickness: 1.8 mm) was prepared by applying it to a hot roll (roll heating temperature: 150° C.).
In addition, using 100% spun-dyed polyester fiber (fineness: 2.2 dtex, fiber length: 38 mm), the fibers were opened using a card machine to form a fiber web, and then needle punched from one side at a needle density of 400 needles/ ^cm2. The nonwoven fabric 2 (fabric weight: 207 g/m ² , thickness: 1.8 mm) was prepared by processing and then applying it to a hot roll (roll heating temperature: 150° C.).

(Comparative example 1)
The nonwoven fabric 1 was dried in a can dryer at a temperature of 160° C. to prepare a surface material (fabric weight: 190 g/m ² , thickness: 1.8 mm).

(Comparative example 2)
A binder liquid was prepared by dispersing acrylic resin A (does not have a branched carboxylic acid moiety having a total carbon number of 9 or more and 11 or less, Tg: -38°C) in water.
Then, a foamed binder liquid is applied from the main surface of the nonwoven fabric 2 opposite to the main surface on which the needling was applied, and after applying it between rolls (gap interval: 0.25 mm), By drying with a dryer, the spun-dyed polyester fibers are bonded and integrated with the acrylic resin to form a binder-bonded nonwoven fabric (fabric weight: 212 g/m ² , binder resin content: 5 g/m ² , thickness: 1.7 mm) ) was prepared.
A printing liquid was prepared by dispersing acrylic resin A and a pigment in water.
Then, after applying printing liquid using a stencil printing machine (cylinder-type printing plate) to the main surface of the binder-adhesive nonwoven fabric opposite to the main surface on which the needling was applied, the printing liquid was applied again in the same manner. Coated.
Thereafter, by drying with a tenter dryer at a temperature of 180°C, the pigment is fixed to the main surface of the binder-adhesive nonwoven fabric by acrylic resin A, and the surface material (fabric weight: 220 g/m ² , content of acrylic resin A: 13 g) /m ² , thickness: 1.6 mm) was prepared.

(Comparative example 3)
A binder liquid was prepared by dispersing acrylic resin A (does not have a branched carboxylic acid moiety having a total carbon number of 9 or more and 11 or less, Tg: -38°C) in water.
Then, a foamed binder liquid is applied from the main surface of the nonwoven fabric 1 opposite to the main surface on which the needling has been performed, and after being applied between rolls (gap interval: 0.25 mm), a baking sheet at a temperature of 160° C. By drying with a hair dryer, the spun-dyed polyester fibers are bonded and integrated using acrylic resin, and the surface material (fabric weight: 193 g/m ² , binder resin content: 3 g/m ² , thickness: 1.8 mm) was prepared.

(Comparative example 4)
A surface material (fabric weight: 195 g/m ² , binder resin content: 5 g/m ² , thickness: 1.8 mm) was prepared in the same manner as in Comparative Example 3 except that the amount of applied binder liquid was increased. .

(Example 1)
A binder liquid was prepared by dispersing a versatic acid vinyl ester copolymerized acrylic resin (Tg: -50°C) in water.
Then, a foamed binder liquid is applied from the main surface of the nonwoven fabric 1 opposite to the main surface on which the needling has been performed, and after being applied between rolls (gap interval: 0.25 mm), a baking sheet at a temperature of 160° C. By drying with a hair dryer, the spun-dyed polyester fibers are bonded together using acrylic resin, and the surface material (fabric weight: 195 g/m ² , binder resin content: 5 g/m ² , thickness: 1.8 mm) was prepared.

(Example 2)
A surface material (fabric weight: 200 g/m ² , binder resin content: 10 g/m ² , thickness: 1.8 mm) was prepared in the same manner as in Example 1 except that the amount of applied binder liquid was increased. .

Table 1 summarizes the composition of each surface material prepared as described above.

In addition, various physical properties of each surface material prepared as described above were evaluated and summarized in Table 2.

(Evaluation method of moldability)
The surface material was placed in a mold with a high expansion rate and thermoformed, and then cooled to prepare an interior material (exterior material). Then, in the prepared interior material (exterior material), the main surface derived from the main surface of the fiber aggregate on the side opposite to the needling side was visually observed.
As a result of the observation, if wrinkles were observed on the main surface, it was determined that the surface material had poor moldability and was marked with an "x" in the table.
On the other hand, if no wrinkles were observed on the main surface as a result of observation, it was determined that the surface material had excellent moldability, and was marked with "O" in the table.

(Evaluation method of wear resistance)
In accordance with JIS K7204:1999 (Plastic - Abrasion test method using wear wheels), in the interior material (exterior material) prepared in the above-mentioned (formability evaluation method), the side opposite to the needling side of the fiber aggregate The wear resistance test of the main surface derived from the main surface was evaluated.
The abrasion tester, rotational speed, abrasion wheel, load applied to the abrasion wheel, and number of abrasion cycles were as follows.
(1) Wear tester: Rotary abrasion tester Toyo Seiki Seisakusho Co., Ltd. (2) Rotational friction speed: 70 r/min
(3) Used wear wheel No.: H-18
(4) Load: 9.8N
(5) Number of wear: 100 times The main surface portion of the surface material treated with the worn ring after the test was visually observed and evaluated based on the following criteria.
Grade 3: Although some wear was observed, no major scratches were observed.
Grade 2: Partially large scratches were observed on the main surface where the worn ring had been treated.
Grade 1: In the main surface portion where the worn ring was treated, occurrence of large abrasion to the extent of forming a hole was observed.

(Method for evaluating the difficulty of napping)
The need of the fiber aggregate in the interior material (exterior material) prepared in the above-mentioned (formability evaluation method) in the same manner as in the above-mentioned (abrasion resistance evaluation method) except for the following configuration changes. The difficulty in generating naps on the main surface derived from the main surface on the opposite side to the side to which the ring was applied was evaluated.
(3) Used wear wheel No.: CS-10
(4) Load: 4.9N
(5) Number of wear: 100 times The treated main surface of the worn wheel after the test was visually observed and evaluated based on the following criteria.
Grade 3: Although some napping occurred, no major change was observed.
Grade 2: More napping occurred than in the results of Grade 3, and a major change was observed.
Grade 1: More napping occurred and a larger change was observed than in the results of Grade 2.

(Evaluation method for appearance retention)
As a result of subjecting to the above-mentioned (abrasion resistance evaluation method) and (evaluation method of raising difficulty), items that were rated 3rd grade in both evaluation results are marked with "" in the table as having excellent appearance retention. 〇” was written. On the other hand, those that were not rated 3rd grade in any of them were marked with an "x" in the table, indicating that they were inferior in appearance retention.

From the results in Table 2, the surface material of the example was superior in both formability and appearance retention, whereas the surface material of the comparative example was inferior to the example in at least either formability or appearance retention. .
In addition, from the results of comparing Comparative Example 2 and Comparative Example 3, in which the 20% modulus in the vertical direction is the same value as 43N/30mm, in order to provide a surface material with excellent formability, the 20% modulus in the horizontal direction is From the results of comparing Comparative Example 4 and Example 1, in which the 20% modulus in the horizontal direction is the same as 10 N/30 mm, the present invention provides a surface material with excellent formability. It has been found that in order to achieve this, the 20% modulus in the longitudinal direction needs to be less than 45N/30mm.

(Comparative example 5)
A binder liquid was prepared by dispersing acrylic resin B (does not have a branched carboxylic acid moiety having a total carbon number of 9 or more and 11 or less, Tg: -15°C) in water.
Then, a foamed binder liquid is applied from the main surface of the nonwoven fabric 1 opposite to the main surface on which the needling has been performed, and after being applied between rolls (gap interval: 0.25 mm), a baking sheet at a temperature of 160° C. By drying with a hair dryer, the spun-dyed polyester fibers are bonded together using acrylic resin, and the surface material (fabric weight: 200 g/m ² , binder resin content: 10 g/m ² , thickness: 1.5 mm) was prepared.

(Comparative example 6)
A surface material (fabric weight: 199 g/m ² , binder resin content: 9 g/m ² , thickness: 1.5 mm) was prepared in the same manner as in Comparative Example 3 except that the amount of applied binder liquid was increased. .

(Comparative example 7)
A surface material (fabric weight: 200 g/m ² , binder resin content: 10 g/m ² , thickness: 1.5 mm) was prepared in the same manner as in Comparative Example 3 except that the amount of applied binder liquid was increased. .

Table 3 summarizes the composition of each surface material prepared as described above. For ease of understanding, the configurations of the surface materials prepared in Comparative Example 1 and Examples 1 and 2 are also shown.

In addition, various physical properties of each surface material prepared as described above were evaluated and summarized in Table 4. For ease of understanding, various physical properties of the surface materials prepared in Comparative Example 1 and Examples 1 and 2 are also listed.

From the results in Table 4, the surface material of the example was superior in both formability and appearance retention, whereas the surface material of the comparative example was inferior to the example in at least either formability or appearance retention. .
In addition, Comparative Example 5, which had a mass loss of 72.8 mg, was inferior to the Example in appearance retention, whereas Comparative Example 6, whose mass loss was 72.0 mg, was equivalent to the Example. It had good appearance retention properties. From this result, it was found that in order to provide a surface material that can be used to prepare interior and exterior materials with excellent appearance retention, the weight loss needs to be less than 72.8 mg.

From the above, a surface material that satisfies the configuration according to the present invention has better moldability even when subjected to a thermoforming method with a high expansion rate, and can produce interior and exterior materials that have excellent appearance retention. It turns out it can be done.

Furthermore, from the results of comparing Comparative Examples 1, Comparative Examples 3 and 4, and Comparative Examples 6 and 7, it was found that simply increasing or decreasing the amount of binder resin contained in the surface material resulted in a surface material with excellent moldability and appearance retention. It turned out that it was not possible to provide this.
The reason for this is thought to be that there is a trade-off relationship between the moldability of the surface material and the appearance retention of the interior and exterior materials made of the surface material.

For reference, the configuration and various physical properties of the surface materials prepared in Comparative Example 1, Comparative Examples 3-4, and Comparative Examples 6-7 are summarized in Table 5.

The surface material of the present invention is a surface material that can be used as an interior material or an exterior material. In particular, it is a surface material that can be used to prepare interior materials for interior parts such as vehicle pillar garnishes, doors, instrument panels, steering wheels, shift levers, console boxes, tonneau covers, luggage floors, and luggage sides.

Claims (1)

A surface material comprising a fiber aggregate and a binder resin,
The binder resin is a versatic acid vinyl ester copolymerized acrylic resin with a glass transition temperature lower than -38°C,
A surface material having a 20% modulus in the vertical direction of less than 45 N/30 mm, a 20% modulus in the horizontal direction of less than 22 N/30 mm, and a weight loss calculated by subjecting to the following measurement of less than 72.8 mg.
The mass reduction in the surface material was determined by subjecting the surface material to the JISL1096:20108.19.3C method (Taber method).
・Used wear wheel No.: H-18,
・Load: 9.8N,
・Test rotation number: 100 times,
・Rotational friction speed: 70r/min,